Neither "Hogarth" or "Accura" were the name of a machine-tool manufacturer but a brand used during the 1930s by an English import company - almost certainly Soag Machine Tools of London SE2. The lathes were then offered directly to end users, badged "Accura" or, for distribution through larger and more successful independent dealers such as Percy Martin of Leicester, as "Hogarth". It is entirely possible that other names were used as well - reflecting a situation almost as confusing as that during the later years of the 20th century when machines from the Far East arrived packed with a selection of spurious brand-name labels for the importer or wholesale dealer to affix.
Of the known types, six variations on a single model of the "Hogarth" were offered: the almost identical VR-18, VRZ-21 and VRA-23 versions of 7, 8.25 and 9-inch centre height respectively and a range of lathes badged VR-21, VRZ-23 and VRA-25 that, whilst looking very similar, were of generally more massive proportions and heavier build. Soag appear to have advertised only one version of the "Accura", the Model DH-17, a machine identical to the "Hogarth" VRZ-21 in all but its 17 to 750 rpm speed range. Of amazingly clean, angular lines for their era all these lathes would, if mounted on full cabinet stands, still not have looked out of place in the late 1960s. A rather different "Hogarth", a production version, the V.L.15, with a limited number of speeds and feeds, was also listed.
For both size groups quite why such differing model designations were used is a mystery for, apart from the height of the headstock and tailstock castings (and presumably the necessary alterations to saddle, cross and top slides to adjust the tool height) each machine (in the two groups) was identical to the others and shared the same bed, headstock contents, screwcutting gearbox, apron, leadscrew, powershaft and even (when fitted) size of electric motor. As a concession to size, and to allow better use to be made of the gap-turning capacity, the speed range of the VRA-23 was slightly modified from the 15 to 650 rpm of the smaller pair to 12 to 540 rpm. The VR-18, VRZ-21 and VRA-23 lathes had a V-way, chilled cast-iron bed 11.375-inches wide with heavy cross bracing and to a Brinelle hardness of approximately 200. The carriage ran on the outer pair of Vees and the tailstock on an inner V-way and flat. All equipped as standard with a detachable gap piece with the maximum diameters that could be turned being (respectively): 21.5-inches, 24-inches and 25.5-inches - and the greatest thickness that could be accommodated on a faceplate the same, at 8-inches, for all machines.
Continued below:
"Hogarth" Model VR-18. The VRZ-21 and VRA-23 versions of the lathe were both of almost identical appearance
Continued:
The 12-speed oil-bath headstock was of interesting construction with the 2-inch bore spindle in a tough steel, ground finished and running in a pair of parallel-bore bronze bearings tapered on their outside to allow for adjustment by serrated ring nuts and with end thrust taken by a ball race. The main drive gear was of a "semi-helical" form, keyed to the spindle in the usual place immediately behind the front bearing. The three headstock layshafts all ran on ball races and carried hardened nickel-chrome steel gears with the input shaft at the rear carrying two multi-plate clutches - in a manner eventually adopted by Colchester in the 1960s - and by which means the spindle could be instantly started, stopped and reversed by a single lever on top of the headstock. The headstock was closed by a rear-hinged cover that fitted into a lipped recess arranged around the periphery of the opening; in the bottom of the recess was a series of drain holes to return lubricant that had leaked passed the edges of the lid. Leadscrew reverse gears, controlled by a lever, were positioned on the inside of the headstock, where they benefited from the headstock oil supply. The headstock could be arranged for drive by either flat belt from an overhead line-shaft system - in which case the input pulley was 8-inches in diameter and 3.125-inches wide - or by a motor fastened to an adjustable plate on the back of the bed in which case a V-pulley was used.
The compound slide rest was fitted with taper gib strips and both top and cross slides had micrometer dials of - typically for the era - far too small a diameter.
The oil-bath screwcutting gearbox was of the Norton quick-change type and able to generate a useful 40 English pitches from 2 to 28 t.p.i and, with the aid of extra changewheels, 24 metric from 0.5 to 9 mm pitch. Unusually, the box was fitted with a coarse-threading attachment whereby a 2 or 16-times increase in pitch could be obtained - though the drive was still taken down the standard 1.375-inch diameter by 4 t.p.i. leadscrew rather than through an auxiliary shaft at the back of the bed as was sometimes used by other makers.
The apron was of the proper double-wall type with the all-steel gears running in oil splashed up from a sump supply. Power sliding and surfacing feeds were provided by a separate keyed power shaft geared from the leadscrew just outboard of the screwcutting gearbox. The shaft passed through the usual type of worm-and-wheel mechanism connected to a train of gears whose selection and engagement was controlled by a single 3-position quadrant lever on the face of the apron. There was no engagement clutch and, whilst the sliding feed could be automatically disengaged by an adjustable collar on the power shaft (but only when moving towards the headstock), the cross feed could only be stopped by returning the engage/selection lever to its central position. Sliding rates of feed varied from 0.0031 to 0.047-inches and surfacing from 0.0016 to 0.024-inches per revolution of the spindle.
The set-over tailstock was heavily built with a 1.75-inch, 3-Morse taper barrel with a double clamp.
All models were available with 30, 40 50 or 60 inches between centres and weighed from 2050 lbs for the shortest bed VR-18 to 3400 lbs for the longest bed VRA-21.
The heavier machines, catalogued as the VR-21, VRZ-23 and VRA-25 had centre heights of 8.25, 9 and 10-inches respectively with the ability to turn in their gaps a disc of material 9-inches thick and, respectively, 25.5-inches, 27-inches and 28.5-inches in diameter.
Although the lathes all used a bed that was, at 12.75-inches, wider and heavier than that used on the smaller range the headstock internals and its bearings were identical - though the 12 spindle speeds were arranged to be slightly slower at between 12 and 540 r.p.m. and a 4-step V-pulley was used from the 4 or 5 h.p. motor. Although the screwcutting gearbox, powershaft and apron also appeared to be identical the feeds were slowed slightly to between 0.0039 and 0.059-inches per revolution of the spindle sliding and 0.0020 and 0.0276-inches surfacing.
Available bed lengths gave a choice of 40, 50 or 60 inches between centres with weights varying from a low of approximately 2640 lbs on the short-bed VR-21 to a maximum of 4530 lbs for a long-bed VRA-25..
Hogarth VS18 - the flat-belt drive version of the VR-18
The oil-bath headstock had a 2-inch bore spindle in a tough steel, ground finished and running in a pair of parallel-bore bronze bearings tapered on their outside to allow for adjustment by serrated ring nuts and with end thrust taken by a ball race.
Simple diagram of the Hogarth's geared headstock
The apron was of the proper double-wall type with the all-steel gears running in oil splashed up from a sump supply. Power sliding and surfacing feeds were provided by a separate keyed power shaft geared from the leadscrew just outboard of the screwcutting gearbox.
Optional taper-turning attachment. Note the large pressed-steel swarf guard
作者: 小编薇薇 时间: 2017-12-11 15:55
【二】
An Operation & Maintenance Manual is available for the Accuratool lathe
Distributed by Dowland & Doll, one of UK's leading specialist machine-tool agents during the 1950s and 1960s, the Accuratool capstan lathe was built in at least three version, the two shown here and a larger, more sophisticated type. Designed to complete with similar, lighter machines from Murad, Exacta, Smart & Brown and the conversions of standard centre lathes offered by such as Raglan, Atlas and Churchill, the two smaller types were listed as Capstan and Second Operation models. However, both were identical in all but one of their mechanical aspects - the through-collet capacity of the former being 5/8" (16 mm) and the latter 13/16" (21 mm). The essential difference between the two versions lay with the equipment fitted as standard - the capstan being equipped with the usual bed-mounted 6-station turret head and either a lever or screw-operated cut-off and forming slide while the second operation model had a lever-operated compound slide assembly and a tailstock arranged for the quick travel of its No. 2 Morse spindle by the use of a 4-spoke capstan handle. Of course, equipment could be provided to convert one lathe into the other - yet, unusually and inexplicably, the makers did not bother to offer a general-purpose toolmaker's type with ordinary screw-driven feeds to the compound slide and tailstock - something that most other makers of the type did, typical examples being the Smart and Brown Model L, Schaublin 102 and Mikron 90.
Carried on a cabinet stand constructed from heavy-gauge welded steel plate (with a deep, full-length chip tray and a coolant tank bolted to its right-hand face), the lathe had a centre height of 4 inches over the bed and just under 1.5 inches over the cross-slide. Drive came from an oil-bath lubricated 2-speed motor-gearbox unit (that incorporated a multi-plate clutch) mounted in the base of the stand. Able to be ordered as either a 2 h.p. 1430 r.p.m. single speed, or a 1.5/0.75 h.p. 1430/710 r.p.m. 2-speed, the motor was mounted on top of the gearbox and drove down to it using a standard V-belt running over a 4-step pulley. Fitted with the single-speed motor the spindle could be made to rotate at 75, 125, 200 and 330 r.p.m. in low range and 675, 1125, 1800 and 3000 r.p.m in high while with the 2-speed version fitted the sixteen speeds ran from 37 to 3000 r.p.m. However, as an option for customers doing mainly small diameter work needing higher speeds, an alternative range running up to 4000 r.p.m. was available. Drive was taken to the spindle by a pair of segmental belts, tension being adjusted in the usual way by adding or subtracting links.
A single lever, positioned within easy reach of the operator's left hand, controlled the clutch and gearchange; without having to waste time stopping the motor, moving the lever to the left from its central, neutral position gave the low-speed range and moving it from centre to the right the high-speed setting - the lever could also be pushed to an inward position where the same left and right movements gave spindle speeds in reverse. The multi-plate clutch, an oil-immersed type, was designed to absorb endless abuse and so was able to stop and start the spindle several times a minute without slipping, dragging or wearing out prematurely.
Running in a pair of opposed, high-precision taper roller bearings at the front and roller bearings at the rear, the high-tensile steel spindle carried dead-length collets opened and closed by a lever mechanism - an air-operated attachment also being available. Although the spindle nose lacked a thread and was equipped just for collets, the makers did offer a backplate conversion - it replaced the collet-closing sleeve - that allowed chucks and other fittings to be mounted.
Carrying six tools mounted on 3/4" shanks, the capstan head had a stroke of up to 3 inches and could be arranged so that there was a maximum clearance between it and a collet nose of 10.5 inches. As an option the turret could be fitted with an air-hydraulic drive unit, this being mounted at the rear with the necessary compressor built into the motor-gearbox unit (the air supply generated also being used for a the bar-feed and headstock collet-closer and spindle brake attachments).
Both the standard lever-operated and optional screw-type cut-off and forming slides fitted to the capstan version had a maximum space between front and back toolposts of 4.25 inches with cutting tools up to 3/8" square able to be fitted. The lever-operated compound slide rest - as fitted to the second-operation version of the lathe - was able to be swung 45° each side of central with both top and cross slide having the same 4 inches of travel. Rather handily, instead of needing a spanner and screwdriver to adjust, the travel stops could be set by hand, each being provided with a knurled-edge disc on their end.
One useful accessory, employed for short but large diameter screwcutting work, was the heavily-built thread-chasing attachment. Driven by changewheels - and so of the more complex type - it could generate, for each master thread and follower fitted, three different pitches in the ratio of 1 : 1, 2 : 1 and 4 : 1. The cutting tool, held in an adjustable holder with a micrometer dial graduated in 0.001" , was intended to be of the: "D. and D. ground-form circular type with which a new cutting edge is readily obtained by rotating the cutter." A forward-pointing curved arm was used to rotate the cutter assembly into position, the end of the arm resting on a hardened adjustable guide positioned at the front of the cross slide. The guide was formed with an angled section at one end that caused the tool to be automatically lifted clear of the job as the cut was finished. Taper threads could be generated by fitting a spring-loaded follower and setting the guide block at an angle.
Supplied as standard with each new machine was a single-speed 3-phase motor, a complete set of switchgear, an electric coolant pump, tank and associated fittings, one round collet and the necessary spanners and keys..
Accuratool capstan lathe with 5/8" collet capacity and fitted with the standard cut-off slide and 6-station bed-mounted capstan unit
Accuratool Second Operation lathe with l13/16" (21 mm) collet capacity, a lever-operated compound slide rest, capstan-handle operated tailstock and the optional thread-chasing attachment
Thread Chasing Attachment
Heavily-built and, being driven by changewheels, of the more complex kind, the thread-chasing attachment could generate, for each master thread and follower fitted, three different pitches in the ratio of 1 : 1, 2 : 1 and 4 : 1. The chasing tool was set in an adjustable holder with a micrometer dial graduated in 0.001" and was designed to use "D. and D. ground-form circular chasers with which a new cutting edge is readily obtained by rotating the cutter." A forward-pointing curved arm rotated the cutter assembly into position, the outer end of the arm resting on a hardened adjustable guide (see left in the picture) formed with an angle at one end that caused the tool to be automatically lifted clear of the job as the cut was finished. Taper threads could be generated by fitting a spring-loaded follower and setting the guide block at an angle
Drive came from an oil-bath lubricated motor-gearbox unit (that incorporated a multi-plate clutch) mounted in the base of a cabinet stand constructed from heavy gauge welded sheet steel. The motor, mounted on top of the gearbox with initial drive by V-belt running over a 4-step pulley, could be had a 2 h.p. 1430 r.p.m. single speed or a 1.5/0.75 h.p. 1430/710 r.p.m. 2-speed.
As an option, an built-in air compressor was could be fitted, the supply being used to drive extra-cost fittings that provided air-hydraulic actuation of the turret, headstock collet closer, spindle brake and bar feed
Lever-operated compound slide rest as fitted to the second-operation version of the Accuratool capstan lathe. Able to be swung 45° each side of central, both top and cross slide had 4 inches of travel
Optional screw-operated cut-off and forming slide fitted to the capstan version of the Accuratool. The maximum space between front and back toolposts was 4.25" and the maximum size of cutting tool accommodated 3/8" square
Carrying six tools mounted on 3/4" shanks, the capstan head had a stroke of up to 3 inches and could be arranged so that there was a maximum clearance between it and a collet nose of 10.5 inches. The turret could also be fitted with an air-hydraulic drive unit, this being mounted at the rear with a compressor built into the motor-gearbox unit (the air supply generated also being used for the optional bar-feed, headstock collet-closer and brake attachments).
Air-hydraulic turret attachment
Capstan handled tailstock: the No. 2 Morse taper spindle had 3.25" of travel
Headstock equipped with air-operated collet closer. A spindle brake unit, with Ferodo-lined shoes, was also available
Little known and seldom encountered, the background to Accuro 6 mm watchmakers' lathe is unknown - though it may be of British manufacture. With the maker's name cast into the front face of the headstock this would not have been a re-branded, re-badged or badge-engineered product, but instead almost certainly of indigenous manufacture.
Of the typically light Geneva-pattern (this design being preferred by some experts for delicate or intricate work) the Accuro had the flat on its otherwise round bed to the usual position at the rear and a headstock with what may have been bronze instead of the usual hardened-steel bearings. A 3-step pulley headstock to take drive by a round rope was provided, though oddly the front face of the largest diameter lacked the almost universally provided ring of 60 division holes.
Whether the Accuro was available with range of extras common to most other makers - such as a compound slide-rest assembly, a second tailstock with lever feed, single and double roller rests, fixed steady, saw table, Jacot Drum, pivoting and lapping attachments and various types of collet, etc. - is not known.
A detailed manual is available for the "Ace" 9-inch lathe
ACE Lathes Continued
Although the history of the Ace Company is not known - they appear to have been shy of advertising - the branding was used on lathes from the 1920s until the 1940s and possibly later. A number of different sizes were offered, some looking to be German in origin and nearly all having some easily-changed part like a cast-iron door changed to accommodate the "Ace" logo (examples are shown lower down the page). However, one Ace model machine is instantly recognisable, a straightforward copy of the well-known American 9-inch South Bend - in this case to "Model A" specification with a screwcutting gearbox, power sliding and surfacing feeds and as made from the late 1930s. Marked as "British Made", it retained the main dimensions of the original but with a slight increase in centre height (achieved by thickening the depth of the cross slide) and with the capacity between centres set at around 24 inches. The main mechanical parts of the lathe, bed, headstock, the complete carriage assembly and tailstock - appear to have been faithful reproductions of the South Bend. However, as was often the case with similar 9-inch clones, a number of modifications and improvements were incorporated to address some of the original's shortcomings: the bed feet were made longer, the cross and top-slide micrometer dials increased in diameter (a most useful modification) the all-important countershaft bolted to the back of the bed to make a complete, self-contained unit. The tailstock was given a permanently-mounted lever to lock it to the bed, a much longer arm to lock the barrel - and with the latter carrying both inch and metric ruler graduations. The original South bend had its leadscrew end float taken out at just the gearbox end but the Ace provided screwed adjuster rings at each end - probably allowing the leadscrew to be set in tension. Unlike most South Bend bench lathes produced before the late 1940s, the Ace enjoyed complete, factory-installed belt guarding - something that took the American company many years to provide on other than versions intended for training use.
Oddly, the changewheel cover resembled - somewhat - the much narrower unit used on very early versions of the 9-inch, as made from late 1933 as the Model 5.
If you have an Ace lathe of any type, or advertisements featuring the machines, the writer would be very interested to hear from you..
作者: 小编薇薇 时间: 2017-12-11 16:09
【五】
Ace Minor Advertisements
A Data Pack of: Handbook, Assembly Instructions
& other literature is available for these and similar lathes
badged as Flexispeed, Norfolk and Simat, etc.
First in a long line of variations on a common theme, the 'Ace Minor' by Perris was supposedly the product of a marketing company, Urquhart Machine Tools Ltd. of Clerkenwell, under whose label it received a glowing review in the January 1965 Model Engineer. However, the same machine was sold as the Centrix 'Micro', ostensibly the product of the 'Centrix Works' of Centrix Precision Products Ltd., Shoreham-by-the-Sea, Sussex (which co-incidentally, was where Brian Perris started his own engineering firm in the early 1960)s. Despite the distributors' assertions that rebranded Perris lathes were their own products, Perris Engineering built them all, initially at Shoreham and then at 4 and 5 Meadow Rd. Industrial Estate, Worthing, Sussex. With a 0.5" x 16 t.p.i. BSF mandrel nose and two 0-MT taper sockets, the three PL90 variants were badged as the 'Ace Minor' and 'Centrix Micro': (a) plain-turning, (b) back-geared but without a powered leadscrew, and (c) 'horological.' The latter was wishful thinking for its distinction was a collet-holding spindle with unfortunate and significant design limitations. The two PL90 variants sold under the Perris name were called the 'PL90 Standard' and the 'PL90 Special', collectively known as the 'Perris Model Maker's Lathe', and characterised by a finer (0.5" x 20 t.p.i. UNF) spindle thread - the re-badged versions having the same two No. 0 Morse taper sockets but a 0.5" x 16 t.p.i. BSF nose.
Marketed by the UK Atlas Agents the "Acorn Machine Tool Company 1936 Ltd." of 610 - 614 Chiswick High Road, London W.4, the British Halifax Model "524" 5-inch centre height by 24 inches between-centres lathe of the late 1940s and early 1950s was very recognisably based on the American Atlas "10-inch". Sold originally with a Halifax badge it was renamed, probably in 1951, as the "Acorntools" to match the name already given by the company to their capstan version of the Atlas 10-inch. Like the similar "Sphere" model it was, in both Halifax and Acorntools guises, essentially identical to the original American machine and, allowing for the 1450 rpm English motor rather than the 1725 rpm American one, had the same speed range; both the countershaft unit and the headstock were of the Atlas 10F "vertical" type but with the changewheel and headstock-belt covers manufactured in engineering plastic. A bold feature was the early use of the same plastic for the headstock and countershaft pulleys; this appears to have been an entirely successful idea for the author remembers examining, some years ago, a completely worm out Halifax where the pulleys were still in perfectly serviceable condition - although had a heavy object dropped on them no doubt they would have been less far less able to shrug it off than ones in cast-iron, aluminium or ZAMAK.
Details of where and how the Halifax/Acorntools was constructed are lost in time but there is one small clue in a 1956 letter from Acorn to a Midlands distributor where they refer to an Atlas parts lists as containing: "….all spares which go into the manufacture of a Halifax Lathe". This statement would appear to lend some strength to the proposition that Halifax (and possibly Sphere) lathes were built from a mixture of UK-sourced parts and genuine Atlas spares; however, whether these parts were from existing stocks or specially imported is unknown. A further puzzle is the reason for commissioning specially-made plastic changewheel guards and countershaft and headstock pulleys when metal originals would have been available cheaply from the USA. There was also a price difference between the Halifax and Atlas machines: for an equal specification with 24-inch between-centres capacity (and including a motor), in 1949 the Atlas was £84 : 10s : 0d and the Halifax £74 :10s : 0d. - a useful saving of some 12%. Some, if not all Halifax, Acorntool and Sphere lathes were fitted with a broader and longer cross slide that ran on wider ways, a feature that partially addressed one of the main weakness of the original Atlas design. With so many alterations and specially-constructed parts the writer now leans towards the idea that these lathes were indeed constructed in the UK - though with some of the otherwise expensive-to-produce ZAMAK components imported. As a point of interest, on the broader slide the wider section of the dovetail was 2.96" across (Atlas about 2.15") and the narrower 2.66" (Atlas 1.83"). The full width of the wider cross-slide casting was 4.21" with the result that the circular boss carrying the top-slide swivel degree marks was set completely inside the edges, instead of reaching or even overlapping them as on the original design.
Acorn offered a complete range of Atlas, Halifax and Sphere parts and some of the 1955-prices make interesting reading (average weekly earning during 1955 were just short of £11 per week): a bare headstock casting was £7 : 10 : 0d with a spindle, amazingly, at exactly the same price; Timken bearings were £2. : 15 : 0d each and, while the very large "bull" gear on the spindle was £2 : 10 : 0d the smaller bronze gear was £3 : 12 : 6d. For £23 : 5 : 9d. Acorn offered the owners of plain "babbit" bearing Atlas lathes a Timken taper roller bearing conversion kit; this included a new headstock casting, spindle, bearings (and assorted small parts) with the remainder of the items coming from the existing assembly. They also offered a new, fully-machined headstock casting fitted with bronze-bearing for those whose babbit bearings were worn out.
Another British-market version of the Atlas, the "Sphere", can be seen here. and full details of the original Atlas 10-inch lathes here. The standard handbook for the 10-inch Atlas covers these lathes in every detail.
If any reader can supply high-quality pictures of an original Halifax lathe, or has any sales literature, the author would be very interested to hear from them.
Sphere Lathe
A direct mechanical copy of the American Atlas 10-inch lathe the Sphere, like the other English "Halifax" and "Acorntools" clones, had several interesting changes to the specification and materials used in its construction. It is entirely possible that the whole machine was made in Britain, but also feasible for larger parts such as the bed and headstocks to have been imported - for example, the "Sphere" logo and description "British Made" was cast into the headstock foot, an easily-changed component. However, as the range of changes and modifications were so numerous this would indeed appear to have been a UK product: the cross slide was wider and, on some of the changewheel-equipped models, the casing of the leadscrew reversing gearbox was made in a hard black engineering plastic, a material also used for the changewheel case, the headstock belt covers, the double-step pulley on the countershaft, the two matching 4-step pulleys on countershaft and headstock and, on some lathes, the carriage-traverse handwheel. While some Sphere lathes may have been supplied with plain bearings (the Acorntools version certainly was) more than one example has been found with shouldered Timken taper rollers--but instead of being pressed into the headstock housing they were secured using the twin-bolt caps from the plain-bearing model. A gearbox-equipped version was also offered, though this, like the Atlas equivalent, is far less common The standard handbook for the Atlas 10-inch lathes covers the Sphere, Halifax and Acorntools models in every detail..
Catalogue picture of a Halifax 254. Note the single bolt securing the tailstock end of the bed; on the original Atlas machine two bolts were used, one at the front and one at the back
Although it is apparent in this publicity picture that the pulleys are made from plastic the finish of the inner and outer changewheel guards hides the fact that these too are made from the same material.
The "Halifax" bade was a riveted-on plate - the Sphere logo was cast into the bolt-on bed foot
On this version of the Halifax the Timken taper-roller bearings are held in place by bolt-on caps
Like the Halifax, the Sphere had an appreciably broader cross slide than the Atlas version with the wider section of the dovetail being 2.96" across (Atlas about 2.15") and the narrower 2.66" (Atlas 1.83"). The full width of the Halifax/Sphere cross-slide casting was 4.21"
On some versions of the changewheel-equipped Sphere even the casing of the leadscrew reversing gearbox was made in a hard black plastic, a material also used for the gear-case and headstock covers as well as the double-step pulley on the countershaft and the two matching 4-step pulleys on countershaft and headstock. The "Sphere" logo was cast into the headstock foot - an easily-changed component.
Not all Sphere lathes had the leadscrew reversing gearbox casing in plastic, the one on this model is in metal, yet still different to the original Atlas design.
An engineering-grade plastic was used for the changewheel and headstock covers as well as the double-step pulley on the countershaft and the two matching 4-step pulleys on countershaft and headstock.
The inner plastic changewheel guard cover was well ribbed on the inside and fastened to the end face of the headstock by three screws. The countershaft was an integral unit, bolted to the back of both bed and headstock.
Roller-bearing headstock parts. Note the plastic pulley
A gearbox-equipped version of the Sphere was also available
A well-used Sphere of which the owner makes some useful comments - especially regarding the need to level the machine accurately: I found your request for owners of Sphere lathes to contact you on your website.
I have owned this one for about 20 years. As you can see it is not quite standard as the screw thread counter has gone as had the original tumbler lead screw reversing gearbox. This had been replaced by a home made one that operates directly on the output from the headstock. That works well but it does compromise the selection change gears that can be easily fitted. The tool post does not look original. It came with the legs for the base but no coolant tray; so I made one out of a stainless steel sidepiece to a urinal (unused). The three lathe mounting feet were not accurately in the same plane; so the bed was twisted when the bolts were tightened. I cured this by careful shimming under the feet. The bed/ legs assembly had insufficient longitudinal stiffness. I cured this by triangulating it. Please see the two inch diameter bar running top left to bottom right. The switch gear is all my own work.
Sorry about the cluttered background. The photo does not flatter the lathe - it looks rather better than that. It still does most of which I want but a milling capability would have been nice. However, one fault is that it doesn't really like parting off.
作者: 小编薇薇 时间: 2017-12-11 16:20
【七】
Acme Power Equipment Lathe
Very rare - the writer knows of only one example - the plain-turning American Acme Power Equipment lathe was probably intended as a simple machine for use in garages and repair workshops. With a centre height of around 4.5 inches and admitting something like 24 inches between centres, while it lacked backgear-driven low speeds it appears to have been sold complete with a neat, built-on countershaft consisting of a tall tube carrying, at the top, a cross shaft with a V-belt drive pulley overhung on one side to connect to the motor and, on the other, a 3-step flat-belt pulley to drive the lathe spindle. As flat belts work best when well spaced apart, this particular arrangement, though looking ungainly, is likely to have been effective in use.
With its flat top and V-edged ways the bed resembled those most often seen on small English lathes with a simple carriage carrying an apron-mounted "full nut" that could not be disengaged from the leadscrew; the result was that, without a quick-action rack-and-pinion drive, every movement up and down the bed required a furious twirling of the (un-graduated) tailstock-end handwheel. Unfortunately, instead of a proper compounded slide rest, or a single swivelling tool slide, only a single non-swivelling type was fitted - this arrangement severely limiting the lathe's versatility.
Most unusually, instead of changewheels taking a drive from headstock spindle to leadscrew, the "Power Equipment" employed a vertical shaft with worm-and-wheel gearing at each end - an exposed view of what this looked like can be seen here on the British Flexispeed lathe. Although the gear-holding tube appears to have been fixed permanently in position -and hence the gears constantly in mesh - to disengage the drive a handwheel was fitted to the left-hand end of the leadscrew, this operating either cone-friction clutch, or possibly a positive-action dog clutch of some sort.
The tailstock could be set over for the turning of slight tapers and appears to have been fitted with a No. 2 Morse taper spindle.
If you have a Acme Power Equipment lathe (or other machine tool by the Company, the writer would be interested to hear from you.
Providence, Rhode Island, was home to many makers of machine tools including at least four (and possibly five) lathe-manufacturing companies: E.A.Eddy, E.A.Adams, Adams Bros, the Diamond Machine Co. and E.B. Bosworth. Unfortunately, apart from Diamond, little is known about the background to any of them , the historical record being, for the moment, blank. While the simple, plain-turning Adams Bros. Lathe would have been made around 1870 to 1880 and intended just for woodwork, the E.A. Adams machine was of very unusual design and of a somewhat later date, probably from the two decades spanning the 19th and 20th centuries. .
Of 4-inch centre height and 10-inches between centres, the plain-turning (non-screwcutting) E.A.Adams also lacked backgear but had its unusually wide, flat-topped V-edged bed formed from a good-sized box-section casting. However, in a reversal of usual practice this was cantilevered out to the left instead of to the right - an arrangement that would have offered the headstock somewhat reduced support. In fact, so odd is this construction that the writer believes the lathe may have been modified to accommodate the leadscrew - for some reason this needing a reversal of headstock and tailstock on the bed. Lending support to this idea is that an almost identical lathe, the E.B. Bosworth, is arranged conventionally (the headstocks look to be interchangeable). If the arrangement is original then the slender tailstock, with its spindle clamp a crude, direct-acting screw, was better provided for and, when extended to allow the lathe's maximum capacity to be used, was only a little to the right of the main mass of the bed. The headstock, whose bronze bearings were threaded on their ends and, for adjustment, drawn down into their tapered seats by large ring nuts, continued the theme of "flexibility in construction" with the left-hand bearing held on the end of a slender arm and the right on top of a short, un-braced vertical post. On the lathe illustrated, the headstock pulley looks to have been change for one in Zamak, as originally fitted, for example, to the 10-inch Atlas. The pulley may well have been, originally, identical to that used on other versions of the lathe perhaps with the same two wide steps and intended for industrial use - this arrangement being common on lighter and bench precision lathes of the time (a similar 2-step arrangement being used on the headstocks of the W.H.Nichols and (three-bearing) Ames). Threaded on their ends for adjustment and drawn down into their tapered seats by large ring nuts, both headstock bearings were mounted in a light casting with that on the left held on the end of a slender arm cantilevered out to the left and that on the right on top of a short, un-braced vertical post
Although the makers were good enough to specify a compound slide rest this was, unaccountably, carried on top of a vertical slide running in ways formed on the front face of the apron. Although this arrangement meant that the tool height could be quickly and accurately adjusted (by a very small-diameter handwheel) it brought in its train both expense in its manufacture together with even less rigidity between the cutting tool and workpiece.
Bereft of micrometer dials, the compound slide rest feed-screws gave very limited travel while their end-of-slide supports were simple flat plates - and not the type of extended housing that would have allowed the slide extra travel by being allowed to pass over its ways.
Two other lathes of virtually identical appearance and from the same area were the Bosworth, Warren, RI, this too having a flat-topped, V-edged bed and an elevating slide rest (though with just a lever-feed cross slide driven by toggle levers) and the E.A.Eddy, Providence RI, again with just a cross slide but this time moved by rack-and-pinion gearing. It appears incontrovertible that all must be by the same makers and badged, as required, by the customer for sale into the trade.
"tom_boctou" on the Practical Machinery Antique forum has managed to discover that Bosworth has been a well-known name in Warren, RI business circles for a considerable length of time and that both E. A. Eddy and E. A. Adams were in the machinery and jewellery business, both as manufacturers and as resellers, with E. A. Adams & Sons surviving until as late as 1982. A web search revealed a number of obituaries and resumes of ex-employees, so the likelihood is that this was a considerable business; in the Providence Jewelers Circular, of 4 Aug 1920, it says: The EA Eddy Machinery Co has purchased the manufacturing jewelry plant of the HA Kirby Co 85 Sprague St and will sell the tools machinery etc in lots to suit purchasers: and The offices of the EA Eddy Machinery Co have been removed upstairs in their building corner of Clifford and Eddy Sts thus giving additional space for the display of jewelers and general machinery on the lower floor.
Should any reader be lucky enough to own an E.A.Adams lathe, (or an E.A.Eddy, Bosworth or Diamond) the writer would be interested to hear from you..
Almost a mirror-image lathe of convention where, instead of the tailstock being cantilevered out to the right, the headstock was pushed out to the left into a position with little support.
No micrometer dials and the feed-screw end plates simple flat housings that abutted against the end of the ways to limit slide travel. The 4-step headstock pulley looks to have come from an Atlas 10-inch
The compound slide was carried on top of a vertical slide running in ways formed on the front face of the apron. A long lever was used to lock the slide once the tool height had been set.
Providence, Rhode Island, was home to many makers of machine tools including at least four (and possibly five) lathe-manufacturing companies: E.A.Eddy, E.A.Adams, Adams Bros, the Diamond Machine Co. and E.B. Bosworth; unfortunately, apart from Diamond, little is known about the background to any of them , the historical record being, for the moment, blank.
While the novel and individualistic E.A.Adams would have been made in the two decades spanning the 19th and 20th centuries, the very simple, plain-turning Adams Bros. dates from around 1870 to 1880 - and, although intended just for wood turning, the maker's did offer a compound slide rest to enable basic metal jobs to be tackled.. However, although a simple machine, it was well made, the bed having flat and V-ways (a more expensive undertaking than the usual flat type used for this class of lathe) and with both the hand T-rest and tailstock fitted with robust, quick-release-and-tighten tighten lever-operated clamps. When slackened, the hand T-rest could both be slid along the bed and swivelled, its loose upper section being fastened to the lower by a bolt sliding in a T-slot - a common arrangement now for well over 120 years.
Fitted with a 3-step cone pulley to take an unusually wide flat belt, the headstock spindle ran in plain bearings - the fit and finish of the components looking to be of a high standard. It's highly likely that the makers would have offered a compound slide rest for light-duty metal turning. The style of bed, together with the provision on the tailstock of a socket to take a dipper rod to apply a white lead lubricant onto its centre, offer clues that the maker might have offered other, better-specified models possibly incorporating backgear and screwcutting.
Should any reader have an Adams Brothers lathe the writer would be interested to hear from you.
With thanks to George Langford in the U.S.A. who supplied the photographs
Based in High Holborn, London, England George Adams (sometimes calling themselves "The Pittler Company") were machine-tool dealers, manufacturers and assemblers who also commissioned various makers, in the UK and Europe, to make machine on their behalf - with some being copies, not originals, of existing designs by Lorch, G.Boley, Wolf Jahn and Portass. The company sold a very wide variety of lathes (and associated tooling) and were best known for their small machines aimed at watch, clock and instrument makers. However, Adams had strong connections with Germany and was, for many years, the UK representative for the Pittler Company and also sold larger lathes almost certainly manufactured by Oscar Ehrlich - a well known and long-established lathe maker with premises in Chemnitz. One highly unusual George Adams lathe was a round-bed model, first offered in 1902 after he had parted company with Pittler. Based on Pittler lines the lathe incorporated some of that maker's features and examples are known to survive (should any reader have one, the writer would be interested to know). George Adams died in 1935, with a "closing-down" sale held during the early 1930s and the remains of the enterprise incorporated into Tyzack & Son - well known in the 1930s for their extensive mail-order tool and machinery catalogues.
A close examination of Adam's products shows that the quality was highly variable: some machines were entirely acceptable, others less so, while elements of the various designs were often, to be kind, rather unusual.
Shown immediately below is a typical larger George Adams lathe, a 4.75" x 20" pedestal mounted machine looking very much like an early Ehrlich (a well-known German exporter of machine tools to the retail trade) that shows, in the context of its era, evidence of thoughtful design and attention to detail. Also found in Europe and Australia (where is was badged as the Aster), it had a heavy, cast-iron pedestal that doubled as the support for very heavy flywheel and treadle assembly - the latter having a most unusual arrangement of crank rods to transmit the drive from foot bar to flywheel shaft. As on many lathes of that era, the pedestal also provided a handy storage compartment for the screwcutting changewheels, these being held, individually, in narrow wooden shelves.
Because the bed was of cantilever form, it should have been free from distortion when clamped to its base support. The lathe was fitted with a 16" capacity gap, a 0.9" hole through the headstock spindle, tumble reverse, backgear, split clasp nuts on the apron, a set-over tailstock with a proper barrel clamp (rather than the "split" casting then so common) - and, one final clue to the lathe's quality, an oil reservoir and dipper rod fitted to the tailstock - so there was no excuse for not lubricating (usually with poisonous white lead, not oil) the "back centre" as it was then known. The artist (or engraver) of the picture seems to have limited the top slide to a rather meagre length of travel, in reality it was rather longer than illustrated.
Should you have a George Adams lathe or other machine tool of any description, the writer would be interested to hear from you..
George Adams lathe, a 4.75" x 20" pedestal mounted machine probably by Ehrlich and also found in Europe and Australia - in the latter country being badged as the Aster
A rare survivor - and still with its original plinth-mounted treadle drive
George Adams TE6 2.25" x 8" precision lathe - a heavy-duty watch and clockmaker's lathe based on the American WW type. Typical of the many different small precision lathes "manufactured" and factored by the George Adams Company before WW2, this example is probably a German Lorch
A Portass Mk. 5 badged as a George Adams - this example lacks the top slide
Amongst the plethora of models listed by Portass from the 1930s to the 1950s the 3" x 16" Mk. 5 (not to be confused with the later PD5) must be amongst the rarest - only a handful having come to light in recent years. An entirely conventional machine, the lathe was also, surprisingly, badged as a "George Adams" - a brand more normally associated with high-class machine tools with prices to match. Weighing around 50 lbs, the Mk. 5 was entirely conventional with a simple, split-bronze bearing backgeared headstock (at a ratio of 1 : 6.75) and a spindle bored through 3/8" with a No. 1 Morse taper socket and a 3/4" 12 t.p.i BSF nose. Oddly, the headstock has been found both as a bolt-on unit and cast as-one with the flat-topped , V-edged, gap bed. Driven by changewheels 3/8" thick, with a 5/8" keyed bore and a sixth-of-an-inch circular pitch - about 18.812. DP - an odd figure presumably caused by the economical use of pre-war, non-standard gear cutters. The 24-inch long leadscrew was threaded for 11 inches of its length with a 9/16" 8 t.p.i. square thread and gripped by proper clasp nuts. Although a low-cost product the lathe still had a compound slide assembly with a T-slotted 5¼ x 2½" cross slide driven by a 5/16" 18 t.p.i. screw,
Of the simplest kind, the tailstock was unable to be set-over for taper turning and held a 2-inch travel barrel (lock with a crude, direct-acting screw) with a 10 t.p.i. square thread that passed thorough the smooth-edged handwheel - an unfortunate oversight when it was likely to be gripped by oily hands.
Although most owners were happy to save the pennies and risk their fingers, Portass did offer a swing-open, cast-iron changewheel guard, though few can have been sold.
George Adams badged Portass Mk. 5 photographic essay here
Beautifully made, the little George Adams 21/2" centre height precision lathe has been a machine sought after by generations of amateur machinists - especially clockmakers - keen to get their hands on a genuinely high-quality product (though it must be said that the design quirks, present on nearly all George Adams's products, were present on this version too). Also found badged as the R.Kelly of Manchester & Liverpool, the lathe was almost certainly inspired by German Wolf Jahn practice with very small marks - usually saying just "Germany" in tiny letters - sometimes being found stamped on various parts using that company's recognisable style. In addition the accessories also confirm such a connection, being constructed in an identical way and directly interchangeable with the Wolf Jahn originals. Normally sold in plain-turning form, the 21/2" could also be fitted with two types of screwcutting arrangement: the first, using a straight shaft direct from changewheels to the top slide was at odds with the normal practice of using a keyed and universally jointed shaft; the second consisted of a proper bed-mounted leadscrew - in which latter form it is particularly rare. Made for several decades, from approximately 1900 until the mid 1930s, it had a bed of typically English/German pattern, being flat on top with the location for headstock, carriage and tailstock formed by vertical flat shears between the two ways. An unusual feature was the mounting of the bed feet - they were simply bolted to rather ugly-looking lugs formed at each end of the casting. However, being finely machines on both top and bottom surfaces - and located on the machined underside of the bed - the feet did add slightly to the bed's stiffness.
Like all "Precision" George Adams lathes, the headstock of the 21/2" followed the well-established pattern for a high-quality "Bench Lathe*" of having bearings made from opposed , hardened steel cones that closed down on similar hard cones fastened to or formed as part of the spindle. Provided a supply of clean oil was maintained, this type of bearing proved capable of almost infinite life - some American lathes (by Stark and Wade) having successfully absorbed over fifty years of commercial use without failure. The headstock spindle (or mandrel as it was then called) accepted a hardened, tapered insert that took standard 8 mm collets. This insert can, incidentally, be hard to see, being a very close fit within the 7/8" diameter, 20 t.p.i nose, and must be removed if use of the full spindle bore is required.
Designed to be driven by a round leather rope - or "gut" in popular contemporary parlance - the 3-step cast-iron pulley was locked to the spindle was a somewhat over-engineered (though delightful) collet-like method where the smaller end of the pulley was turned parallel for a short distance and slotted with four equally-spaced slits; a large clamping ring was slipped over the slotted section and tightened by four screws until it closed down onto the spindle - the arrangement can clearly be seen in the pictures below.
Equally neat, though not unique - it also being employed by Rivett - was the method of securing the "balanced" ball-ended handles on the very long-travel compound slide rest; a long screw, with its slotted head moulded so as to blend in with the end of the ball, passed right down the stem of the cross piece to engage with the end of the feed screw. The design of the compound slide assembly was unusual, and incorporated some weaknesses; the feed screws were 25 t.p.i. with brass micrometer dials, finished, on early examples, with a double rim and traditional "rope" knurls, engraved with divisions of 0.002". The slide rest changed over the years with some being in proportion to the rest of the machine (with the expected lengths of travel) while other were noticeably different with considerably longer cross slides and more modern-looking micrometer dials. Unfortunately the top slide - which on all models had at least a useful 3 inches of movement - had no degree marking for its swivel settings; and, equally disappointing for a quality lathe (though in line with later Schaublin practice), was the use of a long horizontal slot in the tailstock casting to act as a clamp for locking the (short) No. 1 Morse-taper barrel. The danger of the casting being over tightened, and broken off, was mitigated against (to some extent), by the provision of two adjustable stop screws that passed through the slot - one at each side of the clamping screw; the general arrangement of the tailstock slit can be seen in the third picture below.
An unusually wide variety of accessories was available for the lathe enabling it to be used for grinding, screwcutting, precision sawing, milling and light production work.
Original colours used on George Adams lathes included plum red and emerald green.
*Including: American Watch Tool Company, Arrow, B.C.Ames, Bausch & Lomb, Benson, Boley, Bottum, Boxford, B.W.C., Carstens, Cataract, Cromwell, Crystal Lakes, CVA, Derbyshire, Elgin, Hardinge, Hjorth, Juvenia, Karger, Leinen, Levin, Lorch, Mikron, W.H.Nichols, Potter, Pratt & Whitney, Rambold, Rebmann, Remington, Rivett, Saupe, Schaublin, See (FSB), Sloan & Chace, Smart & Brown, T & L.M., U.N.D., Van Norman, Wade, Waltham Machine Works, Weisser, Wolf Jahn and (though now very rare), Frederick Pearce, Ballou & Whitcombe, Sawyer Watch Tool Co., Engineering Appliances, Fenn-Sadler and the "Cosa Corporation of New York.."
The standard GA 21/2 plain-turning lathe.
Screwcutting attachment driving through a straight shaft to the top slide - an arrangement at odds with the normal practice of using a keyed and universally jointed shaft
The maker's lever-action toolpost grinding attachment fitted neatly into the cross-slide T slot. The unit was very well built and incorporated a oil-bath gearbox to increase the wheel speed. Driven from an extension of the lathe countershaft the gearing allowed a work piece in the chuck to run at a modest 350 rpm whilst the grinding spindle rotated in the opposite direction at up to 12,000 rpm.
George Adams geared Toolpost Grinder - an expensive accessory at over half the price of the basic lathe.
GA 21/2F Precision Manufacturing Lathe. The Model F was supplied with a capstan unit mounted on the tailstock and a double-toolholder cross slide for forming and parting-off work.
The headstock was specially constructed to accept collets of a much greater-than-standard capacity - 11/16" in the nose and 9/16" pass-through - however, to achieve this within the confines of a 2.5" centre height and transmit enough power to make the enterprise worthwhile, the large-bore spindle had to run in such massive bearings that only a single wide pulley could be accommodated between them.
The Capstan tailstock that could be fitted to all GA 21/2 lathes. The barrel had a hole of unspecified taper into which a single tool could be inserted. A rotating stop provided an accurate depth location for each rotation of the handle - with the tool being automatically ejected at the end of the stroke.
The simple Forming and Parting Single Slide that attached to the cross slide of the compound rest.
The long-travel tool slides of the George Adams 21/2" Precision. Note, on this example, the raiser block under the headstock to increase capacity and the spacer at the front of the cross slide to increase its travel.
GA 21/2 plain-turning lathe on the maker's very light treadle and flywheel stand
George Adams made, or marketed, both the European "Geneva" (sometimes called "Swiss") and the American WW (Webster-Whitcomb) styles of watchmaker's lathes; the American design, being a heavier and more robust machine, cost some 30% more. A wide range of additional fittings was available and the lathes could be had in a basic form, or cased together with various selections of collets and accessories - a WL Geneva-pattern lathe, for example, rose in price from £3 : 10 : 0 to £6 : 6 : 0 when presented in a lockable wooden box containing: a handrest with 2 Tee rests, a single chuck to carry 4 cement plates, a set of 12 wire collets, a single "8-screw" bell chuck, a taper-hole collet with male and female centres, driver plate, emery wheel and mandrel, circular-saw mandrel, guide pulley on eccentric arm, hollow runner No. 34 - complete with its 14 accessories - and two collet-mounted fine centres..
A "Swiss" or "Geneva" pattern light-duty watchmaker's lathe made by Lorch and sold under the George Adams label. The lathe was available in two Models: the "WL" took Size L collets of 6 mm shank whilst the "V1" accepted an 8 mm collet. In the early 1930s the smaller capacity machine cost £3 : 15 : 0 whilst the smaller was 'five-bob' cheaper at £3 : 10 : 0. The weight was 5 lbs.
George Adams AA Precision on a single foot with 12" long bed, plain runner tailstock and a headstock spindle to take Size A 8 mm collets.
Although the catalogue does not mention the fact, the lathe was constructed to American Webster-Whitcomb standards with a 1.968" centre height. The finish was in nickel plate and, at 10 lbs, it weighed twice as much as the "Geneva" pattern model shown above.
George Adams AA Precision with a 20" long bed on twin feet and fitted with a compound-slide rest, 3-jaw chuck and a heavier, screw-feed tailstock.
George Adams WW-pattern lathe with screwcutting attachment (including 14 changewheels) compound slide rest and screw-feed tailstock.
Whilst the basic WW lathe cost (in 1931) £4 : 10 : 0 this version, with a 20" bed and nickel-plate finish. was (at £16 : 1 : 0) very nearly four times as expensive.
Unusually for such a tiny lathe the screwcutting gears were driven through what, in the UK, is called a "tumble-reverse". This clever mechanism, first used in the early part of the 19th century, consists of a pivoting arm fitted with three shafts arranged to carry gears so that two of them form an "upper pair" - one of which is meshed with an 'output' gear on the stud below. The arm moves through an arc and has three indented locations; placing the arm in its upper position causes one gear of the upper pair to engage with the headstock spindle gear and, with the spindle running "forwards", the output gear revolves in a clockwise direction. When the lever is moved so that its locating plunger locks into the lowest hole, the other gear of the upper pair is swung into engagement with the spindle gear and the direction of rotation of the drive - and hence the 'hand' of the thread being generated by the leadscrew - is reversed. In the middle position neither gear is engaged - and the spindle is able to run freely and quietly.
The output gear is often twice as long as the others - and usually divided so that the outer part can be changed to alter the drive ratio.
Tumble-reverse detail
George Adams Type GA 11/2 lathe. This model was designed for heavy-duty where it would be subjected to the rigors of production or very high-speed use. The headstock, which accepted Size L 6 mm collets, was of the "all-hard" kind with spindle and bearings manufactured from high-speed tool steel and able to run continuously at very revolutions. Although built on the WW pattern bed, the centre height was reduced to 1.5" and the accessories were the same as those designed for the lighter WL Geneva-Pattern lathe illustrated at the top of the page. Although illustrated with a simple T rest, the machine was supplied as standard with a compound slide. It cost, in the early 1930s, £8, making it more expensive than all but the best equipped of the longer-bed WW types.
George Adams Model AAA enlarged-pattern WW-type (Webster Whitcombe) lathe with a 23/8" centre-height and standard 16" bed.
For this heavier style of Watchmaker's lathe the increase in centre height from 1.968" to 2.375" brought an entirely different set of more robust headstock and tailstock castings, a longer standard bed, a range of slightly larger, strengthened accessories and a japanned finish - but no unfortunately no increase in the size of collets that could be used .
George Adams AAA 23/8" centre-height watchmaker's lathe complete with a rather ugly and out-of-proportion 17/8" wide gap that allowed work up to 8" in diameter to be swung. Mounted on the lathe are a variety of accessories: lever and screw-feed tailstocks, 3-jaw chuck, compound slide, hand rest with short T, large dividing plate and pointer, vertical slide and a high-speed spindle.
Circa 1907 - a neatly-arranged (and expensive) bench and countershaft assembly driving a WW pattern watchmaker's lathe. It would be many years before similar self-contained, motorised assemblies were available for small screwcutting lathes.
The larger pattern AAA lathe on a self-contained stand with a ball-bearing countershaft. The electric motor is of the type first used on industrial sewing machines where a clutch was carried on its output shaft. These units are well-worth seeking out and rebuilding; they were designed for continuous and arduous use in garment factories and were of the very highest quality.
A similar motor and clutch unit was used in the 'Mardive' stands supplied for Pultra precision lathes in the 1950s and 1960s - Mardive being an English maker of industrial sewing-machine drive systems based in Stockport, near Manchester.
The tall stem (A) was used for tensioning the drive to ancillary equipment - high-speed milling and grinding heads for example - the middle unit (B) provided a total of 16 speeds (assuming a 4-step pulley on the motor and lathe) whilst the two-speed unit in the background (D) was listed as a "Foot Wheel" and available in two weights (24 lbs and 38 lbs) - both of which could be mounted either underneath the bench, or on the floor.
Typical of the bench countershaft made by many companies to drive their watchmakers' lathes this Lorch, or Lorch inspired unit, had a double swivel base and a choice of three pulleys to accept or transmit the drive. Used in combination with a tension-adjusting post (as illustrated above) and quickly-joined plastic - or round leather belting - this type of countershaft could be set up to drive the headstock and any type of toolpost-mounted spindle that the user cared to arrange.
A most unusual machine and of very high quality, the George Adams 4" x 19.5" round-bed lathe is especially rare. Sometimes found for bench mounting, the makers also offered a very heavy, self-contained cast-iron plinth-like stand with a built-in treadle drive, the foot pedal being to the front in the normal way with the drive pulley overhung on the left-hand face; a picture of this assembly can be seen on this page.
With a headstock bearing some similarity to that used on the Pittler B2 (for which Adams were the UK agents) it's possible that the round-bed was manufactured by the English firm of Milnes - some Pittler lathes being built by them either officially, under licence, or merely copied. As the versatile Pittler would have been an expensive lathe to engineer and clone perhaps George Adams, looking for similar functionality, retained the compact, Pittler-type epicyclic backgear (built into the largest diameter of the headstock pulley), but simplified other matters with a round instead of trapezoidal bed. Like the Pittler, the George Adams round-bed was able to rotate the complete carriage around the bed - but in this case instead of only partially, it could be turned through 180° to bring a permanently-mounted, T-slotting boring table to the top while leaving the complete compound slide rest undisturbed. In addition the lathe has a number of other interesting features including, Mounted on the front face of the headstock was a handwheel by which means the carriage could be moved along the bed. Interestingly, this could be operated in two ways, either with a direct drive at a ratio of 1 : 1 or though built-in reduction gearing that gave a carriage advance of 0.010" per revolution. Inside the handwheel was a pair of gears, one small the other large, with the former connected to a push button that allowed it to be engaged and disengaged. When engaged the pair of gears acted as an epicyclic - though of course for this to happen the larger gear had to be locked in place, this being achieved by a peg on the handwheel-mount engaging a hole in the larger gear. With the gears engaged and the larger gear locked, when the assembly was rotated the reduction in ratio was obtained.
In practice users found that the 1 : 1 ratio was difficult to use: the handle being too small and the torque needed to turn it considerable. However, the reduction mechanism worked perfectly and was the one used most of the time; if a faster rate of feed was needed, for example to reposition the carriage quickly, the large handwheel at the tailstock end of the leadscrew worked with ease.
To engage, disengage and reverse the hand-feed feed a sliding knob was provided at the front base of the headstock; sliding the knob to the right caused the carriage to advance towards the headstock when the handwheel was turned anti-clockwise (and vice-versa). Setting the knob to the left reversed the motion so that turning the handwheel anti-clockwise moved the carriage away from the headstock (and vice-versa). With the knob in the central position the leadscrew was disengaged and could then be turned by the tailstock-end handwheel. The same sliding mechanism also engaged the screwcutting feed between the changewheel train and the leadscrew - two oil caps at the back of the headstock allowing lubrication of the internal gears that connected everything together. In addition the lathe was also fitted with an automatic disengage to the carriage drive - a rod being attached to the slider that engaged and disengaged the leadscrew feed. With the slider pushed to the right and the screwcutting (power) feed operating, the rod and slider moved out together towards the carriage and, when contact was made, the carriage pushed the slider back to its central position and so disengaged the drive. In theory it would have been possible to add extensions to the disengagement rod using and screwcut for a fixed distance or up to a shoulder - though for safety this would have need a slow spindle speed and care in setting up. While lathes of this type and class are frequently found with some sort of indexing arrangement on the headstock - usually one or more circles of holes drilled into the front face of the headstock pulley with an indent pin for registration - the George Adams arrangement was different with the flat front face of the largest headstock pulley inscribed every 10° with a line. Bearing against the face, and providing a reference point, was the flatted tip of a bronze bar bolted, at its lower end, to the outside face of the headstock. Thus equipped, it was possible for a turner to index the spindle to a chosen poition - but not lock it..
Of evidently high quality, this round-bed George Adams has been in the hands of one owner since 1981 and has recently complete all the machining necessary to built a 3 inch scale (7.25 inch narrow gauge) Hunslet quarry-type steam locomotive
In this photograph the carriage-feed handwheel has been removed from the front face of the headstock showing, below the mounting boss, the pin that locked the large gear to convert the mechanism to a slow-feed epicyclic drive.
Like the lathe that might have been the inspiration for the George Adams Round-bed, the
Pittler B2 , the headstock was fitted with an epicyclic (speed-reducing) backgear system.
Backgear was provided by epicyclic gearing built into an extension to the front face of the headstock pulley. Above the epicyclic gear lock is shown free and below engaged. With the pin holding the inner drum from rotating, the sun and planet pinions inside caused the right-hand drum (and hence the spindle to which it is attached) to turn at a reduced speed. Exactly the same arrangement was used on the Pittler B2 lathe for which George Adams was the
For comparison, the headstock assembly of the Pittler B2
An interesting innovation was the provision of a handwheel by
which means the carriage could be moved along the bed.
Inside the fine and coarse-fine-feed mechanism. In this setting the plunger pushed in and the smaller gear engaged with the larger
Plunger pulled out and the gears disengaged
Carriage-feed handwheel has been removed from the front face of the headstock showing, below the mounting boss, the pin that locked the large gear to convert the mechanism to a slow-feed epicyclic drive. Also visible, bottom right, is the engagement knob for the screwcutting and power drive the carriage
Although almost certainly not original, the countershaft is a good match to the lathe
The original drive would have been by a round leather "gut" rope,
Little was overlooked - even oil caps being provided to allow lubrication of the leadscrew where it passed through the headstock-end casting
A long-travel top slide with two T-slots
The whole saddle assembly could be rotated around the bed to bring a T-slotted boring table to the top. Fitted with good-size micrometer dials the compound slide rest was of rugged construction - and note the rack screwed to the side of the top slide and the hole formed in its base casting, these being the components of a lever-feed attachment. A clue to the age of the lathe lies in the use of awkward-to-use crank
An early quick-set toolpost by the chuck maker Burnerd, the Type TP1, a unit manufactured during the 1950s for use on small lathes
