US2072228A - Last lathe - Google Patents

Description

March 2, u 1937., L. 'E. TOPHAM ET; AL

LAST LATHE Filed Dec. 2 ,1934

8 sheets- -sheet 1 March 2, 1937. E. TOPHAM ET AL 2,072,228

7 LAST LATHE Filed Dec. 28, 1934 8 Sheets-Sheet 2 March 2, 1937.. E. TOPHAM ET AL 2,072,228

LAST LATHE Filed Dec. 28, 1934 8 Sheets-Sheet 3 22; k gw L. E. TOPHAM ET AL 2,072,228

2 March 2, 1937.

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w 34, WVE/VTOR-S March 2, 1937. LE. 'EI'OPHAM ET AL 2,072,228

7 LAST LATHE File d Dec. 28, 1934 s Sheets-Sheet s WVENTOHSI March 2:, 1937. L E. ToPHAM :1- AL LAST LATHE Filed Dec. 28, 1934 8 Sheets-Sheet 7 L E. TOPHAM ET AL LAST LATE E Filed Dec 28, 1934 MarcI1 2, 1 937.

Patented Mar. 2, 1937 U NlTE 2,072,228 LAST LA'r iE Laurence E. Topham, Wenham, and Clyde L. Knott, Beverly, Mass; assignors to United Shoe Machinery Corporation, Paterson, Isolation of New J ersey' ApplicationDeeember 28, 1934,.Sei'ial K13 759580 20 Claims. (Cl. 142--15) This invention relates to copying lathes and is illustrated as embodied ina machine generally,

of the type shown inUnited States Letters Pat'- ent ,No. 1,713,792 granted May 21, 1929, upon an] 5 application of ,L. E.'Topham..

In the machine shown in this patent the cutter and model wheel carriages are driven in opposite directions by a right-, and left-hand threaded feed screw, and the 'leng'thgrading, which inlo volves driving them at different speeds, is effected by providing athird carriage directly driven by one end of the screw and connected to the cutter or model wheel carriage by. 'an ordinary length, grading lever. The present invention simplifies,

" and improves the length grading mechanism by driving the grading carriage directly from the feed screw by means of a differential gearing,

comprising a nut between the screw andthe carriage, the nutitself being driven to modify, the 20 driving action of the screw. In the illustrated; machine, this is effected by a rack which is driv-" en by a slide moving along an angularly adjust: able guide ribas the carriage moves along. Preferably the rotation of the nut is in the same 25 directionv as that of the screw which relieves the pressure betweenthe screw, nut'and carriage; thus avoiding danger of sticking and irregular motion.

The invention also provides an, improved trans: 3QKVGIS orwidth grading mechanism in which the modelwheel, which does the width grading, is,

mounted on a crank arm instead of a slide, which renders its grading movement less liable to ire regularities. In the illustrated machine, a crank wheel crank by a chain of links the adjustment of one pivot in which modifies the action of the fully hereinafter e xplaine d. I

These and other features of the invention comprising certain combinations and arrangements 5Q..of parts will be apparent from thefollowing description of a preferred embodimentoftheinven';

tion, shown in the drawings, inlwhich Fig, l is a plan view ofthe machine; Fig. 2 is a viewin front elevation; Fig.3 is a view inflright-handelevation;

arm'on the swing frame is connected to the model relationship between the model wheel, the cutter Fig. 4. is a left-hand view same machine;

Fi'g; 5" is a1detai1 ofthe length gradingmechanism;

Fig. dis a detail of the driving mechanism; Figsfl and 8 are details of the'clutch Figs; 9,.10and 11 are detailsof the width grad: ing mechanism; Fig.1l2 is a'jdetailof the stoclgingon device;

Fig. 13 isa di'a g ram of the 'width grading mechanism;

"Fig. j 14 is a diagram showing the relation of different model wheelsfto the "length grading i le tes. o he.

p rati n; a d;

Figs. 15 jand'lfi, are perspective views of the Widthjgrading mechanism,

'The instant machine is generally similar in its construction jto the machine shown ingL'etters Patent. Nd, 1,713,792, 'hereinbefore referred to. Reference should be made to this patent for more exhaustive description of certain matters not "so fully treated herein. In the followingdescription, rfererice'numerals, in parenthesesrefer to analo gouspartsin ,the'lmachineshown in the patent. 'The machine has a main frame iilwithlongi tudinal slideways l2 (l2), M l6), on which slide a cutter'c'arriage 16426)} and amodelwheel carriage, |8,(l8),. These are d'rivenby right: and left-,hand threaded "screws 124,) constructedas one'inte'gr'a 'fmember. whichturnsas shown by the arrow in, Fig. 1,, and engages nuts '22, 24 mounted in the carriages ,l 6 and l 8, respectively. These nuts are provided with. gear teeth 25 which engagefi racksjone of which, 28, is used for length gradingpurposes, as will be explained, and the other of which (not shown) engages the nut 22 andflis usedforsetting itin order to adjust the machinew hen it, is being builtgremaining lunal terd in position thereafter. The machine also has a swing"frameidcomprising the square pivot shalt}01148).,vvhichf carries the dog and gearing hbiisings tiln). 34 (52), 35] (14).. The screw 201s turnable'by hand .by m'e'a ns' ofthe'jhandle 38,.and gearing 49,.in orderto traverse the carriagesfrapidly. The swing frame is pulled toward the model .wheel by a spring 4|.

The machine is driven by a motor 42 mounted under its left end, and driving a shaft 44 sprocketgeared to a shaft 46, The shaft 46 is connected to ajshaft 43 by a change gear 50 (Fig. 4) The shaft 4 8,; bymeans of spiral gearing 52, drives the longitudinallyslidable clutch member 54 on the shaft 554mg. 6) which, by bevel gearing 5s, 53 at its frontend, drives the idler gear 60. (Fig s. tend 15 whioh drives the dogs in the swing frame by the gears 62, 64, 66, 68. The gear 59 is rotatable on the shaft 30. The model I and block I2 are mounted to face in opposite directions on the axis I4 in the swing frame, where they are traversed by the model wheel I6 and cutter I8 which both move toward the center of the machine when a block is being cut. The gearings in the boxes 32, 34, 36 are identical and are so designed that the rotation of the swing frame, per se, effects no alteration in the respective orientations of the model and model wheel center, and of the block and cutter center. This is explained in the patent referred to. The face plates 80 are mounted on the ends of a single spindle 62 on the axis I4 (56), thus preventing any discrepancies between the model and work piece due to looseness in the gearing, as explained in the patent referred to. The axes of the model wheel and cutter are placed at an angle of about 30 to the axis of the feed screw 20, as explained in United States Letters Patent No. 1,330,841, granted February 17, 1920, on the application of F. 8. Buck, and the cutter head I8 is constructed substantially as shown in that patent.

The feed screw 20 is driven from the shaft 56 as follows. A spiral gear 84 on the shaft 56 (Fig. 6) drives the gear 86 on the shaft 88 which extends to the center of the machine, and there carries a spiral gear 90 (Fig. 7) meshing with a gear 92 in a housing 94 pivoted on the shaft 83. The gear 02 drives a shaft 95 with a spiral gear 66 on its rear end engaging the gear 98 which is pinned to the screw 20. The housing 94 latches, by means of a rod I00, over a slidable but normally fixed ledge IOI to hold the gears 96, 98 in mesh, the latch being operated by the handle I02. The housing 94 is urged upward by the spring I04 toward the position in which the gears 96, 98 are disengaged. As the carriage I6 nears the left ward extremity of its movement, a lug I on it (Fig. 8) strikes a sliding bar I06 and urges it to the left in Fig. 3 and toward the observer in Fig. 7. The bar I06 has a cut-out portion forming the ledge IOI and the end of the ledge is thus carried 'past the latch rod I00 permitting the spring I04 to disconnect the gears 96, 98. In case the operator has his hand on the handle I02 at this time, a lug I01 on the bar I06 strikes a pin I01 on a pawl shaft I08 which positively forces the housing 64 down into inoperative position (Fig. 8).

The gearing is so timed that one revolution of the screw 20 corresponds to one revolution of the model and block in the swing frame.

The length grading device is shown in Fig. 5.

: The pitch of the left-hand end of the screw 20 is greater than that of the right-hand end, so that the model wheel carriage normally travels faster than the cutter carriage. The machine is designed so that it grades down 6 sizes under these conditions, the function of the length grader being to grade always up from the normal 6 sizes down. The grade up is effected by moving the sliding rack 28 which turns the nut 24 counterclockwise as seen from the left end of the machine. In other words, the rack 28 turns the nut 24 in the same direction as that in which the screw 20 turns and relieves the pressure between the carriage I8 and the screw thread, instead of wedging the nut in tighter between them. This avoids sticking and irregular movement which might result from the latter procedure, in the case of grading down with the two screw ends alike.

The rack 28 is pulled toward the back of the machine by a block IIO which slides on an inclined guide II 2 as the carriage I8 moves to the left, carrying the rack 28 with it. The guide H2 is mounted on a plate II4 pivoted at II6 on the frame I0 and is angularly adjusted by a segment I I8 pivoted at I20 on the frame and linked to the plate H4 at I22, I24. The segment is adjusted by a worm I26 on a shaft I28 operated by handles I30, I32. When the guide H2 is parallel to the axis of the screw 20, the rack 28 does not operate and the grade is 4%; sizes down. When the guide I I2 is. swung to its extreme angular position (Fig. 5), corresponding to the smallest model wheel provided, the grade is 6 sizes up, the rack 26 then actually effecting a grade of sizes. A second Worm I34 on the shaft I28 operates a small segment 168 on a shaft I36, which carries a pointer I40, the end of which can be read against a chart on a revolving chart plate I42, in case it be desired to effect continuous control of the grading factor as explained in the Topham patent referred to.

The width grading mechanism is shown in Figs. 9 to 11, and is diagrammatically shown in Fig. 13. The end of the shaft 30 is rounded to turn in its bearing I43 and carries a housing I44 rotatably mounted on it. Ordinarily this housing is held rigid with the shaft 30 by a link I46 extending between an arm I41 on the shaft and an arm I4l on the housing. The housing I44 has another arm I46, which, together with the swing frame 29 and the link I46, forms a rigid bell crank. The end of the arm I48 is connected by a link I50 to the end of a link I52, the other end of which is pivoted to a segment I54, pivoted at I56 on the frame I0. This segment is angularly adjustable by the width grading handle I58. The junction of the links I50, I52 is connected to an arm I60 on a shaft I62 by a link I64. The links I50 and I64 and the arm I48 are of the same length. In Fig. 9 the axis I4 of the swing frame dogs, 1. e., the turning axis of the model and block, is shown in alinernent with the face of the model wheel I6. This is called the neutral position of the swing frame and of the model wheel. With this position, if the model grading handle I58 is set to zero, the design is such that the upper end of the link I52 is in line with the axis of the shaft 30 and the links I50 and I64 lie exactly behind the arm I48, the ends of the arms I48 and I68 being in line. The model wheel I6 is carried on an arm I 68 which, with the arm I60, normally forms a rigid lever, as will be seen, and which is normally rotatively rigid with the shaft I62 when the machine is running, and the width grading is rllsone by the movement of the shaft I62 and arm The swing frame being in the neutral position, as above stated, the crank arm I48 and its connection to the link I50 are fixed in position. The other end of the link I50 is connected by the link I64 to the arm I60. The links I50 and I64 being equal in length to the crank arm I48, the junction of the link i64 and the crank arm I60 will be coaxial with the end of the crank arm I48 and any adjustment of the handle I56 and segment I54 will merely swing the junction of the links I50 and I64 up and down without moving the arm I60, so that adjustment of the width grader when the swing frame is in neutral position affects nothing else in the machine.

When the width grader is set at zero, the junction of the links I50 and IE4 is permanently coaxial with the shaft 30, and movement of the swing frame merely rocks these links around the axis of the shaft 30, the junction of the link I64 to the arm I60 remaining fixed. It should be jected to, will all be correct owing to the abovedescribed arrangement.

This is illustrated in Fig. 14, which shows two wheels 16A and 16B representing the extreme members of the line of wheels provided. These wheels are both shown in neutral position withtheir front faces on the axis 14 of the model, and with their leading points HA and HE on the length grading center line G.

The grading mechanisms of the illustrated machine have been constructed to effect geometric grading, in accordance With the method described in United States Letters Patent No. 1,948,547, granted February 27, 1934, upon an application of L. E. Topham. The handle I30 (Fig. 6), for example, is set into any one of three holes in the dial plate over which it turns, and the dimensions of the parts shown in Figs. and 9 to 11 are so designed that movement of the handle from one hole to the next effects a /2 size change on a grade of about 3% per size.

A pivoted width grade indicator E88 is linked to the segment I54, and reads on the chart plate hi2. This chart plate is rotated by gears if), I I34, the latter of which is on the end of the screw shaft 20.

An automatic stop (Fig. 6) has also been pro vided to stop the rotation of the model and block at the same place in their cycle. See Fig. 6. A gear E96 on the shaft 56 operates a gear I98 which is loosely mounted on the screw shaft 20. This gear I98 is integral with a cam 206 which has a hump in it arranged to rock a lever 202 pivoted on the shaft I38. The rear end of the lever is pivoted toa slotted bar 264 which carries a spring-pressed pivot pin 205 in its slot. The front end of the bar 204 is linked to an arm 286 on a spring-pulled lever 268 connected to a handle 21B.

When the operator desires to stop the machine he pulls the swing frame out until it latch'es at 2l2. A lug 2M on the frame then engages a lug 2116 on the handle 2 l0 and pulls it out to a position somewhat short of that shown in Fig. 6. This tilts the member 204 into such a position that the next time the cam hump 200 passes under the end of the lever 202, the member 204 will be given a further movement counterclockwise and will operate the bell-crank lever 2E8, which is connected to the pin 285, to disconnect the clutch 54. This will always take place at the same point of the rotation cycle of the model and block. In case the operator desires to stop them where they are at any instant, he pulls the handle 2H3 way out to the Fig. 6 position, so that it latches at 22!), and this movement alone throws the member 285 sufliciently to disconnect the clutch.

As explained in the first Topham patent above mentioned, it is sometimes desirable to impose an .entirely arbitrary width grading cycle on the work as, for example, when holding the bottom unchanged in grading the AA and AAA widths. This is accomplished (Fig. 4) in the instant machine by disconnecting the link I46 between the swing frame and the housing 144 and connecting it between the housing 144 and the end of a lever 222, the other end of which runs on a suitably shaped cam 224 on the end of the screw 20. The cam 224 then controls the movement of the arm I60 and the width grading cycle.

Having described our invention, what We claim as new and desire to secure by Letters Patent of the United States is:

1. In a copying lathe, a work holder, a model holder, a tool carrier and a model wheel carrier, and driving mechanism for effecting relative traversing movements between them in pairs, said driving mechanism comprising a differential gear device, one member of said device determining the relative traversing movement of one said pair, and the other member of said device determining the relative traversing movement of the other said pair.

2. In a copying lathe, a work holder, a model holder, a tool carrier and a model wheel carrier, and driving mechanism for effecting relative traversing movements between them in pairs, said driving mechanism comprising a screw associated with each carrier, a nut mounted on each screw and rotationally but not translationally mounted in the carrier, and means for effecting relative rotations at different speeds between the nuts and their screws.

3. In a copying lathe, a work holder, a model holder, a tool carrier and a model Wheel carrier, and driving mechanism for effecting relative traversing movements between them in pairs, said driving mechanism comprising a screw associated with each carrier, a nut mounted on each screw and rotationally but not translationally mounted in the carrier, means for normally effecting relative rotations at the same angular velocities between the nuts and their respective screws, and means for eifecting a differential relative rotation between the nuts and their respective screws to render the said angular velocities unequal.

4. In a copying lathe, a work holder, a model holder, a tool carrier and a model wheel carrier, driving mechanism for effecting relative traversing movements between them in pairs, said driving mechanism comprising a screw, a nut associated with each of the carriers and mounted on the screw, and means for continuously rotating the screw and one of the nuts.

5. In a copying lathe, a work holder, a model holder, a tool carrier and a model wheel carrier, driving mechanism for effecting relative traversing movements between them in pairs, said driving-mechanism comprising a main driving gear member, and a differential gear member operatively located between the main driving gear member and one of the carriers.

6. In a copying lathe, a work holder, a model holder, a tool carrier and a model wheel carrier, driving mechanism for effecting relative traversing movements between them in pairs, said driving mechanism comprising a rotating screw, a nut operatively located between the screw and one of the carriers, and means for differentially rotating the nut during the rotation of the screw.

7. In a copying lathe, a work holder, a model holder, a tool carrier and a model wheel carrier, driving mechanism for effecting relative traversing movements between them in pairs, said driving mechanism comprising a rotating screw, a nut operatively located between the screw and one of the carriers, and means for rotating the nut during the rotation of the screw, said means being controlled by the movement of the nut along the rotating screw.

8. In a copying lathe, a work holder, a model holder, a tool carrier and a model wheel carrier, driving mechanism for effecting relative traversing movements between them in pairs, said driving mechanism comprising a rotating screw, a

nut operatively located between the screw and one of the carriers, and means for rotating the nut during the rotation of the screw, said means comprising an angularly adjustable slide, a rack stages fprogrejssively"movableby the slide as the nut :moved along thefls'crew, and pinionteeth'on the nut engaging the rack.

9 In a copying lathe, a, work holder, a model holder, atool carrier anda'fmodel wheel carrier, and driving mechanism for effecting relative traversing movements between them in pairs comprising a rotating screw having threads of difierent leads on its ends, and two nuts mounted one on each end of the screw, and having driving relation with the carriers, respectively, whereby one carrier is normally driven faster than the other.

10. In a copying lathe, a work holder, a model holder, a tool carrier and a model wheel carrier, and driving mechanism for effecting relative traversing movements between them in pairs comprising a rotating screw having threads of different leads on its ends, two nuts mounted one on each end of the screw and having driving relation with the carriers, respectively, whereby one carrier is normally driven faster than the other, one of said nuts having a toothed periphery, and a rack driven by the movement of that nut along the screw for turning the nut as the nut moves along the screw.

11. In a copying lathe, a work holder, a model holder, a tool carrier and a model wheel carrier, and driving mechanism for effecting relative traversing movements between them in pairs comprising a rotating screw having threads of two different leads on its ends, two nuts mounted one on each end of the screw and having driving relation with the carriers, respectively, whereby one carrier is normally driven faster than the other, one of said nuts having a toothed periphery, and a rack driven by the movement of that nut along the screw for turning the nut as the nut moves along the screw, said turning movement of the nut being in the same direction as the turning movement of the screw, whereby pressure between the nut and the screw, on one side, and the carrier with which the nut is associated, on the other side, is relieved.

12. In a copying lathe, a work holder, a model holder, a tool carrier and a model wheel carrier, and driving mechanism for effecting relative traversing movements between them in pairs comprising a rotating screw having threads of different leads on its ends, two nuts mounted one on each end of the screw and having driving relation with the carriers, respectively, whereby one carrier is normally driven faster than the other, one of said nuts having a toothed periphery, a rack driven by the movement of that nut along the screw for turning the nut as the nut moves along the screw, an angularly adjustable segment, a slideway mounted on the segment, and a slide block on the slideway for actuating the rack when the slideway isoblique to the axis of the screw.

13. In a copying lathe, a carrier for a model Wheel, a carrier for a cutter, a model holder and a work. holder, a screw for driving the carriers,

following lateral face of the modeP-wheel to the length grading center of the'machinewhen the [two said pivots are'inalinement, irrespective of *the' dimensions of thatparticular model wheel. 14:1Ina copying lathe, a pivoted model holder, *amodel wheel carrier pivoted to swing toward and from a model in the model holder in order to effect transverse grading movements, and a transverse grading linkage connecting the holder and the carrier, arranged to effect grading movements of the model wheel in response to movements of the pivoted model holder.

15. In a copying lathe, a work holder, a model holder, a tool carrier and a model wheel carrier, and a transverse grading mechanism comprising a bell crank one arm of which carries one of the holders, a second bell crank one arm of which carries the corresponding carrier, and two links, each extending from the other arms of the bell cranks to the same intermediate point.

16. In a copying lathe, a work holder, a model holder, a tool carrier and a model wheel carrier, and a transverse grading mechanism comprising a bell crank one arm of which carries one of the holders, a second bell crank one arm of which carries the corresponding carrier, two links, each extending from the other arms of the bell cranks to the same intermediate point, and a third link pivoted at one end at the intermediate point and at its other end pivoted at a normally fixed but adjustable point.

17. In a copying lathe, a work holder, a model holder, a tool carrier and a model wheel carrier, and a transverse grading mechanism comprising a bell crank one arm of which carries one of the holders, a second bell crank one arm of which carries the corresponding carrier, two links, each extending from the other arms of the bell cranks to the same intermediate point, and a third link pivoted at one end at the intermediate point and at its other end pivoted at a normally fixed but adjustable point, the two first-mentioned links being of the same efiective length, and the third link being of such length that when its adjustable end is in neutral transverse grading position the said intermediate point is on the axis of the first-named bell crank, any adjustment of the third link carrying the intermediate point away from the axis of the first-named bell crank.

18. In a copying lathe, a model wheel carrying mechanism comprising a bell crank, a member mounted on the axis of the bell crank and rotatively adjustable about this axis, and a block mounted on the member and carrying the model wheel whereby the model wheel may be predeterminedly set out of its normal 1:1 grading position toward a model in order to add a layer 0 uniform thickness to a work piece.

19. In a copying lathe, a carrier arranged to traverse a rotating model from end to end, a slideway adjustable toward and from the model, a slide block on the slideway carrying a model wheel in contact with the model and arranged to be driven along the slideway by the carrier, and a grading mechanism for oscillating the slideway toward and from the model as the rotation of the model efiects relative movements of approach and separation between the model wheel and model.

20. In a copying lathe, a crank arm carrying a rotating model, a carrier arranged to move a model wheel from end to end of the model, a crank arm carrying a slideway, a slide block on the slideway, a model wheel carrying block pivoted to the slide block, said model wheel carrying block having an arm, a guideway on which the outer end of the arm moves as the secondnamed crank arm swings, and a transverse grading mechanism between the two crank arms for swinging the second-named crank arm in response to the encounter of varying radii of the model with the model wheel, whereby the center of the model wheel is kept substantially on a line joining its neutral position and the axis of the model.

LAURENCE E. TOPHAM. CLYDE L. KNOTT.

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