US2531590A

US2531590A - Automatic copying lathe for shoe lasts

Info

Publication number: US2531590A
Application number: US654924A
Authority: US
Inventors: Laurence E Topham; Clyde L Knott
Original assignee: United Shoe Machinery Corp
Current assignee: United Shoe Machinery Corp
Priority date: 1946-03-16
Filing date: 1946-03-16
Publication date: 1950-11-28
Anticipated expiration: 1967-11-28

Description

Now. 28, 1950 E. TOFHAM ET AL AUTOMATIC COPYING LATHE FOR SHOE LASTS 9 Sheets-Sheet 1 Filed March 16, 1946 m/en fors Lauren 0 e E. Tqoham CZ ae, LKnott Npv. 28, 1950 E. TOPHAM ET AL 2,531,590

AUTOMATIC COPYING LATHE FOR SHOE LASTS Filed March 16, 1946 Sheets-Sheet 2 2% 521/612 fors LaurenceE 7bphczm 8 Cl de LKnatt Nov. 28, 1950 L. E. TOPHAM ET AL AUTOMATIC COPYING LATHE FOR SHOE LASTS Filed March 16, 1946 9 Sheets-Sheet 3 fiwenfmzs Lauren a a E 75,0ham

1950 E. ToPi-iAM ET AL 2,531,590

AUTOMATIC COPYING LATHE FOR SHOE LASTS Filed March 16, 1946 9 Sheets-Sheet 4 clur'cnoe E. Epham Clyde LKnott Nov. 28, 1950 E. TOPHAM ET AL AUTOMATIC COPYING LATHE FOR SHOE LASTS 9 shee s-sheet 5 Filed March 16, 1946 hum-furs Lau P621663 E 7'0pham Clyde L. K1702! Aft L. E. TOPHAM ET AL AUTOMATIC COPYING LATHE FOR SHOE LASTS I Filed March 16, 1946 9 Sheets-Sheet 6 Filed March 16, 1946 9 Sheets-Sheet 7 Nov. 28, 1950 E. TOPHAM ET AL 5 5 AUTOMATIC COPYING LATHE FOR SHOE LASTS [In/611mm Laurqae' 76p ha m Kim; 1

Nov. 28, 1950 L. E. TOPHAM ET AL AUTOMATIC COPYING LATHE FOR SHOE LASTS 9 Sheets-Sheet 8 Filed March 16, 1946 fizz/6:21am Lau r'enceE 75pham OZyeL/fnotz T A AE w v .wwy 1 1 9 v u m M w i H J v z w m 7 1 w W 6 9 M HH H. W. 1 1 H .-i--- v M v: 2 mm m F. 7 m 9 W 9 @V. 28, mm E. TOPHAM ET AL 2,531,59U

AUTOMATIC COPYING LATHE FOR SHOE LASTS Filed March 16, 1946 9 Sheets-Sheet 9 [vi/672mm Laurence E. 75 19/2071:

fact that their speeds are not constant.

Patented Nov. 28, 195@ UNITED S GFFKCE AUTOMLATIC CQPYING LATHE FOR SHOE LASTS Application March 1S, 1946, Serial No. 654,924

13 Claims. I

This invention relates to copying lathes, and its purpose is to'provide automatic means for varying the angular turning speed of a lathe in accordance with radial dimensions and surface characteristics of the form to be copied. These dimensions and characteristics, when utilized as herein set forth, will permit relatively rapid turning speed under the more favorable turning conditions, and will retard the speed only when less favorable conditions require retardation, and

thereby insure a corresponding increase in the productive capacity of a lathe consistent with accuracy of the products.

As herein illustrated, the speed-regulating equipment provides three automatic controls derived from a pair of mated models and two individually movable swing frames in which the models are mounted. One of the swing frames is hereinafter termed the master swing frame because its motions determine the shape of the product. Whichever model is mounted in the master swing frame becomes the master model, while the mate thereof serves as a pilot model in the other swing frame which is termed pilot swing frame. The two models are interconnected to rotate at equal speeds despite the Moreover, the face plates or chucks for driving them are out of angular phase, their phase differential being an arbitrary quantity, preferably about 1%", and the pilot model being ahead of the master model in that respect.

A variable-speed driving unit is provided to rotate the models and the work block, and its driving speed is governed by a regulator the movements of which are responsive to the three automatic controls hereinbefore mentioned. One of these controls, termed radius control, derives its speed-regulating movements solely from the pilot swing frame, and its effect is to vary the speed of the driving unit inversely according to the distance between the pilot modelwheel and the turning axis of the pilot model. The lengths of the several radii of the pilot model are the essential factors that enable this control to regulate the angular turning speed of the models and the work-bloclr.

One of the other automatic controls above mentioned can be utilized to vary the turning speed of the models according to the steepness of acclivities and declivities in their contours, and when so utilized it will prevent excessive velocity of the swing frames that would otherwise occur if full advantage is to be taken of the more favorable operating conditions to increase the turning speed. This automatic control is here- 2 inafter termed sustaining modifier because its speed-regulating effect is sustained in accordance with the angular extent of the acclivities and declivities of the models.

The third automatic control is hereinafter termed transitory modifier because it can be utilized to modify the turning speed with a transitory effect. Its purpose is to prevent sudden acceleration of the master swing frame in response to the more abrupt deviations in the contour of the master model. The desired effect is obtained by utilizing the more abrupt deviations in the pilot model, which come into play earlier than those of the master model, to produce transitory components of speed reduction before the corresponding deviations in the master model come to the master model-Wheel, and to eliminate such transitory components gradually as soon as they reach their peak. In this respect, the pilot swing frame detects, in advance, the needs of the master swing frame and activates the transitory modifier accordingly.

The components of speed-regulation derived from the several controls, whether increments or decrements, are communicated to three separate input points of an integrator in triangular relation to each other. Another point of the integrator, constituting the output point thereof, is connected to the speed regulator which is thereby rendered responsive to any one, any two, or all three of the automatic controls.

The novel features of the present invention are illustrated as applied to a copying lathe of the type setforth in United States Letters Patent No. 2,072,228, granted March 2, 1937, on an application filed in our names, but this difference is to be observed, namely, the patented lathe includes only one swing frame, while the present invention utilizes a supplemental swing frame for the pilot model in addition to a master swing frame for the master model and the work-block. The former lathe and that herein illustrated have identically the same provisions for girthgrading and length-grading, with this exception: the model-wheel carriage of the instant lathe is provided with two model wheels, one for the master model and the other for the pilot model, and they are interconnected by means arranged to impart girth-grading movements to the pilot model wheel commensurate with those of the ,master model wheel.

to effect variations in turning speed as promptly as required to satisfy the purpose of the present invention. Because of this consideration the instant lathe is driven by a hydrodynamic variablespeed unit of a well known commercial type that operates with relatively slow angular velocity and with positive effect not only to accelerate but also to decelerate its rotational output. It includes a rotary pump the rotor of which may be driven at a constant speed by an electric motor, and the stator of which may be shifted to and fro to regulate its hydraulic output. The hydrodynamic unit illustrated herein is of the type set forth in United States Letters Patent No. 2,074,068, granted March 16, 1937, and the means for regulating the speed of its rotational output is of the type set forth in United'States Letters Patent No. 2,105,454, granted January 11, 1938. The applicant of both of these patents is Walter Ferris.

Of the drawings,

"Fig. 1 is an elevation of the left-hand'end of'a lathe embodying the invention,'porti'ons of the swing frames being broken away and both models being represented in'section;

Fig. 2 is a top plan View of the lathe. For a topplan view of the models, a work-block, etc.

seeFig. 15;

Fig. 3 is a phantom elevation correspondin to "Fig. 1 but illustrating the transmission means for rotating the models and the work-block;

Fig. 3a is a sectional elevation of transmission gearing for driving the screw-shaft'that feeds the cutter-carriage and the model-wheel car- 'riage;

Fig.4 is a top plan including elements of the transmission means, the model-wheel carriage,

and some of the elements'for'regulating' the turning speed;

Fig. 5 is a sectional elevation of an assemblage of elements of the model-wheel carriage and the master swing frame;

Fig. 6 is an end elevation of an assemblage of elements of the girth-grading mechanism left out'of Fig. 5 foreground;

Fig. "7-is an end elevation, partly in section (line VII-VII of Fig. 8), of theassemblage'represented in'Fig. 6;

Fig. 8 is a plan section indicated by line VIII-VIII in- Fig. 6

Fig. 9 is'a vertical section (line IX I-Xin'Fig. 11) of a modifier for regulating the speed of the lathe according to the steepness of the surfaces of both models;

Fig. 1 0 is a plan section (line X X*in'Fig.' 9)

"of a linkage by which both modifiers (Figs. 9 --and12)-are operated with motions derived from the differential member (Fig. 14)

'Fig. 11 is an end elevation, partly in section,

Fig. 11a is a top plan view of the integrator which has three input points of motion and one output point for operating the speed regulator; Fig. '12 is a front elevation, partly in section, of the assemblage represented in Fig. 11 and some additional elements included in Figs. 1 and 4 (see line XIIXII in Fig. 11)

Fig. 13 is a schematic view in end elevation, as in Fig. 1, of an assemblage including the swing frames, the models, and a linkage of the radius control;

Fig. 14' is an end elevation of an assemblage including the speed regulator,thethree-point integrator and a diiferential member by which both modifiers are operated according to swing frame differentials;

Fig. 15 is a top plan view including both models and a work-block, face plates for supporting their butt ends and driving them, and tailstocks for supporting their toe ends; and

Fig. 16 represents a cross-sectional contour of the pilot model.

Since many of the details of construction and features of organization herein illustrated are the same as, or similar to, corresponding details and features shown and described in our earlier development (United States Patent No. 2,072,228) above mentioned, the present description will be abbreviated with respect to them. It is to be understood, nevertheless, that the present invention is applicable to lathes capable of turning a complete last in one piece instead of the type selected, which is designed to turn foreparts and heel parts individually.

Fig. 2 includes a cutter-carriage Ill and a model-wheel carriage ll both slidable on guide rails l2 and 63 provided by the main frame f4, an electric motor [5 mounted on the carriage I0, a rotary-cutter head l6 carried by the'shaftof the motor, a screw-shaft'l'i' having a left-hand thread for feeding the carriage l0 and a righthand thread for feedingthe carriage ll,an'd;a long swing frame t8 in which two face plates is and 2B and two tail stock centersZl and '22 are arranged on a common turning axis. 'The face plates are both afiixed to a driven spindle '23 and each is provided with crossed'ribs or keys (Fig. 15), those of the plate 19 tobe'n'ested in intersecting grooves 24 in the butt end of a work-block 25, and those of the plate Zil'to be nested in similar grooves 26 in the butt end of a model 21. These elements are separated in this View merely to show clearly their interlocking formations. A small socket 28 isformed in the toe end "of the block 25 to receivethe center 21, and a corresponding socket 253 is in the toe end of the model to receive the center 22.

One of the novel features of the lathe is an auxiliary swing frame 30 located at the rear of the'main frame M opposite the model-carrying section of the swing frame 18. For descriptive and identifying purposes the swing frame |8 is hereinafter termed master swing frame and the swing frame 3i] is termed pilot swing. frame." The latter is shorter and much less heavythan the master swing frame, and itsload is .less heavy than that carried by the master .swing frame. The only load to be carried by the pilot swing frame is a pilot model 3!, which is the mate of the master model 21. Since the inertia factor of the pilot swing frame (including load) is very much less than that of the. master swing frame, it has appreciably lesstendency tocause overtravel during periods of outswing, and requires less power to reverse its directionof travel.

The pilot swing frame carries a tail-stock center 32 and a face plate 34 for supporting and 1:0- tating the pilot model. This face plate is. aduplicate of the face plate 28 and is affixed to. aldriven spindle 33.

The master swing frame I8 includesahorizontal rock-shaft 35 (Figs. 4 and 8) and an extension member l-til afiixed thereto and supported byatrunnion 88 fastened inthe main frame Hi. When a model is set up in this swing frame it is held against a model-wheel 36 bythe. force of a spring 31 connected to-anarm.of--the swing frame (see upper end of Fig. 2). The pilot swing frame to likewise includes a rock-shaft 38 journaled in bearings in the main frame ii. A model set up therein is held against a model-wheel 39 by the force of a spring it] (Figs. 1 and 2) connected to an arm of this swing frame.

Although both model-wheels are mounted o the carriage ll they are movable toward and from each other for girth-grading, and for this purpose the carriage is provided with parallel bearings for two siidable rack-bars ii, 52 (Figs. i and 5) both intermeshed with an interposed pinion $3. The latter turns on a pivot affixed to the carriage and insures equal but opposed endwise movements of the rack-bars. Each rackbar carries a boss id rigidly related thereto. A pivot pin :15 connects an arm it and one boss 4 3, while a similar pin connects an arm ll and the other boss. The model-wheels 3i; and 39 are carried, respectively, by the arms db and ll. The girth-grading movements are communicated to the arm at by a lever 58 (Fig. 5) as in the lathe illustrated in the aforesaid Patent No. 2,072,228. This lever is slidably mounted on a rockshaft at and a parallel bar 50 affixed thereto. The rockshaft is ournaled in bearings in the frame i l. The loaded end of the arm ii is sup-.

ported and guided by a radius link d8 just as that of the arm dti is supported and guided by the lever The link t? is carried by the carriage ii and connected thereto by a pivot-pin 49. I

In Fig. 2 the cutter-carriage it and the modelwheel carriage it stand in their initial locations, widely separated, to be driven toward each other by the screw-shaft H as a turning operation progresses. A nut 51 (Fig. l) anchored to the underside of the carriage l0 cooperates with the left-hand thread of the screw-shaft, while a corresponding nut 52 (Fig. 5) having swivel connection with the carriage H cooperates with the right-hand thread of that shaft. The swivel connection provides for relatively slow automatic turning of the nut 52 for whatever length-grading may be called for. An adjustable track 53 (Fig. 2) pivotally connected to the frame is determines the extent to which the nut 52 will be turned, if at all, and since this length-grading mechanism is like that illustrated in the aforesaid Patent No. 2,072,228, no further description thereof is needed here.

A gear 5% (Figs. 3a and l) is affixed to the screw-shaft it between its screw portions, and rotation thereof is cl=rived from a shaft 55 located at the left-hand end of the lathe. The shaft 55 extends from front to rear and is journaled in bearings in the main frame id. The connections for driving the screW-shaftinclude a worm 50 and gear 5?, a shaft 53, spiral gears 59 and til, a shaft 6i, and a worm 02, the latter being in mesh with the gear 5%. The shaft Si is journaled in a cradle @3, as heretofore, and the latter is hung on the shaft 53 about which it may be rocked to disen age the worm $2 from the gear 55. at the conclusion of a turning operation.

The shaft 55 (Figs. 3 and 4) also carries bevel gears and the former for driving a gear train 56 carried by the master swing frame it, and the latter for driving a corresponding gear train 5? carried by the pilot swing frame 3%. The gear train 0E5 includes a bevel gear 68 and a spur gear rigidly related to each other and both mounted on a cylindrical portion of the rockshaft 35 about which they may rotate without turning the latter. Likewise, the gear train El includes a bevel gear l0 and a spur gear H, rigidly related and rotatably mounted on a cylindrical portion of the rockshaft 38. The gear train 66 is located at the left-hand end of the swing frame it, but two corresponding gear trains (not shown) are also carried by this swing frame, one at its right-hand end and the other about midway between its ends where one of the gears, M (Fig. 15), is affixed to the spindle that'carries the face plates l9 and 23. The three gear trains carried by the swing frame it are all connected by a common transmission shaft '13 (Fig. 3), as heretofore.

In like manner, the pilot swing frame 3%] carries a gear train represented by the gear l t (Fig-15) for driving the face plate 3 3. The trains 6? and M are connected by a transmission shaft l5 (Figs. 2 and 3). When the shaft 5:55 is in rotation the three face plates i9, 22 and 25 3 will all be driven at equal speeds, but the direction of rotation of the pilot model 3i will be the reverse of that of the master model 27 and the work-block 25. Furthermore, considering the angular relation of each model to its points of contact with its model-wheel, the models are out of angular phase with each other, the pilot model being slightly ahead of the master model in this respect. The extent of priority of the pilot model is optional, within an undetermined limit, but a phase differential of ten degrees is satisfactory for turning lasts. The phase differential is one of the fundamentals on which the present invention is predicated. By way of explaining the effect of such a differential, it is pointed out that all motions of the master swing frame it are anticipated by corresponding motions of the pilot swing frame s0, and that the earlier motions of the latter are utilized to increase or decrease, as the case may be, the turning speed of all the face plates simultaneously and equally. The motions of the master swing frame are also utilized for the same purpose, but they are integrated with those of the pilot swing frame to provide composite effects in the matter of speed regulation.

The source of rotation for driving the shaft 55 is a variable-speed motor it (Fig. 3) which, for technical reasons, may be a hydrodynamic unit of the type set forth in the aforesaid Ferris Patents Nos. 2,074,068 and 2,105,454. This unit derives its power from an electric motor ll of the constant speed type, and its regulation of driving speed from an adjustable oscillatory regulator '78. A spring 79 connected to the arm of the regulator normally pulls the arm down to increase the driving speed, but its force is opposed by a vertically movable rod es also connected to the arm. A driving pulley 8! on the shaft of the unit 76, and a pulley 82 on a countershaft 83 are connected by belts 8'2. 85' transmits rotation from the shaft 83 to the driving member 86 of a toothed clutch the driven member ill of which is affixcd to the shaft 55. The driving member 85 may be shifted axially on the shaft 55 to engage and disengage the member 8'? as heretofore, but the present invention is not concerned with starting and stopping the operation of the lathe. It is concerned with automatic regulation of the turning speed of the models and a work-block through the medium of controls yet to be described.

Control integrator A train of gears Mei-Jed in'a'fte'rdescribed, receives components of speedregulating movement from three individually movable

pendular links

95', 92 and 93 on which it is suspended with ball-and-socket connections that enable it to rock in all directions. These connections are located in triangular relation (Fig. 11a), and the triangular area defined by them is provided with many holes 94 in any one of which a socket member 95 may be attached. The member 35 and the upper end of the rod 80 form another call-and-socket connection for shifting the speed-regulator to and fro.

When the lathe is in operation, outward movements of the pilot swing frame raise the pendular link 9|, and inward movements lower it, with corresponding components of rocking movement of the integrator 93. Although these components may be compounded with other components derived from the

links

92 and 93, the purpose of the link 9! is to retard the driving speed of the unit it as the effective radius of the pilot model 3! (reckoned from its turning axis) grows longer, and increase the driving speed as that eifective radius grows shorter. It follows that the turning speed of both models and the work-block will be retarded or increased simultaneously, as the case may be, since their angular coordination is maintained by the interconnection of their transmission gearing. Furthermore, the relative or proportional kinetic value of these components may be varied by adjusting the socket member 55 toward or from the point where the rod 9! and the integrator are connected.

The linkage about to be described is provided to raise and lower the link 9!: an arm 98 (Figs. 1, 2, 4, l2 and 13) is fastened to the rockshaft 38 of the pilot swing frame, and a bell-crank 97 is loosely mounted on a trunnion 38 that supports one end of the master swing frame. This trunnion is fixed in the main frame It. A link 98 connects the arm 96 and the bell-crank to oscillate the latter in timed relation to the movements of the pilot swing frame. A ball-end stud 85 carried by the bell-crank (Figs 8 and 12) has operative connection with a socket at the upper end of the link Si. It is to be understood that the linkage just described receives no motion from any source other than the spring 4-!) (Fig.

l) and the pilot swing frame, and that the speedregulating components communicated thereby to the integrator 9e anticipate all movements of the master swing frame by an interval corresponding to the phase differential between the two swing frames.

The ball-end stud 95 has a cylindrical portion on which a differential lever l 06 is mounted. One end of this lever has sliding connection with a stud lill carried by an arm 32 of the master swing frame. Consequently, the differential lever is carried by two fulcrum studs one of which (59) moves up and down in synchronisrn with the earlier movements of the pilot swing frame, and the other of which (sea moves up and down in synchronism with th later movements of the master swing frame. The lever let is therefore operated conjointly by both swing frames according to their phase difierential. The operating or output end of this lever and a rod its suspended therefrom are connected by a pivot pin Hi l the center of which travels up and down in arcs tangent to the axis of the master swing frame. Furthermore, the elements are so organized that the center of the pin I04 will registers with the axis last mentioned whenever theturnin'g axes ofthe two models areequidistant' from the respective model wheels, however great: the distance may be. In operation, the output end of the differential lever will move up and down according to the difference in radial length between the contact points: on the models and the respective turning axes. At some stages these up-and-down movements may be rapid, and at other stagesthey may be slow. Atsomestages the pin I04 may vibrate above its median level without moving below the latter, at other stages it may vibrate below that level without. rising above it, and at still other it may vibrate between points above and below that level, but,

. wherever it may be, it will not remain at one point for any appreciable period of time.

The foregoing discussion of the behavior of the differential lever is intended to prepare the way for descriptions of two hydraulic modifiers both activated by that lever to furnish components of speed-regulating movement to the integrator 90 and thereby modify the kineti output of the latter according to the contour characteristics of both models. One of these modifiers raises and lowers the pendular link 92 (Fig. 11) with asustaining effect to prevent excessive velocity of the swing frames by reducing the turning speed of the models when steep acclivities and declivities of contour are in contact with the model wheels. The other modifier enables sudden surges, slackenings and reversals of the pilot swing frame to raise the pendular link 93 with a transitory effect of comparatively short duration and thereby furnish special components of speed reduction whenever, surges, slackenings and reversals of the heavier and less sensitive master swing frame are about to occur.

Hydraulic modifiers The rod H33 (Figs. 8, 9, 11, 12 and 14) transmits up and down motions from the differential lever Hill to an arm Hi5 afiixed to a rockshaft me journal-ed in bearings in a casing lfll. Another rcckshaft 108 is likewise journaled and is parallel with the shaft H16 and spaced therefrom. Both hydraulic modifiers are located between these rockshafts. Two forked arms I09 afi'ixed to one of the rockshafts carry a pivot pin H0, and two similar arms H39 afiixed to the other rockshaft carry another pivot pin H0. These pins are connected bya tie-rod HI that maintains a constant distance between them and transmits motion from one to the other. Each pin HQ carries two similar pressing pads H2 and 25, the two pads H2 facing each other to operate the sustaining modifier, and the two pads I25 facing each other to operate the transitory modifier.

Sustaining modifier The sustaining modifier comprises two opposed hydraulic pulsators H3 and H4 (Fig. 9) each a normally expanding bellows, a large duct I l-5 in a fixture connecting their inner ends, a cylinder 1 l6 adjoining the duct, and a ram l I! movable up and down in the cylinder. The chamber formed by these elements is filled with liquid, but the latter is not indicated in the drawings. The upper end of the ram engages and supports an arm H8 affixed to a rockshaft H9 provided with an arm I28 (Fig. 11) from which the link 92 is suspended. One input point of the integrator 30 is thus supported by a column of liquid in the cylinder I I6. Each-bellows is contained in a fixed cage I2 I, and the outer end of each cage is open and provided with a lip I22 which serves as a stop to arrest the back strokes of the end wall I23 of the corresponding bellows. The pads H2 are adapted to enter the cages I2! to compress the respective bellows one at a time, but never both at once because the distance between the confronting faces of the pads is just equal to the greatest distance between the outer faces of the walls I23. Fig. 9 represents a typical relation in which the bellows M3 is partially compressed by the pad abutting its left end, while the opposite pad is retracted from the right end of the bellows H4 which abuts its arresting lip I22. The ram II! is raised above its normal position in consequence of compressing the bellows H3, but the same effect would be produced by compressing the bellows I It to an equal extent.

It may now be understood that the ram II? will stand at its lowest position only when both bellows are distended as far as their arresting lips I22 will permit, and that this position corresponds to the neutral or median position of the assemblage comprising the pads I I2 and the tierod III. It is also to be understood that the neutral position of the pad assemblage corresponds to any position of the differential lever I (Fig. 13) that locates the center of the pin I04 in coincidence with the axis of the master swing frame. Any upward movement of the pin I04 above that axis will compress the bellows I It, and any downward movement below that axis will compress the bellows I I I. In another sense, the last statement means that the sustaining modifier will maintain a variable component of speed reduction whenever the swing frames are unequally displaced by acclivities and declivities of the models, but not when the turning axes of the two models are equidistant from the respective model-wheels, and that the magnitude of this component will vary as the inequality of such displacement varies. Extending this analysis further, the steeper acclivities and declivities in the surfaces of the models will produce greater components of speed reduction than the less steep ones will produce, since the modifier is operable conjointly by both swing frames according to their phase differential.

Transitory modifier This modifier comprises two opposed hydraulic pulsators I26 and IZl of equal capacity (Fig. 12) each a normally expanding bellows, a restricted duct I28 in a fixture connecting their inner ends, two cylinders I29 and I39 communicating with the duct, two vertically movable rams ISI and I32, one in each cylinder, and a needle-valve I33 arranged to regulate the flow of liquid to and fro between the cylinders. The chamber formed by these elements is filled with liquid, but the latter is not indicated in the drawing. Unlike the sustaining modifier, no stops are provided to arrest the back strokes of the outer ends of the bellows I and I21, and the latter therefore remain against the respective pads I25 under all conditions of operation. Both rams ISI and I32 are arranged to support an arm its when the liquid is in equilibrium. This arm is fastened to a rockshaft I35 provided with an arm I36 from which the link 93 is suspended to support one input point of the integrator 95.

In operation, any upward motion of the rod ItIZi derived from the differential lever Hit will compress the bellows I26 and permit a commensurate expansion of the bellows I21. If the quantity of liquid thus displaced exceeds the relief afforded by the needle-valve I33 the surge produced by the bellows I26 will drive the ram I3I upward, with a corresponding component of speed-reducing movement of the integrator 90, but the efiect thus produced will be transitory because the flow of liquid past the needle-valve will tend always to restore equilibrium of the liquid in both bellows and both cylinders I29, I30. In like manner, any downward motion of the rod IE3 will compress the bellows I27 and relieve the bellows I26, and the effect on the integrator will be the same as that described above, but in this case the ram I32, instead of the ram I3l, will be the one to furnish a transitory component of speed-reducing movement to the integrator. The speed-reducing components produced by the transitory modifier occur whenever a surge of the pilot swing frame in either direction is'so great or sudden as to overload the relief afforded by the needle-valve I33, and these components, if the needle-valve be correctly adjusted, begin to lose their effect immediately upon reaching their peak. Nevertheless, their effect may be prolonged sufficiently by the needle-valve to prevent too rapid turning of the master model at those stages when inertia of the master swing frame might otherwise cause separation of the master model and its model-wheel.

The magnitude of these components may be regulated independently of their periods of duration by shifting the output socket member 95 (Fig. 11a) toward or away from the input link 93, and, in like manner, the magnitude of the speed-reducing components derived from the sustaining modifier may be regulated by shifting the same socket member toward or away from the input link 92.

Now, supposing that Fig. 16 represents the cross-sectional contour of a forepart model in a plane intersecting the cone portion thereof, and that this model is set up in the pilot swing frame while its mate is set up in the master swing frame, the pilot model will rotate counterclockwise about its turning axis, represented by a dot ac, and thereby bring the points a, b, c, d and e of this contour successively into contact with the pilot model-wheel. The corresponding points on the master model will be brought into contact with its model-wheel later than those of the pilot model by an interval constituting the phase differential which may be considered as 10.

Following the point of contact as it would progress in a clockwise direction with respect to the pilot model, and considering point a as a starting point for no reason except that the radial dimension of the model is shortest at this point, the pilot swing frame will swing out from a to 12, thereby furnishing speed-reducing components to the integrator 9e (Fig. 11a) by raising the input link 95. During the same period the acclivity of the model contours will cause collapsing of the bellows MS (Fig. 9). Consequently, the sustaining modifier will furnish additional speed-reducing components to the integrator by raising the input link 92. Although the steepness of the acclivity increases from a to b, the increase is gradual and may not produce much, if any, speed-reducing action on the part of the transitory modifier (Fig. 11.). However, if any such action does occur, it will not begin until point I) of the pilot model has nearly reached the point of contact.

As point b of the pilot model is leaving, and point I) of the master model is approaching, the

point .of contact, the differential lever Ito (Figs. 1 and 13) will be rocked suddenly the clockwise direction, partly by downward movement of the fulcrum stud 5.9 and partly by upward movement of the fulcrum stud IBI. At this stage the integrator 90 will reecive speed-reducing com ponents from the bellows II 4 of the sustaining modifier, and additional speed-reducing components from the bellows I21 of the transitory modifier The latter components will cease when point I; .of the master model passes the point of contact.

:Since the effective radial length of the models growsshorter from b to c, the input link 9| of the integrator will furnish speed-increasing components, but these will be partially, if not wholly, counteracted by speed-reducing components due to the declivity and the corresponding action of the sustaining modifier (bellows H4) and the input link 92.

The acclivity from c to d (Fig. 16) is not steep near point but is very steep near point (1, and the speed-reducing effect of the sustaining mod ifier (bellows H3) will be developed accordingly. At the same time, the speed-reducing effect of the radius control (input link 9|) will not only be increased but will be added to that of the sustaining modifier. If these two controls do not retard the turning speed enough to maintain equilibrium of the liquid in the transitory modifier the bellows I 26 will raise the ram I3I and the input link .93, thereby retarding the speed still more.

As the point of contact on the pilot model advances from d to e, the outswing of the pilot swing frame will cease abruptly and the backswing thereof will begin abruptly, but since the inertia factor of the master swing frame is much greater than that of the pilot swing frame, the master swing frame requires greatly reduced turning speed until it, too, has passed the critical stage corresponding to the run from d to e on themaster model. The radius control will undergo only an in ignificant change during this stage, but thetransitory modifier (bellows I21) will receive a great surge from the differential lever Ill!) as the fulcrum stud 99 drops while the stud :IUI continues to rise. Consequently, the input link 93 will rise with great speed-reducing effect. The same rocking motion of the differential lever IBB will transfer the speed-reducing eifect of the sustaining modifier from the bellows H3 to the bellows H4, but the period of transition will be so short that little, if any change of speed will be derived from that modifier.

As the efiect of the transitory modifier subsides .at or near point e, the effect of the sustaining modifier will increase with the steepness of the declivit-y, but beyond that point the diminishing radius of the pilot model will lower the input link .94 of the integrator while, at the same time, the diminishing steepness of the declivities of both models will lower the input link 92. Consequently, the turning speed will receive accelerative components from two controls (radius control and sustaining modifier) from point e to point a.

A recapitulation of the three automatic speedregulating controls could be reduced to the following terms; viz., the radius control is not affected by the phase differential, but utilizes only the outswing of the pilot swing frame to furnish speed-reducing components, and back-swing of that same swing frame to furnish speed-increasing components. The sustaining modifier requires phase differential of two models and two swing frames and is operated conjointly by both swing frames according to their differential The effect of this modifier varies according to the steepness of acclrvities and declivities. The transitory modifier requires the phase differential of two swing frames to enable sudden or abrupt surges and reversals of the pilot swing frame to moderate the corresponding sur es and reversals of the master swing frame. The motions of the radius control may be rendered ineffective by placiugthesocket member '95 (Fig. 11a) on a line intersecting the input links 92 and 53; those of the sustaining modifier may be rendered inefiective by placing that socket member on a line intersecting the input links 9i and and those of the transitory modifier may be rendered ineffective by placing the socket member on a line intersecting the input links SI and 92.

Although the'link-age for imparting girth-grading movements to the model-wheel is the same as the corresponding linkage shown in the aforesaid Patent No. 2,072,228, a brief description thereof now follows. A rocker M (Figs. 4, .6, 7 and 8) affixed to the rockshaft 35, and constituting a part of the master swing frame, carries two trunnions I4], I42, lying on a common axis, but the confronting ends of the trunnions are spaced to clear elements located between them. A pair of links I 43 mounted one on each trunnion are connected by a pivot pin I44 which extends through a link I45. The latter connects the pin I M and an arm I46 affixed to the rockshaft '49 (Fig. 5) from which the model-wheels derive their grading motion. The distance between the axis of the pin I44 and that of the trunnions is exactly equal to that between the axis of the rockshaft 35 and the axis of the trunnions. The pin I 44 may therefore be placed above, below or in alinement with the axis of the rockshaft 35. In the latter relation the pin I44 and the rockshaft 49 will remain stationary while the master swing frame is in motion, and the girth-grading ratio will be 1 to .1. Grading up requires placing the pin I44 below, and grading down requires placing the pin above the axis of the rockshaft 35. For this purpose the lathe is provided with manually operable adjusting means including a crank I47 (Figs. 1, 2 and 12), a rotatable shaft I48, gearing (not shown herein), and a link I49 (Fig. 6) connecting the gearing and the pin I44. This link may be adjusted by the crank I 47 to shift the pin I44 up and down to any selected grading position The link I50 (Figs. '7 and 8) and the arm I5I are provided to facilitate assembling the rockshaft 35 and the rocker I40 in the main frame I4, and to tie them in a constant angular rela tion. The arm I 5| is pinned to the rockshaft, while the link I50 is mounted on the trunnion I4 I. When the link and the arm I5I are connected by a screw 552 the rocker I40 becomes, in effect, a part .of the master swing frame.

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

'1. A copying lathe comprising, a master swing frame, rotatable means journaled therein for carrying a master model and a work-block, a master model-wheel, an individually movable pilot swing frame, rotatable means journaled in the latter for carrying a pilot model, a pilot model-wheel, a variable-speed driving unit, transmission means operable by said unit for driving both of said rotatable means at equal speeds, said rotatable means being less than 90 out of angular phase with each other as between the two models, an adjustable regulator connected to said driving unit for varying the driving speed thereof, and movable linkage connecting the regulator and the pilot swing frame whereby swing of the latter is transmitted to the regulator for shifting the same to and fro.

2. A copying lathe comprising a master swing frame, rotatable means journaled therein for carrying a master model and a work-block, a master model-wheel, an individually movable pilot swing frame, rotatable means journaled in the latter for carrying a pilot model, a pilot model-wheel, a variable-speed driving unit, transmission means operable by said unit for driving both of said rotatable means at equal speeds, said rotatable means being less than 90 out of angular phase with each other as between the two models, an adjustable regulator connected to said driving unit for varying the driving speed thereof, a differential member, means connecting one point of the differential member to the master swing frame and means connecting another point of the differential member to the pilot swing frame, and a member engageable with the regulater and connected to a third point of said differential member for shifting said regulator.

' 3. A copying lathe comprising a master swing frame, rotatable means journaled therein for carrying a master model and a wora block, master model-wheel, an individually movable pilot swing frame. rotatable means iournaled in the latter for carrying a pilot model, a pilot model .el, a variable-speed driving unit, transmission means operable by said unit for driving both of said rotatable means at equal speeds, said rotatable means being less than 95 out of angular phase with each other as between the two models, an adjustable regulator connected to the driving unit for varying the dr ving speed thereof, means for motion of the pilot swing frame to said regulator, a movable member interposed in the motion trans-- mitting means for modifying the effects of said motion transmitting means on the regulator, said modifying member displaceable conjointly by both of the swing frames according to thei phase differential.

4. A copying lathe comprising a master swing frame, rotatable means journaled therein for carrying a master model and a work-block, a master model-wheel, an individually movable pilot swing frame, rotatable means journaled in the latter for carrying a pilot model, a pilot model wheel, a variable-speed driving unit, transmission means operable by said unit for driving both of said rotatable means at equal speeds, said rotatable means being less than 90 out of angular phase with each other as between the two models, an adjustable regulator connected to the driving unit for varying the driv ing speed thereof, differential means operably connected to both swing frames for movement thereby, and means connecting said differential means to said regulator.

5. A copying lathe comprising a master swing frame, rotatable means journaled therein for carrying a master model and a work-block, a master model-wheel, individually movable pilot swing frame, rotatable means journaled in the latter for carrying a pilot model, a pilot model-wheel, a variable-speed driving unit,

transmission means operable by said unit for driving both of said rotatable means at equal speeds, said rotatable means being out of angular phase with each other as between the two models, an adjustable regulator connected to the driving unit for varying the driving speed thereof, a kinetic integrator for shifting the regulator to and fro, means connecting the pilot swing frame and one point of said integrator for moving that point to and from in synchronism with the movements of that swing frame, and modifying means connected to another point of the integrator for moving that point with speed-regulating components, said modifying means being connected to both of the swing frames to be actuated by them conjointly according to their phase differential.

6. A. copying lathe comprising a master swing frame, rotatable means journaled therein for carrying a master model and a work-block, a master model-wheel, an individually movable pilot swing frame, rotatable means journaled in the latter for carrying a pilot model, a pilot model-wheel, a variable-speed driving unit, transmission means operable by said unit for driving both of said rotatable means at equal speeds, said'r'otatable means being out of angular phase with each other as between the two models, an adjustable regulator connected to said driving unit for varying the driving speed thereof, an angularly movable integrator having three points of suspension in triangular relation, means effectively connecting an output point of said integrator and the speed-regulator, displaceable members connected to and actuated by the pilot swing frame alone for furnishing speed-regulating components thereof to one of said three points of the integrator, a sustaining modifier, means connecting said sustaining modifier to another one of said three points for furnishing sustained speed-regulating components thereto, a transitory modifier, means connecting said transitory modifier to the third one of said three points for furnishing transitory speed-regulating components, and differential means for operatingboth of said modifiers at once, said differential means including members movably connecting the swing frames with both modifiers and actuated by both swing frames conjointly according to their phase differential.

'7. A copying lathe comprising a master swing frame, rotatable means iournaled therein for carrying a master model and a work-block, a master model-wheel, an individually movable 'pilot swing frame, rotatable means journaled in the latter for carrying a pilot model, a pilot model-Wheel, a variable-speed driving unit, transmission means operable by said unit for driving both of said rotatable means at equal speeds, said rotatable means being out of angular phase with each other as between the two models, an adjustable regulator connected to said driving unit for varying the driving speed there f, an .angularly movable integrator, means includ' member effectively connecting an output point of said integrator and the speed-regulator, movable members ccnnecting the pilot swing frame and the integrator and actuated by the pilot swing frame alone for furnishing sustained speed-regulating components to one input point of said integrator according to radial variations of the pilot model, a sustaining modifier, means connecting said sustaining modifier to another input point'of said integrator for fllll iing sustainedspeed-regulating components, and a dif- 15 ferential lever having connections with said modifier, and means for operating said differential lever by both of said swing frames conjointly according to their phase differential.

8. A copying lathe comprising a master swing frame, rotatable means journaled therein for carrying a master model and a work-block, a master model-wheel, an individually movable pilot swing frame, rotatable means journaled in the latter for carrying a pilot model, a pilot model-wheel, a variable-speed driving unit, transmission means operable by said unit for driving bothof said rotatable means at equal speeds, said rotatable means being out of angular phase with each other as between the two models, an adjustable regulator connected to said driving unit for varying the driving speed thereof, an angularly movable integrator, a member efiectively connecting an output point of said integrator and the speed-regulator, members connecting the pilot swing frameand the integrator and actuated by the pilot swing frame alone for furnishing sustained speed-regulating components to one input point of said integrator according to radial variations of the pilot model, a hydraulic modifier means connecting said hydraulic modifier to another input point of said integrator for furnishing transitory speed-regulating components, and differential means for operating said modifier, said differential means being connected to and actuated by both of said swing frames conjointly according to their phase differential.

9. A copying lathe comprising a master swing frame, rotatable means journaled therein for carrying a master model and a work-block, a master model-wheel, an individually movable pilot swing frame, rotatable means journaled in the latter for carrying a pilot model, a pilot model-wheel, a variable-speed driving unit, transmission means operable by said unit for driving both of said rotatable means at equal speeds, said rotatable means being less than 90 out of angular phase with each other as between the two models, an adjustable regulator connected to said driving unit for varying the driving speed thereof, a differential member operatively connected to said swing frames for movements according to their phase differential, and mechanism activated by resultant pivotal movement of a portion of said differential member for shifting the regulator.

10. A copying lathe comprising a master swing frame, rotatable means journaled therein for carrying a master model and a work-block, a

master model-wheel, an individually movable pilot swing frame, rotatable means journaled in the latter for carrying a pilot model, a pilot model-wheel, a variable-speed driving unit, transmission means operable by said unit for driving both of said rotatable means at equal speeds, said rotatable means being out of angular phase with each other as between the two models, an adjust able regulator connected to said driving unit for varying the driving speed thereof, a differential member, means connecting said differential member to both swing frames for movement according to their phase differential, a plurality of dissimilar modifiers, means connecting said modifiers to said differential member for movements thereby, a kinetic integrator for shifting the speed regulator, and connections operable by said modifiers respectively for actuating the integrator, said connections being connected to the integrator at separate points of the latter.

11. A copying lathe comprising a master swing iii) frame, rotatable means journaled therein for carrying a master model and a work-block, a master model-wheel, an individually movable pilot swing frame, rotatable means journaled in the latter for carrying a pilot model, a pilot model-wheel, a variable-speed driving unit, transmission means operable by said unit for driving both of said rotatable means at equal speeds, said rotatable means being less than 90 out of angular phase with each other as between the two models, an adjustable regulator connected to said driving unit for varying the driving speed thereof, a differential lever operatively connected to said swing frames for movements according to their phase differential, a modifier operatively interconnected with the regulator and said lever for imparting speed-retarding and -accelerating movements to said regulator in accordance with the steepness of acclivities and declivities in the contours of the models, and a'second modifieroperatively interconnected with the regulator and said lever for imparting transitory surges of supplemental speed-retarding and -accelerating movement to said regulator in accordance with deviations inthe steepness of such acclivities and declivities.

12. A copying lathe comprising a master swing frame, rotatable means journaled therein for carrying a master model and a work-block, a master model-wheel, an individually movable pilot swing frame shorter and lighter than the master swing frame, rotatable means journaled in the pilot swing frame for carrying a pilot model, a pilot model-wheel, a variable-speed driving unit, transmission means operable by said unit for turning said rotatable means in both swing frames at equal speeds, the rotatable means in the pilot swing frame being less than 90 out of angular phase with and ahead of the rotatable means in the master swing frame, a regulator connected to the driving unit for varying the driving speed thereof, and mechanism including pivotally connected levers operated by swinging movements of the pilot swing frame alone for shifting the speed-regulator to and fro according to radial variations in the pilot model.

13. A copying lathe comprising a master swing frame, rotatable means journaled therein for carrying a master model and a work-block, a master model-wheel, an individually movable pilot swing frame, rotatable means journaled therein for carrying a pilot model, a pilot modelwheel, a variable-speed driving unit, transmission means driven by said unit for driving both of said rotatable means at equal speeds, the rotatable means of the pilot swing frame being less than 90 out of angular phase with and ahead of that of the master swing frame, a regulator for varying the driving speed of said unit, a pivotally suspended kinetic integrator actuated in part by movements of the pilot swing frame, means connecting said pilot swing frame to said regulator for shifting the regulator to and fro in accordance with radial variations of the pilot model, a differential lever, members supporting said lever and connected to both swing frames, a hydraulic ram arranged to impart speed-retarding impulses to the integrator, a pair of hydraulic pulsators both engaging the liquid for operating said ram, interconnected members actuated by said differential lever for operating said pulsators alternatively according to whether said lever is in one or the other of two adjoining divisions of its operative range, and stops arrangedto arrest the back strokes of said pulsators 17 at points corresponding to the juncture of said divisions.

LAURENCE E. TOPHAM. CLYDE L. KNOTT.

REFERENCES CITED The following references are of record in the file of this patent: I

Number 18 UNITED STATES PATENTS Name Date Topham Apr. 8, '1930 Black et a1 Mar. 31, 1931 Howe Dec. 31, 1935 Turchan June 1'1, 1946 Johnson June 24, 1947