US2577932A - Copying lathe - Google Patents

Description

5 Sheets-Sheet l L. E. TOPHAM COPYING LATHE Filed Aug. l, 1947 Dec. l l

L. E. ToPHAM 2,577,932

COPYING LATHE I5 Sheets-Sheet 2 Dec. 11, 1951 Filed Aug. l, 1947 By his Attorney Dec. 11, 1951 E. TOPI-IAM COPYING LATHE 5 Sheets-Sheet 3 Filed Aug. 1, 1947 aurence EID/zam Patented Dec. 11, 17951 I COPYING LATHE Laurence E. Topham,

United Shoe Machiner ton, N. J., a corporati Wenham, Mass., assignor to y Corporation, Flemingon of New Jersey Application August 1, 1947, Serial No. 765,575

Claims.

This invention relates to copying lathes, and its purpose is to provide automatic means for modifying the magnitude or the contour of the girth of the copy in one or more selected areas thereof without necessarily modifying other areas in any respect.

To facilitate an understanding of the invention, `the following distinction between girthgrading and girth-modifying should be borne in mind: 'girth-grading affects all radial and girth- Wise dimensions of the copy according to some systematic order of magnification or reduction by a grading factor, whereas girth-modifying, instead of being systematic, may be arbitrary, unsystematic and localized wherever desired, without use of any grading factor.

The invention has special utility for making models from which lasts may be copied in the usual well-known Way. To cite a typical eX- ample forthe purposes of the description to follow, let it be assumed that a shoe manufacturer has selected a last-model of a desired style from the stock of a last manufacturer, but prefers a slight increase of girth in the waist only of the lasts to be supplied to him. To satisfy such a preference a new model must be made from each master model of a set, and it will be termed a copy in this description to avoid confusion with the master model.-

In the example chosen for illustration, the increase of girth in the copy is all above the bottom, that is, in the height of the instep, and none of the increase is in the width of the bottom or insole pattern. A problem of this kind calls for localized modification, not girth-grading, since girth-grading would alter the insole pattern, the profile, the toe-spring and the general style of the copy. Now, increasing the girth of a model as specified above is equivalent to adding a layer of stock to the instep but nowhere else, except the boundary of the modified area Where the added stock may merge with the unmodied area.

To deal with problems of this kind, the present invention provides a copying lathe in which a swing-frame, a model, a model-wheel, a feed carriage, a work-block, a cutter and a cuttercarriage are related and operated as in lathes hitherto used, with this exception, namely, no

girth-grading mechanism is needed or used. In addition to the elements above specied, the invention includes a rotary modifying cam and a cam-follower for shifting the model-wheel back and forth with girth-modifying effects. The model-wheel is carried by the 'cam-follower, and

modifying effects.

is thereby shifted along the length of the model as the follower is shifted along the length of the cam. The modifying cam is at least as long as the model to be copied, and is driven at the same speed as the model and the work-block. Consequently, the point of contact between the cam and its follower will follow a spiral course around the cam as the point of contact between the model and the model-wheel follows a spiral course around the model.

The perimeter of the cam has neutralareas or segments and modifying areas or segments, the neutral areas being cylindrical and of neutral radius, so called because the effect of that radius is to locatethe model-wheel where it will produce neither increase nor decrease in the corresponding radial dimension of the copy. On the other hand, all areas of other radii will place the model-wheel where it will have modifying eects.

The principles of the invention have now been set forth sufficiently to disclose a mechanical distinction between girth-grading and girthmodifying, namely, in girth-grading the backand-forth motions of the model-wheel are derived from, and synchronized with, those of the swing-frame, but in girth-modifying the baci;- and-forth motions of the model-wheel are derived from a source other than the swing-frame, they are arbitrarily timed, and, more likely than not, they are out of phase with the motions of the latter.

It is to' be understood that any modifying cam may be replaced by another having different In some circumstances it might be desired to modify a copy not by altering the girth in the Waist, but by adding a bulge corresponding to a bunion, or, in other circumstances, to modify a copy by making the toe portion thereof wider or not so wide as that of the model, or by altering the prole of the toe only. All these and other alternative modifications are within the range of the invention, and vrequire only modifying cams in which the. desired modifying characteristics have been embodied.

Referring to the drawings:

Fig. 1 represents a top plan view of a portion of a copying lathe in which a modified copy of a model is in process of being generated in accordance with the invention;

Fig. 2 is a front elevation of the assemblage represen-ted in Fig. 1;

Fig. 3`- is a vertical section in a plane indicated by line III-III i-n- Fig.- l but including only those 3 elements that are directly instrumental in modifying the copy;

Fig. 4 is a left side elevation of transmission gearing some of which is enclosed in the casings intersected by line IV-IV in Fig. 1;

Fig. 5 is a front elevation of a model and means for supporting it in the swing-frame of a lathe;

Fig. 6 is a front 'elevation of a modifying cam and means for supporting it in the lathe;

Fig. 7 is a composite view including a section of a model (line VII-VII in Fig. 5), the corresponding girtnwise contour of a modifying cam, and the corresponding modifying effect (dotted line) of the cam superposed on the model; and

Fig. 8 is an end elevation of a modifying cam.

The drawings include a representation of a lastmakers model I of a forepart. The omission of the heel part has no significance related to this invention. Its only significance is that the copying lathe chosen for putting the invention into practice is of a type that produces foreparts and heel parts individually for two-part hinge lasts. Furthermore, a lathe of this type produces a left copy from a right model, and vice versa, but that characteristic of the lathe has no significance related to the present invention.

Figs. 1 and 2 include a work-block II in process of being turned to produce a modified copy of the model I0. The difference between the model and the copy, other than the ordinary difference between a "right and a left, is a quantity added to the copy by a rotary modifying` cam I2. This quantity, when combined with 1' the quantities derived from the model I0, has. the same effect as it would have if embodied in the model itself instead of being embodied, as illustrated, in an individual modifying cam. The fundamental quantities embodied in any selected model I0 remain unchanged so far as the model is concerned, but any desired plus or minus quantities embodied in a modifying cam may be combined with them to produce a modified copy of the model.

Dotted lines I4 in Figs. 5 and 7 indicate the equivalent of the modifying effect of the cam I2. It is to be observed that the modifying quantity derived from the cam I2 is so localized as to increase the girth and depth of the copy without producing any difference in the insole pattern" thereof. Nevertheless, the modifying quantity could be otherwise located by a modifying cam of different design with or without changing the insole pattern of the copy. In brief, then, the modifying quantity represented by the dotted lines I4 may be regarded as the equivalent of a patch fastened to the model. In Fig. the broken line .'c-x represents the rotational axis of the model and means for carrying it. The same axis is represented by a dot :n in Fig. 7. The carrying means include a freely rotatable tail-stock I5, a driving block I6, a. faceplate I1 and a live spindle I8.' The model and the block I6 are provided with interlocking surfaces I9 corresponding to the abutting joint surfaces of a well-known type of hinge last. The confronting faces of the block I6 and the face plate I1 are also provided with interlocking means including a tongue and a groove by which axial alinement and rotational phase of the model and the spindleare maintained.

The cam member I2, when set up for use, is supported by a freely rotatable tail-stock 20 and a face-plate 2| both constrained to a fixed axis y of rotation. The peripheral surface of the cam is the operating'surface, and for the s cific purpose of modifying the instep of a forepart without modifying the insole pattern or other area thereof it is provided with two circumferential bands 22 and 23 of 360, both cylindrical and of an arbitrary neutral radius, a cylindrical segment 24 of the same radius connecting the bands 22 and 23, and the modifying segment I2* of other radii bounded by the bands 22, 23 and 24. The portions 22, 23 and 24 of neutral radius correspond to those portions of the copythat are not to be modified.

The copying lathe partially illustrated in the drawings embodies some of the principles and some of the features of lathe described in United States Letters Patent 2,072,228, granted March 2, 1937, on application of Topham and Knott.

The work block II (Figs. 1 and 2) and a driving block 26 are provided with interlocking joint surfaces and the block 26 and a face-plate 21 have interlocking connections similar to those of the cam I2 and its face-plate. The two faceplates I1 and 21 are rigidly connected to each other by the spindle I8. The toe end of the workblock II is supported by a freely rotatable tailstock 25.

The spindle I8 is journaled in an arm 28 affixed to a rockshaft 32, -and the tail-stocks I5 and are journaled in arms'30 and 3I. The rockshaft and the three arms 28, 30 and 3| constitute a swing frame, the rockshaft being square except its ends which are cylindrical and journaled in bearings in a main frame 33. The arm 28 is hollow and encloses a train of gears 29 one of which is affixed to the spindle I8.

An electric motor 34 (Fig. 1) is fastened to a cutter-carriage 35 and provided with a rotary cutterhead 36 for operating on the work-block II. The carriage 34 is arranged to slide on rails 31, 38 provided by the frame 33.

The rail 31 and a rail 39 provide a track for a follower carriage 40 on which a model-wheel 4I is mounted to cooperate with the model I0. A tension spring 42 (Fig. 3) connected to an arm 43 of the swing-frame normally presses the model against the wheel 4I. l

As in the lathe of Patent 2,072,228, the carriages 35 and 40 are fed toward each other by a shaft having a feed-screw 44 for the cuttercarriage, and a feed-screw 45 of opposite lead for the follower carriage. provided with nuts 46 and 41,Y engaging the feedscrews, respectively, the nut 41 having a spur gear 48 by which it may be rotated with lengthgrading effect while the screw-shaft rotates to move the carriages. Since this type of lengthgrading mechanism is described in the aforesaid Patent 2,072,228, its details need not be described here. The screw-shaft is provided with a spur gear 48 between its screw portions. Other gearing (not shown) transmits rotation to the gear 43 from a Worm 1I (Fig. 4).

The model-wheel 4I is carried by aV follower 50, and the latter is carried by the carriage 48 to which it is connected by parallel links 5I. These links constrain the model-wheel to horizontal movement approximately at right-angles to the turning axis a: of the model. The follower 50 includes an anti-friction roll 52 arranged to run on the'periphery of the modifying cam I2. A tension spring 53 anchored to the carriage 40 will be connected to one of the links 5I of the follower'when the roll 52 is arranged to engage the rear side of the modifying cam, as `repre- VThe carriages are sented in full lin'e's in Fig. 1.v In these cire'urne stances the' follower will be biased against the cam I2 with more power derived' from the spring 53 than the opposing bias of the model against the model-wheel derived from the spring 42 (Fig. 3). Consequently, the position of the modelwheel will be governed by the modifying cam and the spring 53 despite the inferior bias of the spring 42.

On the other hand, if the modifying duty of the cam I2 were to decrease, instead of increase, the girth of a copy, it could be done by shifting the roll 52 to a location indicated in dotted lines 52 where its point of contact with the cam would be 180 from that of the location first specified. When the roll 52 is arranged to engage the front side of the cam the spring 53 (Fig. 1) need not be used, since thel spring 42 (Fig. 3) willthen suffice to bias the roll against the cani as well as t6 bias the model againstv the model-wheel;

The face-plate 2l (Fig. 6) has a groove 54 extending diametrically to receive a metal strip 55 of equal width anlxed to the abutting end of the cam I2. These details provide interlocking means for driving the cam. They also provide for setting the cam in either of two positions 180 apart, according to the setting of the roll 52 for additive or subtractive modifying effect. A hole 56 is made in the strip 55 to receive the head 57 of a pin set in the groove 54 of the face plate and centered on the rotational axis y. The head 51 and the tail-stock 25 maintain the axis of the cam on the rotational axis y, while the strip 55 and groove 54 maintain rotational phase relation of the cam and the model.

The face-plate 2| at the rear of the lathe (Fig. 1) is aixed to a spindle 58 corresponding to the spindle I8 at the front. The two spindles are interconnected by transmission gearing (Fig. 4) including a gear train 23 for the spindle 5B like the corresponding train 29 for the spindle I 8. The transmission gearingalso includes bevel gears 5S, 59 both aixed to a shaft 6I). This gearing synchronizes the rotation of the spindles I8 and 58. Rotation derived from an electric motor 6I is transmitted 'by pulley 52, 63 and a belt 64 to a countershaft 65, thence by gears to another shaft 66, and thence by gears 61 to the driving member 68 of a jaw clutch. The driven member 69 of this clutch is aiixed to the shaft E, but the driving member 68 is arranged to slide on the shaft to engage and disengage the member G9, and is under control of a mechanism represented by a lever 10.

In operation, the model I0, the block I I and the modifying cam I2 will rotate equally and remain in cyclic phase with each other, and whenever the roll 52 is spaced from axis y by a distance equal to the neutral radius of the cam the modifying effect of the model wheel 4I will be zero. If the modifying surface l2* of the cam is in a cavity of less than neutral radius, as illustrated in Figs. 6 and 7, and if additive modifying effect is desired, the roll 52 will be set to bear against the rear side of the cam (solid lines in Fig, 1) and the spring 53 will be used to govern the model wheel accordingly. Therefore, whenever the follower roll 52 enters the cavity in the cam the model wheel 4I will move forward with additive modifying effect. If subtractive modifying effect were desired it could be obtained by shifting the roll 52 to the location indicated at 52*, turning the cam member 180 with respect to its faceplate 2I, and detaching the spring 53. In that event the model wheel 4I would move backward whenever the follower roll enters the'c'avit'y the" cam. lThe forward and backward mdve-`` ments ofthe' model wheel will be outfof phase with the oscillations of the swing frame. w I Considering the specific example of a modify'`4 ing'effec't indicated in Figs. 3 and 7, the longe'r segment dened by' the radial lines a and b is the modifying segment of the cam, and' the shorter segment is the non-modifying or' neutral segment thereof. As'v applied to the ball region of a model, the lines a' and b' at the right of' Fig". 3 Correspond t0 the lilies a and appl-led 15` the modifying carne In this view the model III is displaced to the right of its'nor'inal position a 'f distance equal to the depth of the cavity in the cam member. The normal positions of the roll 52 and the model wheel are indicated with dotted lines. I In Fig. 7, in whicha cross-section of the model is' superposed on a diagrammatic section of fthe modifying cam, the lines a and b define the angular extent of the modifying effect of the cam as applied to the upper portion of the model, but not to the lower portion thereof.

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

1. A copying lathe comprising a swing-frame including rotatable means for carrying a workblock and a model, means for driving said carrying means, a model-wheel for cooperating with 5' including rotatable means for carrying a workblock and a model, a carriage, a cam-follower movably related to said carriage but carried thereby to partake of its traverse, a model-wheel carried by said follower, a rotary cam cooperatively related to said follower for shifting said modelwheel back and forth to modify the motions imparted to the swing-frame by the model, means for driving said rotatable means and said cam at equal speeds, and a cutter-carriage provided with a cutter for operating on the work-block.

3. A copying lathe comprising a swing-frame including rotatable means for carrying a work block and a model, a cam rotatable about a fixed axis, a carriage, a cam-follower peripherally engageable with said cam and movably related to said carriage but carried thereby to partake of its traverse, a model-wheel cooperatively related to the model in the swing frame and responsive to the motions of said follower to modify the motions imparted to the swing-frame by the model, means for driving said rotatable means and said cam at equal speeds, and a cutter-carriage provided with a cutter for operating on the workblock.

4. A copying lathe comprising cutting means for operating on a work-block, a swing-frame including rotatable means for carrying the workblock and a model, a carriage, a cam-follower movably related to said carriage but carried thereby to partake of its traverse, a model-wheel carried by said cam-follower, a rotary cam by which said follower is contacted and linearly moved for shifting the model-wheel back and forth, and means for driving said cam and said rotatable means at equal speeds, said cam having concentric peripheral segments of neutral radius and unequal angular extent and a peripheral segment of other radius for modifying the copy of the model.

5. A copying lathe comprising cutting means for operating on a work-block, a swing-frame including rotatable means for carrying the workblock and a model, a carriage, a cam-follower movably related to said carriage but carried thereby to partake of its traverse, a model-wheel carriedl by said cam-follower, a rotary cam cooperatively related to said follower and rotatable about a fixed axis for shifting said model-wheel back and forth, and means for driving said cam and said rotatable means at equal speeds to` zo 8 modify the motions imparted to the swing frame by a rotating model, said cam having successively eiectlve peripheral segments of a neutral radius by which the model-wheel will be maintained in a non-modifying location.

LAURENCE E. TOPHAM.

REFERENCES CITED The following referencesare of recordrin the file of this patent:

UNITED STATES PATENTS

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