US1979597A - Manufacture of lasts - Google Patents

Description

1934- P. AMANN ET AL MANUFACTURE OF LASTS Filed May 25, 1932 5 Sheets-Sheet l Nov. 6, 1934. P, AM N T AL 1,979,597

MANUFACTURE OF LAST 5 Filed May 25, 1932 3 Sheets-Sheet 2 25 26 HI 9 I? :8 f

n 29 1 k xx 7 \Q/ 97.17. v\ tn ODLLLSL W {AK I A LM 0 'gg g Nov. 6, 1934. P. AMANN ET AL MANUFACTURE OF LASTS Filed May 25, 1932 5 Sheets-Sheet 3 Patented Nov. 6 1934 UNITED STATES MANUFACTURE OF LASTS Paul Amann, Nanterre, and Andre Ple, Paris",

France Application May 25, 1932, Serial No. 613,540 In France June 16, 1931 4 Claims.

The present invention relates to apparatus for manufacturing lasts for the assembling of shoes.

The object of the present invention is to provide a copying lathe for the manufacture of lasts which better answers the requirements of actual practice than similar apparatus used up to this time.

To this eifect, the copying lathe according to our invention comprises a frame upon which can oscillate a rocking arm provided with wheels rotating at the same speed and on which the pattern and the symmetrical elements of the last are fixed respectively. Said rocking arm is controlled by a profiling roller so as to hold the Work in suitable position with respect to milling cutters mounted on carriages the displacements of which are suitably controlled. Of course, in lathes of this type, the above mentioned wheels might also rotate about fixed axes with respect to the frame,

in which case the profiling roller and the cutters would be carried by a rocking arm, this arrangement being the equivalent of that above mentioned. According toour invention, the pattern and the last elements are fixed through plane faces applied against corresponding plane surfaces provided on their supports, said pattern and said last elements being in overhung positions. Furthermore, the pattern is of a shape corresponding to the shape of last that it is desiredto obtain, but with its thickness increased by a constant quantity along its whole surface and the profiling roller is of a shape corresponding to that of the cutting means, but with its thickness reduced by the same quantity over its whole surface, a small piece being secured to the pattern and projecting from the end therefrom, so as to prevent the profiling roller from falling down past said pattern.

Preferred embodiments of our invention will be hereinafter described with reference to the accompanying drawings, given merely by way of example, and in which:

Figs. 1 and 2 are an elevational view and an end view respectively of a copying lathe according to the present invention. I

Figs. 3 and iaresectional views of two different chucks "for secur-ingthe last elements in order to turn them;

Figs. 5 and 6a-re diagrammatical views showing the automatic finishing of the extremities of the last;

Fig. 7 is a plan view of corresponding to Fig. 6.

Fig. "7a shows the completed last;

Figs. 8 and 9 are sectional views of the wooden the pattern and plate blocks from which the elements of the last are made, prior to their fixation to the supporting plates of the lathe;

Figs. 8a and 9a are views corresponding to Figs. 8 and 9 respectively, showing these blocks provided with their hinge elements.

In order to make the following description easier to understand we will first describe, by way of example, a type of wooden last structure which is Well adapted to be used with the machine according to the present invention.

These lasts are made from two blocks 10 and 11 which are first given, in any suitable way, plane faces 7. In these faces we cut semi-cylindrical grooves h and holes 20 and 21, preferably of cylindrical shape and at right angles to groove h, as shown in Figs. 8 and 9. We also drill holes is intersecting these holes 21.

These holes 20, 21 are adapted to receive hinge elements 22 (for block 10) and 23 (for block 11) which are fixed in these holes by means of pins 24 engaged in holes is and extending through corresponding holes provided in the hinge elements.

Hinge element '22 forms a kind of jaw the branches of which are provided with eyes 22b arranged to be in line with groove 11. when element 22 is fitted in position in holes 20, 21. Hinge element 23 is also provided with an eye 23b arranged to lie in line with the semi-cylindrical groove 71 of block 11 when element '23 is fitted in position in holes 29, 21 of this block. Element 23 is adapted to fit between the branches of jaw 22, holes 221)- and'23b then lying all in coaxial relation. The diameter 'of holes 222) and 23b and of grooves 72 is the same.

When the blocks have been given the desired shape by means of the lathe according to our invention, "as will be hereinafter described, these hinge elements 22 and 23 are assembled together by means of a pin .72 passing through the registering respective :holes22b and 23b of these hinge elements and fitting in grooves h, as shown by Fig. "7a. (in this figure, the upper portion of element 1:1 is cutaway obliquely at 11a so as to permit the pivoting of parts 10 and 11 with respect to each other about pin '72) We will now proceed to describe the copying lathe according to our invention.

Copying lathes may be of two different types with the same relative motion of the parts: either the pattern and the pieces of work revolve and are brought by the rocker arm in contact with the profiling roller and the milling tools, which rotate about stationary :axe's, or otherwise the pattern and the pieces 'of work rotate about stationary axes, the profiling roller and the milling tools being mounted on a swinging support.

The arrangement disclosed in Figs. 1 and 2 is shown merely by way of example. It will readily be understood that the characteristic fea tures that are described therein are independent of which type of copying lathe is being used. Obviously the arrangement of Figs. 1 and 2, which relates to the second mentioned type could easily be adapted to the first mentioned one.

Two uprights 27, four horizontal members 28 and 29 form a frame the top of which is provided a shaft 30, which serves to support a swinging frame 31. frame carries at its lower part two circular parts 32 and 33 which each actsas-a casing and a bearing of large diameter.

Two large toothed disks 34 are rigidly secured to the periphery of face plates 26 and 25 and serve to drive them with the same speed of revolution, since they are themselves driven by pinions 35 of equal diameters keyed on a common shaft'36 driven through pulleys 37-38,pulley 38 being mounted on shaft 30.

Plate 26 carries the plattern 10", which is secured to its hub 26 through a threaded jaw and a nut 61. A profiling roller 39, mounted loose on a carriage 40, is applied against the surface of said pattern, which latter acts as a cam there on in the known manner. Milling tools 41- l2 are mounted along the same axis as said profiling roller, but on interconnected carriages. 43-4L A series of suitably chosen gear wheels 45--46-4=748, driven by a worm wheel for instance and cooperating with racks 49 and 50 serves to drive carriages 43 and 44 in opposite directions. It follows that symmetrical last elements are produced by the machine.

Carriage 46 is connected to carriage 13 through any suitable means, for instance a connecting rod 40', but we might quite as well use a panto graph of a known type.

On the otherhand we have shown a profiling roller 39 that is fixed to carriage 40, but it might also be connected to carriage 40 through a reproducing differential gear of a known type.

Plate 25 may consist of two parts 25 connected together through screws 25 and connected to toothed ring 34 through a lateral annular piece 25 fixed through screws 25 (Figs. 1 and 4).

Between said parts 25 there is provided (Fig. 3) a wheel with projecting spokes or fingers 62, which can be operated through apertures 25*. That wheel is mounted on an axis 63 of square section provided on either side of said wheel with right and left threads 63 and 63 on which are screwed the male or female hinge elements 64 which are keyed in parts 25 and to which are jointed, through pins 72 (Fig. 1) the front blocks 10', 10" (or the rear blocks as the case may be) previously fitted with their male or female hinge elements 23 or 22, as above explained (Figs. 8a and 9a). The blocks are thus tightly applied against the face plate 25.

In the embodiment shown in Fig. 4, the'hinge elements 64 screwed on threads 63* and 63 are replaced by expansible sleeves 66, slit along three or four generatrices and through which can slide conical parts 67 the inner ends of which are inwardly threaded so as to be screwed on axis 63. Said expansible sleeves are inserted in the holes 20 of blocks 10 (or 11) to be turned. When wheel 62 is rotated, conical parts 6'? are moved inwardly, toward each other; sleeves 66 are caused to expand and their pressure against the inner walls of central holes 20 of the blocks firmly holds said blocks. The semi-cylindrical projection 68 of plate 25 engages the corresponding groove h of blocks 10 and 11, and thus ensures the centering thereof. With that embodiment, it is possible to turn blocks 10 and 11 and to fit the hinge elements 22 and 23 in said blocks only after the turning operation.

The device that has just been described has many advantages. In particular, the reduced dimensions .of the wooden blocks are favorable as to their cost and their drying. The fixation of the blocks on their respective face plates is obtained through a rigid piece housed in the plate so that the ends can be turned with a fine finish, and the reproduction is perfectly accurate; as the last is applied at its middle part along a perfectlyplane face, the surface along which it is applied against the plate is relatively large, so that it is possible to turn the pieces on the face plate without vibration. On the other hand, as the milling tool carrying shaft does not touch anyportion of the last, it may be short and parallel to the axis of the last which ensures a faithful reproduction. The tool may have a small diameter, making it possible to turn hollow parts of small radius. The turning of two half lasts in a single operation is equivalent to the turning of a whole last at a double speed, or at the same speed, but with a fineness of work such that polishing is made unnecessary. The last is wholly finished at the end of the turning operation, and the two parts, when assembled, have not the play that results from the sawing of the last.

As the swinging frame is made of an alloy of aluminium or any other light metal, its inertia is small. Furthermore, the small cutter carriers arranged parallel to the axis are directly driven by a belt oran electric motor. Finally, allthe known improvements in last lathes of or dinary'types can be adapted without modification to the machine according to our invention, to wit: thickness or. length pantographs; speed changing; automatic stops, and, generally speaking, all auxiliary arrangements known in the art.

It is known that in copying lathes, the cutters generate a tore, and that the profiling roller generally has the shape of a tore having the same characteristics, that is on the one hand the same diameter of revolution and on the other hand the same diameter of the generating circle. It is possible, while maintaining the same diameter of revolution, to choose a diameter of the generating circle that is smaller, for the profiling roller, by a constant quantity e (Figs. 5 and '1 6), but in that case the thickness of the pattern (on which rolls the profiling roller) must be increased by the same quantity along its whole surface.

That arrangement makes it possible to neatly finish the'edges of the last Without wearing those of the pattern.

If now, as shown in Figs. 5 to 7, the extremities of the pattern are provided with a small metallic piece rigidly fixed thereto, and having either the shape of a rod 51, or that of a small plate 52, the drawings show that the extremities of the last are practically finished.

In Fig; 5,,we have shown in dotted lines two positions of cutter 41 as it is finishing the extremity of last 10', and'in solid lines the correspondingpositions of profiling roller 39. Furthermore, we have shown in solid lines the front portion of pattern 10', and in dotted lines the corresponding portion of the last turned by cutter 41. Fig. 6 is a similar view corresponding to the rear part of the last and of the pattern.

The advantage of that arrangement is that the swinging frame can never fall into a position where it would no longer be in contact with the profiling roller and from which the pattern'could not move up without cutting the end of the last. On the other hand the edges of the pattern are not injured since the swinging frame is not allowed to fall past the last into a position from which it could not be restored without injuring the last. Said edges therefore do not need to be lined with metallic pieces so that the reproduction is much more accurate. Finally it is possible to begin the turning at the end of the pieces and to finish it at the middle as the working takes place without vibrations and the roughing down has no influence whatever, since the reactions resulting from the turning practically balance each other, and the drawbacks resulting from accidental inequalities due to the roughing down are thus eliminated.

While we have described what we deem to be preferred embodiments of our invention, it should be well understood that we do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of our invention as comprehended within the scope of the appended claims.

What we claim is:

1. A machine for turning shoe lasts, which comprises in combination, a stationary frame, a swinging frame pivoted to said stationary frame, two parallel face plates carried by one of said frames, a profiling roller and two cutting means carried by the other frame, said profiling roller being located opposite one of said face plates and said cutting means being symmetrically disposed on either side of the other face plate respectively, a pattern secured to the first mentioned face plate in an overhung position and adapted to cooperate with said profiling roller, means for securing a wooden block to each face of the second mentioned face plate in an overhung position, means for causing said cutting means to move symmetrically with respect to the second mentioned face plate in a direction parallel to the axis thereof, means for causing I said profiling roller ,to move in a direction parallel to the axis of said face plate synchronously with the axial displacements of said cutting means, means for causing said face plates to rotate at the same speed relatively to said pro- Y filing roller and to said cutting means respectively, the pattern being of a shape corresponding to the shape of last that it is desired to obtain, but with its thickness increased by a constant quantity over its whole surface, the profiling roller being of a shape corresponding to that of the cutting means, but with its thickness reduced by the same quantity over its whole surface, and a small piece secured to the pattern and projecting from the end thereof, whereby the profiling roller is not allowed to fall down past said pattern.

2. A machine for turning shoe lasts according to claim 1 in which the profiling roller and the cutting means are carried by the stationary frame, while the parallel face plates are carried by the swinging frame.

3. A machine for turning shoe lasts according to claim 1 adapted to be used with wooden blocks having a plane face and a recess in said face adapted to receive a hinge element, in which machine the second mentioned face plate consists of two symmetrical disks secured to each other, the means for fixing a wooden block to each face of the second mentioned face plate comprising a wheel mounted between said'two disks in coaxial relation therewith, a plurality of spokes or fingers radially disposed at the periphery of said wheel, the two disks being provided with apertures through which said fingers may be acted upon for rotating said wheel, said disks being provided with axial holes respectively, a hinge element slid-ably but non-rotatably mounted in each of said holes, the inner end of said hinge element being formed with inner threads, a right and left threaded rod axially keyed to the center of said wheel and extending on either side thereof, so that each of its ends screws in one of the above mentioned hinge elements, and two other hinge elements, each fitted in the corresponding recess of one of the two wooden blocks and pivotally secured to each of the first mentioned hinge elements respectively.

4. A machine for turning shoe lasts according to claim 1 adapted to be used with wooden blocks having a plane face and a cylindrical recess in said face adapted to receive a hinge element, in which machine the second mentioned face plate consists of two symmetrical disks secured to each other, the means for fixing a wooden block to each face of the second mentioned face plate comprising a wheel mounted between said two disks in coaxial relation therewith, a plurality of spokes or fingers radially disposed on the periphery of said wheel, the two disks being provided with apertures through which said fingers may be acted upon for rotating said wheel, and with axial holes extending throughout their thickness, an expansible sleeve having longitudinal slits in its walls fitted at the outer end of each of said holes, a rod adapted to slide in said sleeve, a conical part at the outer end of said rod adapted to expand said sleeve, the inner end of said rod being provided with inner threads, and a right and left threaded rod axially keyed to said wheel and extending on either side thereof so that each of its ends screws in one of the first mentioned rods respectively, whereby each sleeve may be inserted in the recess provided in one of the wooden blocks and caused to expand by rotating said wheel so as to securely hold said block.

PAUL AMANN. ANDRE PLE.

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