US1688781A - Machine for cutting concave surfaces - Google Patents

Description

Get. 23, 1928.

. 1,688,781 J. E. BRANSON momma FOR CUTTING CONCAVE SURFACES Filed July 31, 1925 2 Sheets-Sheet 1 Oct. 23, 1928.

J. E. BRANSON MACHINE FOR CUTTING CONCAVE SURFACES Filed July 31, 1925 2 Sheets-Sheet 2 Patented Oct. 23, 1928.

UNITED STATES JAMES E. BRANSON, F CINCINNATI, OHIO.

MACHINE FOR CUTTING CONCAVE SURFACES.

Application filed July 31, 1925. Serial No. 47,186.

This invention relates generally to ma chines for cutting concave surfaces and par ticularly for concaving the tops of shoe heels, especially heels made of maple and other hard woods.

In the manufacture of wooden shoe heels, concaving the top is, customarily, the final operation in bringing the heel to its final form before applying the covering material of i0 leather, celluloid or cloth. The usual practice is to so concave the top of the heel that a fiatedged margin about 1 16th inch wide remains from the plane surface which comprises the top of the block prior to concaving. For the H3 sake of neat appearance, it is desirable that the edge of the cut made by the concaving tool shall conform with the edge of the outer contour of the heel top. As this contour is curvilinear, and the radius of curvature thereof is changing from one portion to another, some means of traversing the work or the cut ter so that either one or the other will follow the desired path is essential. The operation of concaving has been customarily ac- ).5 complished with a rotary cutter, the cutting edge of which has been ground to the desired curvature in a plane at right angles to the surface to be cut. Ordinarily, the cutter has been revolx 'ed in a fixed plane, and the heel has been 110 traversed beneath the cutter to form the desirable concave surface. In concaving shoe heels by methods heretofore in use, a combination of levers and guiding cams of large radii, has been employed, the work being as traversed beneath the cutter by manual means. The heel must be traversed under the cutter from front to back and returned over the same path without cutting and then traversed under the cutter a second time to 4m trim out the small. amount of material remaining. Should it be attempted to cut on returning from the first cut, as from back to front, the cutter will tear the surface. The manual methods heretofore employed have often resulted in a rough or washboard surface due to the unsteady feed, and the edge of the out being wavy and unsightly, and it is the object of my invention to overcome these cutting defects. It is also an object of m. my invention to increase the output per operative, and to produce a product that is uniform. Another object of my invention is to provide a master cam by means of which, through auxiliary mechanism, the heel may 62 be guided in the proper path beneath the cut-- ter. further object of my invention is the provision of automatic means of clamping the work before, and automatically releasing it after it has been processed. With these and other objects not specifically mentioned in v ew, the invention consists of certain co1n binations, constructions and parts which will be hereinafter described and specifically pointed out in the claims hereunto appended.

In the accompanying drawings whichform a part of this specification:

F igure 1 is a perspective View of one style of wooden heel for shoes, the top of which has been concaved by amachine constructed in accordance with my invention.

Figure 2 is a plan view of a machine constructed in accordance with the invention showing the various parts and their relation one to the other.

F lgure 3 is development of the drum cam 3'? of Figure 2.

Figure 4 is a fragmentary plan view of the mechanism of the work slide and the parts immediately subsidiary thereto.

Figure 5 is an elevation of the work slide and related mechanism, partially in section, the section being taken along the line 55 of Figure 4.

Figure 6 is a plan of a block upon which has been drawn an outline of the master cam 57 In my invention the heel to be processed is clamped to a reciprocating slide, adapted to traverse the heel beneath a suitable revolving cutter. The reciprocating slide is mounted on a pivoted slide carrier, adapted to swing around the pivot in a direction transverse to the longitudinal movement of the slide. The

heel, in its traverse beneath the cutter, may thus be constrained to follow either a straight or a curvilinear path at the will of the operator, or it may be constrained to follow a predetermined path, being guided therein by means of master cam. which has been suitably arranged in connection with the slide.

In the preferred construction, as shown in the accompanying drawings, the master cam is attached to the work slide, and on the end opposite that to which the work is attached. As the slide progresses beneath the cutter, the master cam is broughtinto contact with a roller to which it is held by spring pressure, and the slide is swung to one side causing the heel in process to follow a curved path determined by the contour of the master cam. As the center of the roller and the axis of the cutter are equi-distanthorizontally from the center of the slide carrier pivot, the path followed by the heel is a substantial duplicate of the contour curve of the master cam. Therefore, the contour of the master cam may be generated directly fronrthe contour of the heel top, as will be hereinafter described.

Referring to the drawings, 7 represents the base or table of the machine upon which all the operating mechanism is mounted. The cutter 8 is attached to the cutter shaft 9, and the shaft is, in its turn, mounted in the bearings 10 and 11. Midway between the bearings and attached to the shaft is a pulley 12 on-which is the belt 13, through the medium of which the cutter is driven from any convenient source of power as, for example, an electric motor. The work slide 14 is adapted to be reciprocated in a direction substantially at a right angle to the axis of the cutter shaft 9, and beneath the cutter 8, and is mounted on the slide carrier 15 to which it is fitted by means of suitable guideways 16, these ways being of the same general. form as are employed for the cross-slide of an engine lathe. The carrier 15 is pivotally mounted on the bed 7 by means of the pivot pin 17 attached thereto and preferably made a part thereof as shown in the drawings. The pivot pin is adapted to turn in the bearing 18, which may conveniently be a part of the base 7. The weight of the slide and the carrier is suppprted by circular ways 19 on the base, corresponding ways registering therewith being a part of the carrier as indicated at 20. The carrier with the slide is retained in a midposition with the median line of these parts at a right angle to the axis of the cutter, by means of the springs 21 and 22.

:The inner ends of these springs bear against the ears 23, 24 forming a part of the carrier 15. The outer ends of springs 21 and 22 bear against the inner ends of tension screws 25, 26, the screws being threaded in the abutment !blocks 27, 28, bolted to the base 7, the screws being adapted to be locked in position by 'means of. the internally threaded collars 29,

At the rear of the base 7 is a shaft 31,

which is driven at a desired speed preferably about R. P. M. through the medium of a worm reduction gear which is indicated at 32. As this gear is of the usual conventional type and well known to those skilled .in the art, no details of its construction are shown. This gear is mounted on a shelf 7' of the base which is stepped down from the main surface. The worm shaft, which forms the high speed member of the reducing gear is shown at 33. It is supported at its outer 37, which is secured to the shaft. The cam 37 is provided with a groove 38, the form of the groove being shown in the development in Figure 3, which will be described in detail later. A lever 39, composed of the short arm 39 and the long arm 39", is pivotally mounted on the frame or base 7 by means of the fuicrum pin 40. The rocker arm has attached thereto on the outer end of the short arm 39, a roller 41 engaging the sides of the groove 38. On the extreme outer end of the arm 39 I have provided a rectangular guideway 42 to which there is slidably fitted a rectangular block 43, of which the corners only may be seen. The block 43 is bored to receive the pin 44 which is fixed to the slide 14.

Bolted to the slide is aheel chuck or holding fixture comprised of a base 45, a fixed jaw 46, and a movable jaw 47. The jaws are fitted with inner faces 46' and 47 of babbitt or other metal of low melting point which are formed by casting with a sample of the heel clamped in a mold, the metal being poured around the heel. A heel in its finished form, without the covering, is shown in Figure 1. The same style of heel in place in the chuck is shown in Figure 2 at 48, and a larger heel with an over-hanging top at 48 in Figures 4 and 5. The movable member 47 of the chuck is pivoted to the base by means of the pin 49, and it isextended into an arm 47 to receive the stop screw 50. The jaws are, normally, held together to grasp the work by the spring 51 suitably attached to the jaws. The base 45 is fitted with four set screws 52, secured with suitable lock nuts 53, and the base 45 is held to the slide with T- bolts 54, the heads of the bolts being fitted to the T-slot 55 in the slide 14. The set screws serve to adjust the base 45 both as to to its height and to the proper angle of inclination to conform to the requirements of the heel in process, to bring the heel in correct relation to the cutter, in order that the cut may be made the proper depth and contour, in the heel.

Projecting upwardly from the slide carrier 15 and fixed thereto, is a stop 56 adapted to contact with the screw 50 just as the slide is approaching the end of its longer outward stroke, which is the stroke that approaches that edge of the base shown at the lower edge of Figure 2 in the drawing. This contact of screw 50 with stop 56 opens jaw 47 and unclamps the work, permitting its removal by the operator, and the jawremains in the open position for a length of time sufficient to per-- mit the insertion of an unfinished heel.

Fixed to that end of the slide 14 opposite the end in which the heel is held, is a master cam composed of the wooden center piece 57, surrounded by a metal strap 58, which is attached to the block 57 by means of a bolt 59 passing through both the strap and the block. The purpose of the strap is to provide a harder Jon wearing surface than would be provided by the edge of the wooden center, were the latter required to contact directly with the roller 65. The roller is adapted to remain in a substantially fixed position during the period of contact with the outer surface of the strap 58, and the master cam is attached to the raised pad 60, forming a part of the slide 14, by means of the clamp 61, and the bolts 62 which are of the Thead type and. are so arranged that the heads of the bolts are held in the T-slot 63.

The roller 65 mounted upon a pin 66 attached to the end of the plunger 6'? slidably mounted in the block 68. The block is clamped to the parallel bars 69 69 by means of the bolt to brackets 7l?l fixed to the base. A spring 70, mounted. in compression between the block 68 and the head 67 of the )lunger 67, has a tendency to force the plunger upward. Supported on brackets l 1'. l fixed to base 7 is rocker upon which are pivoted the bell-crank levers 'Z3-73 comprised of the short arms Z+l: l and the lon or arms 75. The outer ends of the arms 74.7 l contact with the tops ot the plung" 67 B? and the outer ends of the arms 75- contact with cam blocks 76 as shown in Fi ure 5. The block 76 is bolted to a disk 77, the disk being attached to the shaft 81. The block 76 is rotated with shaft 31 in the direction of the arrow, thrusting the arm 75 outward as it passes thereunder, rotating the love" around the shaft 72, the arm 7% being swung downward, forcing the plunger 6'? downward and thrusting the roller 65 into the path of the master cam. A second roller (35, which is in dicated in dotted lines in Figure 4-, is manipulated in a like manner by means of a second cam block 7 6 through the medium of the rockor arm 7 8 and the plunger 67.

For convenience of reference, the path of the slot 38 provided in the surface of the cam 37 is divided into sections in the development thereof as shown in Figure 3, and the sections indicated by letters. The direction of rotation of the cam is indicated by the arrow and the direction of the movement of the roller ll slidabiy engaged in the slot 38 is indicated by the double arrow LL. That portion of the slot 38 which is parallel to the side of the cam as indicated by ar a. gives no cross movement to the roller 41. As the section indicated at b of the slot passes beneath the roller, the latter is moved in the direction L, swinging the lever arm 39 in Figure 2 to the right, thus giving the slide 1 2 its first inwarc stroke. As the section shown at c of. the slot passes beneath roller 41, the roller is moved in the direction L, and the arm 39 is swung to the left, but not to the extent of returning it to the position corresponding to that 0811;- pied when the roller is engaged in section :1, of the slot. As the section indicated at (Z is passed by the roller, the roller is again moved in the direction of the arrow L, and the arm 39 is swung to the right for a second time. The third section shown at c of the slot 38 compels the roller to follow the direction L and the roller reaches that portion of the slot indicated at a in Figure 3, and shown at the right side of the figure. As this portion of the groove and that portion marked a at the left side of the figure are continuations, one of the other, the movement of the roller produred by one revolution of the cam 37 is completed when the roller enters section a from section c.

The block 5" of Figure 6 is a blank from which is cut the center 5? of the master cam. This is shown in outline by means of the heavy line 0. In determining the era ct sha a e of the curved portion of the cam outline, the shoe heel to be concaved by the aid of the cam is laid top down on the block and the outline of the top is transferred to the block by erawing a sharp point around the outer edge of the heel top, thereby securing line C mustaarallel the curve 0 being at a distance therefrom equal to the flat'edgeE, Figure 1, plus the thickness of the strap 58. F or example, the width of the flat surface E is about inch and the thickness of the strap 58 about inch, making a total of inch. setting a pair of dividers with their points 2 inch apart, it is a simple matter to generate the curved portion of the outline 0 directly from the curve 0.

The operation of the machine is as follows: lVith the slide clear back and the roller 41 in the section a of the slot 38, the chuck 4-7 is held back against the tension of the spring 51 by the stop 56, and is in the position indicated by the broken lines 47, Figured. The operator sets a shoe heel to be concaved on the plate 45 and against the inner fixed jaw 46, holding it in place until the continued movement of cam 37 brings the roller into section Z) of the slot 38, and the slide moves toward the cutter a sulficient distance to release spring 51 and permit it to pull jaw 4? against the heel, clamping it in place. As section I) of the slot 38 moves beneath the roller 4-1, the

arm 39 is swung to the right, the arm 39" being swung toward the top of the figure, the slide 14 starts toward the back of the base which is at the top of Figure 2, and the heel 48 approaches the cutter 8. During the first portion of this, the first stroke of the slide 14:, the movement of the slide is in a direction at a right angle to the axis of the cutter shaft 9, being constrained to follow this path by the guideways 16 on the carrier 15 and the springs 21, 22, which hold the median line of the carrier in a positionata right angle to the axis of. the shaft 9. As the slide proceeds on its first stroke the roller 65 is depressed into the path of the master cam 57 through the interaction of the cam block 7 6, the rocker arm 73 and the plunger 67 to which the roller 65 is the curve 0. The out-- attached. The roller is held in this depressed position, as the surface of the block 76 slides beneath the lower end of lever 75, and only so long as the block and the lever are in contact. Further progress of the slide 2 brings the heel beneath the cutter 8, and the surface of the cam strap 58 into contact with roller 65, the cutter concaving the top of the heel and the slide 14 deflected from a rectilinear path by means of the master cam, which is held to the roller by the pressure of the spring 22, as illustrated in Figure 4. The deflection of the slide 14 and its carrier 15 causes the cutter 8 to so cut out the top of the heel that the edge of the cut, shown on the left in Figure 2, and shown toward the top in Figure 4, must follow a curved path which is a replica of the curved edge 58 of the master cam. Just as the end of the stroke corresponding to section b of the cam groove 38 is completed, the block 7 6 passes from under the lever 7 5, and the lever slips over the corner w of block 76. Immediately, the spring 7 0 forces the plunger 67 upward and the roller 65 is withdrawn from the path of the master cam 57. Roller 41 now enters sec tion 0 of slot 38, and the arm 39 is swung to the left, starting the slide 14 on its first backward stroke. There being nothing in the path of the cam 57, the'springs 21, 22 hold the carrier and the slide in a central position and the heel is returned from beneath the cutter along a line at a right angle to the axis of shaft 9. The length of this stroke of the slide is about 65 per cent of the first forward stroke, and is not long enough to bring the screw 50 into contact with the stop 57. Hence the chuck does not open. As section d of the slot 38 passes beneath the roller, the arm 39 is again swung to the right and the heel is traversed toward the cutter 8 for the second time. Just as this stroke is started, cam 76' (Figure 2) swinging lever arm 75 outward, depresses plunger 67 and roller 65 is pushed into the path of the master cam 57, and the slide with the carrier is swung in a clockwise direction as seen from above, or in the direction opposite to that shown in Figure 4. The spring 21 is now compressed, and it is the pressure of this spring that holds the cam 57 against the roller 65. The concaving is now completed along the side of the heel opposite to that cut during the first stroke. 1: s the roller 41 is about to enter section 6 of slot 38, block 76' passes from under the end of lever 75, releasing the plunger 67 and roller 65 is withdrawn from the path of the master cam 57, allowing theslide to return along a line at a right angle to the axis of shaft 9. This stroke is the same length as the first forward stroke, and just as the end of this stroke 'is approached, the screw 50 contacts with stop 56, opening the chuck and releasing the finished heel. The roller 41 has now entered section a of slot 38, and the slide 14 dwells at The output per hour is limited only by the dexterity of the operator in removing the finished work and replacing it with an unfinished heel. The facility with which the cam may be developed from the heel to be processed, and the ease with which the work mayv be set to the proper height, inclination and position with reference to the cutter, is a great improvement over methods and devices formely in' use.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

1. In a machine for cutting concave surfaces, a main frame, a pair of bearing blocks attached to the frame and extending upwardly therefrom, a shaft in the bearing blocks, a rotary forming cutter on the shaft and extending thereon over the frame, a work slide beneath the cutter, the slide adapted to be reciprocated in a direction substantially at a right angle to the axis of the cutter shaft, work holding means disposed in one end of the slide, a master cam on the end of the slide opposite the work holding means, a carrier for the slide, the carrier adapted to guide the slide in a direction normally at a right angle to the axis of the cutter shaft, the carrier pivotally mounted on the frame, and means adapted to yieldingly retain the carrier with the median line of the carrier at a right angle to the axis of the cutter shaft.

2. In a shoc-heel concaving machine, a forming cam, the forming cam comprising luu a central block portion, the top and the bottom of the central portion being plane surfaces and parallel one to the other, the edges of the block joining the top and the bottom surfaces being formed in the major part of a curve generated by laying a sample heel inverted on the block, following the contour with a marking instrument, thereby transferring the outline of the heel top directly to the cam block, the cam being completed by sawing out the contour on a line parallel to the outline of the heel top transferred thereto as described.

3. In a shoe heel concaving machine, a

by the'aid of the contour of the forming cam, and means for attaching the forming cam to the work slide.

4. In a shoe-heel concaving machine, a main frame, a forming cutter, a cutter shaft for retaining the cutter, th shaft mounted on the frame, a reciprocating work slide, a carrier for the work slide, the carrier pivotally mounted on the frame, a heel holding filiture attach ed to the slide, a forming cam also attached to the slide, spring elements adapted to maintain the median line of the carrier and of the slide normally at a right angle to the axis of the cutter shaft, retractable plungers, rollers on the lower ends of the plungers, fixed guides for the plungers, means for periodically reciprocating the plungers whereby the rollers thereon are thrust into the path of the forming cam, means for retracting the plungers and withdrawing the rollers from the path of the forming cam, the rollers being thrust into the path of the cam for the purpose of so deflecting the forming cam, the work slide to which the cam is attached, and the heel attached to the work slide so that the edge of the cut on the heel top will conform substantially to the contour of the cam, while the roller is in contact therewith, and the path of the heel top will be along a line at a right angle to the axis of the cutter shaft when both rollers are retracted.

5. In a shoeheel concaving machine, a main frame, a cutter rotatably mounted on the frame, a reciprocating work slide, a carrier for the slide, means of aligning the slide on the carrier, the carrier pivotally mounted on the frame, means for reciprocating the slide, said means comprising a cylindrical cam, a rocker pivoted to the frame carrying a roller adapted to traverse the cam groove, the other contour of one side. of the heel top, means for withdrawing the heel a right angle to the axis of the cutter from beneath the cutter,

means of'moving the slide again beneath the cutter said means adapted to align the edge of the second cut parallel to the outer contour of the otherside of the heel top, means of again withdrawing the heel from beneath the cutter in a path at a right angle to the axis of the cutter, and means of releasing the heel from the Work slide.

'7. in a machine for concaving the tops of shoe-heels, a rotating forming cutter, means for passing the heel beneath the cutter along a path substantialy parallel to the outer edge of one side of the heel top, means for withdrawing the heel along a path at a right angle to the axis of the cutter, said first mentioned means operable for again passing the heel underneath. the cutter along a path substantially parallel to the other side of the heel top, and said second mentioned means operable for again withdrawing the heel along a path at a right angle to the axis of the cutter.

JAMES E. BRANSON.

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