US2424240A

US2424240A - Apparatus for lasting shoes

Info

Publication number: US2424240A
Application number: US527387A
Authority: US
Inventors: Jacob S Kamborian
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-03-21
Filing date: 1944-03-21
Publication date: 1947-07-22
Anticipated expiration: 1964-07-22

Description

y 1947- J. s. KAMBORIAN 2,424,240

APPARATUS FOR LSTING SHOE S Filed March 21, 1944 5 Sheets-Sheet 1 eiacajlmazz'aza y 1947- J. s. KAMBORIAN APPARATUSHFOR LAs'rIN'G SHOES Filed March 21, 1944 5 Sheets-Sheet 2 rzafeizfor July 22, 1947. J. s. KA-MBQRIAN I 7 2,424,240

APPARATUS FOR LAS'IING SHOES Filed March 21, 1944 5 Sheets-Sheet. 3

f'aa'azzlar' we fzea iiimar m y 1947' v J. 5. KAMBORIAN 2,424,240

APPARATUS FOR LASTING SHOES Filed March 21, 1944 5 Sheets-Sheet 4 Patented July 22, 1947 UNITED STATES PATENT OFFICE This invention pertains to machines for stretchin flexible sheet material and uniting it to other parts, the specific embodiment herein 11 Claims. 7 (Cl. 12-2) illustrated by way of example being a machine for lasting shoes, the present invention constituting an improvement over that disclosed in the patent to Kamborian 2,251,285 dated August 5, 1941.

The principal'object of the invention is to provide simple and reliable means for stretching flexible material and for forming and inserting fasteners for uniting the stretched material to another part, for instance, for updrawing and inwiping the upper of a shoe about a last and for forming staples from wire and inserting them through the margin of the upper material and into a sole member, for instance an insole. A further object is to provide a lasting machine capable of lasting shoes (including those having deep shanks) of the McKay, metallic fastener type, not only at the shank and forepart portion but also at both end portions of the shoe and with great rapidity and with highly satisfactory results, but without requiring great skill on the part of the operator. Other and further objects and advantages of the invention will be pointed out in the following more detailed description and by reference to the accompanying drawings wherein Fig. 1 is a fragmentary elevation showing the left-hand side of a lasting machine embodyin the invention;

Fig. 2 is a fragmentary front elevation of the machine shown in Fig. 1;

Fig. 3 is a fragmentary front elevation (partially rotated from normal position and to larger scale), With certain parts removed, showing details of the staple-forming and drivin means;

Fig. 4 is a section substantially on the line l4 of Fig. 3;

Fig. 5 is a fragmentary front elevation similar to Fig. 3 but showing the parts in another position;

Fig. 6 is a section substantially on the line 66 of Fig. 4 but omitting the staple driver;

Fig. 7 is a section substantially on the line 'I-'l of Fig. 4;

Fig. 8 is a section substantially on the line 88 of Fig. 3 but to larger scale;

Fig. 9 is a fragmentary front elevation showing the parts in the position illustrated in Fig. 8;

Fig. 10 is a fragmentary vertical section in the same plane as Fig. 4 but showing the parts in another position;

Fig. 11 is a fragmentary front elevation similar to Fig. 9, but showing the staple as having been formed;

Fig. 12 is an elevation similar to Fig. 1 1 showing the formed staple being driven past the anvil.

Fig. 13 is a section on the line I 3-I3 of Fig. 11;

Fig. 14 is a fragmentary elevation, with the shoe in vertical section, in the plane of theaxes of the lasting rolls, illustrative of the operation of lasting a shoe by means of the present apparatus; and

Fig. 15 is a section substantially on the line I5-I 5 of Fig. 14.

Referring to the drawings the numeral I designates a rigid hollow base, for example of the general type of that shown in the patent to Kamborian above referred to. This base may be a casting or may be built from assembled plates or the like and is provided with a top member l which forms a support for the frame 3 which carries most of the operating mechanism. This frame 3 is preferably a casting and is of rigid and strong material. As illustrated in Fig. 1, this frame comprises a portion 3 which projects forwardly and overhangs the front vertical face I of the base I so as to provide ample space for the manipulation of the shoe durin the lasting operation Without contact of the shoe with the base. The frame 3 is provided with suitable bearings for a main shaft 4 which is provided at its rear end with a pulley 5 which receives a belt 6 which embraces a pulley I of smaller diameter on the shaft 8 of a motor 9 which is mounted on the top member I of the base. A clutch device (not shown) is preferably interposed between the shaft 4 and the pulley 5, the clutch being controlled in conventional manner by means of. a treadle (not shown) accessible to the operator at the front of the machine.

As illustrated in the aforesaid patent to Kamborian, the mechanism herein described comprises a slide member II'I of the same type and guided in substantially the same way as the similarly designated slide member of the aforesaid Kamborian patent. The present machine like that of the patent is provided with a pair of oppositely turning lasting rolls H3 and H4, here shown as provided with helical ribs of opposite pitch, the roll H3 being carried by a vertical shaft (not shown) which i mounted in bearings in the main frame, while the roll H4 is mounted on a parallel shaft II5 having bearings in the slide member I Il The main shaft 4 is provided with an elongated worm (not shown) which at all times meshes with gears for driving the shafts of the rolls H3 and II 4. The slide II I is urged rearwardly by spring (not shown) and may be moved forwardly to separate the rolls I I3 and I I4 by suitable connections including a further actuated treadle (not shown). Reference may be had to the aforesaid patent for details not herein specifically illustrated.

A work-guiding roll I I, of substantially disk shape and havin a substantially fiat upper face and a rounded peripheral work-engaging edge or rim I0, is mounted to turn freely on a vertical spindle carried by a rigid arm I2 projecting forwardly from a bracket I3 secured to the front face of the base. Whereas in the aparatus disclosed in the aforesaid Kamborian patent the marginal material of the upper is stressed inwardly over the insole by a reciprocating wiper device, in the present apparatus a vertically thin stationary wiper blade I4 (Fig. 15) is provided,

this wiper having a smoothly rounded outer edge for engagement with the upper material. This blade closely underlies the lower end of the roll I I3 and is interposed between the plane of the lower end of the roll H3 and the upper surface of the guide roll II. This wiper is supported by or formed integrally with a. bracket I5 fixedly secured to the base I.

At its left-hand side the frame 3 is provided with bearing members It and H for a shaft l8. This shaft I8 is inclined upwardly and forwardly and is driven from the shaft 4 by a belt I20 and pulleys H9 and |2I. The frame also includes the aligned elongate inclined rigid guide members I9 and I 9 which support the staple-forming and driving means, the parts I9 and I9 being inclined (Fig. 2) to the vertical plane of the driving shaft 4 at an angle of approximately and to the vertical forward face l of the base (Fig. 1) at an angle of approximately 10.

The part I9 (Fig. 8) is provided at its forward face with an elongate guide slot 29 designed to receive a slide member 22 (Fig. 12) whose lower end is shaped to take part in cutting and forming the staple. The forward surface of the slide 22 is substantially flush with the forward surface of the guide member I9 and is held in place in. the slot by means of removable cover-plates 2| and 2|- (Figs. 4 and 10) which are secured to the member |9 by screws or bolts. At its left-hand side the slide 22 is provided with a projecting ear 23 (Fig. 3) which extends through an elongate slot 23 in the member I9 and which is connected by a pivot pin 24 to the lower end of an eccentric rod 25, a spacer sleeve 24 (Fig. 4) preferably being interposed between the ear 23 and the lower end of the rod 25. The eccentric rod is connected to the eccentric strap 26 which embraces an cecentric 21 on the forward end of the shaft I8. Thus as the shaft I3 rotates the slide 22 is moved up and down in the slot 20.

and slide 28 (Figs. 3 and 4) which is held within the slot by the cover plate 2| and which has, at its upper end, an upwardly extending rod or post 29 (Figs. 1 and 2) which slides freely in a guide opening in a boss 30 integral with the frame member I9. A coil spring 3| bears at its upper end against the under surface of the boss 39 and at its lower end against a collar 32 fixed to the rod 29, the spring embracing the rod and tending constantly to force the rod and the slide 28 downwardly. Near its upper end the rod 29 carries a resilient Washer 32 which bears against an adjustable adjustment nut 33 having threaded engagement wtih the upper end of the rod. This resilient washer 32 cushions the shock of downward movement of the slide 28 when the latter is projected downwardly by the sprin 3|. The slide 28 is provided with a roller 34 (Figs. 1 and 2) which engages the edge of a cam 35 mounted on the shaft I8 just to the rear of the eccentric 21. This cam having a substantially radial edge 36 (Fig. 3) at the end of its riser portion 36 so that when the roll 34 reaches the end of the riser .36 it is free to drop radially along the surface .50 In the upper part of the slot 20 there is a sec- 36 and thus permit a very sudden downward movement of the slide 28 by spring 3 I.

The slide 22 is provided with a slot 31 (Fig. 6), cruciform in transverse section, having the oppositely directed transverse arms 38 each of a size to receive one leg of the staple which is formed and to confine such leg with a close sliding fit. Within this slot 31 there is arranged a driver slide 39 (Fig. 7) which has lateral fins 40 which slide in the transverse arms 38. The lower end of this driver slide 39 constitutes the stapleadvancing and driving element. At its upper end (Fig. 3) this slide 39 is provided with an elongate head 39 having a slot 4| which receives screws 42 whereby the head 39 is adjustably secured to the slide 28.

The lower end (Fig. 4) of the guide slot 29 in the part I9 is defined by a substantially horizontal shelf 29 which constitutes the top surface of a downward extension I9 of the frame member I9. Removable guide members 42 and 43 (Fig. 3) are secured to opposite sides respectively of the extension I9 by means of screws or bolts, the

parts

42 and 43 having

vertical guide slot

44 and 44 in their opposed surfaces respectively which form in effect continuations of the arm 38 of slot 31 in the slide 22. The

parts

42 and 43 terminate in smoothly rounded ends 45 and 46 respectively, designed to engage the marginal material of the upper as thelatter is forced inwardly over the edge of the insole by the wiper. As illustrated in Fig. 3, the

parts

42 and 43 are of different lengths so that the ends 45 and 46 may both contact the margin of the upper with substantially the same pressure, even though the member I9 is inclinedasshowninFig. 1.

The member [9 is furnished with a rearwardly extending boss 41 (Fig. 4) having a horizontal bore 48 which receives a slidable anvil carrier 49. This anvil carrier is furnished with an elongate slot 59 which receives a pin 5| extending transversely through the boss 41, the pin thus preventing the anvil carrier from rotating about its own axis. The anvil carrier is hollow and houses a coiled spring 52 one end of which bears against the pin 5|. The spring tends constantly to move the anvil forwardly, that is to say into operative position, its forward movement being limited by engagement with the plate 2| The forward part of the anvil carrier is shaped to provide a narrow lower portion 53 (Fig. 3) and the anvil proper 54, the latter being of a transverse section similar to the shape of the staple to be formed. At opposite sides of the part 53 the anvil carrier is provided with forwardly and downwardly sloping surfaces 55 designed to be engaged by cam surfaces 56 at the rear portion of the slide 22 so that when the slide moves downwardly to its lowermost position these cam surfaces, by engagement by the inclined surfaces 55, force the anvil carrier 49 rearwardly so as to remove the anvil from the formed staple.

At its left-hand side the part I9 is provided with a boss 51 (Fig. 5) which supports the tubular wire guide 58. This wire guide extends inwardly to the recess 20 and terminates in a beveled end 59 (Fig. 8). The slide 22 is provided at its lefthand side with a beveled surface 69 (Fig. 9) which slides in close contact with the surface 59 of the wire guide as the slide 22 moves downwardly, the lower edge of the beveled surface 69 cooperating with the surface 59- to out OK the wire at an angle so as to provide the staple with a sharp point,

A rigid tubular conduit BI is secured to the outer face of the boss 51 and leads to a stationary feed block 62 mounted on the plate l This feed block is provided with guideways for a sliding feed member 63 (Fig. 1) which carries a pair of depending or pendulous wire-feeding pawls 64 urged downwardly into engagement with the wire by springs 65. The block 62 has a stationary bracket 68 which supports a third pivoted and spring-pressed pawl 6'! designed to prevent rearward movement of the wire as the feed slide 63 is retracted. The feed slide is provided with a rearwardly directed arm 68 carrying a roll 69 which engages a cam 'Hl on the shaft l8. Preferably a wire-tensioning guide roll H is provided. This roll is mounted on a pivoted arm 12 which is urged in the proper direction by a spring (not shown) thereby to tension the wireand take up slack as the wire passes from the reel to the feed block 52. As the feed slide 53 is reciprocated by the cam '19 the wire W is advanced by the pawls t4 and fed forward through the tubular conduit 6! and the tubular guide 58 until its advancing end contacts the inner surface 2E1 (Fig. 8) of the recess 29. The length of wire thus provided and which extends across the recess 20 is sufiicient to form a staple.

Assuming that such a length of wire has been advanced by the feed means as shown in Figs. 8 and 9 and that the anvil 55 is in its advanced position and that the slides 22 and 28 are in their upper positions, the cycle of movements is as follows, first the slide 22 is moved down by the eccentric 21', and as it moves downwardly its beveled lower edge cooperates with the beveled surface 59 of the wire guide 58 to sever the length of wire which is left resting, by its mid-portion, upon the anvil 54. However substantially as the wire is cut, the lower end of the slide 22 engages the wire and as the slide continues to descend it forces the right and left-hand end portions of the wire downwardly about the anvil 54 so as to form a staple having the central transverse portion W (Fig. 12) and the parallel legs W these legs being disposed at opposite sides of the anvil and being housed in the transverse portions 38 of the recess 3'! of the slide 22. staple has thus been formed, the anvil is retracted by engagement of the cam surface 55 of slide 22 with the surface 55 of the anvil carrier. The cam 35 now suddenly releases the roll 34 and the driver is projected downwardly by the compressed spring 3!. The lower end of the driver engages and imparts a sharp blow to the transverse portion W of the staple, forcing the latter down along the guide grooves 44 and M and through the marginal material of the upper and intothe insole. The cam 35 immediately begins to retract the driver and at the same time to compress the spring 3|, the slide 22 rises and releases the anvil. and the spring 52 advances the anvil in readiness for the formation of another staple.

During the above operation of forming and driving the staple, the upper material U (Fig. 14) of the shoe is engaged between the rolls H3 and H4 and is being subjected to an upward stress so as to draw the upper snugly about the last L. At the same time the operator is pressing the shoe rearwardly against the roll H, and the stationary wiper H3 is forcing the stressed material of the upper inwardly over the edge ofthe insole S. As the upper material is thus laid down against the under surface of the insole it is engaged by the

ends

45 and 35 of the

members

42 and 43 which hold it in place while the staples are being driven. The operation of lasting thus progresses As soon as the about the periphery of the shoe bottom, the upper being stressed, wiped in and stapled without interruption except as the operation may be interrupted by the operator. If desired the shoe may thus be lasted beginning at any given point and continuing progressively about the entire periphery of the shoe. Alternatively, the lasting operation may be performed at one side of the shoe and then at the other and substantially at the toe, or the lasting may be performed at the toe first and then at other points, as desired.

While one desirable embodiment of the invention has herein been illustrated by way of example it is to be understood that the invention is not necessarily limited to the specific construction here suggested but is to be regarded as broadly inclusive of all equivalent constructions falling within the terms of the appended claims.

I claim:

1. A lasting machine of the kind wherein a rotary work-advancing roll and a cooperating part, having a work-engaging surface substantially parallel to the axis of the roll, grip the upper between them and advance the work uninterruptedly while updrawing stress is being applied to the upper, and having a gauge for contact with the outer surface of the upper thereby properly to locate the shoe relatively to the work-advancing means, characterized in that the gauge is a disk-like roll disposed to turn freely about a substantially vertical axis and. having a substantially flat upper surface and a work-engaging edge, and a stationary rigid Wiper blade, Vertically thin and horizontally disposed, having a free end portion provided with a smoothly rounded work-engaging edge, said wiper blade being interposed between the planes of the lower end of the work-advancing roll and the upper surface of the gauge roll, the free end portion of the wiper blade being so located relatively to the axis of the work-advancing roll that it overlaps the bottom of a shoe whose upper is Ope atively engaged by the work-advancing roll and contacts the upper closely adjacent to the delivery side of said roll.

2. A lasting machine of the kind wherein a rotary upper advancing roll and a cooperating part, having a work-engaging surface substantially parallel to the axis of said roll, grip the upper between them and advance the work uninterruptedly while updrawing stress is being applied to the upper, and having a stationary rigid vertically thin wiper for wiping the margin of the upper downwardly onto the insole, said wiper being horizontally disposed and having a free end portion provided with a smoothly round ed work-engaging edge, said stationary wiper having its operative portion in a plane directly below the plane of the lower end of the workadvancing roll, the free end portion of the Wiper being so located, relatively to the axis of the work-advancing roll, that it overlaps the bottom of a shoe whose upper is operatively engaged by the Work-advancing roll and contacts the upper closely adjacent to the delivery side of said roll.

3. In a lasting machine of the class described having means for imparting an updraw to a shoe upper assembled with a sole member on a last, a stationary rigid guide having an elongate slot which makes an angle of approximately 10 with the vertical, a slide movable in said slot toward and from the sole member, an anvil normally projecting into said slot in the path of the slide, means for delivering a length of Wire so as to lay it transversely across the anvil, a cutter element carried by the slide, means for actuating the slide to cause the cutter element to sever the wire, means carried by the slide for forming the severed length of wire into a staple about the anvil, means carried by the slide for Withdrawing the anvil from the formed staple, stationary guid members fixed to said rigid guide and acting to direct the formed staple into contact with the bottom of the shoe and a driver movable relae tively to the slide within said rigid guide and stationary guide members for advancing the formed staple from said rigid guide through said stationary means and into the shoe.

4. In a lasting machine of the class described having means for imparting an updraw to a shoe upper assembled With a sole member on a last, a stationary rigid guide having an elongate slot which makes an angle of approximately 10 with the vertical, the lower portion of the slot constituting a staple-forming chamber, an anvil disposed in said chamber, means for disposing a length of wire across the anvil, a slide movable in the slot and having at its lower end surfaces cocperable with the anvil to bend the length of wire and form a staple having substantially parallel legs and to retract the anvil from the formed staple, stationary rigid guide means mounted upon said stationary rigid guide extending from said staple-forming chamber to the surface of the shoe bottom and providing parallel channels each for the reception of one leg of the staple, a driver having elements which also fit in the respective guide channels, cam means for raising the driver, and spring means for imparting a downward driving movement to the driver to advance the staple from said stationary rigid guide through said rigid guide means.

5. In a lastin machine of the class described having means for imparting an updraw to a, shoe upper assembled with a sole member on a last, a rigid guide having an elongate slot, a slide movable along the slot toward and from the operative position of the sole member, means for reciprocating the slide, an anvil normally disposed across the slot in the path of the slide, a tubular wire guide projecting laterally into the slot and having a vertical beveled end surface, the slide having a beveled surface cooperable with said end surface of the tubular guide to sever a, length of wire protruding from the wire guide into the slot, means for advancing a length of wire through the wire guide and into the slot, the slide having staple-forming means ccoperable with the anvil to form the severed length of wire into a staple, means carried by the slide for retracting the anvil from the formed staple, stationary guide members mounted upon said rigid guide, the ends of which guide members rest against the updrawn upper; a driver for driving the formed. staple through said guide members into the work, and means including a spring for imparting a driving blow to the driver.

6. In a lasting machine of the class described having means for imparting an updraw to a shoe upper assembled with a sole member on a last, a stationary rigid guide the ends of which rest against the updrawn upper, said guide having an elongate slot, a slide movable in said slot, the slide having therein an elonagte cruciform slot each of whose transverse arms is of a size to receive and closely to confine one leg of a staple to be driven, means for projecting a length of wire transversely across the guide slot, cutting means including a cutter element carried by the slide for severing the length of wire, an anvil normally disposed in the path of the slide and across which the severed length of wire extends, means carried by the slide for bending the length of wire about the anvil to form a staple and for disposing the legs of the staple in the transverse arms of the cruciform slot, means for withdrawing the anvil from the formed staple, stationary guide members mounted upon said rigid guide and a driver fitting and sliding on the cruciform slot, and means for imparting a sudden downward movement to the driver thereby to drive the staple through said stationary guide members into the work.

7. In a lasting machine of the class described having means for imparting an updraw to a shoe upper assembled with a sole member on a last, stationary rigid guide members, staple forming and driving means carried by said guid members and including an anvil reciprocable transversely of said guide members, spring means tending-to hold the anvil in operative position, means for disposing a length of wire across the anvil, a slide reciprocable in said guide members, said slide being cooperable with the anvil to form the length of wire into a stap e and to retract said anvil after the staple has been formed, stationary means providing parallel guide channels for the respective legs of the staple, said guide channels closely confining each respective leg of the staple and extending to the surface of the shoe bottom, and a driver reciprocable in said guid members for advancing the formed staple along said guide channels.

8. In a lasting machine of the class described having means for imparting an updraw to a shoe upper assembled with a sole member on a last,

stationary rigid guide members, staple forming and driving means carried by said guide members and including an anvil reciprocable transversely of said guide members, a fixed tubular Wire guide, and wire-advancing means so constructed and arranged as to project a length of wire from the tubular guide across the anvil, the end of the wire guide being beveled to form a cutting edge, a reciprocating cutter cooperable with the beveled end of the tubular wide guide to sever the protruding length of wire, a slide reciprocable in said guide members, said slide being cooperable with the anvil to form the length of wire into a staple and to retract said anvil after the staple has been formed, stationary means extending to the surface of the shoe bottom and providing guide channels for the respective legs of the staple, and a driver slidable in said guide members for advancing the staple along said guide channels toward the work.

9. In a lasting machine of the class described having means for imparting an updraw to a shoe upper assembled with a sole member on a last, stationary rigid guide members, staple forming and driving means carried by said guide means and including an anvil, a fixed tubular wire guide, and wire-advancing means so constructed and arranged as to project a length of wire from the tubular guide across the anvil, the end of the wire guide being beveled to form a cutting edge, means reciprocable within said guid members, which means cooperate with the beveled end of the tubular wire guide to sever the protruding length of wire, and with the anvil to form the length of wire into a staple and to retract said anvil after the staple has been formed, said stationary rigid guide members having smoothly rounded lower ends for engagement with the wiped-in marginal material of the shoe upper, said guide members having parallel channels in their opposed faces, each channel being of such dimensions as to receive and closely to confine one leg respectively of the formed staple, and a driver slidable in said guide members for advancing the staple along said guide channels into the work.

10. In a lasting machine of the class described having means for imparting an updraw to a shoe upper assembled with a sole member on a last, stationary rigid guide members, staple forming and driving means carried by said guide members and including an anvil reciprocable transversely of said guide members, spring means tending to hold the anvil in operative position in said members, means for disposing a length of wire in said members across the anvil, a slide reciprocable in said guide members, said slide being co-operable with the anvil to form the length of wire into 2, staple and to retract said anvil after the staple has been formed, stationary means mounted at the end of said guide members, said means providing parallel guide channels for the respective legs of the staple, said guide channels closely confining each respective leg of the staple and extending to the surface of the shoe bottom, a driver reciprocable in said guide members for advancing the formed staple along the guide channels of said stationary means into the sole of the shoe, means for retracting said driver and means for suddenly advancing the driver into contact with the formed staple.

11. In a lasting machine of the class described having means for imparting an updraw to a shoe upper assembled with a sole member on a last, stationary rigid guide members, staple forming and driving means carried by said guide members and including an anvil reciprocable transversely of said guide members, spring means tending to hold the anvil in operative position in said members, means for disposing a length of wire in said members across the anvil, a slide recipro- 10 cable in said guide members, said slide being cooperable with the anvil to form the length of wire into a staple and to retract said anvil after the staple has been formed, stationary means mounted at the end of said guide members, said means providing parallel guide channels for the respective legs of the staple, said guide channels closely confining each respective leg of the staple and extending to the surface of the shoe bottom, a driver reciprocable in said guide members for advancing the formed staple. along the guide channels of said stationary means into the sole of the shoe, means for retracting said driver and means for suddenly advancing the driver into contact with the formed staple, said last named means including a spring which is compressed by said driver retracting means and suddenly released thereby.

JACOB S. KAMBORIAN.

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

UNITED STATES PATENTS Number Name Date 817,660 Nolle Apr, 10, 1906 1,163,597 Russell Dec. 7, 1915 2,230,375 Clark Feb. 4, 1941 2,251,284 Kamborian Aug, 5, 1941 2,251,285 Kamborian Aug. 5, 1941 2,286,362 I-Iammann June 16, 1942 1,625,958 Reed Apr. 26, 1927 1,657,133 Newhouse Jan. 24, 1928 1,718,199 Baumann June 18, 1929 1,744,715 Allen Jan, 28, 1930 2,297,223 Kleinschmit Sept. 29, 1942 FOREIGN PATENTS Number Country Date 371,949 Germany Mar. 23, 1923