US2147039A - Measured stretch, tension distributing machine - Google Patents

Description

Feb. 14, 1939. c. H JOHANSON MEASURED STRETCH; TENSION DISTRIBUTING MACHINE Filed Dec. 14, 1936 ,3 ShGGtS-Sht l Feb. 14, 1939.

MEASURED STRETCH. TENSION DISTRIBUTING MACHINE c. H. JOHANSON 2,147,039

Filed Dec. 14, 1936 3 Sheets-Sheet 2 m. wsw Tan ,Ja'imnson Feb. 14, 1939. C H, JQHANSQN 2,147,039

MEASURED STRETCH, TENSION DISTRIBUTING MACHINE max 70R, Jziawzsa 7 Patented Feb. 14, 1939 PATENT OFFICE MEASURED STRETCH, TENSION DISTRl BUT- f ING MACHINE Carl Hugo J chanson, Los Angeles, Calif., assignor to Olivia S. Johanson, Los Angeles, Calif.

Application December 14, 1936, Serial No. 115,706

'12 Claims.

This invention is an apparatus and a method for preparing stretchable and contractive sheet material, of low elastic factor, for the cutting therefrom of given pattern pieces by the use of pat-' tems or dies. The invention is related to the class of invention generally shown in- U. S. patent application Ser. No. 96,415 to which reference is made for disclosure of the old practice of hand stretching of glove skins for the cutting of glove blanks.

In picking up a skin from a supply stack an ope'rative (in a glove factory) will scan the skin for shape, size, holes and other defects and then determine whether it shall be first stretched from neck to rump, or first from flank to flank across the back. The stretch from neck torump will herein be called the lengthwise stretc and from flank to flank will be called the cross- Wise stretch. In either case the skin, or other appropriate material being treated, will contract transverse to the direction of the applied tension.

If the skin is properly tensioned or stretched one way all over the contracted width or direction is supposed to contain in each given unit, say three-fourths of an inch, across the direction of tension, a latent or possible stretch of onequarter of an inch, as an example, so that each three-quarters of an inch across the stretched goods or skin may be counted as an available inch of leather. By the old hand stretching method it is practically impossible to even fairly set uniform stretch all over the skin, for many reasons. One is that only a comparatively; small zone of the skin can be stretched betweenthe operatives hands in one gripping of the opposite edges of the skin, and repeated, changed grips must be taken to work completely across the skin, with no reliability of uniformity in the stretched skin.

Also, in every skin (glove stock) it is known that a zone from the neck to the rump is the thickest, and that it gradually thins toward'the flanks; that is, the stomach area of the skin. An object of this invention is to provide a method and apparatus whereby this difference in the thickness is taken into consideration and whereby the skin is so stretched that it will have a uniform, substantially measured, latent stretch evenly distributed throughout. That is, a given unit of measure across the stretch will contain, in any portion of the skin, an'am'ount of possible or latent stretch equal to that of any other portion.

From this it will be seen that if the operative works the skin properly in accord with the method and sets the skin so that a given unit of measure will have an inherent, uniform stretch value all over the skin, then, by the use of a cutting pattern or of a cutting die which is constructed on a corresponding unit scale, the whole skin may be cut into pieces all of which will be of the same latent stretch and a true size glove will be had in the ultimate product. Reference is made to the provision, in this invention, of pattern guides, dies or forms whose width or size number is predicated on a measuring unit which corresponds to the unit of measured stretch; say an inch of leather for each threequarter inch across the stretch direction of the 10 prepared skin.

It is understood that different tensions will be employed in setting different skins according to the variance in the quality or stiffness of the skin.

It is an object to provide means for subjecting the entire central back zone from the neck to the rumip to a firm, uniform transverse tension to initially reduce its thickness and then to work the tensioning means outwardly toward the flanks While the whole intervening skin between gripping devices is subjected to a uniform tension in a plane from end to end of the skin; provision being made to slip the skin between the tensioning means during its operation.

Further, an object is to provide means whereby to subject the thicker, central neck-to-rump, narrow, back strip of the skin to a higher degree of tension, when stretching the skin lengthwise,

than is applied to the'portions of the skin from said strip or back zone to the edges of the side flanks, and still to provide means which will act in one operation entirely across the skin from flank edge to flank edge preferably in a plane.

Also, an object is to provide means operative during the stretching process of a skin to tend to work out wrinkles by a spread-effect on the goods passing into the active tensioning means.

Another object is to provide, in one machine, means to accomplish both lengthwise and crosswise stretch, in successive operations, although separate machines are here provided for the accomplishment, respectively, of only one of the stretching functions,

The invention consists in certain advancements in this art as set forth in the ensuing disclosure and having, with the above, additional objects and advantages as hereinafter devolped, and whose construction, combination and details of means, and manner of their operation, and the steps of the skin working method, will be made manifest in the description of the herewith illustrative embodiment; it being understood that modifications, variations and adaptations may be resorted to within the scope, principle and spriit of the invention as it is more directly claimed hereinbelow.

Fig. 1 is a plan of a skin before stretching. Fig. 2 is a plan of a preferred form of machine for lengthwise stretch of a skin, and Fig. 3 is in part a central longitudinal, vertical section thereof. Fig. 4 is a cross-sectional detail of a skin gripper and its co-acting, bladed bench medially of its length. Fig. 5 is a plan of a preferred form of machine for cross-stretch of a skin; that is, transverse to its thick, longitudinal, central back zone.

Fig. 6 is a vertical, medial, longitudinal section of the sliding leaves and their skin gripping devices (the drive mechanism being omitted). -"Fig. 7 is a vertical, medial sectional detail of -a tensioning leaf provided with both a transverse or cross-stretching means and a lengthwise stretching means, and Fig. 8 a p'l'an of p'a'r-ts of-the lengthwise-stretching gripper. Fig. 9 Ba plan, and Fig. 10 a face view of a part of a' gripper showing the-facing thereof to effect a spreading tendency of the goods beingwork'ed on. "Fig: 11 is a plan-of afragm'ent of charted skin and applied die; Fig. 12'is a-plan of-a gripper strip with one form of spring means to exert different degrees of pressure from the; central back toward thesofter flanks-of a: skin, and Fig. liv'showsa modified form thereof. Fig. 14 is a cross-section through oneend of the device of -Fig. 12. "Figs. 15 and 16 are front and side views; respectively, of another form= ofv the lengthwise stretching mechanism.

a In Fig-.- 1 is s'hownaskinindicated asa whole S; the thickest central back zone is indicatedat T'extending from neck to rump and one step of the "instant method is to uniformly stretch this zone transversely to asuitable-degree as indicated by the line T. This isdone by means firmly gripping the skin alongpa'rallellines' from neck 35" to rump" and moving the gripping m'eans apart substantiallywi thout slip ofthe gripped skin.

To accomplish this preliminary crosswise stretch there is shown inFigs. 5 and 6, the table 2 of a machine including an opposed pair of substantial slides 3 and 4, of U shape plarr and which are movable inwardly toward each other between their guide and supporting rails 5- 5.

Fixed, upstanding, rigid skin-flexing blades 6" and I present straight, top edges'transversely above and along the'inner' portions of the-slides 3-4 and are movable with and bythe slides into the desired spaced distance to be"overla-id by the back'zone'Tof an applied skin' to be stretched; the adjusted space-of the-blades-6-"-'1being de teri 'nined'by the varyingwidths-of the s'aid 'zone indifferent skins. 'Along" theouter-sideface of each blade isfiked apressurestri or benchB' over which the flanks F- -F are draped in arranging the skin to be stretched; the length' of the benches and their blades-being such as to accommodate the average large skin in a supply batch of 'glove'material, "for'instance.

Each slide 3--4 is provided with means to be moved into pressure applying" relation with the relative straight-edged blade" B-'I and its back strip or bench 8 for the purpose of gripping the interposed skin and placing it under tension by a'relative separating or outward motion of the slides on the table 2, whichmay be accomplished by manual effort or by power means as later described with respect to Fig. 3. "The gripping means of Figs. 5, 6 and 7 include a straight, transverse presser bar l0 having hinge pivots I l permitting the upward swing of the bar from its blade bench for'the insertion of the skin to be worked; and preferably the effective face of the gripping bar llL'or of the'b'ench 8, or both, is provided with a suitable friction strip 12, Figs. 9 and 10, as of rubber or other suitable material.

After the skin S'has been arranged over the inwardly shifted slides 34 and between the opened gripper and presser bars In these are moved into closed position on the interposed portions' of the skin and caused to grip the skin with a suitable degree of pressure by means provided forsuch function. The pressure applying means ofFigs. 5-6 is a clamp lever l3 pivoted at M onthe relative slide of each bar l0 and having a turnable screw l5 adapted to be run into a fixed nut l6 in the slide-top; the lever l3 being engageable with a rigid part ll of the related presser bar I when the latter is in applied position and'the clamp lever is tipped over or astraddle the lug I! to bring the screw I5 into engagement with the fixed nut I6.

The presser'bars are-at first set so tight on the skin that it cannot slip'while the slides 34 vare forced outward or apart to initially stretch the back zone 'T to reduce its thickness to the desired'degree; the gripping means being effective from neck to rump and tensioning the skin transversely while gripped from end to endin a smooth plane. 1 After this initial, non-slipping, pulling grip on the skin is completed. then the pressure is released at the pressure control device'or lever I3 of each slide to! permit the-engaged portions of the skin to slide between the gripping bars and their benches and over the relative straight blades 6 and I so that the whole portion ofv the skin from end to end and from blade to blade is evenly tensioned and lengthened transversely, meanwhile contracting transverse to the line of stretch. The degree of contraction is carefully controlled and measured by the operative so that each unit of measure transverse to the direction of stretch may be given or caused to contain a desired amount of stretch or leather in a blank which is cut from the skin on a size unit of measure-based on the adopted unit'of measure of the contracted skin. 7

While it may suflice in some class of glove work tostretch the skin S in one direction only, according to the condition, size and quality of a given skin, it is preferably given a second stretch which is in a direction transverse to the first stretch.

In Figs. 2, 3, '7 and 8 are illustrated means adapted for the stretching of a skin lengthwise, that is, from neck N to rump R, Fig. 1. Since the longitudinal zone T is the thickest or toughest it is desirable that it be given a higher degree of lengthwise tension than is imposed on the side or flank portions F, and also that the degree of longitudinal tension be graduated downwardly from the center of the skin outwardly to the flank edges, because the skin gradually thins that way.

To that purpose the tensioning slides 3 and 4 Figs. '2 and 3, have their stretching blades 6* and I arranged in a regular arc inwardly toward the center line of the table 2, with the top, effective edges in a commonplane for an overdraped skin S to be stretched from neck to rump; each blade having an outer pressure bench 8 against which the interposed skin is pressed. In this case the presser means includes a stiff segmentZll w'hose inner or effective edge 2! is curved to match the curvature of the relative blade and bench device li -8 and is preferably provided with a friction strip I2, above mentioned. The presser segment is movably mounted, as by slide pins 22 working in a bridge 23 which, in turn, is slidably mounted on its relative main slide, as 4*, or 3*, so that the bridge 23 may be quickly moved in or out with its slidable gripping end pressure element or segment 20, to grip or release the inserted skin. Clamp jaws at the ends of the bridge 23 (on each slide) may be closed on contiguous slideways 26 to hold the bridge in its inwardly adjusted position.

In order to vary and control the amount of gripping pressure of the segments 20 on the engaged skin S, in the machine, spring means 21 are interposed between the segment and its bridge and a control screw 28 is adjustable in the bridge (ineither slide) to regulate the degree of pressure of the spring 21 against the presser segment when this is in pressure position on skin on the relative, curved blade 6 or 1 It will be seen that the stretching tension is greatest along the shortest line between the opposed curved gripping means on the slides 3*--4 and that this tension decreases on parallel lines running from neck to rump of the skin as the lines increase in length between the reversely curved, opposed gripping segments 29, shown in dotted lines in l A fifty pound pull on the shortest or central *line from one segment to the other will have less stretching effect on the parallel lines of greater length on either side thereof; the efiect decreasing as the distance increases toward the edges of the flanks of the engaged skin.

Various suitable means'may be employed to con currently shift the slides of the machines here shown outwardly or inwardly. Fig.8 shows the slides 3 4*- as having fixed nuts 30 engaging reverse pitch screws 31" of acommon shaft on which is fixed a drive element 32,-connected by a belt or chain 33 to a counter-shaft 34 which is driven by a suitably connected motor 35; preferably of reversible electric type, under suitable control by the operative as to speed and direction of drive of the screw-shaft 3|. The drive mechanism is suitably mounted in the frame of .the table 2 of the machine.

Fig. 4shows in about full size the details of assembly of a renewable, friction strip l2 of a presser element, as segment 20.

The friction strip I2, whether mounted on the 7 blade, or on the bench, or on the efiective edge of the moveable presser device, It! or 20, has its face provided, preferably,with diagonal, shallow corrugations, H Figs. 9 and 10, which are so pitched that they have a re-actingtendency to press the engaged skin outwardly from the center line of tension on a skin, as indicated at L, Fig. 10 and from which line the diagonal corrugations are reverse.

In Figs. 7 and 8 there is illustrated a machine .slide 3 provided with both straight-edge tensiening device as Iii-45, of Fig. 5, and a curvededge tension device as 6 2ll the part 20 being a segment whose ends are hinged at 20 on the relative slide 3 this segment having'a suitable clamp 20 whereby it may be set with desired pressure against the cooperative skin supporting blade and bench device on the slide. In Fig. '7 the clamp nut of member I!) is shown in detached position. If a skin is applied to and stretched by the use of the outer devices Zil -ii it overlays the closed inner devices l06 without interference.

A modified form of presser segment is shown in Fig. l2 as including a strip 40 which is supported by a set of thrust springs 4! each of which decreases in strength according to its position outward from the center of the segment, whereby to secure a gradually reduced pressure on an engaged skin S from the back zone T to the The same decrement in pressure of the strip 40 may be obtained as shown in Fig. 13 by use of springs 42 each of the same strength but are spaced closer together, along the arched strip, inwardly from the outer, flank stretching ends of the strip. The strips 40 are attached by sliding bolts 43 to their slide mounts 44.

A further variation of the form of the stretching machine is depicted in Figs. 15 and 16 where segmental wings are pivoted on a hinge 5| in a suitable frame 52. The outer or swinging ends of the wings are connected by a pair of toggle links 53 attached to a truss bar 54 connected to an actuating lever 55, operable by desired means to raise or lower the bar 54 to spread or contract the wings so as to tension a skin S draped over the top edges of the wings and gripped by presser means, as of the kind above described. This machine, by reason of the convex curve of its top edges and relative gripping means functions to apply greater tension along the line of the thick back T of a skin S, Fig. 1, than along the flanks from neck to rump of the skin since the crown or top of the arched edges of the wings move a greater distance, in the same action by the toggle, than the ends of the arcs of the wing edges, about the hinge axis 5|.

It will be seen that by reason of the pre-stretching of the thick back zone T transverse to its length between the straight line gripping and presser means extending from neck-to rump of the skin, and by reason of the subjection of the skin to lengthwise stretch between the peculiar curved-line gripping and presser means with a tension which diminishes on lines from neck to rump in zones on each side of the back zone T, that the operative can produce rapidly and accurately stretched skins that have uniformly all over a desired measured stretch of goods, that is a known amount of latent leather to work out in true size gloves when the blanks are cut from the skin by the use of dies which are calculated in units of size which correspond to the adopted unit of measure across the contracted direction of the prepared skin.

In Fig. 11 a fragment of the skin S is shown charted into oblong areas C whose narrow dimension indicates the stretchable unit of measure along which a die, pattern or form member D is laid for the cutting or marking out of a relative glove blank, it being understood that the member D is based on a width, size scale corresponding to the unit width or narrow dimension of the oblongs of the areas C. That is the size number of a given glove, in inches across the glove,'is utilized in counting the number of the contracted areas C, plus one more for silking and stitching, and since the skin has been uniformly contracted so that. each oblong will measure, say of an inch and will be stretchable up to an inch, a die which is made on the measure of the contracted unit will provide for the ultimate stretch of the cut blank to make a true size or properly fitting glove.

The U-shaped plan of the table slides carrying the stretching means enable the operative to stand in close to the several operative parts of the machine for the facile tucking of the skin in place over blade edges and under the adjustable gripping or presser devices.

What is claimed is:

l. Stretching sheet-like material by gripping it along continuous, opposed, arcuate lines thereof and shifting the lines of gripping pressure apart to first stretch the skin all over in one direction '75 onlyrfrom; side: to side between::.ungripped ends;

said lines having such relationthatas the gripped lines of'thesheet are shifted apart a greater'tension is created in'an-intermediate'zone across the sheet than is set up in zoneslateralto the intermediate zone, and then subjecting the stretched skin to the same mode of treatment on lines transverse to the first stretch to contractthe first lines of stretch.

2. Stretching :sheet-like material by applying gripping pressure along continuous lines parallel to a given zone of the material and cross-tensioning the material by relative separation of the lines ofpressure or grip without slip, then reducing the gripping pressure and continuing the separation to cross stretch accompanied by a slipping of the material under the gripping pressure, and then subjecting the said stretched material to tension in a direction across the first stretch and in such amanner that the stress is highest along a central line, in the direction of the stretch, and which stress gradually diminishes in' portions" lateral and parallel to the said central line.

3. A machine for stretching glove skins or other 25t-material, including a support having a pair of opposed slides operative thereon in a common plane and each slide having an incurved, outer bench edge transverse to their line of motion, the said r edges being concaved toward each other and over -which a skin may be draped from one slide to the other, means for relatively separating the slides while so draped, and presser devices having skin engaging edges convexly 'curved toward each W other and complementary to the opposing bencfi edges of said slides'whereby to grip the skin in curved lines along the outer edges of the slides and to subject the skin to different degrees of tension from slide to slide as these are moved apart, said slides carrying respective, transverse -blades presenting top edges over which the draped skin is flexed and drawn as it is permitted to slide relative to its gripping devices.

4. A machine for stretching glove skins or other material including a support having a pair of op- 1-posed slides operative in a common plane and having bench edges transverse to their line of motion and over which the skin may be draped from slide to slide, means for relatively separating the slides while so draped, presser devices having -skin engaging edges complementaryto the opposing bench edges of said slides whereby to grip the skin in lines along the outer edges of the slides and to subject theskin to tension as the slides are moved apart relatively, and said slides -carrying respective, transverse blades presenting top edges over which the draped skin is flexed and drawn as it is permitted .to slide as to its relative gripping device. V m 5. A machine as in claim 14,. and in which the presser devices are slidably. guided on and outwardly movablelby and .with respective slides during stretching operation. a

6. In a machine of the class described, a pair of slides movablein acommon' plane, means for motivating theslides, and said slides having, each, a mechanism forgripping 'an interposed skin alongelongate, circuitous lines :from edge to edge of the skin andof such contour that, as the 7 ,-;mechanisms are moved apart relatively by theslides, the taut zone of the skin is subjected to lines of tension varying at different areas between the gripping lines; said slides. having outer edges over which the skin is drapable and ;;said mechanismsbeing slidably mounted to close onsaid draped skin. and movable ioutwardly by r and with the relative slides.

7. A skin or sheet stretching machine including a support, a pair of slides movable in opposition thereon, means for motivating the slides, bench parts on the slides each with a respective straight-edge presser member to slidably grip a skin draped from slide to slide over the bench parts, and each slide having parallel to the bench part a blade presenting a supporting edge over whichtheskin flexed during stretching operation; said members having smoothgripping faces, said support having an intermediate pocket into which thematerial, draped between the presser members and their bench parts, hangs while draped for stretching operation,

8. A machine asin claim '7, and in which said presser member is provided with a yieldable facing medium and said bench parts present a complementary, smooth, firmv face to said presser members for sliding efiiciency.

9. In a sheet stretching machine, a pair of cooperative gripping elements separable for insertion of the sheet and closeable to slidably grip it on a continuous line, and a cushioning medium interposed between said parts as a facing to engage the sheet; and which medium includes a facing strip along one of said elements and a bank of springs interposed therebetween and operative to exert difierential pressure on the strip in degree decreasing outwardly from the center thereof.

10. A machine for stretching glove skin or other desired material, including oppositely spaced members presenting faces to support and over which the skin is draped, a relative skin bending blade in inwardly, fixed association with each of said members, presser means for engaging the skin continuously along the said faces, and for tensioning it from blade to blade, means for regu lating the degree of pressure of said presser means and providing for skin slip during stretching, and means for relatively separating said members while the skin is gripped thereto by the presser means.

11. Glove skin stretching mechanism including oppositely spaced, movable slides having benchforming members and skin bending blades fixed in given relation to each member and presenting spaced top edges to support the skin extending from one member to the other and said members having outer supporting faces for the applied skin extending to and along said edges for the length or width of the skin to its opposite edges, and means to press the applied skin extending from one to the other of said members to the outer faces thereof so that when the members and said means are shifted apart without slipping of the skin therebetween the length of the skin held between the said members is uniformly tensioned from member to member; the presser means being adjustable to allow the interposed skin to slip therebetween after an initial tension operation without slip so that the whole of the skin gripped along continuous linesfrom one edge to the other, of the skin, will be tensioned equally between the gripping means cooperating with said members.

12. Stretching sheet-like material by applying gripping pressure along continuous opposite lines

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