US 2588859 A
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March 11, 1952 H. G. LUMBARD 2,588,859 PROCESS OF AND APPARATUS FOR SLITTING AND STRETCHING INSOLE MATERIAL Filed June 5, 1947 INVENTOR.
ible for use in insoles.
Patented Mar. 11, 1952 FICE PROCESS OF AND APPARATUS FOR SLIT- TING- AND STRETCHING IN SOLE MATERIAL Hen'ry' G. Lumbard, Auburn, Maine Application June 5, 1947, Serial No. 752,768
This invention consists in a new and improved process and apparatus of slitting and stretching fibrous sheet material in order to render it flex- The invention also includes within its scope a novel machine or apparatus whereby the process may be carried out.
One important field for my novel process is in preparing the fibrous sheet material which constitutes the forepart of the well-known Lumflex insole, that is to say, an insole in which the forepart is provided with a series of rows of short, transverse, through-and-through slits which have been opened by stretching the slitted stock sufficiently to give clearance to the opposed edges of the slits in the normal flexing, of the insole under the foot of the wearer.
As disclosed in my prior U. S. patent No. 2,181,787 dated November 28, 1939, the attempt has been made to slit and stretch the stock simultaneously by employing beveled edge blades,
but this procedure is not entirely satisfactory in that the stock is compressed between beveled blades when they are arranged in the desired closeproximity and the desired stretching effect is. not always attained. I have found that a more satisfactory and uniform product can be prepared at a higher rate of speed and under more economical manufacturin conditions by first forming rows of short slits in the fibrous strip and subsequently stretching the slitted strip transversely in longitudinally progressing areas.
Going more into detail, I have found it advantageous from the manufacturing standpoint to slit the fibrous strip by the operation of a gang of rotary cutters and then, as the strip is ad vanced by the action of the cutters and in an area adjacent thereto, temporarily bulging the slitted stock into convex curvature thus progressively stretching the stock and opening the slits.
These and other characteristics of my novel process will be best understood and appreciated from the following description of one form of mechanism by which it may be carried out, selected for purposes of illustration and shown in the accompanying drawings in which:
Fig. 1 is a plan view of one form of apparatus which may be used in carrying out the process of my invention,
Fig. 2 is a similar view showing a piece of stock in process.
Fig. 3 is a fragmentary view in longitudinal section on the line 3-3 of Fig. 1,
Fig. 4 is a fragmentary view on an enlarged scale of the cutting and platen rolls.
Fig. 5 is a detailed view showing one of the cutters in full scale, and
Fig. 6 is a view in perspective of an insole including in its structure the material produced by the process herein disclosed.
The apparatus herein shown for purposes of illustration will first be described, it being understood that the process is in no sense limited to the employment of the illustrated apparatus but may be successfully carried out by any mechanism capable of performing the slitting and stretching steps in the desired sequence. The illustrated apparatus comprises a frame suppjorting a horizontal work table In at convenient height. In the frame are provided journals for a driving shaft H having a roll I2 upon which is mounted a series of uniformly spaced disc cutters I 3. The knives are symmetrically beveled to form a sharpened circumferential cutting edge, and in the edge of each knifeis provided a series of notches 14, for example, seven notches approximately in width. The notches interrupt the cutting edge of the disc and in operation leave the material uncut. The disc knives are uniformly spaced by washers I5 and the whole assembly of knives and washers is clamped in operative position upon the roll I2, this being belt driven by a pulley l 6 on the outer end of the drive shaft H.
The drive shaft ll carries gearing I 1 through which a platen shaft [8 is positively driven at the same speed as the drive shaft. The platen shaft I8 carries a roll l9 upon which is secured a platen sleeve 20 of hard fiber or the like. The disc knives l3 and the platen sleeve 20 are so related that the platen sleeve is indented by the knives and any sheet material passed between them is provided with parallel rows of throughand-throug'h slits,
Edge gauges 2| are adjustably secure-d to the work table 10 in position to direct sheet matejrial in a path at right angles to the rolls of the machine. Beyond the rolls hold-down edge gauges 22 and 23 are also secured to thework table with provision for suitable adjustment. The gauges 22 and 23 comprise bars which are undercut or flanged at their opposite edges so that they have a hold-down function as well as a guiding function.
Midway between the gauges 22 and 23 and spaced a short distance behind the bite of the rolls, is located a convex pear-shaped stretching member 24, this being held permanently in place upon the work table by a countersunk. bolt 25 and a dowel pin 26. The stretching member 24 for example, from 2 to 6 irons. A strip 21 of such stock, first cut to the desired width, is represented as being passed between the gauges 2i to the rolls of the machine. As soon as it reaches the bite of the rolls, the disc knives l3 begin to positively advance it and at the same time form rows of short through-and-through slits2'l. While still controlled by the rolls and positively advanced by the disc knives, the stock positively advanced by the action of the notched knives l3, the stock is forced toward and through the stretching zone formed by the stretching member 24. In the stretching operation it is bulged upwardly out of its initial plane although its side edges are maintained in straight flat position by the gauges 22 and 23.
The slits 28 leave the gang of rotary knives i3 in substantially unstretched condition. Then, as the stock is forced past the stretching member and after the knives have been withdrawn from the stock, the slits are opened to their maximum width by transverse tension in the stock. Finally,
21, now provided with slits 28, is forced against the pear-shaped stretching member 24 and bulged upwardly over the same. Meanwhile both the edges of the stock are held down upon the table II] by the hold-down gauges 22 and '23. The effect of the transverse stretching of the stock is to open the slits 28 into elongated diamond-shaped apertures 29. These are opened to their maximum width in passing over the stretching member 24, and due to the resiliency of the stock, tend to close to some extent in the stock as it passes beyond the stretching. zone. However, suflicient permanent set is imparted to the stock .so that the opposite edges of the opened slits Iclear each other in transverse flexing of the stock corresponding to that to which it might be subjected in wear.
The perforated strip as it comes from theslitting and stretching operation may now be united .with unslitted strips of the same or a harder .fibermaterial, and from the composite strips thus formed insoles are cut out of the general character illustrated in Fig. 6. In these insoles the toe portion 30, together with the shank and heel portion 3|, are formed from the relatively stifi components of. the composite strip, while the forepart 32 which is of course repeatedly flexed in wear is formed from the slitted and stretchedstock .shownin Fig. 2.
' -Asherein shown andas an optional feature,
the forepart of the insole includes a thin cover -ply 33 ofunslitted stock, perhaps 1 -0r 2 irons in thickness.
It will be understood from the foregoing description that the strip stock 21 is presented to the machine in fiat condition upon the work table It and that it remains in substantially fiat condition while it is subjected to the action of the as the stock passes beyond the stretching zone, the slits contract somewhat but remain open to an extent that provides clearance between their The dashes in the left-end of the stock as shown in Fig. 2 indicate that the partially open slots extend in that condition throughout the length of the treated stock.
Having thus disclosed my invention and described in detail an illustrative manner in which it may be put into practice, I claim as new and desire to secure by Letters Patent:
1. The process of rendering flexible a-fibrous strip of insole material, which is characterized by advancing the strip in unheated condition by the rotation of a series of notched concentric rotary slitting knives and thus forming longitudinal slits therein, and stretching the slitted strip transversely in longitudinally progressive areas and opening the slits therein by passing it over a stationary convex former located closelyadjacent to said slitting knives while the stock is to stretch the slitted stock transversely while the slitting knives l3 and the platen sleeve 20. Then,
while still under the control of the rolls and strip is forced against the stretching member by the action of the rotary cutters, and edge gauges positioned on either side of said stretching member for holding both edges of the stock uponthe work table during the stretching operation.
. HENRY G. LUMBARD.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Date Number Name I 1,510,696 'Naugle et a1. Oct. '7, 1924 2,181,787 Lumbard Nov. 28, 1939 2,294,478 Norris et a1. Sept..1, 1942