US2411874A - Method of making hollow flexible boots - Google Patents

Description

- De 3,1946, M. E. GOLDEN 2,411,874

METHOD OF M OOTS Patented Dec. 3, 1946 UNITED STAT-E METHOD OF MAKING HOLLOW FLEXIBLE I BOOTS Milton E. Golden, Chicago, 111.

Application November 27, 1943, Serial No. 511,930

, 2 Claims. (01. 64-32) (Granted under the act of March 3, 1883, as

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relatesto flexible boots of the kind employed to encase a mechanical structure which is subject to elongation or bending in operation. Boots of this class are employed-to keep lubrication in, or'dirt out, or both, yet they must allow freedom of movement of the mechanism within.

An object of the invention is to provide a boot of this description which may be made of readily available material with minimum waste of stock used and time consumed in the making.

Another object of the invention is to develop a novel method of producing the device which is herein shown and described as an embodiment of my invention.

Other objects and advantages Will be evident as the invention is further described and reference is made to the drawing, wherein:

Fig. 1 shows a washer cut from sheet material, this being a first step in making one of the units of my device.

Fig. 2 shows the washer of Fig. l-after it has been cut through on a radial line, this being the second step in the production of a unit of my device.

Fig. 3 shows a series of the cut washers of Fig. 2 after the ends, which were provided by the cuts, were drawn apart so as to. pull each washer into a somewhat exaggerated lock washer shape.

Fig. 4 shows a series of the lock washer shapes of Fig. 3 with the end of one washer permanently joined to the beginning of the next so as to provide, of the several separate washers, a continuous helix.

Fig. 5 shows two of the helices of Fig. 4 laid together with the convolutions of one alongside the convolutions of the other preparatory to joining their edges.

Fig. 6 shows how the inner edges of the two helices of Fig. 5 may be permanently joined, while the outer edges lie contiguous but are not fastened together.

Fig. '7 shows how the outer edges of contiguous convolutions of Fig. 6 are drawn apart preparatory to securing them together, the one of one pair to the other of the next pair.

Fig. 8 shows the drawn-together outer convolutions after they have been permanently joined.

In the drawing, a series of washers l9, Fig. 1, are preferably cut from a sheet of flexible fabric, or thin metal, as the case may require- Each amended April 30,

, stage the outer washeris then slit to compose a split washer [2, Fig. 2, the slit extending from the inner diameter M of the washer to the outer diameter l6, thereby providing the piece with two abutting ends 3 and 20. I

The ends l8 and 2B of the split washers l2, Fig. 2, are then pulled apart as shown in Fig. 3, so as to compose of each piece an exaggerated lock washer shape 22, each piece thus composing one turn of a helix. Three pieces thus treated are shown in Fig. 3, being numbered 22, 22a and 221), the ends of the first piece being referred to as 18 and 20, the ends of the second as l8a and 20a, and the ends of the third as I81) and 20b.

The adjacent ends of the several helical turns 22, 22a and 221) are next fastened together in some suitable manner being preferably sewn if the material is flexible fabric, or being soldered or welded if it is metal, the end 29 being joined to lBa, 29a to I81), etc. When the several ends have been thus joined together, a continuous helix 24, Fig. 4, will have been formed, having an inside helical edge I la and an outside helical edge Ilia, the individual convolutions being designated 24a, 2419,2 50 and 24d.

When two helices M, as shown in Fig. 4 have been provided, theymay be put together as shown in Fig. 5, the second helix, however, being assigned the numeral 25 to facilitate description, and its individual convolutions being for the same reason given the numerals 25a, 25b, 25c and 25d. The inner edge of the helix 25 will be referred to as Mb and the outer edge ltb.

After the two helices 24 and 25 have been assembled as shown in Fig 5, the inner edges of the two, that is, the edges Ma and lb may be laid together and sewn or otherwise joined as shown in Fig. 6. The sewing together of these two edges will consist of one continuous seam throughout the length of the helices. At this edges i511 and Nib still lie alongside but are not fastened together.

After the two helices 24 and 25 are thus joined at the inner edges Ida and Nb, the outer edges Ilia and Hib are pulled apart as shown in Fig. '7, and paired anew, that is, instead of 25a and 25a lying alongside, 25a will be paired with 24b, 25b will be paired with 240, 25c with 24d, etc.

When the outer edges are now sewn together in one continuous seam, the device will have assumed the configuration of Fig. 8, that is, it will have the form of a hollow V screw thread. Here the inner edge of 24a. is paired with the inner edge of 25a, then the outer edge of 25a with the outer edge of 2%, etc. Finally appropriate end pieces 26 and 27 are joined to the ends of the screw, their shape depending on the shape of the part which is to be housed.

In addition to the concentric helically shaped exible boot made of circular discs of uniform diameters as hereinbefore described, various conacter indicated.

It is noted that since the boot is built in the form of a helix it is obviously stronger than one made of circular discs in the conventional manner, that is, sewn together along their inner and outer circumferences. Distortion and stresses are transmitted in a helical direction to all sections of the assembly simultaneously and uniformly, thus making the workin life of the boot, made according to subJect invention, longer.

It is further noted that a boot made to subject invention of 1. The method of making a hollow flexible boot from relatively thin flexible sheet material, which consists of cutting out a series of washers, radially slitting said continuous seam, the first convolution of the sec-- ond helix to the second convolution of the first helix.

2. Steps in the method of making a hollow flexible boot MILTON E. GOLDEN.

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