US2374042A - Check strap - Google Patents

Description

April 1945- H. .1. SHIVELL 2,374,042

CHECK STRAP Filed Feb. 6, 1943 2 Sheets-Sheet 1 INVENTOR flab/18 .7: J'H/YEZL April 17, 1945. H. J. SHIVELL 2,374,042

CHECK STRAP Filed Feb. a, 1943 -2 Sheets-Sheet 2 INVFINTOR Horn-i? .77 TA VE'LL ATTORN Q A X' Patented Apr. 17, 1945 7 UNITED STATES PATENT OFFICE H 2,374,042 f a CHECK STRAP Homer Shivel l, Kingsport, Tenn. I v Application February e, 1943, SerialNo. 4r4,94e (or. 139-465) 6 Claims.

This'invention relates to a checking device for picker sticks in looms.

It has been common practice in loom construction to check the movement of the picker stick in each direction by a strap which is secured to the frame of the loom in such manner as to allow it to yield substantially in absorbing the impact of the picker stick as it reaches the end of the permitted path of travel. In order to insure such movement of the check strap at each end of the picker stick travel, the check strap is'formed into ,a loop encompassing a part of the path of travel the friction of the picker stick against the strap; 7

and, in cases where endless rotating check straps are used, the energy of the impact is in part absorbed as friction between such strap and its supports. The combination of the repeated flexing, the high tensional stresses, the surface friction and abrasion and the heating which results from flexing and friction all tendsto rapid deterioration of the check strap and consequently it has been necessary frequently to replace these straps.

In my prior patent, No. 1,993,531, I have disclosed that by making the check strap in the form of a more or less frusto-conical'loop these destructive tendencies can be more. uniformly distributed over the width of the strap and thereby its life very greatly prolonged. It has also been shown heretofore that the life of such straps, whether straight or frusto-conical, can be further prolonged ,by making the strap into an endless loop and mounting it so that it can rotate during operation and thereby distribute the destructive tendencies over the length of the strap.

I have now discovered that the life of a check strap may, be very much further prolonged if the picker stick. By the use of this supplemental or helper strap I have, in the first place, provided.

. cause it is supported against the tensile strain,

the surface friction' between the check strap proper and' the helper strap; Thirdly, I have introduced forced ventilation and consequent cooling, by reason of the alternate slapping together and separation of the two straps resulting proper of the abrasion and pounding and of the major part of the friction while it serves the function of a tensile member to withstand the impact; the helper'strap takes over the punishment of pounding, abrasionjand friction,but betheeffects of pounding-abrasion and friction are much less destructive than in an ordinary check strap; This separation of functions, therefore, 7

used without the helper strap. Moreover; since the check strap'proper in this composite strap is free from the destructive effects'of abrasion, heat and hammering, it will often outlast several helper straps; and thus, even when failure first occurs, it is not-necessary. to make a full replace-- ment but merely to replace th relatively short a cushion to spread the force of the impact and to reduce the sharpness of the consequent bending of the check strap both at the point of impact of the picker stick and at the point of attachment to the frame. In the'seoond place,I have increased the ability to absorb'the energy of the impact by the additional flexing strength and helper strap. Thus, a saving of leather and, more important, savings of labor and overhead costs involved u in shut-downsand replacements are.

achieved.

icing and replacing. A further object of our in- I vention is to effect economy in the operation of looms by providingimproved checking devices.

A further object of the invention is to segregate the portion of a.cheok strap subjected to the greatest wear .andto so combine it in a composite checking device that it may be readily replaced without replacing or impairing the check strap A further object of the invention is to proper, improve the action, of the picker stick. Other objects and advantages of the invention will be apparent from the followingdescription.

,In the accompanying drawings. and the following specification Ijhave shown and described preferred device embodying my invention and vention and its operation," and thus may be enabled to apply the invention in practical use and embody it in numerous and varied forms, each as may be best adapted to the requirements of any particular use.

In these drawings Figure 1 is a top plan view of a composite check strap embodying my invention showing the mounting bracket and fittings of the loom and the picker stick partly broken away;

Figure 2 is a fragmentary View in side elevation showing the check strap in Figure 1 in its relation to the loom frame and the picker stick;

Figure 3 is a view of the composite check strap as manufactured and distributed in a flat condition;

Figure 4 is a view similar to Figure 3 showing a straight strap embodying the invention;

Figure 5 is a sectional view taken on line 5-5 of Figure 3;

Figure 6 is a fragmentary view similar to the left-hand end of Figure 5,. but showing another type of fastening;

Figure '7 is a view showing the helper strap alone;

Figures 8, 9 and 10 respectively are views similar to Figure 1, but showing modified forms of .the invention.

Referring first to Figures 1, 2 and 3, VI have shown a portion of the loom at l and on this bracket l I designed for mounting a standard check strap.

At I2 is shown a check strap of frusto-conical form substantially of the type described in the prior patent, No. 1,993,531. The picker stick is shown at l3 partially broken away. The path of travel of the picker stick is indicated in broken lines identified by the reference characters 14.

As thus far described, the structure is substantially the same as has been standard prior to my present invention.

According to the present invention I have added to this structure ashorter helper strap I 5. This helper strap, according to the present invention,

advantageously is substantially secured to the inner face of one end of the check strap proper and extends therefrom freely along a portion of said ward its end advantageously by skiving the face which contacts with the check strap proper and then compressing or molding by pressure applied to the opposite side. 4

When the shuttle strikes the picker and drives the picker stick back against the check strap, it comes first into contact with the helper strap 15 and a portion of the energy of the check strap is absorbed in the preliminary bending of the helper strap and in the rubbing of the end It on the inner face of the check strap proper I2 before the picker stick actually begins to exert tension on the check strap. When this does occur, the force of the impact will be distributed by reason of the fact that the relatively heavy end of the helper strap l will then lie between the picker stick and the check strap loop l2.

At this stage the picker stick tends to exert a hammering and excessive tension which, when combined, are most destructive; but, by reason of the structure of the present invention, the helper strap I5 takes the hammering without substantial tension, since the end which is struck by the picker stick is free, whereas the check strap I2 is able to exert the tension necessary to check the movement of the picker stick without being subjected to the hammering and other destructive effects.

When the picker stick begins its return and the check strap is once more free to relax, it tends to assume the position shown in Figure 1, with a space between the check strap l2 and the helper strap It. The opening of this space sucks cool air between the straps. As the picker stick completes its forward stroke and strikes the opposite end of the loop, the check strap [2 pulls taut against the helper strap l5 and again expels the air from between the two straps. This action is repeated on each stroke so that there is a constant forced ventilation between the two straps.

On the forward stroke of the picker stick the impact is much less severe; and ordinarily, therefore, it will not be necessary to provide a helper strap at this end of the loop. However, if desired a second helper strap exactly like the first may be provided or a single strap 15a of greater length may be extended beyond the end of the check strap [2 a shown in Figure 10. Even without the helper in the forward end of the loop, and even on the forward stroke, there is an advantage in the use of the helper strap in that it reinforces the check strap proper and prevents it from making too sharp a bend at the clamp I I;

and, both by friction against the check strap and by the energy absorbed in its own bending, it helps to absorb the impact of the picker stick at the end of its forward stroke.

As stated above, it is advantageous that the helper strap should be secured detachably to the check strap proper. By detachably, I mean that it should be capable of removaland replacement without destroying the usefulness or impairing the strength or subsequent life of the check strap proper. This may be done by an adhesive cement 58, as shown in Figure 5, and this adhesive is preferably of the non-drying type which retains its adhesive quality during use; or it may be by means of a mechanical fastener, e. g., such as shown at 48b in Figure 6. Numerous other means will occur to one skilled in the art.

Instead of making the helper strap separate and detachably securing it to the check strap proper, it may also be made integral, as shown for example in Figure 8 wherein the helper stra 15c is an integral part of the check strap I20 extending beyond the point of attachment to the bracket H, In this case, after the helper strap is worn out it can be detached by cutting away from the check strap proper and a replacement helper strap I50 may then be inserted in its place exactly as shown in Figure 1.

In Figure 4, I have shown a helper strap I50 applied, according to the present'invention, to a straight check strap [2d similar to those used prior to the patent, No. 1,993,531. The present invention is applicable to such a check strap in the same manner as described above excepting that, in the use of such a strap, it is gradually stretched out of shape and it is important, therefore, that when the helper strap ltd is worn out, the replacement should be more or less arcuate in form in order to conform to the stretched out shape of the check strap proper.

Such a replacement is shown in Figure '7. This may be used with any of the several embodi ments described above. In this case an adhesive !8 is provided on the end surface in order that it may readily adhere to the check strap in place of the helper strap which has been removed. If mechanical fasteners are used instead of the adhesive, it is advantageous that such fasteners strap.

should be secured to the helper strap 15, and likewise'to the replacement, in order to make sure that the replacement will be properly secured and related to the check strap.

In Figure 9 I have shown one manner of embodying my invention in connection 'with endless rotating check straps. In this case the check strap 12c, made in the form of an endless loop, which again may be either cylindrical or, advantageously, frusto-conical in form, is supported at opposite sides of the loop by brackets- He and Me, which are designed to engage frictionally the check strap while permitting it to be pulled through-so as to continuousl rotate while in operation. The advantage to be gained from this type of strap is that, due to the rotation, the

'wear and hammering against the belt is distributed along the perimeter of the belt instead of being concentrated at one small area. 'In practice, however, the diiilculty with these straps has been to keep them continuously rotating. 1 have now found that by useof my present invention this can be assured by a ratchet action of the helper strap against the endless check In the embodiment shown, the helper strap is mounted in a clamp on the bracket lie so that it extends along the inner side and across the end of the check strap loop.

When the picker stick, on its forward stroke, strikes the end of the loop opposite to the helper strap, it first pulls the loop through both brackets until it is brought against the helper strap. Thereafter, it is frictionally held by the helper strap and tends, therefore, to yield only on the side opposite to the helper strap, thus giving a substantial rotation. In fact, during such yielding the loop may actually be pulled back toward the helper strap by reason of the different radius of curvature from that of the helper strap.

As the picker stick starts its return trip the check strap loop is released and tends of its own resiliency to readjust itself pulling a part of the loop back through the supporting bracket He; and, at the same time opening a space between the outer loop and the helper strap, as shown in Figure 9.

During this latter stage the relaxing of pressure between the helper strap and the check strap proper and the opening of the space between them will allow the end l6e to slip back over the face of the check strap.

When the picker stick completes its return stroke under the impact of the shuttle, its first effect is to take the slack out of the helper strap and press it back against the loop of the check strap He and this in turn slips the end of the helper strap backward along the loop in adirection opposite to its direction of rotation.-

Upon return of the picker stick the helper strap returns once more, but this time its end is engaged with the loop like the pawl of a ratchet.

This ratchet action can also be attained to some extent and in the case illustrated and described above can be amplified by arranging the grain of the leather and advantageously the direction of hair, if left on the hide, so that it points toward a member which acts as a detent or pawl, in this case the helper strap 15s. This I have illustrated in Figure 9 by fine lines representing the fiber or retained hair.

I claim:. e e

1. A checking device for looms which comprises in combination with a checkv strap arcuate when flat adapted to form a frusto-conical loop about a portion of the travel path of a picker stickless than the full length of said path, a shorter strap detachably secured at one end to said check strap along a portion thereof which lies near the middle of one side of the loop which is parallel to said travel path and extending freely along a portion of said check strap at one end of the loop including the area in which the picker stick engages the loop,-and the shorter strap beingof corresponding approximately arcuate form when fiat, whereby to conform naturally to the looped check strap.

2. A checking device for looms which comprises in combination with a check strap adapted to form a loop about a portion of the travel path of a picker stick less than the full length of said path, a shorter strap secured to said check strap along a portion thereof which lies near the middle of one side of the loop which is parallel to said travel path' and the other end of said shorter strap extending freely along the inside of said loop throughout and beyond the area in which {he picker stick engages the adjacent end of said qop.

3. A checking device for looms which comprisesin combination with a check strap adapted to forina loop about a portion of the travel path of a. picker stick less than the full length of said path, a shorter strap adhesively cemented to said check strap along a portion thereof which lies near the middle of one side, of the loop which is parallel to said travel path said shorter strap extending freely along said looped strap to and across the area on which the picker stick strikes in the end of said loop.

v 4. A checking device for looms which comprises in combination with a check strap adapted to form a. loop about a portion of the travel path of a picker stick less than the full length of said path, a. shorter strap extending freely along the inside of said check strap loop throughout and beyond the area in which the picker stick strikes the loop, and fastening means interengaging between said check strap and the shorter strap at ate form at least throughout and beyond an rmpact area adjacent one end thereof and having at a portion thereof spaced from said impact area means for detachably securing said helper strap to a check strap.

6. A helper strap for picker check straps for looms which comprises a strap arcuate when flat, to fit approximately the inside of one end and a substantial portion of one side of a longused loop check strap including the area where the picker stick strikes the loop, one end of said helper strap being adapted to be secured with respect to the check strap and the other end thereof being tapered in thickness to fit approximately to the curvature in the end of the loop of the check strap when the helper strap extends across the end of the loop with a longer radius of curvature than the adjacent end of the check strap.

HOMER J. BHIVELL.

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