US2682896A - Checkstrap - Google Patents

Description

y 1954 E. s. MESERVEY 2,682,896

CHECKSTRAP Filed Nov. 10, 1950 ZSnventor fpn/m 5. W555? ns'y attorneys Patented July 6, I954 ATENT OFFICE CHECKSTRAP Edwin S. Mcservey, Kingsport, Tenn., assignor to Slip-Not Belting Corporation, Kingsport, Tenn.

Application November 10, 1950, Serial No. 194,993

6 Claims. (01. 139-161) This invention relates to a checking device for picker sticks in looms. More particularly this relates to improvements in checking straps of the type disclosed in the patents to Shivell Nos. 1,993,531 and 2,374,042.

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 of the picker stick, but substantially shorter than the full length of such path of travel. Generally, the check strap has been rigidly attached to the frame at one side of its loop and the energy of the impact has been taken up in the flexing of the stifiiy flexible material of the strap and in the friction of the picker stick against the strap. 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 tends to rapid deterioration of the check strap and consequently it has been necessary frequently to replace these straps.

The Shivell Patent No. 2,374,042 disclosed that the check strap life could be prolonged by supplementing it with a shorter helper strap within the loop of the ordinary check strap, secured at one end under the clamp and extending freely across the path of the picker stick. -This helper strap cushioned and spread the force of impact, reducedthe sharpness of the bending of the check strap at the point of impact of the picker stick and at the point of attachment to the frame, and introduced a forced ventilation and consequent cooling by reason of the alternate slapping together and separation of the two straps.

The increased thickness at the end of this composite strap as disclosed by the Shivell patent re-' quires a special clamping bolt, longer than standard, and brings one of the straps farther out on the bolt where it acts with greater leverage, imposing correspondingly greater stresses on the clamp and the bolt itself. To further increase this thickness of the overlapped ends under the clamping bolt would arouse too much sales resistance so the helper strap has been used on only one end, with the consequence that the composite strap has hadto be made and "stocked in rights and lefts, respectively.

I have now discoveredthat a universal cbmposite check strap of improved life and utility can be obtained by securing a pair of individual helper straps on the check strap near the parts which respectively constitute the opposite ends of the loop when said checkstrap is in use; and.

r length clamping bolts with its consequent reduction of leverage; but even more important is to provide a helper stra with a yieldable reinforcement which can operate to distribute not only the impact stress but also friction and abrasion, thus avoiding localized deterioration which limits the useful life of the strap; and which, moreover, is more effective in circulating air over the areas in which most heat is generated, whereby to avoid the deterioration which has resulted from overheating. Other and further objects and advantages of the invention will become apparent from the following description.

The principles of the invention will be more readily perceived in connection with the following detailed description of a specific illustrative embodiment and from the accompanying drawings in which: 1

Figure 1 is a fragmentary side elevation showing a part of the'mounting bracket and fittings of the loom in relation to the picker stick and its limits of travel;

Figure 2 is a section of line 2--2 of Figure 1 showing the helper straps in their relation to the check strap loop and to the picker stick in its position where it first contacts the helper strap;

Figure 3 is a View similar to Figure 2 showing the relation of the picker stick and straps at one end of the picker'stick stroke;

Figure 4 is a view of the frusto-conical composite check strap as manufactured and distributed in a fiat condition;

Figure 5 is a sectional view taken on line 55 of Figure 4 Figure 6 is a fragmentary view similar to' the left-hand end of Figure 5, but showing another Figure 8 is a view si'milar to Figure 4 showing the helper strap secured to the fastened side of the check strap in an alternative embodiment of some of the features of my invention.

Referring to Figures 1-3, a check strap I0 is mounted on a part of the loom [-2 by bracket M and bolt l6. Picker stick it is shown with its limit of travel indicated by dotted lines 20. Helper strap 22 advantageously is secured to the inner face of the check strap at point 26 which is near the end of the free side of the loop 21. The helper strap extends freely across the end of the loop, across the area of impact of thepicker stick, but does not extend into the clamping bracket, so the clamping bolt only has to go through two layers of leather. Helper strap 24 is similarly secured at point 28 on the opposite end of the loop. The free ends of the helper straps are tapered toward their ends: advantageously by skiving the face which contacts with the check strap proper and then compressing or molding by pressure applied to the opposite side.

The straps I0, 22 and '24 are advantageously tanned hide with the hair left on and the hair 6 side faced inwardly toward the picker stick. The hair may be removed from the area 26 and 28 onthe' strap H! to give a bare surface for adhesive 29. However, it should be understood that other materials such as rubber impregnated fabric or other plastic, laminated or other strong tensile products may be used.

When the shuttle strikes the picker and drives the picker stick back against the check strap, the stick first comes into contact with the helper strap 22 as shown in Figure 2, and a portion of the energy of the picker stick is absorbed in the preliminary bending of the helper strap and the rubbing of the end 24- on the inner face of the check strap proper before the picker stick actually begins to stretch the check strap. When this stretch does occur the force of impact will bedistributed' by the relatively heavy helper strap which will then lie across the end of the check strap so as. to prevent destructive sharp bending of the strap. At this stage the impact of the picker stick is thus taken up entirely in ten sion and compression distributed through the strap which avoids the most destructive action encountered with conventional check straps.

As the picker stick strikes helper strap 22 in Figure 2', it initially bends it causing it to slide along and conform to the check strap. As the picker stick travels further, it distorts the loop until it is in the relation shown in Figure 3, where it is checked. This distortion causes the picker stick to move, with little or no sliding along the surface of the strap 22, pushing the helper strap back against the check strap; and at the same time pulling the attached end 26 with it while the free end slides frictionally along the strap I0 near its secured end. During: this motion air is expelled from between the straps; and, of course, on the recovery fresh air is sucked in. When the helper strap is finally brought up against the end of the check strap loop, the helper strap is substantially free from tension over the point at which it is hammered by the edge of the picker: stick. Thus the check strap which is under tension is not subjected to the hammering and the helper strap which takes the hammering is under compression, which prevents tearing and other destructive effects, and both are protected against sharp bends.

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 2,

with a space between the check strap l0 and helper strap 22. 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 ll] pulls forward the point of attachment 26, which again throws the helper strap 22 against strap l0 and again expels the air from between the two straps. This action is repeated on each stroke so there is a forced ventillation between the two straps.

On the forward stroke of the picker stick the impact is very much less severe and it therefore is not necessary to provide a helper strap at this end of the loop. However, there are other advantages in using a helper strap at both ends in that: (1) they reinforce the check strap at the end opposite to the impact and prevent its bending too sharply at the clamp, (2) they absorb a considerable amount of energy at the end opposite to the impact due to such reinforced bending and the friction between helper strap and dissipate such energy by the forced ventillation described above; and (3) they also make it possible to have a universal strap that can be used on right or left handed installations and can be reversed when the rear helper strap becomes worn,. thus adding still more to the already increased life.

By utilizing a pair of helper straps, one at each end, and making slots in both ends of the check strap lfl- (Fig. 4) a composite strap symmetrical about its central axis is obtained. This strap can thus be used in right or left handed installations, and reversed, as mentioned above.

In Figure 8, I have shown, in accordance with this invention, a helper strap secured near one end of the attached side of the check strap. Although this structure attains some of the advantages. of my invention as shown in Figs. 1-6, it is by nomeans equivalent, because the point of attachment of the straps cannot yield to the impact of the picker stick by moving in the direction of impact as shown by Figures 1 and 4, and therefore isnot relieved of the scraping of the picker stick and still may exert a twisting movement on the stick.

It is an advantage of the invention that the helper strap can be detachably secured to the check strap. In those cases where the helper consistently wears out before the check strap. it isdesirable to be able to replace the helper strap without replacing the whole composite strap, but it is preferable to so choose the ma terials of the respective straps as to equalize their lives. Thus different grades of leather may be used or rubber, rubberized fabric, vinyl or vinylidene plastics, nylon, or other tough plastics may be used in combination with or instead of the leather to meet the particular requirements of service in any case. Especially. the advantageous tensile properties of a leather check strap can be combined with tough wearresisting properties of such plastics used in the helper straps. By detachably I mean that the helper straps are capable of removal and re placement without destroying the usefulness or impairing the strength or subsequent life of the check strap proper. This may be done by use of a soluble, or otherwise releasable adhesive cement 29 (Figure 4). Alternatively, this may be done by stitching as shown (at 29av in Figure 6') or by mechanical fasteners such as shown at 291) in Figure '7.

Although I have shown the instant invention applied to a conical strap of the type disclosed in the Shivell Patent No. 1,993,531, the invention pair of shorter straps detachably secured at one end only to said check strap along portions I which lie near opposite ends of the free side of said loop, and extending freely across the areas at each end of said loop in which the picker stick engages the loop, and the shorter straps being of corresponding approximately arcuate form when flat, 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, at least one shorter strap secured at one end to said check strap along a portion thereof which lies beyond the area of attachment to the 100m and near the end of one side of said loop, and the other end of said shorter strap extending freely across the end of said loop at and beyond the major axis of said loop.

3. 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, at least one shorter strap extending freely across 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 one end of said shorter strap along a portion of said check strap which lies near the end of one side of said check strap loop, to secure them together in laminated relation and being detachable from at least one of them.

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 pair of shorter straps extending freely across the inside of said loop throughout and terengaging between said check strap and said shorter straps at one end of said check strap along portions thereof which lie near opposite ends of the free side of said loop to secure them in laminated relation and being detachable from at least one of them.

5. 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, at least one shorter strap adhesively cemented to said check strap along a portion thereof which lies near one end of a side of said loop, 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.

6. A checking device for looms which comprises, in combination with a check strap adapted to be clamped in a loop about a portion of the travel path of a picker stick less than the full length of said path, a pair of shorter helper straps secured at one end only thereof to said check strap along portions thereof which lie near the opposite ends of the free side of said check "strap loop, said helper straps extending freely across the areas at each end of said loop in which the pickerstick engages the loop and being of a relatively stiffer configuration than said check strap so as to leave strap cooling air spaces in the ends of said p and to reinforce both ends of said check strap loop without interfering with the strap clamping means.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 22,509 Brandon July 4, 1944 2,220,512 Clayton Nov. 5, 1940 2,374,042 shivell Apr. 17,1945

2,509,676 Dickinson May 30, 1950 FOREIGN PATENTS Number Country Date 357,442 Great Britain Sept. 24, 1931

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