US3228429A - Check strap assembly - Google Patents

Description

Jan. 11, 1966 c. R. MESSER 3,223,429

CHECK STRAP ASSEMBLY Filed May 22, 1964 POLYURETHANE IMPREGNANT POLYURETHANE 2 IMPREGNANT 2O INVENTOR. CHESTER R. MESSER BY M ATTORNEYS United States Patent 3,228,429 CHECK STRAP ASSEMBLY Chester R. Messer, Concord, N.H., assignor to Page Belting Company, Concord, N.H., a corporation of New Hampshire Filed May 22, 1964, Ser. No. 369,386 3 Claims. (Cl. 139-161) This invention comprises a new and improved check strap assembly of the type characterized by a U-shaped loop slidable upon a fixed guide rod under the actuation of a picker stick which is confined and limited in its stroke by the loop.

Check straps of this type are subjected to very severe duty and for many years the textile industry has devoted extensive research and effort to increasing the life of the strap. Every advance in that direction is of great importance as it permits the employment of looms operating at increased speed and with reduced down time. A gain in speed of only a few picks per minute may make the difference between profit and loss to the manufacturer. It has been found, however, that every increase in loom speed magnifies the severity of duty, reduces the life of the check strap assembly and must be offset by effective improvement in the check strap itself to meet the manufac turers demand for faster operation.

I have discovered structural and functional improvements which are effective to increase the life and efiiciency of such check strap assemblies and are therefore of outstanding importance and unexpected benefit to the textile industry.

The assembly employs a composite U-shaped loop of laminated straps, one of heavy textile webbing and the other of leather. This loop is perforated at its ends and mounted to slide back and forth upon a fixed guide rod under the reversing impact of the oscillating picker stick. In this movement, the loop is subjected to the retarding action of friction fingers which engage an intermediate area of the loop at one side of the plane of the picker stick oscillation. This portion of the loop is thus constrained to travel in a path generally parallel to the plane of the picker stick. Accordingly, the picker stick, at each end of its stroke, tends to form a hinge or angle in the loop and it is important that the structure of the loop should permit the natural formation of such hinges at the proper location in the straps of the loop. It is equally important that the loop should pass smoothly back and forth through the friction fingers without tendency to kink or bind which would otherwise impart irregular movement to the loop as a whole.

In accordance with the present invention, that difiiculty is obviated, the action of the loop improved and its length of service increased by impregnating with polyurethane or equivalent composition selected areas of the loop which impart thereto a stitfening and smoothening texture. These areas may comprise that portion of the textile loop which is engaged by the friction fingers and the two end areas of the loop adjacent to the guide rod. In this manner, the effect of the friction fingers upon the loop is made smooth and regular, all tendency to kink or bind is obviated and between the areas of impregnation the loop remains in condition to facilitate the formation of a natural hinge when subjected to impact of the picker stick at each end of its stroke.

As an optional but desirable feature the entire body of the textile strap may be impregnated with polyurethane sufliciently to impart a slight stifiening thereto with a tendency to maintain its loop shape.

These and other features and advantages of the invention will be best understood and appreciated from the following description of a preferred embodiment thereof,

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selected for purposes of illustration and shown in the accompanying drawings, in which:

FIGS. 1 and 2 are plan views of the check strap assembly, with certain parts shown in cross section and the picker stick shown in two different positions.

As here shown the assembly includes a metal guide rod 10 having an elongated central lug 11 by which the rod is supported in horizontal position from a bracket (not shown) attached to part of the loom frame. The rod is of conventional shape and carries at each end an attached bumper head 12. Movably mounted on the rod between these two heads is the loop-shaped body of the check strap. This comprises a pair of superposed straps 13 and 14 of which the outer strap 13 is formed of heavy webbing, such as canvas or nylon, and the inner strap 14 of flexible high grade leather. At-each end of the loop the straps 13 and 14 are reinforced by overlapping tongues or helpers 15 lying inside the loop. The straps 13 and 14 together with the helpers 15 are perforated to fit loosely upon the guide rod 10 so that the loop may slide back and forth on the rod in checking the swing of the picker stick 22.

The perforated ends of the loop are compacted and further reinforced by outer and inner clamping plates 16 and 17. These may be formed of stiff fibrous or plastic material. The inner plates 17 are notched at their inner edges to clear the guide rod 10 and the outer reinforcing plates 16 are perforated to clear the guide rod and flared outwardly. The components of the loop are all permanently bonded together at each end by rivets or other fasteners. The bound ends of the loop extend beyond the guide rod 10 where they are connected by a tie member 18 that converts the loop into D-shaped formation. The tie member 18 is held under tension by and between the ends of the loop.

As herein shown, the loop is engaged at the other side of the guide rod 10 by friction fingers 20 and 21 which exert a frictional retarding action on the loop as it travels back and forth under the actuation of the picker stick 22. The friction fingers are somewhat rounded for engagement with the loop and are pressed into yielding frictional engagement by means not herein shown.

In FIG. 1, the picker stick 22 is represented as moving in its power stroke to actuate the shuttle and at this point of the cycle it has not yet engaged the loop which remains in the position to which it has been moved by the picker stick in its idle stroke.

In FIG. 2, the picker stick is represented at the end of its power stroke where it has already contacted, the shuttle and moved the loop to its extreme left hand position causing the formation of a hinge at about its point of contact.

As herein shown the textile strap 13 is impregnated in the darkened areas with polyurethane. These areas include that portion of the strap which is engaged in any time by the friction fingers and the perforated end portions of the strap. A polyurethane impregnant solution containing about 40% solids has been found suitable for effecting outstanding improvement of the check strap assembly in the respects above noted and also in substantially reducing wear and unraveling of the textile strap in the vicinity of the holes for passage of the guide rod.

If desired the entire body of the strap 13 may be lightly impregnated in the polyurethane, as by treating the undarkened areas with a solution of 20% solids. This tends to maintain the straps in their loop-shaped formation while the heavier impregnation of the darkened areas facilitates the creation of a smooth wave of deflection under the action of the friction fingers 20, 21. While polyurethane is the preferred impregnant any equivalent thermosetting resin could be employed within the scope of the invention.

Having thus disclosed my invention and described in detail an illustrative embodiment thereof, What I claim as new and desire to secure by Letters Patent is:

1. In a check strap assembly, a composite loop comprising a strap of leather and a strap of textile Webbing, the loop being perforated at its ends and mounted upon a fixed guide rod to slide under the actuation of a picker stick, together with stationary friction fingers engaging an intermediate area of the loop; that improvement in which the strap of textile webbing is impregnated in an intermediate area within range of said friction fingers with polyurethane, thereby smoothening and stiffening the strap, an d reducing tendency to-ripple in passing through said fingers while leaving the strap free for the formation of a natural hinge in its unimpregnated portions.

2. In a check strap assembly, a composite loop as defined in claim 1, further characterized in that the end portions of the textile strap are also impregnated with polyurethane thus leaving spaced unimpregnated areas of the strap for the formation of natural hinges.

3 In a check strap assembly, a U-shaped strap of textile Webbing impregnated throughout its length with cured polyurethane and having perforated end areas and an intermediate-area impregnated with a substantially greater concentration of polyurethane than the remainder of the strap thereby facilitating the formation of hinges in the areas of less impregnation.

References Citedby the Examiner UNITED STATES PATENTS 2,721,811 10/1955 Dacey et al. 2,775,264 12/1956 R-ockoif 139-161 2,822,828 2/1958 Crocker 139161 2,884,961 5/1959 Plante et al. 139166 3,114,397 12/1963 Messer 139161 3,126,922 3/1964 Randlett et al 139-165 FOREIGN PATENTS 745,224 2/ 1956 Great Britain.

DONALD W. PARKER, Primary Examiner.

Claims (1)

1. IN A CHECK STRAP ASSEMBLY, A COMPOSITE LOOP COMPRISING A STRAP OF LEATHER AND STRAP OF TEXTILE WEBBING, THE LOOP BEING PERFORATED AT ITS ENDS AND MOUNTED UPON A FIXED GUIDE ROD TO SLIDE UNDER THE ACTUATION OF A PICKER STICK, TOGETHER WITH STATIONARY FRICTION FINGERS ENGAGING AN INTERMEDIATE AREA OF THE LOOP; THAT IMPROVEMENT IN WHICH THE STRAP OF TEXTILE WEBBING IS IMPREGNATED IN AN INTERMEDIATE AREA WITHIN RANGE OF SAID FRICTION FINGERS WITH POLYURETHANE, THEREBY SMOOTHENING AND STIFFENING THE STRAP, AND REDUCING TENDENCY TO RIPPLE IN PASSING THROUGH SAID FINGERS WHILE LEAVING THE STRAP FREE FOR THE FORMATION OF A NATURAL HINGE IN ITS UNIMPREGNATED PORTIONS.

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