US3411379A - Multiple loop tie-bar - Google Patents

Description

Nov. 19, 1968 s. P. DEYERLING 43,411,379

MULT IPLE LOOP TIE-BAR Filed March 13, 1967 2 Sheets-Sheet l [N VENTOR.

GEE/4E0 F? DE YE EL ING E; wwiw /4 7' TOENE Y N V- 1968 3. P. DEYERLING- 3,411,379

MULTIPLE LOOP TIE-BAR Filed March 15, 1967 2 Sheets-Sheet 2 Q INVENTOR.

GE EAED 1? DE YEEL/NG ATTOENE Y United States Patent 3,411,379 MULTIPLE LOOP TIE-BAR Gerard P. Deyerling, South Bend, Ind., assignor to The Bendix Corporation, a corporation of Delaware Filed Mar. 13, 1967, Ser. No. 622,789 11 Claims. (Cl. 74579) ABSTRACT OF THE DISCLOSURE A tension-torsion tie-bar having a plurality of bands of parallel filaments encased in a flexible substance about and bonded to end fittings providing separate elements for carrying tensile loads while being torsionally flexible.

S am In my As the use of laminated filament tape tie-bars increases, a need has arisen to improve the factor of safety beyond that attendant with present day methods. It has been adequately proven that singular bands of layers of flexibly integrated filaments will perform with a degree of satisfaction not heretofore thought possible. However, these methods have provided larger, and consequently heavier structures than is attendant when one utilizes less dense bands in accordance with this invention which are united to bushings so that they are equally loaded. To some extent present day tie-bar constructions, because of the increasing length of layers about layers, have inner layers carrying more load than the outer layers. In a tie-bar of the design taught by this invention all layers reinforce each other.

Drawing description FIGURE 1 is an end view of a tie-bar in accordance with the principles of this invention; I

FIGURE 2A is an end view along lines 2A-2A of FIGURE 2; and

FIGURES 2, 3 and 4 are partial cross sectional plan views of the tie-bar construction afforded by this invention.

Detailed description There is shown a tie-bar construction employing spherical end fittings or bushings and 12 (see FIGURE 2). These bushings have a pattern of grooves, one overlying the other on the rear face, as at 14, for receiving a plurality of closed loop bands 16, 18, 20, 22 and 24. The bushings 10 and 12 are flattened, as at 26 and 28, on the top and bottom, and the front face 30 is machined to be flat. Face 30 is finished so that the bands 16 thru 24 leave the bushing tangentially therewith at the face 30'. In the construction shown this face 30 is of smaller area than'if the bands were to extend straight from one bushing 10 to the other bushing 12. This is because the bands 16-24 are drawn together into a column appearing center section (see FIGURE 2A) by a pair of rings 34 and 36. These rings are formed by joining two portions 38 and 40 with an annular band 42, which may or may not be similar to the construction of the flexibly integrated filament bands 16-24.

The grooves for bands 20, 22 and 24 are shown in the cross sectioned bushing 10 with the bands 22 and 24 in cross section to show the flexibly integrated fiaments 44 in each of the bands in parallel arrangement one to the other. By using the spherical contour for bushings 10 and 12 and with the path of a closed loop chosen for bands 16-24 the loading in the bands will not be substantially additive one on the other. This is due to large radius of the bearing surface of the band to the bushing which prevents compressive loading at the point of intersection 14.

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The bands are bonded in the grooves of bushings 10 and 12 by the same substance, preferably, that flexibly integrates the filaments 44, such as polyurethane or a resin having sufiicient flexible additives to provide torsional resiliency to each band. Pinholes 46 and 48 are drilled from one flat surface to the other for receipt of pins to unite the tie-bar to surrounding structure. This could be a pin through the rotor arm and a pin through the rotor blade of a helicopter rotor system where tensile loads are accompanied by torque which to a degree is permitted as long as restoring forces are present.

Having fully described a preferred construction of a tiebar in accordance with the tenets of my invention, it is now desired to set forth its intended scope of protection sought as follows.

I claim:

1. A tension-torsion tie-bar comprising:

first and second spherical end bushings each having a plurality of circumeferential grooves intersecting on the rear face; and

multiple bands circling said first and second bushings,

each band being contained in one of the circumferential grooves and bonded therein to said first and second bushings to space said bushings into a torsionally flexible tension carrying member.

2. A tie-bar according to claim 1 wherein said bands lie in said grooves to be flush with the spherical contour of said first and second bushings.

3. A tie-bar according to claim 1 wherein said bands pass from said first bushing to said second bushing in a closed loop pattern of substantially the same axial length.

4. A tie-bar according to claim 1 wherein said first and second bushings are flattened on top and bottom and provided with means to connect said bushings with structures to be united by said tie-bar.

5. A tie-bar according to claim 4 wherein said means is a pinhole extending from top to bottom of said bushing.

6. A tie-bar according to claim 1 wherein the front facing surfaces of said bushings is flattened to eliminate 0 -comprise semi-circular portions having a mating groove with a band about two portions in said groove to unite same.

11. A tie-bar according to claim 9 wherein said ring holds said bands in a circular profile with their side edges facing each other to form a tubular column between said end fittings.

References Cited UNITED STATES PATENTS 1,426,834 8/1922 Mechling 74579 3,279,278 10/1966 Eldred 74-579 3,362,252 1/ 1968 Ditlinger 74-579 3,362,253 1/ 1968 Ditlinger 74579 3,370,483 2/ 1968 Ditlinger 74579 FOREIGN PATENTS 1,334,446 7/1963 France.

FRED C. MATTERN, IR., Primary Examiner.

B. T. CALLAHAN, Assistant Examiner.

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