WO2019171232A1

WO2019171232A1 - Systems for connecting adjacent track shoes

Info

Publication number: WO2019171232A1
Application number: PCT/IB2019/051699
Authority: WO
Inventors: Jonathan RALBAG
Original assignee: Urdan Metal & Casting Industries Ltd.
Priority date: 2018-03-07
Filing date: 2019-03-03
Publication date: 2019-09-12

Abstract

A system includes two adjacent track shoes (10) with track lugs (12, 62) protruding therefrom. At least one torsion bar (18) pivotally connects the adjacent track shoes (10) together. The torsion bar (18) includes a force transfer member (20) located between end connectors (22). The force transfer member (20) is received in a member (14) coupled to at least one of the track shoes (10), so that the force transfer member (20) can transfer force to the track shoes (10).

Description

SYSTEMS FOR CONNECTING ADJACENT TRACK SHOES

FIELD OF THE INVENTION

The present invention relates generally to endless tracks for propelling vehicles and particularly to systems for connecting adjacent track shoes.

BACKGROUND OF THE INVENTION

Various types of tracked vehicles exist for industrial and military uses. For example, tracked vehicles are used in the construction and agricultural industries, for hauling heavy vehicles or equipment, tanks, and much more.

Tracked vehicles have a propulsion unit (engine) operatively connected via a transmission system to an endless track via a drive axle. Drive sprockets are mounted to the drive axle, each sprocket including sets of sprocket teeth that engage corresponding track lugs (also referred to as track teeth or internal lugs) of the endless track to provide traction between the sprockets and the endless track.

The track lugs protrude from track shoes (also called track plates) which are connected to each other. There are two broad families of tracks:“dead track” and“live track”. In dead track, each track shoe is connected to the adjacent track shoe with hinge- type pins. The dead track lies flat on the ground and the drive sprocket pulls the track around the wheels with no assistance from the track itself.

A typical prior art live track is shown in Figs. 1A-1E. Two adjacent track shoes 1 (with track teeth 2) are connected by a metal (steel) pin 3 that passes through a metal (steel) bushing or collar 4, and is connected to track shoe 1 via elastomeric (rubber) bushing 5. Pin 3 is secured by fasteners (nuts) 6 at each of its ends. The use of elastomeric bushings allows the track shoe to bend slightly. Although the drive sprocket still pulls the track around the wheels, the track itself tends to bend inwards (due to the metal bushings insert angles), slightly assisting the sprocket and somewhat conforming to the wheels.

SUMMARY OF THE INVENTION

The present invention seeks to provide improved systems for connecting adjacent track shoes, as is described more in detail further below. Unlike the prior art, in the present invention, the live track does not employ any elastomeric bushings. Instead, the present invention employs one or more torsion bars or springs to transmit force between the track shoes.

It is noted that the term“bar” encompasses any elongate member, such as but not limited to, a bar, rod, shaft, pin, lug, screw, bolt and the like, and may have different cross-sectional shapes. There is provided in accordance with an embodiment of the present invention a system including two adjacent track shoes with track lugs protruding therefrom, and at least one torsion bar that pivotally connects the adjacent track shoes together, the at least one torsion bar including a force transfer member located between end connectors, wherein the force transfer member is received in a member coupled to at least one of the track shoes, so that the force transfer member can transfer force to the track shoes.

In accordance with an embodiment of the present invention the member is formed with an aperture whose inner contour is shaped to compliment an outer contour of the force transfer member, so that the outer contour of the force transfer member can abut against the inner contour of the aperture and transfer force to the track shoes.

In accordance with an embodiment of the present invention the force transfer member includes a non-cylindrical shape and radially protrudes from the torsion bar.

In accordance with an embodiment of the present invention the member that is coupled to at least one of the track shoes includes a force-receiving lug that extends from at least one of the track shoes.

In accordance with an embodiment of the present invention a portion of the torsion bar is received in a sleeve. Opposite ends of the sleeve may be received in openings formed in lugs of the track shoes. The purpose of the sleeve is to carry the shear forces allowing the torsion bar to carry only torsion.

In accordance with an embodiment of the present invention each of the end connectors is secured to the track shoes with a locking member.

In accordance with an embodiment of the present invention the locking member includes keying surfaces that mate with corresponding keyways formed in a portion of each of the track shoes.

In accordance with an embodiment of the present invention each of the end connectors has a threaded portion which is secured by a fastener.

In accordance with an embodiment of the present invention the torsion bars are received in a double receiving member.

In accordance with an embodiment of the present invention each of the torsion bars is received in a clamp lug, which includes mating clamp members and which defines apertures in which the torsion bar is received.

In accordance with an embodiment of the present invention track lugs protrude from one of the clamp members.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which:

Figs. 1A, 1B, 1C, 1D and 1E are perspective, top-view, partially sectional front- view, detailed sectional, and exploded illustrations, respectively, of a prior art live track, Fig. 1C being taken along lines C-C in Fig. 1B;

Figs. 2A, 2B and 2C are simplified perspective, exploded and end-view illustrations, respectively, of a connection system for track shoes, having a single torsion bar, in accordance with a non-limiting embodiment of the present invention;

Fig. 3 is a simplified sectional illustration of a locking member for the torsion bar, in accordance with a non-limiting embodiment of the present invention;

Figs. 4A, 4B and 4C are simplified perspective, exploded and end-view (with a cut-out section) illustrations, respectively, of a connection system for track shoes, having double torsion bars, in accordance with a non-limiting embodiment of the present invention;

Figs. 5A, 5B and 5C are simplified perspective, exploded and end-view illustrations, respectively, of a connection system for track shoes, having double torsion bars, in accordance with a non-limiting embodiment of the present invention; and

Figs. 6A, 6B and 6C are simplified perspective, exploded and end-view illustrations, respectively, of a connection system for track shoes, having double torsion bars, in accordance with a non-limiting embodiment of the present invention.

DETAILED DESCRIPTION

Reference is now made to Figs. 2A-2C, which illustrate a connection system for track shoes, in accordance with a non-limiting embodiment of the present invention.

The system is for connecting adjacent track shoes 10. A track lug 12 protrudes from the track shoe 10, preferably but not necessarily, from the central portion of the track shoe 10 and perpendicular to the track shoe 10. The track shoe 10 includes circumferential lugs 14 separated by gaps 16. As is well known in the art, a plurality of such track shoes 10, connected to each other, will circumferentially pass around the drive wheels of a tracked vehicle (not shown), and the sprocket teeth of the drive sprocket of the tracked vehicle will engage the track lugs 14.

The connection system includes a torsion bar 18 that pivotally connects adjacent track shoes 10 together. Torsion bar 18 may be made of a suitably strong material, such as but not limited to, a steel alloy. Torsion bar 18 may be rigid or alternatively may have springiness or flexibility, which may be advantageous in use as a live track. Torsion bar 18 includes a force transfer member 20 (that is, one or more force transfer members 20) and end connectors 22. In the non-limiting illustrated embodiment, torsion bar 18 includes a non-cylindrical force transfer member 20 which radially protrudes from torsion bar 18. The non-cylindrical shape of force transfer member 20 may be polygonal (such as hexagonal or octagonal) or other shapes (such as a star shape, e.g., a TORX fastener star shape or a gear shape). The force transfer member 20 is received in an aperture 24 formed in one lug 14 of the track shoe 10, referred to as a force-receiving lug 14M. The force receiving lug 14M is received in the gap 16 between lugs 14 of the adjacent track shoe 10. The inner contour aperture 24 of the force-receiving lug 14M is shaped to compliment the outer contour of force transfer member 20. For example, for an outer hexagonal shape of force transfer member 20, the aperture 24 will have an internal hexagonal shape, and so forth. In this manner, the outer surfaces of force transfer member 20 abut against the inner surfaces of aperture 24 and thus transfer force to the track shoe 10.

Aperture 24 may be formed in the material of force-receiving lug 14M or alternatively may be part of an insert which is inserted and affixed in force-receiving lug 14M.

The portion of torsion bar 18 between force transfer member 20 and each of the end connectors 22 may be received in a sleeve or pin 26. Opposite ends of sleeve 26 may be received in openings 28 formed in lugs 14 and 14M (aperture 14 is inwards of opening 28 in lug 14M).

Reference is now made to Fig. 3, which illustrates a locking member 30 for the torsion bar 18 (also seen in Fig. 2B).

Locking member 30 may have splines or keying surfaces 32 that mate with corresponding grooves or keyways 34 formed in lug 14. The end connector 22 may have a threaded portion which is secured by a fastener 36, such as a threaded nut 36. Thus, as seen in the final assembly of Fig. 2B, the ends of torsion bar 18 are secured to lugs 14 by means of keying surfaces 32 of locking member 30 being held in keyways 34 of lug 14 and tightened by fastener 36.

In this manner, torsion bar 18 transmits force to the adjacent track shoes 10. The track shoes 10 can bend inwards as in the prior art, but with the advantage of less parts, and no elastomeric bushings.

Reference is now made to Figs. 4A, 4B and 4C, which illustrate a connection system for track shoes, having double torsion bars 18. This embodiment is similar to the previous embodiment, except that the end connectors 22 of the pair of torsion bars 18 are received in a double receiving member 40, which includes the locking member (described above). The ends of the torsion bars 18 pass through clearance holes 42 in double receiving member 40 and are secured by fasteners 36.

Reference is now made to Figs. 5 A, 5B and 5C, which illustrate another version with double torsion bars 18. In this embodiment, each torsion bar 18 is received in a sleeve 50 formed with inner surfaces 52. Instead of lugs, there is a clamp lug 53, made of mating clamp members 54 and 56 fastened together by a fastener 58, such as a screw. Clamp lug 53 defines two apertures 59 in which are received sleeves 50. The adjacent track shoes 10 are connected by the pair of sleeves 50 that pass through the two apertures 59 and double receiving members 40. The force transfer member 20 of each torsion bar 18 cooperates with surfaces 52 formed in sleeves 50 to transfer force to the track shoes 10.

The end connectors 22 of the pair of torsion bars 18 are received in locking members 40, and are also locked by locking members 30, as described above.

Reference is now made to Figs. 6A, 6B and 6C, which illustrate another version of the connection system of Figs. 5A-5C. In this version, clamp lugs 60 are used which include track lugs 62 that protrude from one of the clamp members.

Claims

CLAIMS What is claimed is:

1. A system comprising:

two adjacent track shoes (10) with track lugs (12, 62) protruding therefrom; and at least one torsion bar (18) that pivotally connects said adjacent track shoes (10) together, said at least one torsion bar (18) comprising a force transfer member (20) located between end connectors (22);

wherein said force transfer member (20) is received in a member (14) coupled to at least one of said track shoes (10), so that said force transfer member (20) can transfer force to said track shoes (10).

2. The system according to claim 1, wherein said member (14) is formed with an aperture (24) whose inner contour is shaped to compliment an outer contour of said force transfer member (20), so that the outer contour of said force transfer member (20) can abut against the inner contour of said aperture (24) and transfer force to said track shoes (10).

3. The system according to claim 1, wherein said force transfer member (20) includes a non-cylindrical shape and radially protrudes from said torsion bar (18).

4. The system according to claim 1, wherein said member (14) that is coupled to at least one of said track shoes (10) comprises a force-receiving lug (14M) that extends from at least one of said track shoes (10).

5. The system according to claim 1, wherein a portion of said torsion bar (18) is received in a sleeve (26).

6. The system according to claim 5, wherein opposite ends of said sleeve (26) are received in openings (28) formed in lugs (14, 14M) of said track shoes (10).

7. The system according to claim 1, wherein each of said end connectors (22) is secured to said track shoes (10) with a locking member (30).

8. The system according to claim 7, wherein said locking member (30) comprises keying surfaces (32) that mate with corresponding keyways (34) formed in a portion of each of said track shoes (10).

9. The system according to claim 1, wherein each of said end connectors (22) has a threaded portion which is secured by a fastener (36).

10. The system according to claim 1, wherein said at least one torsion bar (18) comprises a plurality of torsion bars (18).

11. The system according to claim 10, wherein said torsion bars (18) are received in a double receiving member (40).

12. The system according to claim 10, wherein each of said torsion bars (18) is received in a clamp lug (53), which comprises mating clamp members (54, 56) and which defines apertures (59) in which said torsion bar (18) is received.

13. The system according to claim 12, wherein track lugs (62) protrude from one of said clamp members.