US3618840A

US3618840A - Endless track devices for laying cables and the like

Info

Publication number: US3618840A
Application number: US889139A
Authority: US
Inventors: Bernard Francois Mauri Courret
Original assignee: Etat Francais
Current assignee: Etat Francais
Priority date: 1968-12-31
Filing date: 1969-12-30
Publication date: 1971-11-09
Anticipated expiration: 1988-11-09
Also published as: DE1963870A1; NL6915272A; FR1602079A; GB1234888A

Abstract

A pair of opposed endless track devices have adjacent branches whose links cooperatively engage a cable therebetween and advance the cable with the links. The links travel in rails and form chambers therewith in which pressure fluid is supplied to force the links into engagement with the cable while advancing the links and cable therewith.

Description

United States Patent [56] References Cited UNITED STATES PATENTS 2,792,930 5/1957 Graham....

[72] Inventor Bernard Francoh Maurice Courret Toulon, France [21 Appl. No. 889,139

22 WU un 6 22 Z 2,935,178 5/1960 Lutcke.... 3,024,956 3/1962 Gretterm.

[22] Filed Dec.30,l969 [45] Patented Nnv.9, I971 73 Assi nee Etat Francala De atlon Mlnhterielle pour l 1 8 L'Arnienent kg FOREIGN PATENTS 3/1965 France Perle, France m m Wm w h N& 0 QR r 3 MW i, We 0" W mm 8 6 9 1 v o 1 am mnu FI- .w n O n P nun BBB [54] ENDLESS TRACK DEVICES FOR LAYING CABLES AND THE LIKE ABSTRACT: A pair of opposed endless track devices have adjacent branches whose links cooperatively engage a cable therebetween and advance the cable with the links. The links travel in rails and form chambers therewith in which pressure fluid is supplied to force the links into engagement with the 2 ,l nmnn l HhZ M2 11 Claims, 7 Drawing Figs.

[52] US. (11...... [5|] Int. [50] Field of cable while advancing the links and cable therewith.

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Ill 5 5 i I *4 L ,5- \,l N 2 i A A +/4 H f nude BRIEF SUMMARY OF THE INVENTION The invention relates to endless track a cable or the like.

Such endless track devices Navy, for hauling or restraining as pipes, towing lines, etc.

- These devices comprise two endless tracks composed of continuous chains arranged on both sides of the site to be occupied by the object to be laid.

Contact of the tracks with such object is obtained by ad justably spaced longitudinal rails in which the links of the chains are guided during forward advance by driving sprockets on which the chains travel.

Such an arrangement leads toconsiderable stresses and friction, on the rails and on the tracks themselves and especially to very great strain on the link pins.

An object of this invention is to allowing uniform distribution of stresses over the whole length tact with the object to be laid.

For this purpose, according to the invention, rails and track links are so arranged as to form chambers in which pressure fluid is supplied to force the links into contact with the object to be laid or hauled and to advance the links and the object therewith.

By this arrangement the links are subjected, during their travel between the rails, to a force which is resolved into one component normal to the object to be laid or hauled, assuring proper grip thereon, and a second component in the direction of movement of the track.

This resolution of the total force into simple forces brings about a reduction of internal strains and consequent decrease in weight and initial cost of the arrangement as well as a reduction in operation costs.

Furthermore, the gripping and tractive forces are exerted by the links themselves, which canthen simply travel on idler pulleys. The tracks no longer are subjected to the tractive effort and their pin joints are relieved.

A single, generally hydraulic, fluid serves for producing the gripping and tractive efforts. Braking can be obtained by reducing the pressure of the fluid, which provides a further simplification.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic plan view of an endless track device according to the invention,

FIG. 2 is a view of a portion of the device on a showing the drive thereo FIG. 3A is a section taken on line A-A of FIG. 2,

FIG. 3B is a section taken on line BB otFlG. 2,

FIG. 4 is a perspective view of the body of a track link,

FIG. 5 is a similar view of the body frame, and

FIG. 6 is a section on a larger scale of a portion of the links showing the waterproof sealing arrangement for the track.

DETAILED DESCRIPTION In the embodiment shown in the drawing, the tractive or hauling device essentially comprises two endless tracks 1 arranged on both sides of a towline 2 to be hauled, the line being clasped between links of the tracks 1 (FIG. I).

The tracks I are formed by links 3 joined to each other by pins 4 to form endless chains riding on free, idler sprockets 5 mounted on axles 6 parallel to pins 4.

In their travel, the links contact the towline, and the tracks I are guided by longitudinal blocks formed by spaced parallel rails 7 whose spacing can be adjusted by a cross coupling 8 which for example may be hydraulic cylinders or transverse screws.

As can be seen more clearly in FIGS. 2, 3A and 38, each link engages the towline 2 by means of a flange 9 shaped to devices for advancing are used, particularly in the cables or similar objects such minimize these stresses by the holding and tractive of the sides of the tract in conthe support larger scale with one another laterally conform to the towline, and made of rubber or similar comparatively hard elastomer of a SHORE hardness greater than 60 Towline 2 is of the faired type, with a shell 10 surrounding a load rope II and containing a hole 12 for fittings 13 as shown in FIG. 38.

With such construction, flange 9 is substantially J-shaped to enclasp the part of the shell adjacent the load rope.

Flange 9 rests on a pad 14 secured in a shell 15. The pad 14 is made of rubber or a similar soft and resilient substance.

Pad 14 performs a threefold function, namely:

a. by reason of its own resilience, it sustains an initial pressure grip on the towline;

b. it compensates for irregularities of thickness in the towline;

c. the pad undergoes warping to resist shear force in the lengthwise direction, and compensate for variation in length of the towline occurring between its entry and exit from the endless tracks by the fluctuation in tension to which the towline is subjected at these two points.

Pad 14 is embedded at its base in the shell 15 which, as shown in FIG. 4, has a U-shaped channel 16 for housing the pad.

The shell 15 is composed of a metal frame I7 onto which a thermosetting synthetic plastic is molded.

The lateral faces of the shell are engaged with slight friction in the guide rail 7 which has a lengthwise U-shaped channel for this purpose.

The rails include flanges towline 2 as shown in FIG. 38.

For the joining of the links, shell 15 carries lugs 19 and 20 (FIG. 4) in which suitable extensions of frame 17 are moulded (FIG. 5). Successive chain links are joined by pins 4.

Links 3, as shown particularly in FIGS. 2 and 3, include a longitudinal rib 21 on the outer side flanked by two hollows or chambers 22 which along their length are of approximately sinosoidal shape, the two crests being located at the respective ends of the link. Frame 17 extends into rib 21.

This rib becomes a supporting and friction surface when in contact with the bottom of rail 7. The outer surfaces of the flanges on the link prevent the link from tilting under the reaction of the towline on the flanges 9 and also guarantee sealing and tightness laterally in relation to chambers 22 defined on both sides of the rib 21 by the link and the walls of the rail.

At the forward end of each link relative to the direction of motion of the endless track, a transverse sealing arrangement consisting of a sealing member 23 seated in groove 24 of the link body is provided. Groove 24 extends behind the sealing member 23 to chamber 22 through channels 25 machined in the link, as shown in FIG. 6.

At the other or trailing end of each link there are provided grooves 26 to form decompression chambers.

As will be evident in FIGS. 1, 2 and 3A, the chambers 22 are used for propelling or restraining the endless tracks and for this purpose each of the rails 7 is provided with spaced chests 27 for the inflow and outflow of a pressure fluid.

The spacing between two consecutive chests 27 is established such that a whole number of links equal in number to the chests extends in the space between the extreme chests 27a, 27b, so that in this way there is a smooth and steady shift from one link to the next, between each link and the chest opposite it, which provides a practically steady stress on the endless tracks 1.

Each chest 27 comprises two identical chambers 28 (FIGS. 2 and 3A) separated by a bafile 29 equal in thickness to rib 21 against which the bafile is engaged. Chambers 28 are rectangular in section perpendicular to the rail 7 and they link up on the walls of the rail.

The chambers 28 contain rollers 30, whose thickness is equal to the width oi chambers 22, while their diameter is substantially twice the rnaximum depth of the chambers 22.

In the bottom of each chamber 28 is an inlet channel 31 for pressure fluid. A corresponding communicating channel 32 to 18 to provide protection for chamber 22 for this fluid is machined in the front wall of chest 27 at chambers 2%.

In the rear walls of chest 27 at chambers 2h, outflow channels 33 are formed on both sides of bafile 29.

In operation, the pressure fluid enters channels 32 and flows into chambers 22 esmhlished between the rail and the link, and the pressure fluid pushes the rollers 34) rearwards to seal securely at 34 on the rear wallof chat 2? as shown in FIG. 2. The rollers 30 thus move transversely, as the track advances longitudinally, by rolling along the sinosoidal surface of the chambers 22. The rollers divide each chamber 22 into forward and rearward compartments which vary in volume during advance of the track.

n the one hand, the pressure fluid applies the link against the towline, and on the other hand it exerts a force on that link urging it to move in the direction shown by arrow f (FIG. 2). During this time, the fluid located in chambers 22 at the back of the rollers 30 flows out through channels 33.

End chests 27a and 27b include only an outflow or an inflow channel as the case may be.

The movement of the endless track is facilitated on one side by the separation of rib 21 which no longer rubs on the bottom of the rail, and on the other by the fact that the rollers 30 roll on the back of the links and therefore do not rub thereagainst with friction.

On the contrary, when the pressure drops, the track, under the resilient force of 14 is pressed against the bottom of the rail thus providing efficient braking. For this purpose the coefficient of friction between the rail and the links is of advantage since the static tractive force on the towline may then be borne without movement.

The tension of the return side of the track can be zero or set to some fixed value to facilitate operation.

Chests 27 are supplied under balanced pressure and variable discharges to adjust the running speed of the towline in its travel. The number of chests can be adjusted as required and adapted to the requirements of diflerent particular cases.

What is claimed is:

l. Apparatus for advancing a cable comprising at least one moveable endless track device for engaging a cable to advance the same lengthwise thereof, said track device comprising a plurality of links and a rail supporting said links and defining chambers therewith, and means for supplying a pressure fluid to said chambers to apply the links against the cable, said chambers being so formed that the pressure of the fluid therein produces a longitudinal force on the links to advance the links and the cable therewith.

2. Apparatus as claimed in claim 1 comprising a second endless track device opposed to the first to clamp the cable between the links thereof to advance the cable.

3. Apparatus as claimed in claim 2 wherein each link has at least one hollow which forms with the associated rail in respective of said chambers, said means for supplying pressure fluid comprising an inlet and an outlet, and means dividing each said chamber into two compartments which vary in volume during advance of the track, one compartment being in communication with said inlet and the other in communication with said outlet.

4. Apparatus as claimed in claim 3 wherein said hollow is approximately sinusoidal in shape, said means dividing each chamber into two compartments comprising a transversely displaceable member engaging each link along said hollow.

5. Apparatus as claimed in claim 4 wherein said transversely displaceable member is a roller having a diameter greater than the maximum depth of the hollow, said means for supplying pressure fluid comprising a chest with spaced walls and provided with said inlet and outlet, said roller being guidably movable between said walls.

6. Apparatus as claimed in claim 4 wherein said rail has a U- shape cross section, each said link having outer surfaces in frictional engagement with said rail.

7 Apparatus as claimed in claim 6 wherein each link has two of said hollows and a central rib between said hollows, said rib frictionally engaging said rail upon cessation of supply of pressure fluid, each said hollow having one said transversely displaceable member therein.

8 Apparatus as claimed in claim 3 wherein said means for supplying pressure fluid comprises a plurality of spaced chests along said rail, each chest having one said inlet and one said outlet, said chests being spaced such that a plurality of links equal in number to the number of chests are disposed between the endmost chests.

9 Apparatus as claimed in claim 1 wherein each link comprises a rigid body supported by said rail, a flange conforming to the shape of the cable for engaging the same, and a resilient pad supporting the flange on the body.

10. Apparatus as claimed in claim 9 wherein said link comprises a frame and a molded covering on said frame of synthetic plastic material.

11. Apparatus as claimed in claim 1 wherein each said link has a forward end and a rearward end relative to the direction of travel of the track, and means at the forward end of each link forming a watertight seal with said rail for the associated chamber.

I! 4 8 II a

Claims

1. Apparatus for advancing a cable comprising at least one moveable endless track device for engaging a cable to advance the same lengthwise thereof, said track device comprising a plurality of links and a rail supporting said links and defining chambers therewith, and means for supplying a pressure fluid to said chambers to apply the links against the cable, said chambers being so formed that the pressure of the fluid therein produces a longitudinal force on the links to advance the links and the cable therewith.

3. Apparatus as claimed in claim 2 wherein each link has at least one hollow which forms with the associated rail a respective of said chambers, said means for supplying pressure fluid comprising an inlet and an outlet, and means dividing each said chamber into two compartments which vary in volume during advance of the track, one compartment being in communication with said inlet and the other in communication with said outlet.

4. Apparatus as claimed in claim 3 wherein said hollow is approximately sinosoidal in shape, said means dividing each chamber into two compartments comprising a transversely displaceable member engaging each Link along said hollow.

6. Apparatus as claimed in claim 4 wherein said rail has a U-shape cross section, each said link having outer surfaces in frictional engagement with said rail.

7. Apparatus as claimed in claim 6 wherein each link has two of said hollows and a central rib between said hollows, said rib frictionally engaging said rail upon cessation of supply of pressure fluid, each said hollow having one said transversely displaceable member therein.

8. Apparatus as claimed in claim 3 wherein said means for supplying pressure fluid comprises a plurality of spaced chests along said rail, each chest having one said inlet and one said outlet, said chests being spaced such that a plurality of links equal in number to the number of chests are disposed between the endmost chests.

9. Apparatus as claimed in claim 1 wherein each link comprises a rigid body supported by said rail, a flange conforming to the shape of the cable for engaging the same, and a resilient pad supporting the flange on the body.