GB2348412A

GB2348412A - Tow hitch

Info

Publication number: GB2348412A
Application number: GB9907205A
Authority: GB
Inventors: Louwrens Booysen
Original assignee: TRAPEZIUM DEVELOPMENTS CC
Current assignee: TRAPEZIUM DEVELOPMENTS CC
Priority date: 1999-03-30
Filing date: 1999-03-30
Publication date: 2000-10-04
Also published as: GB9907205D0; AU2250599A

Abstract

A tow hitch comprises a first body member 14 adapted to be secured to a vehicle, a second body member 12 adapted to be secured to a trailer, and pivotal arm members 16 which couple together the first body member 14 and the second body member 12, one end of the arm members is pivotally mounted to the first body and the other end is pivotally mounted to the second body. The arm members are arranged such that angular movement between the first and second body members 14,12 will cause pivotal movement of the arm members 16 resulting in relative lateral movement between the first an second body members. Mounting means are also disclosed.

Description

Tow Hitch TES invention relates to a tow hitch which is adapted in use to couple a towing vehicle to a trailer or the like. The term"trailer"herein is meant to include any towed vehicle or unit.

It is well recognized that lateral swaying motion of a trailer can cause instability of a towing vehicle and trailer arrangement. It is accordingly an object of the present invention to provide a tow hitch which will to some extent alleviate the above mentioned problem.

According to the invention, a tow hitch comprises a first body member adapted to be secured to a towing vehicle, and a second body member adapted to be secured to a trailer, and pivotal arm members which couple together the first body member and second body member, with the leading ends of the arm members being pivotally mounted to the first body member or second body member, and the trailing ends of the arm members pivotally mounted to the second body member or first body member respectively, the arm members being arranged such that relative angular movement between the first body member and second body member will cause pivotal movement of the arm members resulting in relative lateral movement between the first body member and second body member.

Further according to the invention, two arm members are provided and arranged generally parallel to the longitudinal axis of the towing vehicle and trailer. In a preferred arrangement, the arm members will be inclined slightly inwardly from their trailing ends to their leading ends relative to the longitudinal axis of the towing vehicle and trailer.

Also according to the invention, the trailing ends of the arm members are pivotally mounted on the first body member which is adapted to be secured to the towing vehicle, and the leading ends of these pivotally mounted on the second body member which is adapted to be secured to the trailer.

In a preferred arrangement the arm members will be pivotally mounted on their respective body members by means of spigot and socket arrangements, with the sockets being defined at the leading and trailing ends of the arm members.

Still further according to the invention, the tow hitch includes a control lever which extends from a body member and which is adapted to be coupled to the trailer to translate swaying motion of the latter into angular movement of one body member and consequently corresponding lateral movement thereof. Thus in use, as the trailer sways in a to and fro fashion, the second body member will be correspondingly rotated by the control lever, and consequently cause a degree of lateral movement of the second member relative to the first member to reduce lateral forces on the vehicle.

A further feature of the invention provides for locking means for locking the tow hitch in an inoperative position wherein relative angular or lateral movement between the first body member and the second body member is substantially prevented, such means preferably comprising a plate-like locking member secured to the first body member or second body member and adapted selectively to engage an arm member to prevent pivotal movement thereof. Thus in one arrangement, the plate member will be secured to one body member, and adapted to engage the other body member, preferably via the leading or trailing ends of the arm members, to prevent movement between the first and second body members. With such an arrangement, a release mechanism is provided to render the locking means inoperative, and may comprise a portion of the control lever when the latter is mounted on a body member. In one arrangement the control lever will be receivable in a transverse bush, and act to urge the plate member out of engagement with the body member upon insertion into such bush.

, Also included within the scope of the invention, is mounting means for mounting the tow hitch to a towing vehicle, comprising a bracket defining an engagement formation and adapted to be secured to the towing vehicle and a mating engagement formation on the first or second body member. Preferably the engagement formation on the bracket will be in the form of a generally U-shaped tongue formation which is adapted to engage a corresponding engagement formation in the form of a generally inverted U-shaped peripheral groove formation on the first or second body, member to mount the latter on the bracket.

The scope of the invention extends separately to the tow hitch, the body members thereof, and the arm mernbers and their pivots, to the control lever, and to the mounting means for mounting the tow hitch to a towing vehicle.

The present invention will now be described further hereinafter by way of example only with reference to the accompanying drawings ; in which: Figure 1 is a perspective view of a tow hitch according to the invention; Figure 2 is a perspective exploded view of means for mounting the tow hitch in Figure 1 to a trailer; Figure 3 is a perspective assembled view of the mounting means in Figure 2; Figure 4 is a sectioned elevation of the mounting means in Figure 2; Figure 5 is a perspective exploded view of the tow hitch in Figure 1; Figure 6 is a plan view of the tow hitch in Figure 1; Figure 7 is a plan view from below of the tow hitch in Figure 1; Figure 8 is a side view of the tow hitch in Figure 1; Figure 9 is a schematic side view of a trailer hitched to a vehicle via the tow hitch in Figure 1; and Figures 10 & 11 are schematic plan views of the tow hitch in Figure 1, depicting the opposite extreme positions of a second body member of the tow hitch, relative to a first body member thereof.

Referring to the drawings, a tow hitch 10 comprises a first body member 14 which is adapted to be secured to a towing vehicle 26, and a second body member 12 which provides a tow ball 18 or other suitable hitch for connection to a trailer 70, Figure 9. The first body member 14 and second body member 12 are coupled together by means of pivotally mounted arm members 16 whereof the trailing ends are pivotally mounted on the first body member 14 and the leading ends are pivotally mounted on the second body member 12. The arm member 16 are mounted spigot and socket fashion, on post-like spigots 30, which are receivable within sleeves or sockets 28 disposed at each end of the arm members 16. It is envisaged that the posts 30 will be permanently secured in apertures 34 in the ir respective body members, by means of welding or the like. The sockets 28 are held in position on the posts 30 by means of a washer 36 and locking fastener 34, which engages in a threaded bore 32 at the free end of each post member 30.

The tow hitch of the invention further includes a control lever 20 which is adapted to be secured to the trailer 70 towards its one end by means of a bracket 45 which is mounted on the trailer 70 by means of a fastener 46, and which defines a sleeve 47 within which the free end of the control lever 20 is longitudinally slidable. The other end of control lever 20 is secured to the second body member 12 by means of transverse arm 38 which passes through spaced apertures 50 in the second body member 12 as shown in Figure 1. A locking screw 51 is adapted to penetrate into one or both the apertures 50 to engage a peripheral slot 52 in the transverse rod 38 for locking the latter in position. With reference to Figure 1, the control lever 20 is secured to the transverse rod 38 by means of. threaded fasteners 48 which pass through the leading end of the control lever 20, and through slots 49 in a plate 50 which forms an extension of the transverse rod 38. It will be noted that the slots 49 are elongated to permit the control lever 20 to be angularly adjustable relative to the longitudinal direction of the towing vehicle and trailer.

In the arrangement illustrated, the first body member 14 of the tow hitch 10 will be secured to the towing vehicle by means of a quick release assembly 60. Such assembly comprises a bracket 61 which is adapted to be secured to the towing vehicle 26 by means of nuts and bolts 69, and which defines an inverted U-shape tongue formation 62. The tongue formation 62 is adapted to seat snugly within a mating recess 64 formed within a U-shaped formation 63 which extends from the first body member 14. It is envisage that a locking screw 65 can be provided to pass through the structure 63, and engage the tongue formation 62 to lock the latter two members together. A locking ear 66 is provided for securing the locking screw 65. With the above arrangement therefore the tow hitch 10 can be uncoupled from the towing vehicle 26 by simply unscrewing the locking screw 65 and lifting the hitch 10 from the brackets 61.

The tow hitch 10 of the invention is further provided with a locking plate 67 which is designed selectively to prevent relative angular movement between the first body member 14 and the second body member 12. The purpose of the locking plate 67 is therefor to lock the arm members 16 against movement, for example when the tow hitch 10 is not in use, or when the control lever 20 is not connected to the trailer 70.

Thus when in the locked position, the tow hitch 10 can act as a conventional towing means.

The locking plate 67 comprises a resilient plate member which is secured to the second body member 12, preferably by locating the plate on the posts 30 which are fixed to the second body member 12 with posts 30 passing through apertures 68 in the plate 67. The plate.. 67 is further provided with apertures 69 which engage the other set of posts 30 which are mounted on the first body member 14. In the arrangement illustrated, the apertures 69 engage the fasteners 34 which protrude slightly from the post members 30 on the second plate 14. When thus engaged, the second body member 12, as well as the arm members 16, are locked against relative angular movement. Means for unlocking the locking plate 67 comprises an outwardly projecting lug formation 70 which is adapted to be engaged by the transverse arm 38. When the latter is inserted into the apertures 50 it acts to urge the locking plate 67 towards the second body member 12, so that the apertures 69 disengage the post members 30. In order to re-lock the locking plate 67, the transverse rod 38 will thus be withdrawn from the apertures 30.

In use, lateral to and fro swaying movement by a trailer, will be transmitted via the control lever 20 to the second body member 12, causing angular movement of the second body member 12 relative to the first body member 14. Such angular movement will be translated by the pivotal arm members 16 into a degree of relative lateral movement between the second body member 12 and the first body member 14. In this way a stabilizing effect between the towing vehicle and its trailer results.

Doubtless variations of the invention in detail exist without departing from the principles set out in the appende claims. In order to ensure maximum strength of the tow hitch of the invention, it is preferred that the pivotal arm member 16 will be relatively short, preferably between 25mm and 100mm. Preferably the length of the arm members 16 between the centers of the bushes 28 will be 65mm.

Claims

Claims 1. A tow hitch comprising a first body member adapted to be secured to a towing vehicle, and a second body member adapted to be secured to a trailer, and pivotal arm members which couple'together the first body member and second body member, the leading ends of the arm members are pivotally mounted to the first body member or second body member, and the trailing ends of the arm members pivotally mounted to the second body member or first body member respectively, the arm members being arranged such that relative angular movement between the first body member and second body member will cause pivotal movement of the arm members resulting in relative lateral movement between the first body member and second body member.
2. The tow hitch according to claim 1 wherein trailing ends of the arm members are pivotally mounted on the first body member and the leading ends of the arm members are pivotally mounted on the second body member.
3. The tow hitch according to claim 1 or claim 2 wherein two arm members are provided and arranged generally parallel to the longitudinal axis of the towing vehicle and trailer.
4. The tow hitch according to claim 1 or claim 2 wherein two arm members are provided and the arm members are inclined inwardly from their trailing ends to their leading ends relative to the longitudinal axis of the towing vehicle and trailer.
5. The tow hitch according to any one of claims 1 to 4 wherein the trailing ends of the arm members will be pivotally mounted on the first body member which is adapted to be secured to the towing vehicle, and the leading ends of these pivotally mounted on the second body member which is adapted to be secured to the trailer.
6. The tow hitch according to any one of claims loto D wherein the arm members are pivotally mounted on the respective body members by means of spigot and socket arrangements.
7. The tow hitch according to claim 6 wherein the sockets are defined at the leading and trailing ends of the arm members.
8. The tow hitch according to any one of claims 1 to 7 including a control lever which extends from a body member and which is adapted to be coupled to the trailer to translate swaying motion of the latter into angular movement of such body member and consequently corresponding lateral movement thereof.
9. The tow hitch according to any one of claims 1 to 8 wherein locking means for locking the tow hitch in an inoperative position wherein relative angular or lateral movement between the first body member and the second body member is substantially prevented, such means comprising a locking member secured to the first body member or second body member and adapted selectively to engage the other body member to prevent relative angular movement thereof.
10. The tow hitch according to claim 9 wherein the locking member is secured to one body member, and adapted to engage the other body member, via the leading or trailing ends of the arm members, to prevent movement between the first and second body members.
11. The tow hitch according to claim 9 or claim 10 including a release mechanism which is adapted selectively to release the locking means, comprising a portion of the control lever which acts on the locking member when the control lever is mounted on a body member.
12. The tow hitch according to claim 11 wherein the control lever is receivable in a transverse bush mounted on the first or the second body member, and acts to urge the locking member out of engagement with a body member upon insertion into such bush.
13. The two hitch according to any one of claims 1 to 12 including mounting means for mounting the tow hitch to a towing vehicle, comprising a bracket adapted to be secured to the towing vehicle and defining an engagement formation, with a mating engagement formation being defined on the first or the second body member.
14. The tow hitch according to claim 13 wherein the engagement formation on the bracket is in the form of a U-shaped tongue formation which is adapted to engage a mating formation in the form of an inverted U-shaped peripheral groove formation on the first or the second body member.
15. A tow hitch substantially as herein described and exemplified with reference t ( the accompanying drawings.
16. A body member for a tow hitch as claimed in any one of claims 1 to 15 comprising a plate adapted to be coupled to a towing vehicle or a trailer, and spigot formations extending from the plate for receiving mating sockets or spigot formations of pivotal arm members.
17. A body member according to claim 14 substantially as herein described and exemplified with reference to the accompanying drawings.
18. A control lever for a tow hitch as claimed in any one of claims 1 to 15 comprising an elongated arm and securing means at one end thereof for engaging a trailer, and securing means at the other end thereof for engaging the tow hitch to translate swaying movement of the trailer to angular movement of the tow hitch.
19. A control lever according to claim 16 substantially as herein described and exemplified with reference to the accompanying drawings.
20. Mounting means for a tow hitch as claimed in any one of claims 1 to 15 comprising a bracket adapted to be secured to the towing vehicle and defining an engagement formation, with a mating engagement formation being defined on the first or the second body member.
21. Mounting means according to claim 20 substantially as herein described and exemplified with reference to the accompanying drawings.