AU762597B2

AU762597B2 - Safety catch for a vehicle electrical plug connection

Info

Publication number: AU762597B2
Application number: AU16372/00A
Authority: AU
Inventors: Trevor Charles Kalms
Original assignee: Kalms Therese Anne
Current assignee: Kalms Therese Anne
Priority date: 1999-02-18
Filing date: 2000-02-14
Publication date: 2003-06-26
Anticipated expiration: 2020-02-14
Also published as: AU1637200A

Description

Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: Trevor Charles Kalms Actual Inventor: Trevor Charles Kalms Details of Associated Provisional Application No: PP 8746 dated 18ms February 1999 Adelaide, South Australia, Australia The following statement is a full description of this invention, including the best method of performing it known to me.

This invention relates to an improved safety interlock device for an electrical connection between a towing vehicle and a trailer, and more particularly to a safety catch arrangement for preventing inadvertent disengagement of an electrical plug from its socket in an electrical plug connection between a prime mover and its trailer.

It is of course common practice for a trailer to be electrically coupled to a towing vehicle by means of a wired plug located on the trailer and which connects to a complementary electrical socket mounted at the rear of the towing vehicle. One of the problems associated with such electrical couplings, especially with large prime movers and their trailers, is the accidental or inadvertent separation of the plug from its socket. One well known solution to this problem has been the use of a spring loaded closure plate pivotally mounted to the socket housing and which is pivotal S• between a fully open position where it allows the plug to be axially inserted into the ••socket, and a partly closed position where the closure plate holds the plug firmly S: 15 clamped within its socket by means of a pair of locking formations which firmly abut against diametrically opposed shoulder formations formed on the body of the plug at the rear thereof. With the plug removed, the closure plate can be swung down to a fully closed position to completely close off the entry to the socket.

20 While the above described spring loaded closure plate works reasonably well with smaller towing vehicles and conventional trailers, they are not considered sufficiently robust or adequate when used with semi-trailers where very large towing and towed vehicles are involved.

It is the main object of the present invention therefore to provide an improved electrical plug safety catch device, which is especially suitable for electrically coupling large trailer vehicles to a prime mover, which will effectively prevent accidental detachment or separation of the plug from its socket connection on the towing vehicle, and which is designed to firmly clamp the plug within its socket thereby ensuring more effective electrical contact between the two components.

2 Broadly according to this invention therefore, an improved safety catch arrangement for connection between a towing vehicle and a trailer wherein an electrical plug on the trailer is adapted for axial insertion within a complementary socket of a socket fitting on the towing vehicle, comprises a pivotal catch member having a distal end and a proximate end, said proximate end being pivotally mounted on the body of the electrical plug to enable the catch member to pivot about a transverse axis between a raised, unlocked position wherein the plug and socket can be axially separated or engaged with one another, and a lowered locking position wherein the catch member bridges the plug and socket and the plug is restrained against axial separation from the socket, the arrangement being such that the plug can be axially engaged with its said socket when the catch member is in its opened position, and thereafter firmly clamped within said socket with the catch member in its lowered locking position.

Preferably, the leading end of the catch member is provided with transversely opposed locking formations which, when the catch member is in its closed locking position, lockingly engage with respective keepers adjacent opposite sides of the housing of the socket.

20 Desirably the pivotal catch member is arcuately shaped and is pivotally attached at opposite sides thereof to a clamping collar which encircles the body of the plug, said collar being removably mounted on said plug body.

Desirably the keepers are provided on a separate backing plate which is attached to the rear end face of the socket housing. Desirably the backing plate is provided with a pair of forwardly projecting transversely spaced apart parallel flanges which straddle the socket housing and each of which has mounted on its inner surface a respective said keeper.

Preferably the catch member is shaped and dimensioned so that it can be used in conjunction with a conventional spring loaded closure or cover plate which is hingedly mounted to the body or casing of the socket, the socket normally being fixed to a support bracket at the rear of the vehicle, and arranged in such a way that when the catch member is in its closed locking position, the conventional spring loaded closure plate cannot be opened. This allows the plug to be firmly retained within its socket by two oppositely rotating clamping devices, one of which is swingably mounted on the body or casing of the plug, with the other being swingably mounted on the complementary socket fitting.

While the catch arrangement of the present invention is preferably designed as an after market accessory for an electrical coupling between towing and towed vehicles, it should of course be readily appreciated that the pivotal catch member and the co-operable keepers can be fitted as original equipment and form integral parts of the plug and socket fitting respectively.

•In order to more fully explain the present invention, a preferred embodiment thereof is described hereunder in some further detail with reference to and as illustrated in the accompanying drawings wherein: o Fig 1 is a perspective view of an electrical coupling for use between towing and towed vehicles, showing the plug clamped axially within its complementary 20 socket by means of a catch device according to this invention; Fig 2 is an exploded side view of the coupling shown in Fig 1, with the catch device in its open unlocked position and the spring closure plate on the body of the socket also in its fully opened position so as to enable axial insertion of the plug; Fig 3 is a front view of the socket component of the electrical coupling shown in Fig 1, with its closure or cover plate in its fully opened position; while Fig 4 is a front view of the plug component of the electrical coupling shown in Fig 1, but with the catch member in its raised, open unlocked position.

Referring to the drawings, there is shown an electrical coupling arrangement between towing and towed vehicles (not shown) comprising an electrical plug 11 which is normally connected to electrical wiring on the trailer or towed vehicle and a complementary electrical socket 12 which, in accordance with the practice of prior art, is affixed to a support bracket (not shown) mounted at the rear of the towing vehicle. Both the plug 11 and socket 12 are of conventional design, with the plug being provided with contact pins projecting axially for coupling with corresponding female contact members of the socket 12.

Also in accordance with prior art, the housing or casing 13 of the socket 12 has hingedly mounted thereto a pivotal spring loaded closure plate 14 which can be hinged between a fully opened upright position to enable the plug 11 to be inserted into the socket 12, and a partly closed locking position (refer Fig 1) wherein the plate 14 clampingly retains the plug 11 in its engaged position with the socket 12, this being achieved by means of a pair of transversely spaced locking fingers 15 which project inwardly at right angles to the plane of the plate 14 and clampingly engage against respective lugs or shoulder formations integrally formed on the housing or body of the plug 11 at the rear end thereof. Generally, the spring loaded closure plate 14 is adequate to firmly retain the plug 11 coupled to its socket 12. However, 20 with large semi-trailers, where far more substantial vibrational forces are present, it Shas been found that the closure plate 14 by itself is not reliable to maintain the plug in clamped engagement with the socket.

In accordance with a feature of the present invention, there is provided a pivotal catch 17 on the body 19 of the plug 11, with the catch 17 being rotatable about a transverse axis between a raised unlocked position (shown in Fig 2) and a lowered locking position (shown in Fig 1) where it bridges the plug 11 and the socket 12 and partly overlies the closure plate 14. In this embodiment, the catch 17 is hingedly mounted by means of pivot bolts 22 to a clamping collar 18 which is clamped around a cylindrical perimeter portion of the plug body 19.

In order to lock the catch 17 with the plug 11 and socket 12 firmly clamped together, there is provided a backing plate 20 fixed to the rear face of the housing or casing 13 of the socket 12 and which is formed with a pair of transversely spaced apart opposed parallel inturned flanges 21 which locate to either side of the casing 13 and each of which has a fixed keeper element 23 located on its inner surface.

In this embodiment the distal or leading end of the pivotal catch 17 is provided with a pair of transversely opposed depending lugs 24, the rear edges of which are shaped so as to provide locking recesses 25 each of which is arranged to lockingly engage with a respective keeper element 23 when the catch 17 is in its lowered locking position. The locking lugs 24 and the keepers 23 are configured in a manner so that the catch 17 engages with a snap action when fully locked. In this S•embodiment the keeper elements 23 are formed as cylindrical metal discs or buttons.

oo.

As shown in Fig 1, the catch 17 is provided with a closed finger engaging handle 26 adjacent its leading end and located centrally thereof in order to facilitate operation of the catch 17 between its locked and unlocked positions.

In this embodiment, although the catch 17 is arcuately shaped in transverse o 20 cross-section, it should be appreciated that the design configuration of the catch can S. be widely varied and may, for example, be shaped and dimensioned so that it almost completely conceals the closure plate 14 when both the latter and the catch 17 are in their locked positions. In this embodiment however, the catch 17 is formed with a concave rear edge so as to provide sufficient clearance for the catch to swing upwardly to its raised position without interference by the closure plate 14. With the catch 17 in its fully opened raised position, easy access can be gained to the closure plate 14 so that it in turn can be unlocked and swung to its raised, open unlocked position (as shown in Fig 2).

In order to engage the coupling arrangement shown in Fig 1, the catch 17 on the plug 11 is rotated to its raised position shown in Fig 2 and the plug axially inserted into its mating socket 12 which has its hinged closure plate 14 also in its raised, open position as shown in Fig 2. When the plug 11 is fully inserted, the closure plate 14 is swung downwardly to its lowered locking position where the locking fingers 15 clampingly engage the projecting lugs 16 on the end face of the plug body 19. Thereafter the catch 17 is similarly hinged downwardly to a position where the lugs 24 lockingly engage the keeper elements 23 which locate in respective recesses 25 on the catch 17. With the catch 17 thus engaged, the plug 11 is firmly clamped in its engaged position and provides a very effective safeguard against inadvertent separation or disengagement of the plug from its socket.

A brief consideration of the above described embodiment will indicate that the invention provides for a very simple yet effective safety catch for the mating components of an electrical coupling so that they do not inadvertently or accidentally disengage or separate from one another.

*e eee •oee

Claims

1. A safety catch arrangement for an electrical coupling between a towing vehicle and a trailer wherein an electrical plug on the trailer is adapted for axial insertion within a complementary socket of a socket fitting on the towing vehicle, said safety catch arrangement comprising a pivotal catch having a distal end and a proximate end, said proximate end being pivotally mounted on the body of the electrical plug to enable the catch to pivot about a transverse axis between a raised unlocked position wherein the plug and socket can be axially separated or engaged with one another, and a lowered locking position wherein the catch bridges the plug and socket and lockingly engages with catch engaging means on opposite sides of the socket fitting to thereby clampingly retain the plug to the socket so that the plug is restrained against axial separation from the socket.

2. A safety catch arrangement according to claim 1 wherein said catch engaging means comprise keepers fixed with respect to the socket adjacent opposite sides thereof, and wherein the catch is provided with transversely opposed locking tongues at its distal end, each said locking tongue when the catch is in its locking position, lockingly engaging with a respective said keeper. i

3. A safety catch arrangement according to claim 1 or claim 2 wherein said catch S is arcuately shaped and is pivotally attached at opposite sides thereof to a clamping collar which encircles the body of the plug, said collar being removably mounted on said plug body.

4. A safety catch arrangement according to claim 2 or claim 3 wherein said socket fitting comprises a separate backing plate attached to the rear end face of the socket housing, said backing plate having a pair of forwardly projecting transversely spaced apart parallel flanges which straddle the socket housing, each said flange having mounted on its inner surface a respective said keeper.

A safety catch arrangement according to any one of the preceding claims wherein said socket fitting comprises a conventional spring loaded closure or cover plate hingedly mounted to the body of the socket and which is arranged to close off access to the socket when not in use and moveable to a locking position wherein its distal end clampingly engages against respective lugs or shoulder formations on the body of the plug at the rear end thereof so as to firmly retain the plug when coupled to the socket, arranged so that when the catch is in its lowered locking position, the conventional spring loaded closure plate is restrained against upward movement.

6. A safety catch arrangement according to any one of the preceding claims wherein said catch comprises a finger engaging handle adjacent its distal end for facilitating movement of the catch member between its locked and unlocked positions. So7. A safety catch arrangement for an electrical coupling connection between a towing vehicle and trailer substantially as hereinbefore described with reference to 15 and as illustrated in the accompanying drawings. Dated this 14th day of February 2000. TREVOR CHARLES KALMS By his Patent Attorneys MADDERNS o.