TECHNICAL FIELD

The present invention relates generally to an apparatus for coupling a trailer to a towing vehicle. In particular, the present invention relates to an apparatus for coupling a trailer to a tow ball of the towing vehicle.

BACKGROUND ART

The process for coupling a trailer to a towing vehicle with known ball and socket type couplings can prove time consuming and difficult. One traditional method involved trial and error in manoeuvring the towing vehicle so that the tow ball is directly beneath the trailer coupler assembly. The coupler assembly could then be lowered onto the tow ball. In practice this can be difficult, as the vehicle must be manoeuvred with a high degree of accuracy in order to bring the tow ball directly beneath the coupler. Often this must be done in circumstances where neither the coupler nor the tow ball can be seen by the driver of the vehicle. Many apparatus have been proposed which attempt to improve upon this method through the use of visual alignment markers, photoelectric sensors and alerting devices, or ultrasonic transducers.

However, these solutions face their own disadvantages, including being unreliable, costly, time consuming to install, and subject to damage and theft.

New Zealand Patent No. 607349 (the content of which is incorporated herein by reference) describes a mechanical apparatus which counters some of these disadvantages. The apparatus involved two abutting portions positioned to contact the posterior and anterior portions of the tow ball. The first abutting portion is positioned at the end of the support member and the second abutting portion is positioned at the end of a pivot arm. A lever is then used to lift the pivot arm over the tow ball and then towards the support member, so the first and second abutting portions enclose the tow ball. This apparatus mitigates many of the problems described above as it is no longer necessary to manoeuvre the vehicle such that the tow ball is directly beneath the coupler. While this apparatus works well, it would be improved by a more convenient means of locking the coupling in the closed or engaged configuration, and by inclusion of a means for ensuring the abutting portions are correctly aligned when the tow ball is engaged. It is an object of the present invention to overcome or ameliorate one or more of the problems of the prior art discussed above, or to at least provide a useful choice.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country. Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of "including, but not limited to".

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only. DISCLOSURE OF THE INVENTION

According to one aspect of the present invention there is provided a coupler assembly for connecting a trailer to a towing vehicle, the coupler assembly comprising: a body comprising a first tow ball engaging portion configured to engage a first side of a tow ball in use; a first member comprising a second tow ball engaging portion configured to engage a second side of the tow ball in use; a lever member rotatably connected to the body and rotatably connected to the first member, the lever member comprising a handle portion at a distal end of the lever member to the connection to the body; and a locking means comprising a second member rotatably connected to the body, the second member further comprising an abutment formation; wherein rotation of the lever member relative to the body to a first position causes the second tow ball engaging portion to move away from the first tow ball engaging portion to an open position, and rotation of the lever member relative to the body to a second position causes the second tow ball engaging portion to move towards the first tow ball engaging portion to a closed position, and wherein, when the second tow ball engaging portion is in the closed position the second member can be rotated to a locking position wherein the abutment formation is engaged with an abutment portion of the lever member to thereby prevent rotation of the lever member. Preferably the second member is biased towards the locking position.

Preferably the lever member comprises a first portion which is connected to a first side of the first member by a first rotatable connection, a second portion which is connected to a second side of the first member by a second rotatable connection, wherein an axis of rotation of the first rotatable connection is substantially collinear with an axis of rotation of the second rotatable connection, the lever member further comprising a connecting portion connecting the first portion of the lever member and the second portion of the lever member.

Preferably the connecting portion of the lever member comprises the abutment portion.

Preferably an axis of rotation of the rotatable connection between the locking means and the body is substantially parallel to an axis of rotation of the rotatable connection between the body and the lever member.

Preferably the body comprises mounting means for mounting the body to a trailer in use. Alternatively, the body comprises an aperture with threaded walls for mounting to a brake master cylinder in use.

Preferably the coupler assembly further comprises an alignment means comprising a protrusion and a recess, wherein one of the body and the first member is provided with the protrusion and the other of the body and the first member is provided with the recess; wherein when the second tow ball engaging portion is moved to the closed position, the protrusion of the alignment means moves into engagement with the recess of the alignment means, thereby ensuring the first and second tow ball engaging portions are vertically aligned correctly.

According to a second aspect of the present invention there is provided a coupler assembly for connecting a trailer to a towing vehicle, the coupler assembly comprising: a body comprising a first tow ball engaging portion configured to engage a first side of a tow ball in use; a first member comprising a second tow ball engaging portion configured to engage a second side of the tow ball in use; a lever member rotatably connected to the body and rotatably connected to the first member, the lever member comprising a handle portion at a distal end of the lever member to the connection to the body, wherein rotation of the lever member relative to the body to a first position causes the second tow ball engaging portion to move away from the first tow ball engaging portion to an open position, and rotation of the lever member relative to the body to a second position causes the second tow ball engaging portion to move towards the first tow ball engaging portion to a closed position, the coupler assembly further comprising an alignment means comprising a protrusion and a recess, wherein one of the body and the first member is provided with the protrusion and the other of the body and the first member is provided with the recess; wherein when the second tow ball engaging portion is moved to the closed position, the protrusion of the aligning means moves into engagement with the recess of the aligning means, thereby ensuring the first and second tow ball engaging portions are vertically aligned correctly.

Preferably the coupler assembly comprises a plurality of alignment means.

Preferable the or each recess is flared outward toward an open side of the recess so that the corresponding protrusion can be captured by the recess and guided into a correct position as the first and second tow ball engaging portions move together.

Preferably the or each protrusion is wedge shaped and the or each recess has a complementary shape.

According to a third aspect of the present invention there is provided a coupler assembly substantially as herein described with reference to Figures 1 to 4 or Figures 5 to 8. BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a coupler assembly according to one aspect of the invention seen from above and one side; Figure 2 shows a cross-section side view of the coupler assembly of Figure 1 through plane B-B;

Figure 3 shows a side view of the embodiment shown in Figure 1;

Figure 4 shows a plan view of the embodiment shown in Figure 1;

Figure 5 is a perspective view of a coupler assembly according to another aspect of the invention seen from above and one side;

Figure 6 shows a front view of the embodiment shown in Figure 5;

Figure 7 shows a side view of the embodiment shown in Figure 5; and

Figure 8 shows a plan view of the embodiment shown in Figure 5. BEST MODES FOR CARRYING OUT THE INVENTION

The invention is now described in relation to a first embodiment of the present invention as shown in Figures 1 to 4. It should be appreciated that the invention may be varied from that shown in the figures without departing from the scope of the invention.

Figures 1 to 4 show a coupler assembly for coupling a tow ball of a trailer to a towing vehicle according to one embodiment of the invention.

The coupler assembly comprises a body portion 1 which includes a first tow ball engaging portion 2 which engages the posterior portion of the tow ball (not shown) in use. A lever member 3 (shown in Figures 1, 3 and 4) connects to the body 1 by a first rotatable connection 4 and connects to a first member 5 via a second rotatable connection 6. The first member 5 of the apparatus includes a second tow ball engaging portion 7 which engages with the anterior portion of the tow ball in use. The first tow ball engaging portion 2 and the second tow ball engaging portion 7 fit together to enclose the tow ball.

Using the handle portion 8 of the lever 3, the lever member 3 can be rotated into an open position (not shown) in which the first two ball engaging portion 2 and second tow ball engaging portion 7 are separated, enabling the user to disconnect the trailer from the towing vehicle. In some embodiments the first and second tow ball engaging portions 2, 7 include an alignment means comprising complementary guiding and locking protrusions and recesses (shown in Figure 2). In the embodiment shown the sides of the second tow ball engaging portion 7 have convex protrusions 9 which fit into corresponding concave recesses 10 in the sides of the first tow ball engaging portion 2. Each recess is preferably flared outward toward the open side of the recess so that the corresponding protrusion can be captured by the recess and guided into the correct position as the tow ball engaging portions move together.

In the embodiment shown in Figure 2 the protrusion 9 is substantially frustopyramidal or wedge shaped and the recess 10 has a complementary shape, however in alternative embodiments the protrusions may be rounded or alternatively shaped (with corresponding changes to the shape of the recesses). In some embodiments the protrusions may be part of the first tow ball engaging portion with the recesses being part of the second tow ball engaging portion, or a protrusion on a first side of the coupling may be part of the first tow ball engaging portion and a protrusion on a second side of the coupling may be part of the second tow ball engaging portion. The interlocking alignment means provides the advantage of better guiding the second tow ball engaging portion into correct alignment with the first tow ball engaging portion. The connection between the protrusions and the recesses also restrains the two tow ball engaging portions vertically, so ensuring the coupling is made correctly and is safer and more secure.

Additionally, or alternatively, the coupling may be provided with a central alignment means (shown in Figure 2) in which the first member 5 has one or more convex protrusions 11 which fit into one or more corresponding concave recesses 12 in the body 1. This central retaining formation provides a similar function to the alignment means of the tow ball engaging portions, and aids in constraining the first member vertically to ensure correct alignment.

The apparatus preferably includes a locking means 13 (seen best in Figures 1 and 2) which includes a second member 14 which is connected to the body of the apparatus via a rotatable connection 15. The second member includes an abutment formation 16 which engages with an abutment portion of the lever 17. When the abutment formation 16 and the abutment portion of the lever 17 are engaged, the second member 14 prevents the lever from rotating into the open position. Since the rotatable connection 15 of the locking means 13 is offset from the rotatable connection 4 of the lever member 3, the abutment formation 16 stops the abutment portion 17 of the lever member 3 from moving vertically, so preventing rotation of the lever member 3. The rotatable connection 15 is preferably spaced apart from the abutment formation as much as possible so that the arc described by the abutment formation 16 when the second member 14 is rotated has the largest possible radius.

Furthermore, the position of the rotatable connection 15 is preferably such that the abutment portion 17 is moving substantially parallel to a plane of an abutment surface 16a of the abutment formation 16 as it engages the abutment formation. In preferred embodiments the locking means is configured such that the biasing means automatically moves the abutment portion 17 into engagement with the abutment formation 16 when the first 2 and second 7 tow ball engaging portions are moved to the closed position. The locking means 13 can be engaged when the tow ball engaging portions have successfully enclosed the tow ball and will ensure that they do not disengage. The second member 14 includes a biasing means, for example a spring 18, which biases the second member 14 towards the locked position. The locking means 13 is preferably used in combination with the alignment means described above, but may also be useful with embodiments of the invention which do not comprise an alignment means. Similarly, the alignment means may be used in embodiments in which no locking means is present.

In preferred embodiments an aperture 19 for a locking pin is provided, as best seen in Figures 1, 2 and 3. This aperture extends through the body 1 as well as the first member 5 and allows an additional locking pin to be inserted which can provide additional restraint, ensuring the tow ball engaging portions do not disengage.

Referring to Figure 4, a pair of guiding plates 20 may be attached to the first tow ball engaging portion 2. These may be angled to guide the first tow ball engaging portion to engage with the posterior portion of the tow ball. This is an advantage when manoeuvring the towing vehicle into the correct position with the trailer, as the tow ball and the apparatus may not be exactly aligned.

Figure 2 also shows the central threaded hole 21, parallel to the longitudinal axis of the coupling, for connection to a brake assembly. This threaded hole matches with a threaded part of a coupling brake assembly. The handle portion of the lever 8 is also mounted to the side of the body 1 (as shown in Figure 4) to prevent the lever arm from interfering with the parts of a hydraulic or spring actuated coupling brake, such as the oil reservoir or master cylinder assembly. These features have the advantage of ensuring the apparatus does not interfere with components of the brake coupling.

Referring next to Figures 5 to 8 as second embodiment of the invention is described. This embodiment is adapted for use with a trailer which does not have an overrun braking system. The coupler assembly shown in Figures 5 to 8 is generally the same as that of the first embodiment, the primary difference being the provision of a mounting face 22 for mounting the coupler directly to the drawbar of the trailer. The mounting face 22 has bolt holes 23 (shown in Figures 5 and 8) which allow the coupling assembly to be bolted to the trailer.

According to a further embodiment of the invention the first tow ball engaging portion 2 may further comprise an anti-rattle means. The anti-rattle means may comprise a chock located in a recess on the first tow ball engaging portion 2 and configured to contact the posterior end of the tow ball. The recess contains a spring component attached to the chock. The chock extends from the recess partway into the cavity formed by the first and second tow ball engaging portions 2, 7. The chock is slidable in the recess and is biased to an extended position by the spring such that it contacts the tow ball in use. The anti- rattle means ensures that the tow ball does not rattle, move or make excessive noise even if the tow ball is not an exact fit for the coupler. The chock may be made of a hard-wearing material, for example a hard-wearing plastic, so that it is long-lasting and doesn't get easily damaged through use of the coupler. In other embodiments the anti-rattle means may be part of the second tow ball engaging portion 7 and may engage the anterior end of the tow ball.

The entire disclosures of all applications, patents and publications cited above and below, if any, are herein incorporated by reference.

Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavour in any country in the world.

The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the present invention.

The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof.