Patent Description:
Quick hitches, also known as quick couplers, are installed on working machines, such as excavators, backhoe loaders and telescopic handlers, to facilitate the connection of attachments or implements, for example working tools or buckets, on the machines.

Known quick hitches suffer the disadvantage that their lifecycle is limited by wear and damage that occurs during use. A further disadvantage of known quick hitches is that whilst they facilitate more rapid installation of attachments or implements on machines, the connection between the attachment or implement and the quick hitch is less robust than for traditional mountings. A yet further disadvantage of known quick hitches is that it is not immediately apparent to an operator of a machine if an implement is locked on the quick hitch.

<CIT> describes a coupler attached to the boom of a tractor or other vehicle. The coupler includes spring-loaded and laterally shiftable pins which automatically latch to the implement when the coupler is shifted forwardly toward the implement. Movement of the handle follows movement of the pins in all positions so that the position of the handle serves as a visual indicator as to whether the pins are latched or unlatched.

It is therefore an object of the present invention to provide an improved quick hitch for mounting an implement on a machine.

The present invention provides a quick hitch according to the appended claims.

According to a first aspect of the present disclosure there is provided a quick hitch for mounting an implement on a machine, the quick hitch including at least one mounting means for connection to a machine and a securing means for securing the quick hitch to an implement, the quick hitch further including at least one removable plate for engagement with a surface of an implement.

The at least one removable plate advantageously prolongs the lifecycle of the quick hitch as they provide a surface that engages the implement and can be replaced if/when the surface becomes worn in use. The at least one removable plate may be mounted on an upper surface of the quick hitch. The at least one removable plate may be mounted on an upper surface of the quick hitch by at least one fastening means, for example a bolt.

The at least one removable plate may have a length and the quick hitch have a length and to the ratio of the length of the removable plate to the length of the quick hitch may be less than one to three. The ratio of the length of the removable plate to the length of the quick hitch may be greater than one to six.

The at least one removable plate may be configured to fit under a lip on an implement. The at least one removable plate may have a surface that engages a lip on an implement in use. The surface of the at least one removable plate may be sloped. The at least one removable plate may include a metallic material. The at least one removable plate may include steel. The quick hitch may include at least two removable plates for engagement with a surface of an implement. The quick hitch may include an enclosure. The enclosure may be any enclosure as described in connection with the second aspect of the disclosure. The quick hitch may include an over-centre mechanism. The over-centre mechanism may be any over-centre mechanism as described in connection with the third aspect of the disclosure. The quick hitch may include a resilient link. The resilient link may be any resilient link as described in connection with the fourth aspect of the disclosure.

According to a second aspect of the present disclosure there is provided a quick hitch for mounting an implement on a machine, the quick hitch including an enclosure, the enclosure including at least one mounting means for connection to a machine, the enclosure accommodating a securing means for securing the quick hitch to an implement, the securing means having a first position in which the quick hitch is secured to an implement and a second position in which the quick hitch is not secured to an implement, the enclosure further including a first aperture through which a portion of the securing means extends when the securing means is in the first position.

The enclosure advantageously prolongs the lifecycle of the quick hitch as it prevents dirt and debris collecting on the quick hitch mechanism in use.

The securing means may include a signal means, the signal means having a first position for signalling that the quick hitch is secured to an implement when the securing means is in the first position and a second position for signalling that the quick hitch is not secured to an implement when the securing means is in the second position and the enclosure further includes an opening through which a portion of the signal means may extend.

The portion of the signal means may extend through the opening when the signal means is in the first position and/or the second position.

The securing means may include an actuator and/or the signal means may be connected to the actuator.

The actuator may be a manual actuator. The manual actuator may comprise a single handle.

The actuator may be an electric actuator.

The opening may include a cover for preventing the ingress of dirt or debris into the enclosure and through which the portion of the signal means may extend. The cover may include a plurality of bristles. The cover may include at least one brush.

The at least one mounting means may be provided on an exterior surface of the enclosure. The at least one mounting means may be a lug.

The enclosure may include a second aperture through which a second portion of the securing means may extend when the securing means is in the first position.

The enclosure may include at least one removable plate for engagement with a surface of an implement. The at least one removable plate may be any removable plate as described in connection with the first aspect of the disclosure.

The quick hitch may include an over-centre mechanism. The over-centre mechanism may be any over-centre mechanism as described in connection with the third aspect of the disclosure.

The quick hitch may include a resilient link. The resilient link may be any resilient link as described in connection with the fourth aspect of the disclosure.

According to a third aspect of the present disclosure there is a quick hitch for mounting an implement on a machine, the quick hitch including at least one mounting means for connection to a machine and a securing means for securing the quick hitch to an implement, the securing means including an over-centre mechanism and a locking member, the over-centre mechanism including a first link and a first pivotable member, wherein the first pivotable member is pivotal at a first axis D relative to a chassis of the quick hitch, a first end of the first link is pivotal at a second axis E relative to a first arm of the first pivotable member, and a second end of the first link is pivotal at a third axis F relative to the locking member, such that with the securing means in a first position, in which the quick hitch is secured to an implement, axis E lies on a first side of a straight line drawn between axes D and F and with the securing means in a second position, in which the quick hitch is not secured to an implement, axis E lies on a second side of a straight line drawn between axes D and F.

The over-centre mechanism advantageously increases the robustness of the connection between the implement or attachment and the quick hitch as it ensures that the locking member is held in position when the securing means is in the first position.

The locking member may include a projection for engaging an implement when the securing means is in a first position.

The quick hitch may include a first pin and the first pivotable member may include a second arm, such that with the securing means in the first position, the second arm is in abutment with the first pin and with the securing means in the second position, the second arm is spaced from the first pin.

The quick hitch may further include a second pivotable member and the securing means may include a second link, wherein a first end of the second pivotable member is pivotal at a fourth axis A relative to the chassis of the quick hitch, a first end of the second link is pivotal at a fifth axis B relative to the second pivotable member, and a second end of the second link is pivotal at a sixth axis C relative to the first pivotable member, such that with the securing means in the first position, axis B lies on a first side of a straight line drawn between axes A and C and with the securing means in the second position, axis B lies on a second side of a straight line drawn between axes A and C.

A second end of the second pivotable member may be an actuator for moving the securing means from the first position to the second position. The actuator may be a manual actuator. The actuator may comprise a single handle.

The second end of the second pivotable member may include a signal means, the signal means having a first position for signalling that the quick hitch is secured to an implement when the securing means is in the first position and a second position for signalling that the quick hitch is not secured to an implement when the securing means is in the second position.

The first link and/or the second link may be a resilient link.

The securing means may include an actuator that is operably connected to the first pivotable member such that actuation of the actuator causes the securing means to move from the first position to the second position.

The actuator may be a screw actuator. The actuator may be an electric actuator.

The quick hitch may include a second pin and the first pivotable member may include a leg, such that with the securing means in the first position, the leg is in abutment with the second pin and with the securing means in the second position, the leg is spaced from the second pin.

The leg may include a signal means, the signal means having a first position for signalling that the quick hitch is secured to an implement when the securing means is in the first position and a second position for signalling that the quick hitch is not secured to an implement when the securing means is in the second position.

The over-centre mechanism of the securing means may be a first over-centre mechanism, the locking member may be a first locking member, the first link may be a first first link, the first pivotable member may be a first first pivotable member, the first axis D may be the first first axis, the second axis E may be the first second axis, the first arm of the first first pivotable member may be the first first arm and the third axis F may be the first third axis, the securing means may further include a second over-centre mechanism and a second locking member, the second over-centre mechanism may include a second first link and a second first pivotable member, wherein the second first pivotable member may be pivotal at a second first axis D' relative to a chassis of the quick hitch, a first end of the second first link may be pivotal at a second second axis E' relative to a second first arm of the second first pivotable member, and a second end of the second first link may be pivotal at a second third axis F' relative to the second locking member, such that with the securing means in a first position, in which the quick hitch is secured to an implement, axis E' lies on a first side of a straight line drawn between axes D' and F' and with the securing means in a second position, in which the quick hitch is not secured to an implement, axis E' lies on a second side of a straight line drawn between axes D' and F'.

The quick hitch may further include at least one removable plate for engagement with a surface of an implement. The at least one removable plate may be any removable plate as described in connection with the first aspect of the disclosure.

The quick hitch may further include an enclosure. The enclosure may be any enclosure as described in connection with the second aspect of the disclosure.

The resilient link may be any resilient link as described in connection with the fourth aspect of the disclosure.

According to a fourth aspect of the present disclosure there is provided a quick hitch for mounting an implement on a machine, the quick hitch including at least one mounting means for connection to a machine and a securing means for securing the quick hitch to an implement, the securing means including a locking member and a second pivotable member, wherein the locking member and the second pivotable member are connected by a resilient link; the securing means having a first position in which the quick hitch is secured to an implement and a second position in which the quick hitch is not secured to an implement, wherein when the securing means is in the first position, the resilient link allows movement of the securing means to a third position which is between the first position and the second position.

The resilient link advantageously increases the robustness of the connection between the implement or attachment and the quick hitch as it ensures positive engagement of the locking member and maintains the quick hitch in compression to prevent the locking members becoming loose and rattling which may cause the implement to become dislodged from the quick hitch.

The locking member may have a first position when the securing means is in the first position and a second position when the securing means is in the third position and the first and second positions of the locking member may be separated by an axial distance.

The axial distance may be less than <NUM> millimetres, preferably less than <NUM> millimetres. The axial distance may be greater than <NUM> millimetres, preferably greater than <NUM> millimetres.

The securing means may further include a first link, a first pivotable member and a second link, wherein the first pivotable member is pivotal at a first axis D relative to a chassis of the quick hitch, a first end of the first link is pivotal at a second axis E relative to a first arm of the first pivotable member, a second end of the first link is pivotal at a third axis F relative to the locking member, a first end of the second pivotable member is pivotal at a fourth axis A relative to the chassis of the quick hitch, a first end of the second link is pivotal at a fifth axis B relative to the second pivotable member, and a second end of the second link is pivotal at a sixth axis C relative to the first pivotable member.

One or more of the first link, the first pivotable member, the second link and/or the second pivotable member may be the resilient link. The first link may be the resilient link.

The second pivotable member may include a signal means, the signal means may have a first position for signalling that the quick hitch is secured to an implement when the securing means is in the first position and a second position for signalling that the quick hitch is not secured to an implement when the securing means is in the second position.

The locking member may be pivotally connected to the resilient link.

The second pivotable member may be a manual actuator. The manual actuator may comprise a single handle.

The securing means may include an electric actuator. The electric actuator may be operably connected to the second pivotable member such that actuation of the actuator causes the securing means to move from the first position to the second position.

The quick hitch may include a second pin and the second pivotable member may include a leg, such that with the securing means in the first position, the leg is in abutment with the second pin and with the securing means in the second position, the leg is spaced from the second pin.

The locking member may be the first locking member, the second pivotable member may be the first second pivotable member, and the resilient link may be the first resilient link, the securing means may further include a second locking member and a second second pivotable member, wherein the second locking member and the second second pivotable member are connected by a second resilient link, wherein when the securing means is in the first position, the second resilient link allows movement of the securing means to a third position which is between the first position and the second position.

The quick hitch may include at least one removable plate for engagement with a surface of an implement. The at least one removable plate may be any removable plate as described in connection with the first aspect of the disclosure.

The quick hitch may include an enclosure. The enclosure may be any enclosure as described in connection with the second aspect of the disclosure.

Embodiments of the present invention will now be described with reference to the accompanying Figures in which:.

Referring now to <FIG>, <FIG>, <FIG>, <FIG>, there is shown a quick hitch <NUM> according to a first embodiment of the invention.

<FIG> and <FIG> show the quick hitch <NUM> in an unlocked position and <FIG>, <FIG>, <FIG> and <FIG> show the quick hitch <NUM> in a locked position.

The quick hitch <NUM> has a body <NUM>, mounting means 6a, 6b, 6c for mounting the quick hitch <NUM> on a machine and securing means <NUM> for securing an implement to the quick hitch <NUM>.

The quick hitch <NUM> also includes a first pin 49a, second pin 49b and pivots <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. Each of the first pin 49a, second pin 49b and pivot <NUM> which has an axis G, pivot <NUM> which has an axis D, pivot <NUM> which has an axis C, pivot <NUM> which has an axis D', pivot <NUM> which has an axis G' are mounted on a chassis of the quick hitch <NUM>.

The body <NUM> has side walls <NUM>, <NUM>, a base <NUM>, an upper surface <NUM>, a front wall <NUM> and a rear wall <NUM>.

The base <NUM> has a pair of apertures 28a, 28b.

The upper surface <NUM> has an opening <NUM> and a plate <NUM>. The plate <NUM> has an opening <NUM> that corresponds to the opening <NUM> in the upper surface <NUM>. The plate <NUM> has brushes (not shown) within the opening <NUM>.

The front wall <NUM> is generally U-shaped.

The rear wall <NUM> includes a pair of access doors 34a, 34b. The mounting means 6a, 6b, 6c are mounted on the rear wall <NUM> and have lugs 7a, 7b, 7c, with apertures 9a, 9b, 9c for receiving supporting pins (not shown). The rear wall <NUM> also includes a pair of upwardly extending arms 18a, 18b. The upwardly extending arms 18a, 18b have removable plates 26a, 26b mounted thereon.

The side walls <NUM>, <NUM>, base <NUM>, upper surface <NUM>, front wall <NUM> and rear wall <NUM> of the body provide an enclosure or casing for the securing means <NUM>.

The securing means <NUM> includes a first over-centre mechanism 36a and a first locking member 38a. The first over-centre mechanism 36a includes a first link 40a and a first pivotable member 42a.

The first link 40a has a first end 50a and a second end 50b. The first end 50a has a pivot <NUM> which has an axis F. As shown in <FIG>, the first link 40a is a resilient link and has a hollow cylindrical body <NUM>, a piston member <NUM> and a spring <NUM>.

The first pivotable member 42a includes a first arm <NUM>, a second arm <NUM> and a third arm <NUM>. The first arm <NUM> has a pivot <NUM> which has an axis E.

The first locking member 38a includes a first projection 48a.

The securing means <NUM> includes a second over-centre mechanism 36b and a second locking member 38b. The second over-centre mechanism 36b includes a second first link 40b and a second first pivotable member 42b.

The second first link 40b has a first end 62a and a second end 62b. The first end 62a has a pivot <NUM> which has an axis F'. Similarly to the first link 40a, the second first link 40b is a reslient link and has a hollow cylindrical body <NUM>, a piston member <NUM> and a spring (not shown).

The second first pivotable member 42b includes a first arm <NUM>, a second arm <NUM> and a third arm <NUM>. The first arm <NUM> has a pivot <NUM> which has an axis E'.

The second locking member 38b includes a second projection 48b.

The securing means <NUM> further includes a second link 44a and a second second link 44b.

The second link 44a has a first end 56a and a second end 56b. The first end 56a has a pivot <NUM> which has an axis A. The second end 56b has a pivot <NUM> which has an axis B.

The second second link 44b has a first end 68a and a second end 68b. The first end 68a has a pivot <NUM> which has an axis A'. The second end 68b has a pivot <NUM> which has an axis B'.

The securing means <NUM> further includes a second pivotable means <NUM>. The second pivotable member <NUM> has a first end 58a, a second end 58b and a plate <NUM>.

The plate <NUM> has a first end 65a and a second end 65b. The plate <NUM> also has three holes 164a, 164b, 164c. Hole 164a is located adjacent to the first end 65a of the plate <NUM>, hole 164c is located adjacent to the second end 65b of the plate <NUM> and hole 164b is located between hole 164a and 164c along the length of the plate <NUM>.

Assembly of the securing means <NUM> of the quick hitch <NUM> of the first embodiment will now be described.

The first over-centre mechanism 36a is assembled as follows.

The first pivotable member 42a is pivotably mounted at pivot <NUM> such that the first pivotable member 42a is able to pivot relative to the chassis of the quick hitch <NUM> about axis D. The second end 50b of the first link 40a is pivotably mounted to the first arm <NUM> of the first pivotable member 42a such that the first link 40a and the first pivotable member 42a are able to pivot relative to each other about axis E. The first end 50a of the first link 40a is pivotably mounted to the first locking member 38a such that the first link 40a and the first locking member 38a are able to pivot relative to each other about axis F. The first locking member 38a is pivotably mounted at pivot <NUM> such that the first locking member 38a is able to pivot relative to the chassis of the quick hitch <NUM> about axis G.

The second over-centre mechanism 36b is assembled as follows.

The second first pivotable member 42b is pivotably mounted at pivot <NUM> such that the second first pivotable member 42b is able to pivot relative to the chassis of the quick hitch about axis D'. The second end 62b of the second first link 40b is pivotably mounted to the first arm <NUM> of the second first pivotable member 42b at pivot <NUM> such that the second first link 40b and the second first pivobtable member 42b can pivot relative to each other about axis E'. The first end end 62a of the second first link 40b is pivotably mounted to the second locking member 38b at pivot <NUM> such that the second first link 40b and the second locking member 38b can pivot relative to each other about axis F'. The second locking member 38b is pivotably mounted at pivot <NUM> such that the second locking member 38b is able to pivot relative to the chassis of the quick hitch <NUM> about axis G'.

The second end 58b of the second pivotable member <NUM> and central hole 164b of plate <NUM> are mounted on pivot <NUM> such that the second pivotable member <NUM> and the plate <NUM> can rotate about axis C.

The first over-centre mechanism 36a is linked to the second pivotable member <NUM> and the plate <NUM> by second link 44a. The third arm <NUM> of the first pivotable member 42a is pivotally mounted to the first end 56a of the second link 44a such that the first pivotable member 42a and the second link 44a can pivot relative to each other about axis A. The second end 56b of second link 44a is mounted on hole 164a at the first end 65a of the plate <NUM> at pivot <NUM> such that the second end 56b of the second link 44a can pivot about axis C.

The second over-centre mechanism 36b is linked to the second pivotable member <NUM> by second second link 44b. The third arm <NUM> of the second first pivotable member 42b is pivotally mounted to the first end 68a of the second second link 44b such that the second first pivotable member 42b and the second second link 44b can pivot relativ to each other about axis A'. The second end 68b of the second second link 44b is mounted on hole 164c at the second end 65b of the plate <NUM> at pivot <NUM> such that the second second link 44b can pivot about axis C.

The body <NUM> is partially constructed by assembling the front wall <NUM>, the side walls <NUM>, <NUM>, the base <NUM> and the upper surface <NUM>.

The securing means <NUM> is placed within the partially constructed body <NUM> such that the first end 68a of the second pivotable member <NUM> extends through the opening <NUM> in the upper surface <NUM>, the first projection 48a of the first locking member 38a is positioned adjacent to aperture 28a in the base <NUM> and the second projection 48b of the second locking member 38b is positioned adjacent to aperture 28b in the base <NUM>.

The rear wall <NUM> is then mounted to the side walls <NUM>, <NUM>, the base <NUM> and the upper surface <NUM> to complete the body <NUM>.

Plate <NUM> is mounted on the upper surface <NUM> of the body <NUM> using fasteners <NUM> such that the opening <NUM> of the plate <NUM> corresponds to the opening <NUM> of the upper surface <NUM> and the first end 68a of the second pivotable member <NUM> extends through opening <NUM> in the upper surface <NUM>, the brushes (not shown) and opening <NUM> in the plate <NUM>.

Removable plate 26a is mounted on upper arm 18a using fasteners <NUM>. In the same way, removable plate 26b is mounted on upper arm 18b using fasteners <NUM>.

Use of the quick hitch <NUM> to mount an implement, for example a shovel <NUM>, as shown in <FIG>, <FIG> on a machine (not shown) will now be described.

The quick hitch <NUM> is secured on the machine (not shown) with the rear wall <NUM> of the quick hitch <NUM> facing the front of the machine (not shown). The mounting means 6a, 6c, 6c are secured on complementary mounting means (not shown) on the machine (not shown) by pins (not shown).

The shovel <NUM> has a base <NUM>, side walls 184a, 184b and a rear wall <NUM>. The rear wall <NUM> has a lower lip <NUM>, an upper lip <NUM> and an outer surface <NUM>. The upper lip <NUM> has a lower surface <NUM>.

The machine with the quick hitch <NUM> in the unlocked position (as shown in <FIG>) and the shovel <NUM> are brought into close proximity such that the front wall <NUM> of the quick hitch is adjacent to the outer surface <NUM> of the rear wall <NUM> of the shovel <NUM>. The upper arms 18a, 18b are positioned under the upper lip <NUM> such that the removable plates 26a, 26b are in contact with the lower surface <NUM> of the upper lip <NUM>. The base <NUM> of the quick hitch is lined up with the lower lip <NUM> such that the apertures 28a, 28b are adjacent to the lower lip <NUM>.

To lock the shovel <NUM> on the quick hitch <NUM>, the first end 58a of the second pivotable member <NUM>, which acts as a manual actuator or handle, is moved from the position shown in <FIG> and <FIG> to the position shown in <FIG> and <FIG>. The first end 58a advantageously provides a single lever or handle for operating i.e. engaging and disengaging the quick hitch mechanism.

This causes the second end 58b of the second pivotable member <NUM>, the second end 56b of the second link 44a and the second end 68b of the second second link 44b to be pivoted anticlockwise about axis C.

The pivoting movement of the second end 56b of the second link 44a about pivot C causes the first end 56a of the second link 44a and the third arm <NUM> of the first pivotable member 42a to pivot clockwise relative to axis A, the second arm <NUM> of the first pivotable member 42a to pivot clockwise relative to axis D and the first arm <NUM> of the first pivotable member 42a to pivot clockwise relative to axis E.

The distance travelled by the second arm <NUM> of the first pivotable member 42a is limited by pin 49a against which the second arm <NUM> abuts when the securing means <NUM> is in the locked position.

The pivoting movement of the first pivotable member 42a causes the second end 50b of the first link 40a to pivot anticlockwise relative to axis E and the first end 50a of the first link 40a to pivot anticlockwise relative to axis F.

The pivoting movement of the first link 40a causes the first locking member 38a to pivot anticlockwise relative to axis F which causes the first projection 48a to move downward and to extend through aperture 28a in the base <NUM>.

The first projection 48a engages the lower lip <NUM> of the shovel <NUM> to lock the shovel <NUM> to the quick hitch <NUM>.

When the securing means <NUM> is in the locked position, upward movement of the first projection 48a is restricted by the resilient link 40a.

The pivoting movement of the second end 68b of the second second link 44b about pivot C causes the first end 68a of the second second link 44b and the third arm <NUM> of the second first pivotable member 42b to pivot anticlockwise relative to axis A', the second arm <NUM> of the second first pivotable member 42b to pivot anticlockwise relative to axis D' and the first arm <NUM> of the second first pivotable member 42b to pivot anticlockwise relative to axis E'.

The distance travelled by the second arm <NUM> of the second first pivotable member 42b is limited by pin 49b against which it abuts.

The pivoting movement of the second first pivotable member 42b causes the second end 62b of the second first link 40b to pivot anticlockwise relative to axis E' and the first end 62a of the second first link 40b to pivot clockwise relative to axis F'.

The pivoting movement of the second first link 40b causes the second locking member 38b to pivot clockwise relative to axis F' which causes the second projection 48b to move downward and to extend through aperture 28b in the base <NUM>.

The second projection 48b engages the lower lip <NUM> of the shovel <NUM> to lock the shovel <NUM> to the quick hitch <NUM>.

When the securing means <NUM> is in the locked position, upward movement of the second projection 48b is restricted by the resilient link 40b.

When the quick hitch <NUM> is secured to the shovel <NUM> (as shown in <FIG>) axis E of the first over-centre mechanism 36a lies on a first side of a straight line drawn between axes D and F and when the quick hitch is not secured to the shovel (as shown in <FIG>) axis E lies on a second side of a straight line drawn between axes D and F. In a similar way (not shown in the Figures) axis E' of the second over-centre mechanism 36b lies on a first side of a straight line drawn between axes D' and F' when the quick hitch <NUM> is secured to the shovel <NUM> and when the quick hitch <NUM> is not secured to the shovel <NUM>, axis E' lies on a second side of a straight line drawn between axes D' and F'.

In this way the first and second projections 48a, 48b are preventing from pushing against the second pivotable member <NUM> when they are in the locked position.

The inclusion of a resilient, or spring-loaded, first link 40a on one side of the securing means and a second first link 40b on a second side of the securing means <NUM> ensures positive engagement of the first and second projections 48a, 48b and keeps the securing means <NUM> in compression to prevent the securing means <NUM> from ratting, which may result in the first and second projections 48a, 48b disengaging from the lower lip <NUM> of the shovel <NUM>.

The inclusion of the solid piston or plunger <NUM> in a hollow cylindrical body <NUM> having a spring <NUM> limits the upward movement of the first and second projections 48a, 48b to no more than <NUM> millimetres when the second pivotable member <NUM> and securing means <NUM> are in the locked position. This ensures attachment engagement at all times when the second pivotable member <NUM> and securing means <NUM> are in the locked position.

The position of the second pivotable means <NUM> through the opening <NUM> in the upper surface <NUM> and the opening <NUM> in the plate <NUM> when the quick hitch <NUM> is in the unlocked position compared to the position of the second pivotable means <NUM> through the opening <NUM> in the upper surface <NUM> and the opening <NUM> in the plate <NUM> when the quick hitch <NUM> is in the locked position indicates to an operator whether or not the shovel <NUM> is secured on the quick hitch <NUM>.

The provision of the body <NUM> to enclose the securing means prevents damage being caused to the securing means <NUM> by dirt and debris. The provision of brushes (not shown) within the opening <NUM> of the plate further prevents the ingress of dirt and debris into the body <NUM> of the quick hitch <NUM>.

The provision of removable plates 26a, 26b on the arm portions 18a, 18b which engage the lower surface <NUM> of the upper lip <NUM> of the shovel <NUM> increase the lifecycle of the quick hitch as the plates 26a, 26b can be removed from the quick hitch <NUM> when worn and replaced with new, unworn, plates.

Referring now to <FIG>, <FIG>, <FIG>, <FIG>, there is shown a quick hitch <NUM> according to a second embodiment of the invention.

<FIG> and <FIG> show the quick hitch <NUM> in an unlocked position and <FIG> and <FIG> show the quick hitch <NUM> in a locked position.

The quick hitch <NUM> also includes a first pin 49a, second pin 49b, a third pin 249c and pivots <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. Each of the first pin 49a, second pin 49b and pivot <NUM> which has an axis G", pivot <NUM> which has an axis D", pivot <NUM> which has an axis C", pivot <NUM> which has an axis D'", pivot <NUM> which has an axis G‴ are mounted on a chassis of the quick hitch <NUM>.

The securing means <NUM> includes a first over-centre mechanism 236a and a first locking member 238a. The first over-centre mechanism 236a includes a first link 240a and a first pivotable member 242a.

The first link 240a has a first end 250a and a second end 250b. The first end 250a has a pivot <NUM> which has an axis F". The first link 240a is a resilient link and (as shown in <FIG> in relation the first link 40a of the first embodiment) has a hollow cylindrical body <NUM>, a piston member <NUM> and a spring <NUM>.

As shown in <FIG>, the first pivotable member 242a includes a first arm <NUM>, a second arm <NUM>, a third arm <NUM> and a leg <NUM>. The first arm <NUM> has a pivot <NUM> which has an axis E". The leg <NUM> has a hook portion 253a.

The first locking member 238a includes a first projection 248a.

The securing means <NUM> includes a second over-centre mechanism 236b and a second locking member 238b. The second over-centre mechanism 236b includes a second first link 240b and a second first pivotable member 242b.

The second first link 240b has a first end 262a and a second end 262b. The first end 262a has a pivot <NUM> which has an axis F'". Similarly to the first link 240a, the second first link 240b is a resilient link and has a hollow cylindrical body <NUM>, a piston member <NUM> and a spring (not shown).

The second first pivotable member 242b includes a first arm <NUM>, a second arm <NUM> and a third arm <NUM>. The first arm <NUM> has a pivot <NUM> which has an axis E'".

The second locking member 238b includes a second projection 248b.

The securing means <NUM> further includes an actuator <NUM>. As shown more clearly in <FIG>, the actuator <NUM> has a screw actuator <NUM> and a motor <NUM>. The screw actuator <NUM> has a first end 366a and a second end 366b.

Assembly of the securing means <NUM> of the quick hitch <NUM> of the second embodiment will now be described.

The first over-centre mechanism 236a is assembled as follows.

The first pivotable member 242a is pivotably mounted at pivot <NUM> such that the first pivotable member 242a is able to pivot relative to the chassis of the quick hitch <NUM> about axis D". The second end 250b of the first link 240a is pivotably mounted to the first arm <NUM> of the first pivotable member 242a such that the first link 240a and the first pivotable member 242a are able to pivot relative to each other about axis E". The first end 250a of the first link 240a is pivotably mounted to the first locking member 238a such that the first link 240a and the first locking member 238a are able to pivot relative to each other about axis F". The first locking member 238a is pivotably mounted at pivot <NUM> such that the first locking member 238a is able to pivot relative to the chassis of the quick hitch <NUM> about axis G".

The second over-centre mechanism 236b is assembled as follows.

The second first pivotable member 242b is pivotably mounted at pivot <NUM> such that the second first pivotable member 242b is able to pivot relative to the chassis of the quick hitch about axis D'". The second end 262b of the second first link 240b is pivotably mounted to the first arm <NUM> of the second first pivotable member 242b at pivot <NUM> such that the second first link 240b and the second first pivotable member 242b can pivot relative to each other about axis E'". The first end 262a of the second first link 240b is pivotably mounted to the second locking member 238b at pivot <NUM> such that the second first link 240b and the second locking member 238b can pivot relative to each other about axis F'". The second locking member 238b is pivotably mounted at pivot <NUM> such that the second locking member 238b is able to pivot relative to the chassis of the quick hitch <NUM> about axis G'".

The first over-centre mechanism 236a is linked to the second over-centre mechanism 236b by the actuator <NUM>. The second arm <NUM> of the first pivotable member 242a is mounted on the first end 366a of the screw actuator <NUM>. The third arm <NUM> of the second first pivotable member 242b is mounted on the second end 366b of the screw actuator <NUM>.

The securing means <NUM> is placed within the partially constructed body <NUM> such that the leg <NUM> of the first pivotable member 242a extends through the opening <NUM> in the upper surface <NUM>, the first projection 248a of the first locking member 238a is positioned adjacent to aperture 28a in the base <NUM> and the second projection 248b of the second locking member 238b is positioned adjacent to aperture 28b in the base <NUM>.

Plate <NUM> is mounted on the upper surface <NUM> of the body <NUM> using fasteners <NUM> such that the opening <NUM> of the plate <NUM> corresponds to the opening <NUM> of the upper surface <NUM> and the leg <NUM> of the first pivotable member 242a extends through opening <NUM> in the upper surface <NUM>, the brushes (not shown) and opening <NUM> in the plate <NUM>.

The machine with the quick hitch <NUM> in the unlocked position (as shown in <FIG>) and the shovel <NUM> are brought into close proximity such that the front wall <NUM> of the quick hitch <NUM> is adjacent to the outer surface <NUM> of the rear wall <NUM> of the shovel <NUM>. The upper arms 18a, 18b are positioned under the upper lip <NUM> such that the removable plates 26a, 26b are in contact with the lower surface <NUM> of the upper lip <NUM>. The base <NUM> of the quick hitch is lined up with the lower lip <NUM> such that the apertures 28a, 28b are adjacent to the lower lip <NUM>.

To lock the shovel <NUM> on the quick hitch <NUM>, the actuator <NUM> is activated to move the leg <NUM> of the first pivotable member 242a from the position shown in <FIG> and <FIG> to the position shown in <FIG> and <FIG>.

This causes the first pivotable member 242a to rotate in a clockwise direction such that the hook portion 253a of the leg <NUM> abuts the pin 249c, the second arm <NUM> abuts pin 49a and the actuator <NUM> is moved in an upward direction.

The rotation of the first pivotable member 242a causes the first link 240a to rotate in an anticlockwise direction.

The pivoting movement of the first link 240a causes the first locking member 238a to pivot anticlockwise relative to axis F" which causes the first projection 248a to move downward and to extend through aperture 28a in the base <NUM>.

The first projection 248a engages the lower lip <NUM> of the shovel <NUM> to lock the shovel <NUM> to the quick hitch <NUM>.

When the securing means <NUM> is in the locked position, upward movement of the first projection 248a is restricted by the resilient link 240a.

The upward movement of the actuator <NUM> causes the third arm <NUM> of the second first pivotable member 242b to pivot anticlockwise relative to axis A'", the second arm <NUM> of the second first pivotable member 242b to pivot anticlockwise relative to axis D‴ and the first arm <NUM> of the second first pivotable member 242b to pivot anticlockwise relative to axis E'".

The distance travelled by the second arm <NUM> of the second first pivotable member 242b is limited by pin 49b against which the second arm <NUM> abuts when the securing means <NUM> in the locked position.

The pivoting movement of the second first pivotable member 242b causes the second end 262b of the second first link 240b to pivot anticlockwise relative to axis E‴ and the first end 262a of the second first link 240b to pivot clockwise relative to axis F'".

The pivoting movement of the second first link 240b causes the second locking member 238b to pivot clockwise relative to axis F‴ which causes the second projection 248b to move downward and to extend through aperture 28b in the base <NUM>.

The second projection 248b engages the lower lip <NUM> of the shovel <NUM> to lock the shovel <NUM> to the quick hitch <NUM>.

When the securing means <NUM> is in the locked position, upward movement of the second projection 248b is restricted by the resilient link 240b.

When the quick hitch <NUM> is secured to the shovel <NUM> (as shown in <FIG>) axis E" of the first over-centre mechanism 236a lies on a first side of a straight line drawn between axes D" and F" and when the quick hitch is not secured to the shovel (as shown in <FIG>) axis E" lies on a second side of a straight line drawn between axes D" and F". In a similar way (not shown in the Figures) axis E‴ of the second over-centre mechanism 236b lies on a first side of a straight line drawn between axes D‴ and F‴ when the quick hitch <NUM> is secured to the shovel <NUM> and when the quick hitch <NUM> is not secured to the shovel <NUM>, axis E‴ lies on a second side of a straight line drawn between axes D‴ and F‴.

In this way the first and second projections 248a, 248b are prevented from pushing against the actuator <NUM> when they are in the locked position.

The inclusion of a resilient, or spring-loaded, first link 240a on one side of the securing means <NUM> and a second first link 240b on a second side of the securing means <NUM> ensures positive engagement of the first and second projections 248a, 248b and keeps the securing means <NUM> in compression to prevent the securing means <NUM> from ratting, which may result in the first and second projections 248a, 248b disengaging from the lower lip <NUM> of the shovel <NUM>.

The inclusion of the solid piston or plunger <NUM> in a hollow cylindrical body <NUM> having a spring <NUM> limits the upward movement of the first and second projections 248a, 248b to no more than <NUM> millimetres when the securing means <NUM> is in the locked position. This ensures attachment engagement at all times when the securing means <NUM> is in the locked position.

The position of the leg <NUM> of the first pivotable means 242a through the opening <NUM> in the upper surface <NUM> and the opening <NUM> in the plate <NUM> when the quick hitch <NUM> is in the unlocked position compared to the position of the leg <NUM> of the first pivotable means 242a within the body <NUM> of the quick hitch (i.e. not visible to an operator) indicates or provides a signal to an operator whether or not the shovel <NUM> is secured on the quick hitch <NUM>.

The provision of removable plates 26a, 26b on the arm portions 18a, 18b which engage the lower surface <NUM> of the upper lip <NUM> of the shovel <NUM> increase the lifecycle of the quick hitch <NUM> as the plates 26a, 26b can be removed from the quick hitch <NUM> when worn and replaced with new, unworn, plates.

In the embodiments described above the quick hitches <NUM>, <NUM> included wear plates 26a, 26b in addition to a body <NUM> for enclosing the securing means <NUM>, <NUM>, an over-centre mechanism 36a, 36b, 236a, 236b and a resilient link 40a, 40b, 240a, 240b. It will be understood by a person skilled on the art that a quick hitch according to the present invention could include any combination of the aforementioned advantageous features.

Claim 1:
A quick hitch (<NUM>) for mounting an implement on a machine, the quick hitch including an enclosure, the enclosure (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) including at least one mounting means (6a, 6b, 6c) for connection to a machine, the enclosure accommodating a securing means (<NUM>) for securing the quick hitch to an implement, the securing means having a first position in which the quick hitch is secured to an implement and a second position in which the quick hitch is not secured to an implement, the enclosure further including a first aperture (28a) through which a portion of the securing means extends when the securing means is in the first position,
wherein the securing means includes a signal means (<NUM>), the signal means having a first position for signalling that the quick hitch is secured to an implement when the securing means is in the first position and a second position for signalling that the quick hitch is not secured to an implement when the securing means is in the second position;
wherein the enclosure further includes an upper surface (<NUM>) having an opening (<NUM>) through which a portion of the signal means extends when the signal means is in either the first position or the second position; and
wherein the opening includes a cover (<NUM>) for preventing the ingress of dirt or debris into the enclosure and through which the portion of the signal means may extend.