GB2515829A - Latch mechanism - Google Patents

Abstract

A structure 10, which may be a livestock transporter has a deck 14 which can be retained at an intermediate height (Figure 6), be lowered (Figure 10) below the intermediate height and be raised (Figure 16) above the intermediate height. A latch mechanism 20 comprising a freely rotatable catch 30 mounted to the deck 14, upper 22 and lower 24 alignment guides mounted to a side element 19 and a spring 28 biased trigger 26 pivotally mounted on the side element 19 between the alignment guides 22, 24 and a support abutment 29 mounted to the side element and laterally spaced from the lower alignment guide 24. The guides 22, 24 and trigger device 26 are arranged so on actuation to raise the deck 14 the catch 30 is orientated by contact with the lower guide 24 so the catch 30 passes adjacent the lower guide 24 and between the lower guide 24 and the abutment 29.

Description

Latch mechanism (0001] This invention relates to a latch mechanism for a structure having a floor and a ceiling and a deck which can be deployed selectively to a level intermediate the floor and the ceiling or can be lowered to lie adjacent the floor or raised to lie adjacent the ceiling.

BACKGROUND

(0002] Containers for livestock transport, whether integrally provided on a vehicle or on a trailer, typically have a deck which can be deployed selectively to a level intermediate the floor and the ceiling to subdivide the enclosed space into upper and lower compartments, as required for transporting sheep or other small livestock, or can be lowered to lie adjacent the floor or raised to lie adjacent the ceiling, so that the entire interior space of greater height can be used, as required for transporting cattle or other larger livestock.

Such containers have a side element, typically a side wall, relative to which the deck can be supported in a predetermined intermediate position and a powered mechanism, typically a hydraulically actuated pulley mechanism, for raising and lowering the deck.

(0003] When the deck is being moved up from the floor to the intermediate level, an operator typically switches on the hydraulic mechanism, watches the deck rise and by inspection stops the mechanism just above a required mid-level height. The operator then mounts or otherwise deploys supporting pegs on the side walls, then operates the mechanism in reverse to lower the deck to a position resting upon the support pegs. It is not desirable that the deck be held simply by the cables of the pulley mechanism. Robust fixed support of the deck at the intermediate level is required to avoid strain on the cables and/or for safety reasons.

[0004] In the context of livestock containers an object of the invention is to provide a latch mechanism which may enable the deck selectively to be retained and supported at the predetermined intermediate position, yet also be capable of being released for lowering to adjacent the floor, and also be capable of being raised to lie adjacent the ceiling. It is desirable that the mechanism should be highly reliable and substantially automatic in that manual intervention preferably not be required other than actuation of the powered mechanism for raising and lowering the deck.

BRIEF SUMMARY OF THE DISCLOSURE

[0005] The present invention provides a structure having a floor and a ceiling and providing an enclosed or partially enclosed space, as for storage and/or transport of livestock or other goods or for temporary accommodation or performance, said structure comprising: a deck which can be deployed selectively to a level intermediate the floor and the ceiling to subdivide the enclosed space into upper and lower compartments or arenas or can be lowered to lie adjacent the floor or raised to lie adjacent the ceiling; a side element relative to which the deck can be supported in a predetermined intermediate position; a mechanism for raising and lowering the deck; and a latch mechanism enabling the deck selectively to be retained and supported at a predetermined intermediate position or to be released for lowering to adjacent the floor or to be raised to be adjacent ceiling, the latch mechanism comprising a catch which is mounted onto one side of the deck in a freely rotatable manner, upper and lower alignment guides fixedly mounted to the side element, a spring biased alignment trigger device pivotably mounted to the side element at a location between the upper and lower alignment guides! and a support abutment mounted to the side element at a lateral spacing from the lower alignment guide; the guides and the trigger device and the abutment being disposed relative to each other and each being configured so that, in use, upon actuation of the mechanism to exert a first force sufficient to raise the deck from floor level to the predetermined intermediate position, the catch is orientated by contact with the lower guide to pass adjacent the lower guide, between the lower guide and the abutment, until it contacts the trigger device, the catch is then orientated by contact with the trigger device to drop into contact with the abutment in such a disposition that it is held between the abutment and the lower guide with the deck supported at the intermediate position; upon subsequent actuation of the mechanism to lower the deck, which involves uplift of the deck prior to lowering, the catch is caused again to contact the trigger device and to be orientated so as to pass downwards adjacent the lower guide, between the lower guide and the abutment; upon actuation of the mechanism to exert a second force sufficient to raise the deck to lie adjacent the ceiling (or to any other position above the predetermined intermediate position), the upward force exerted on the catch causes the catch to pivot the trigger device against its spring bias and thereafter move upwards adjacent the upper guide; and upon subsequent actuation of the mechanism to lower the deck, the catch is orientated by contact with the upper guide so as to pass downwards beyond the trigger device and between the lower guide and the abutment.

[0006] Although the invention has been devised in the context of a livestock container, it must be appreciated that any structure which may have a comparable deck for deployment in similar manner between upper, ceiling level disposition, lower, floor level disposition and at least one predetermined intermediate position may employ a latching mechanism in accordance with the invention. Such structures may be building structures which provide for intermediate level platforms which may or may not be deployed, for example theatrical stages, or adaptable living or office accommodation or industrial storage premises.

[0007] The latch mechanism in accordance with the invention is designed to be failsafe.

Its main advantage is in allowing the deck automatically to be supported at the intermediate level in absence of continued operation of the deck raisingllowering mechanism, so the weight of the deck does not have be taken by the lifting mechanism.

Without any requirement for significant manual intervention the latch can be released from the supported intermediate position and be lowered again, or alternatively it can be raised from the lower position or the intermediate position into a higher position.

[0008] In preferred embodiments of the invention the latch mechanism includes a projection mounted to said one side of the deck at a spacing from the catch so that upon lowering of the deck from a position adjacent the ceiling (or from any other position above the predetermined intermediate position) said projection serves to pivot the trigger device against its spring bias to enable the catch to pass downwards beyond the trigger device.

[0009] Also in preferred embodiments of the invention the catch of the latch mechanism is configured to have opposing pairs of prongs defining opposing notches to facilitate its appropriate orientation by contact with the respective guides and the trigger device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A preferred practical embodiment of the latching mechanism of the invention will now be described, by way of example, with reference to the accompanying drawings, in which figures 1 to 23 are fragmentary side views showing the sequence of operation of the latch mechanism when mounted into a livestock container.

DETAILED DESCRIPTION

[0011] The drawings show a region near a rear end 12 of a livestock container in which a deck 14 is deployable selectively to a level intermediate the floor and the ceiling to subdivide the enclosed space into upper and lower compartments for transport of small livestock, such as sheep, or alternatively the deck 14 can be lowered to lie adjacent the floor or raised to lie adjacent the ceiling when larger livestock, typically cattle are to be conveyed. Thus, a rear end of a sidewall 10 of the container is in the plane of the paper, around the mid height level where the deck 14 would be held in its predetermined intermediate position. The rear of the container is the end where an opening is provided for the livestock to be moved in and out, and onto the deck 14 by means of a ramp, as necessary. A vertically extending side guide 16 is shown, which provides a vertical track for a rear slider 15 of the deck 14 when it moves upwards, as shown in figures 3 to 9. A latch mechanism, designated generally by reference 20 is mounted on a side wall element 13. The latch mechanism 20 comprises a bracket 17 fixed onto the side element 13 and component parts mounted on this bracket 17, namely upper and lower alignment guides 22, 24, an alignment trigger device 26, which is pivotably mounted about a pin 27 and biased by a torsion spring 28, and a support abutment 29 mounted to a limb 19 of the bracket 17 and thus at a lateral spacing from the lower alignment guide 24. The upper and lower guide 22,24 are mounted to the brackets 17 by means of screws or bolts 18 or similar.

[0012] The latch mechanism 20 also comprises a catch 30 which is mounted onto one side of the deck 14 in a freely rotatable manner. The catch 30 is mounted on a pin 32 on a bracket 34 which projects obliquely upwards and to the rear of the side of the deck 14. The catch 30 is of oblong shape and is configured to have opposing pairs of prongs 36 defining opposing notches 38 to facilitate its appropriate orientation by contact with the respective guides 22, 24 and the trigger device 26 in operation, as will be explained shortly by reference to the sequence of figures.

[0013] The bracket 34 and the deck 14 also carry a projection 35 mounted at the same side as the catch 30 but at a spacing apart from the catch. Upon lowering of the deck 14 from a position adjacent the ceiling of the container this projection 35 serves to pivot the trigger device 26 against bias of its associated spring 28, as shown in figures 19 and 20, to enable the catch 30 to pass downwards beyond the trigger device 26.

[0014] The container has a system of pulleys and cables powered by a hydraulic mechanism for raising and lowering the deck. This system is known and details of same are not relevant to the invention, and it is not shown in the drawings.

[0015] The latch mechanism 20 enables the deck 14 selectively to be retained and supported at a predetermined intermediate position or to be released for lowering to adjacent the floor or to be raised to be adjacent ceiling.

[0016] In use, and following the sequence of the drawings, upon actuation of the pulley system to exert a first force sufficient to raise the deck from floor level to the predetermined intermediate position, the catch 30 is orientated, i.e. appropriately rotated, by contact with the lower guide 24, to pass adjacent the lower guide, between the lower guide 24 and the abutment 29, until it contacts the trigger device 30. More specifically, as shown in figure 2, the prongs 36 at one end of the catch 30 contact a lower finger 23 of the lower guide 24 causing the catch 30 to be rotated into an appropriate alignment to traverse upwardly between the lower guide 24 and the abutment 29, as shown in figure 3.

[0017] By inspection, an operator releases actuation of the pulley system once the deck 14 has reached the required intermediate level. Marking may be provided on the exterior or interior of the container for this purpose. As the deck 14 reaches this required intermediate level the catch 30 is orientated by contact with the trigger device 26 to drop into contact with the abutment 29 in such a disposition that it is held between the abutment 29 and the lower guide 24, as shown in figure 6, with the deck 14 supported at the intermediate position. More specifically, as shown in figures 4 and 5, one of the prongs 36 of the catch 20 contacts a laterally projecting "beak" 46 on the trigger device 26, namely a contoured end portion of the device 26 which is effectively a lever pivoting about the pin 27, but held under spring bias. The catch 30 is thereby rotated further to appropriate disposition to be wedged against the abutment 29.

[0018] Upon subsequent actuation of the pulley system to lower the deck 14, which involves uplift of the deck 14 prior to lowering, the catch 30 is caused again to contact the trigger device 26 and to be further orientated so as to pass downwards adjacent the lower guide 24, between the lower guide 24 and the abutment 29. At this stage, as shown in figure 7, the prongs 36 at one end of the catch 30 contact a protrusion 48 on the trigger device 26 which is formed between the beak 46 and the pivot pin 27 on which the device is mounted. The catch 30 is thereby further rotated so as to be able to pass downwards again between the lower guide 24 and the abutment 29 as shown in figures 8 to 10.

[0019] Upon actuation of the pulley system to exert a second force sufficient to raise the deck 14 to lie adjacent the ceiling (or to any other position above the predetermined intermediate position), the upward force exerted on the catch 30 causes the catch 30 to pivot the trigger device 26 against the bias of its spring 28 and thereafter move upwards adjacent the upper guide 22, as shown in figures 11 to 16. As shown in figure 11, the prongs 36 at one end of the catch 30 engage the beak 46, just as in previous figure 5, but now the upward force is maintained, as the actuation of the pulley mechanism is not released, so that, as shown in figure 12, the upward force of the catch 30 pushes the projecting lever end of the catch 30 upwards, to allow the catch to pass. The catch then travels on upwards, rotating further so as to be orientated to pass adjacent the upper guide 22, as shown in figures 13, 14 and 15, with contact with a lower, laterally projecting finger of the upper guide 22, as necessary, as shown in figure 15.

[0020] Upon subsequent actuation of the pulley system to lower the deck 14, the catch is further orientated by contact with the upper guide 22 so as to pass downwards beyond the trigger device 26 and between the lower guide 24 and the abutment 29, as shown in figures 17 to 20. More specifically, one of the prongs 36 of the catch contacts an upper, laterally projecting finger 45 on the upper guide 22, causing the catch to rotate to an orientation for passing adjacent the trigger device 26 on the way down, as shown in figures 17 to 19. At the position shown in figure 19 the projection 35 mounted to the side of the deck 14 and the bracket 34, at a spacing from the catch 30, engages the end of the lever, constituted by the catch, at the other side of the pivot pin 27 to the beak 46 and thereby, owing to downward force of the entire deck 14, pivots the trigger device 26 against its spring bias, as shown in figure 20. This effectively moves the trigger device 26 out of the way to enable the catch 30 to pass downwards beyond the trigger device, as shown in figures 21 and 22.

[0021] Figure 23 shows the arrangement where the deck 14 is continuing downwards to its fully lowered condition, but also shows it where it is in the process of being raised, just prior to the position shown in figure 1.

[0022] In the arrangement shown in these drawings, as will be typical in any livestock container, the rear end of the deck 14, which may also comprise a ramp portion, is pivoted at its front end (out of view beyond the right hand end of the figures) such that it moves upwards towards the latch mechanism along an arcuate path. However, in other embodiments, whether in a livestock container, or any other structure where the latch mechanism may be used, the deck may be moved upwards and downwards in a disposition substantially perpendicular to the latch mechanism and would work in exactly comparable manner.

[0023] The foregoing is illustrative and not limited to the scope of the invention and details of the latch mechanism may vary in other embodiments. In particular, the precise shape of the upper and lower guides and of the trigger mechanism and of the catch may be different to the illustrated embodiment. Also, the guides and the trigger device may be mounted directly onto a side wall or side element, without requirement for the bracket.

Additionally, although the upper and lower guides in the illustrated embodiment are fixedly mounted, and that is preferred for simplicity of design and installation, it is possible in further embodiments that they could be mounted in a manner enabling pivoting or rotation, possibly under spring bias. The abutment device may also differ in nature to the illustrated embodiment, where a tubular peg mounted to a bolt has been found a satisfactory abutment. Further, the catch may be rotatably mounted directly to the deck without need any additional bracket, as in the illustrated embodiment. Finally, although a hydraulically powered pulley mechanism his been referred to for raising and lowering the deck, any other mechanism for this purpose, whether powered or merely manually actuated, may be employed within the scope of the invention. Other variations are possible.

[0024] Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of them mean "including but not limited to"! and they are not intended to (and do not) exclude other components. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0025] Features described in conjunction with a particular embodiment or example of the invention are to be understood to be applicable to any other embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims and drawings) may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Claims (5)

1. CLAIMS1. A structure having a floor and a ceiling and providing an enclosed or partially enclosed space, as for storage and/or transport of livestock or other goods or for temporary accommodation or performance, said structure comprising: a deck which can be deployed selectively to a level intermediate the floor and the ceiling to subdivide the enclosed space into upper and lower compartments or arenas or can be lowered to lie adjacent the floor or raised to lie adjacent the ceiling; a side element relative to which the deck can be supported in a predetermined intermediate position; a mechanism for raising and lowering the deck; and a latch mechanism enabling the deck selectively to be retained and supported at a predetermined intermediate position or to be released for lowering to adjacent the floor or to be raised to be adjacent ceiling, the latch mechanism comprising a catch which is mounted onto one side of the deck in a freely rotatable manner, upper and lower alignment guides fixedly mounted to the side element, a spring biased alignment trigger device pivotably mounted to the side element at a location between the upper and lower alignment guides, and a support abutment mounted to the side element at a lateral spacing from the lower alignment guide; the guides and the trigger device and the abutment being disposed relative to each other and each being configured so that, in use, upon actuation of the mechanism to raise the deck from floor level to the predetermined intermediate position, the catch is orientated by contact with the lower guide to pass adjacent the lower guide, between the lower guide and the abutment, until it contacts the trigger device, the catch is then orientated by contact with the trigger device to drop into contact with the abutment in such a disposition that it is held between the abutment and the lower guide with the deck supported at the intermediate position; upon subsequent actuation of the mechanism to lower the deck, which involves uplift of the deck prior to lowering, the catch is caused again to contact the trigger device and to be orientated so as to pass downwards adjacent the lower guide, between the lower guide and the abutment; upon actuation of the mechanism to raise the deck to lie adjacent the ceiling (or to any other position above the predetermined intermediate position), the upward force exerted on the catch causes the catch to pivot the trigger device against its spring bias and thereafter move upwards adjacent the upper guide; and upon subsequent actuation of the mechanism to lower the deck, the catch is orientated by contact with the upper guide so as to pass downwards beyond the trigger device and between the lower guide and the abutment.
2. 2. A structure according to claim 1 wherein the latch mechanism further comprises a projection mounted to said one side of the deck at a spacing from the catch so that upon lowering of the deck from a position adjacent the ceiling (or from any other position above the predetermined intermediate position) said projection serves to pivot the trigger device against its spring bias to move said trigger device out of the way and enable the catch to pass downwards beyond the trigger device.
3. 3. A structure according to claim 1 or claim 2 wherein the catch is configured to have opposing pairs of prongs defining opposing notches to facilitate its appropriate orientation by contact with the respective guides and the trigger device.
4. 4. A structure according to any preceding claim wherein the trigger device is configured to define respective contact locations for the catch for orientating the catch when it is being raised from a lowered position to the intermediate position and respectively for further orientating the catch when the deck is subsequently to be lowered.
5. 5. A latch mechanism for a structure having a floor and a ceiling and a deck which can be deployed selectively to a level intermediate the floor and the ceiling or can be lowered to lie adjacent the floor or raised to lie adjacent the ceiling, enabling the deck selectively to be retained and supported at a predetermined intermediate position or to be released for lowering to adjacent the floor or to be raised to be adjacent ceiling substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.Amendments to the claims have been filed as followsCLAIMS1. A structure having a floor and a ceiling and providing an enclosed or partially enclosed space, as for storage and/or transport of livestock or other goods or for temporary accommodation or performance, said structure comprising: a deck which can be deployed selectively to a level intermediate the floor and the ceiling to subdivide the enclosed space into upper and lower compartments or arenas or can be lowered to lie adjacent the floor or raised to lie adjacent the ceiling; a side element relative to which the deck can be supported in a predetermined intermediate position; a mechanism for raising and lowering the deck; and a latch mechanism enabling the deck selectively to be retained and supported at a predetermined intermediate position or to be released for lowering to adjacent the floor or to be raised to be adjacent ceiling, the latch mechanism comprising a catch which is mounted onto one side of the deck in a freely rotatable manner, upper and lower alignment "cf 15 guides fixedly mounted to the side element, a spring biased alignment trigger device pivotably mounted to the side element at a location between the upper and lower (3 alignment guides, and a support abutment mounted to the side element at a lateral 0 spacing from the lower alignment guide; CO the guides and the trigger device and the abutment being disposed relative to each other and each being configured so that, in use, upon actuation of the mechanism to raise the deck from floor level to the predetermined intermediate position, the catch is orientated by contact with the lower guide to pass adjacent the lower guide, between the lower guide and the abutment, until it contacts the trigger device, the catch is then orientated by contact with the trigger device to drop into contact with the abutment in such a disposition that it is held between the abutment and the lower guide with the deck supported at the intermediate position; upon subsequent actuation of the mechanism to lower the deck, which involves uplift of the deck prior to lowering, the catch is caused again to contact the trigger device and to be orientated so as to pass downwards adjacent the lower guide, between the lower guide and the abutment; upon actuation of the mechanism to raise the deck to lie adjacent the ceiling, or to any other position above the predetermined intermediate position, the upward force exerted on the catch causes the catch to pivot the trigger device against its spring bias and thereafter move upwards adjacent the upper guide; and upon subsequent actuation of the mechanism to lower the deck, the catch is orientated by contact with the upper guide so as to pass downwards beyond the trigger device and between the lower guide and the abutment.2. A structure according to claim 1 wherein the latch mechanism further comprises a projection mounted to said one side of the deck at a spacing from the catch so that upon lowering of the deck from a position adjacent the ceiling, or from any other position above the predetermined intermediate position, said projection serves to pivot the trigger device against its spring bias to move said trigger device out of the way and enable the catch to pass downwards beyond the trigger device.3. A structure according to claim 1 or claim 2 wherein the catch is configured to have opposing pairs of prongs defining opposing notches to facilitate its appropriate orientation by contact with the respective guides and the trigger device.4. A structure according to any preceding claim wherein the trigger device is configured to define respective contact locations for the catch for orientating the catch when it is being raised from a lowered position to the intermediate position and respectively for further orientating the catch when the deck is subsequently to be lowered.5. A latch mechanism for a structure having a floor and a ceiling and a deck which o can be deployed selectively to a level intermediate the floor and the ceiling or can be lowered to lie adjacent the floor or raised to lie adjacent the ceiling, enabling the deck o 20 selectively to be retained and supported at a predetermined intermediate position or to be released for lowering to adjacent the floor or to be raised to be adjacent ceiling substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.