GB2173386A - Catch system for headgate - Google Patents

Abstract

A catch assembly for headgates includes gates 20 that can be opened inwardly or outwardly and trapped in an intermediate position between inner (52) and outer (62) latch means. There may be inner and outer latch plates 52,62, each of which is displaceable by gates 20 moving from the corresponding side so that they can pass. Gates moving outwardly cannot pass the outer plate 62 unless this is manually displaced, because it is not (or not sufficiently) displaced automatically. Gates moving inwardly can pass both plates, e.g. because the outer plate 62 carries the inner plate 52 with it. <IMAGE>

Description

SPECIFICATION Catch system for headgate The present invention relates to a catch system for use in controlling a movable barrier, particularly but not exclusively a headgate. In another aspect it concerns a barrier assembly including such a catch system.

In a conventional headgate assembly, there are two opposed gates with a gap between sufficient for an animal's neck, but not for its head. In use, the gates are opened so that an animal can push its head past them. They are then closed, trapping the animal. Subsequently the gates are released again so that the animal can escape. The gates must then be reset. The operation of the gates is not always easy. When trying to catch an animal, if the gates are not locked soon enough it can go straight through, whereas if they are locked too soon, the animal can retreat, and it may then be unwilling to go forward again and be caught. Furthermore, it is generally necessary for the person operating the gate to be standing near it. This may be alarming to the animals, and furthermore means that one person can do little more than operate the gate.

According to the present invention there is provided a catch system for a movable barrier such that the barrier has first and second configurations and an intermediate locking configuration between them, the arrangement being such that when the barrier is moved from the first towards the second configuration it tends to become locked in the intermediate configuration until released; whereas it is freely movable from the second to the first configuration.There are various ways in which this can be achieved For example there may be a pair of displaceable latch means each of which has a locking configuration in which it is impassable by the barrier, the latch means being arranged so that movement of the barrier from the first configuration into the intermediate configuration displaces only the first latch means, whereas movement from the second configuration into the intermediate configuration displaces both latch means, thus allowing the barrier to continue into the first configuration. The latch means may be biased into their locking configurations, so that when the barrier moves from the first into the intermediate configuration, the first latch means returns to its locking configuration, so that the barrier is trapped by the two latch means, being unable to move in either direction until released.

In another aspect the invention provides a headgate assembly including such a catch system. It may include a pair of barriers, which may both be movable, and whose movement may be linked together. The assembly may include side barriers defining a stall leading to the movable barriers. The first configuration may have the barriers open inwardly such that an animal can pass its head between them, and then push them forwardly with its body.

The intermediate configuration may have the barriers opposed, thus defining a narrow nip between them for trapping the animal. The second configuration may have the barriers open outwardly. Preferably the barriers are biased from the second to the first configuration, so that as soon as an animal has departed they return to the initial state, ready to trap another. Preferably the barriers are releasable from the intermediate configuration by an operator who is remote from them, e.g.

standing at the rear of the barrier assembly.

An embodiment of the invention will be described in greater detail by way of example with reference to the accompanying drawings in which: Fig. 1 is a schematic front elevation of a headgate assembly embodying the invention, with two barriers open inwardly (in the first configuration); and Figs. 2 to 5 are schematic views showing the operation of the catch system, viewed along A-A in Fig. 1.

The illustrated headgate assembly has a frame 10 that includes a pair of upright gateposts 12 connected near their top by a crosspiece 14. There is a base 16 which extends rearwardly, and from the sides of which rise side barriers (not shown) connected to respective gateposts 12. Each gatepost 12 bears three fixed collars 18. A pair of gates 20 each comprise three uprights 22,24,26, and top and bottom crosspieces 28,30. The uprights 26 at the hinging sides rise substantially above the top crosspieces 28. They pass through the fixed collars 18, which thus serve for hinging. At the upper ends of the tall uprights 26, there are short transverse bars 32.

Regions of the bars 32 spaced from the uprights 26 are connected by a swivellable strut 34, so that the movements of the gates 20 are coordinated. (Of course, they could be independent if desired.) Each gate 20 has an inwardly and upwardly projecting latch portion 36, constituted in this example by portions of the crosspieces 28 which are bent upwardly and supported by diagonal stays 38. Each latch portion 36 has a respective engagement surface 40. The dimensions of the gates 20 and frame 10 are such that when the gates are in their closed position (in which they are coplanar) there is a gap between the adjacent uprights 22 which is insufficient for passage of a cow's head, but large enough to accommodate its neck. The latch portions 36 are then quite close together, with their engagement surfaces 40 a little way below the central portion of the crosspiece 14 of the frame 10.

The central portion of the crosspiece 14 bears an upright pillar 42. Four slidable collars 44,46,48,50 are engaged over it. The top and third collars 44,48 are fast with a rear latch plate 52. This has an upright portion 54 (to which the collars 44,48 are welded) and, at the bottom, a rearwardly extending guide surface portion 56, which slopes downwardly towards the upright portion 54.

Similarly, the second and fourth collars 46,50 are.secured to the upright portion 60 of a front latch plate 62, which likewise has a guide surface portion 64 extending upwardly away from its lower end, in this case in a forward direction. This forward guide surface portion 64 is longer than the rearward portion 56. It is strengthened by a central flange 66.

An upper region of the front latch plate 62 is pivotally connected to a rod 68 of a control linkage, which may be pivotally supported by a support member 70 secured to the crosspiece 14 of the frames 10. A member fast with the rod 68 may extend rearwardly, and be provided with a handgrip at the rear end.

When the latch plates 52,62 are unsupported, as shown in Fig. 3, the bottom collar 50 which is fast with the front latch plate 62 rests on the crosspiece 14. The lower collar 48 of the pair fast with the rear latch plate 52 is supported on the bottom collar 50. The upper collar 46 of the front plate 52 is spaced above the bottom rear collar 48. The top collar 44 of the rear plate 52 may rest on the collar 46.

If the gates are in the rearwardly open configuration shown in Fig. 1, the collars 44-50 are as shown in Fig. 3. If the gates are then moved towards the closed position, the engagement surfaces 40 on their latch portions 36 come in contact with the guide surface portion 56 of the rear latch plate 52. This is shaped so that with little force the gates can continue to close, and the latch plate 52 is raised. Its associated collars 44,48 rise with it as shown in Fig. 2, the gap between the front collars 46,50 being sufficient to accommodate the movement of the lower rear collar 48.

When the gates get into their closed position, their engagement surfaces 40 pass beyond the rear latch plate 52, which thus drops down to give the situation shown in Fig. 3.

Thus the gates are now held fast, unable to move forwardly or rearwardly owing to the front and rear latch plates 62,52. In order to permit the gates to open forwardly, the front latch plate 62 must be raised. This may be done by means of the control linkage, by means of which the rod 68 is pivotted about the support 70. Fig. 4 shows the front latch plate 62 raised, and a gate moving forwardly.

In order to return to the initial position, the gates must move back through the closed configuration. They may be biased to do so, e.g. by means of tension spring 70 coupled to the linkage 34 (and suitably connected to the top of the pillar 42). As the gates reach the front latch plate 62 from the front, contact of their latch portion engagement surfaces 40 with the guide surface 64 raises the plate 62. Since the bottom collar 48 of the rear latch plate 52 is resting on the bottom collar 50 of the front latch plate 62 (and the upper collars 46,44 may be in a similar relationship), the raising of the front latch plate 62 causes the rear latch plate 52 to be raised.If the gates 20 are travelling at adequate speed, as they will be if they are suitably spring-urged, they can pass right through the locking position before the latch plates 52,62 can drop back and trap them. It will be noted that, in their lowest positions, the guide surface portion 56 of the rear latch plate 52 is somewhat higher than that of the front latch plate 62, so as to make this easier. The start of this movement is shown in Fig. 5.

The illustrated assembly is intended for cattle, though of course different sized versions could be produced, e.g. appropriate to sheep.

Although the gates 20 are shown as having outer uprights 22 which are straight, it may be preferred to have. these shaped, so that they define an aperture for an animal's neck, thus limiting its vertical movement. (The general spacing of the uprights 22 in the closed position would then be rather less than as shown here.) For using the illustrated device, the gates 20 are normally in the inwardly-open configuration shown in Fig. 1. The operator may stand at the rear of the assembly, so as to guide in an animal. The control linkage coupled via the rod 68 can extend two the rear (e.g. consisting of a torsion rod by means of which the rod 68 can be caused to pivot about the support 70). An animal will be relatively willing to enter the stall since it can see that the barriers are partly open.But when it gets to the end, and passes its head between the gates, its shoulders push the gates shut, where they lock as just described (Fig. 3).

Some desired activity can then be performed.

The operator can then release the animal by raising the front latch plate 62 by means of the control linkage, so that the animal can push the gates open forwardly. As soon as the animal is clear, the gates swing back to the initial position, and the cycle can repeat.

In the preceding description it has been assumed that the gap between the gates in their closed configuration is small enough to trap an animal whose neck extends between them.

This may not be necessary, e.g. if there is something else preventing the animal's retreat, such as a revolving rump rail (see e.g. GB 1395153). Of course, the gap must be small enough to prevent passage of the animal's shoulders.

Sometimes, particularly with gates having a fairly wide gap in the closed configuration, it may not be necessary to use an inwardly open initial position to encourage an animal to move towards the gates. The gates might then be movable only between "closed" and "forwardly open" configurations, being biased so as to move from the latter to the former, where they may be trapped until released by the operator. The front latch plate 62 could be generally as described, but raisable without removing a barrier to rearward movement.

(There could be a selectable non-rising barrier provided in an assembly generally as illustrated, so that the gates could be used with three configurations or, by engagement of the non-rising barrier, in the two-configuration mode.) In the illustrated embodiment, the two latch plates 52,62 can move independently.

The gates are trapped when moving outwardly, because only the rear latch plate 52 is (momentarily) raised. Inwardly moving gates can pass the latches because both are raised for a sufficient period. This is facilitated by the vertical spacing of the plates. The front one 62 extending significantly lower than the rear one. In a simplified embodiment, the plates 52,62 can be linked so as to move together, and rely on vertical spacing to treat inwardly and outwardly moving gates differently. The plates may be arranged as shown, or with a greater vertical differential. A forwardly moving gate raises both of them sufficiently to pass the rear one (52), but cannot pass the front one (62) because it was not raised sufficiently (or because it will have dropped back sufficiently before the gate reaches it). A rearwardly moving gate raises both plates to a higher level. If it moves at at least an expected speed, it passes the rear plate 52 before this can drop to obstruct its path.

Claims (6)

1. A movable barrier assembly comprising a movable barrier and a catch system such that the barrier has first and second configurations and an intermediate locking configuration between them, the arrangement being such that when the barrier is moved from the first towards the second configuration it tends to become locked in the intermediate configuration until released; whereas it is freely movable from the second to the first configuration.

2. An assembly according to claim 1 wherein the catch system comprises a pair of displaceable latch means at spaced locations along the path of the barrier so that the barrier is engageable between them in an intermediate configuration, each latch means being displaceable between a locking configuration in which it cannot be passed by the barrier, and to which it is biased, and a free configuration in which it can be passed; each latch being displaceable to its free configuration by the barrier moving from the side remote from the other latch; and both latches being displaceable by the barrier moving from the second towards the first configuration.

3. An assembly according to claim 2 in which the arrangement is such that movement of the barrier from the first configuration into the intermediate configuration displaces only the first latch means, whereas movement from the second configuration into the intermediate configuration displaces both latch means, thus allowing the barrier to continue into the first configuration.

4. An assembly according to claim 3 wherein each latch means comprises a respective latch plate having a cam portion engageable by an engagement surface associated with the barrier to displace the latch means; displacement of the cam portion of the second latch means being arranged to displace also the first latch means.

5. A movable barrier assembly substantially as any herein described with reference to and as illustrated in the accompanying drawings.

6. A headgate assembly for retaining an animal and comprising a movable barrier assembly according to any preceding claim.