GB2520340A

GB2520340A - Latch mechanism

Info

Publication number: GB2520340A
Application number: GB1320363.3A
Authority: GB
Inventors: David Looker; Michael Houghton
Original assignee: Parkhouse Country Estates Ltd
Current assignee: Parkhouse Country Estates Ltd
Priority date: 2013-11-19
Filing date: 2013-11-19
Publication date: 2015-05-20
Also published as: GB201320363D0

Abstract

A latch mechanism comprising a bolt 6 sliding between extended and retracted positions by a pivotal handle 8 via a rack and pinion 14, 16. Preferably the rack of teeth is integral with the bolt and the pinion forms part of or is connected to the handle which may rotate 180 degrees. The bolt may be spring biased into the extended latched position and the housing may include a spring loaded ball catch 22 protruding from the housing to engage with a recess in the handle to retain the handle in a second position corresponding to the retracted position of the latch. The latch may be used on a door of a vehicle such as a livestock trailer.

Description

Latch Mechanism The present invention relates generally to a latch mechanism, which might be alternatively or additionally described as a lock mechanism. More particularly, the invention relates to a rack and pinion based latch mechanism.

Latch mechanisms take many forms, ranging for example from a simple slider-based mechanism to more complex mechanisms comprising multiple moving parts, springs, pivots and the like. Simple mechanisms of the type already known are often not robust enough to be used frequently in a heavy duty and/or dirty environment. More complex mechanisms might find use in more heavy duty environments, but may be prone to wear and tear as a result of the complexity, for example due to the ingress of dirt causing the mechanism to cease to function.

It is an example aim of embodiments of the present invention to provide a latch mechanism which obviates or mitigates one or more problems other prior art, whether defined herein or elsewhere, or at the least provide an alternative latch mechanism.

According to the present invention there is provided an apparatus and method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows.

According to a first aspect of the present invention, there is provided a latch mechanism (sometime referred to as a lock mechanism), comprising: a housing; a bolt moveable within the housing from a first bolt position to a second bolt position, the first bolt position being when the bolt protrudes further from the housing than when in the second bolt position; a handle, moveable in a pivotal manner from a first handle position to a second handle position, to move the bolt from the first bolt position to the second bolt position, wherein the handle and bolt engage with one another via a rack and pinion arrangement.

The handle may be in engagement with, and/or comprise, the pinion.

The bolt may be in engagement with, and/or comprise, the rack.

The latch mechanism might further comprise a bolt biasing element, which is arranged to bias the bolt toward the first bolt position.

The latch mechanism might further comprise a handle retainer, for selectively retaining the handle in the second handle position.

The handle retainer may comprise a biased protrusion that protrudes from the housing.

The protrusion may be ball-shaped.

The handle may comprise a recess for receiving the protrusion.

The handle may be located on a face of the housing.

The handle may be shaped such that the handle remains within outer extremities of the face when in one or more of: the first handle position, the second handle position, and/or in-between the first and second handle positions.

An angle between the first and second handle positions may be substantially 180°.

The second bolt position is when the bolt is retracted within the housing, or is flush with an extremity of the housing.

According to a second aspect of the present invention, there is provided a vehicle comprising the latch mechanism of an aspect of the invention.

According to a third aspect of the present invention, there is provided a method, the method comprising mounting to a vehicle the latch mechanism of an aspect of the invention.

According to a third aspect of the present invention, there is provided a rack and pinion based latch mechanism.

One or more features of one or more aspect of the invention may, where clear to the skilled person from a reading of this disclosure, be combined with and/or replace one or more features of one or more other aspects of the present invention, without departing from the scope of the invention as defined by the claims that follow.

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic figures in which: Figure 1 schematically depicts a perspective view of a latch mechanism according to an example embodiment; Figure 2 schematically depicts a side-on view of a handle used in the latch mechanism of Figure 1; and Figure 3 schematically depicts the latch mechanism of Figure 1, but with a panel removed to expose the inner workings of the mechanism.

According to an example embodiment, it has been realised that a rack and pinion based latch mechanism provides both the simplicity and yet robustness that is required, for instance, in heavy duty environments. For instance, a rack and pinion based latch mechanism is relatively cheap and compact, yet robust and reliable. This is of course useful in general, but particularly useful in certain circumstances, for example in relatively dirty environments and/or where the latch mechanism has to be operated very easily and quickly. Also, the rack and pinion based latch mechanism readily facilitates conversion of rotational motion of a handle into driven linear motion of a bolt of the mechanism. There may be no intermediate parts between a pinion driven by the handle, and the rack forming part of the bolt. This allows the bolt to be actuated in a more direct manner, which assists in achieving robustness and reliability, even if dirt gets into the mechanism itself, for example on the rack, or on the pinion.

Figures 1 to 3 will now be referred to in combination, to describe an example embodiment of a rack and pinion based latch mechanism.

A rack and pinion latch based mechanism 2 is shown. The mechanism 2 comprises a housing 4. A bolt 6 is provided. The bolt 6 is movable within the housing 4 from a first bolt position to a second bolt position. The first bolt position is typically when the bolt 6 protrudes further from the housing 4 than when in the second bolt position. For example, the first bolt position might coincide with a latched position, and the second bolt position may coincide with an unlatched position. When in the second or unlatched position, the bolt 6 might be retracted within the housing 4, or be flush with an extremity of the housing 4. This might facilitate more effective unlatching, and/or prevent damage to the bolt 6.

The mechanism 2 also comprises a handle 8. The handle 8 is pivotally mounted 10 with respect to the housing 4. The handle 8 is therefore movable in a pivotal manner from a first handle position to a second handle position, in order to move the bolt 6 from the first bolt position to the second bolt position.

The Figures show the bolt 6 in the second bolt position, and the handle 8 in the second handle position.

Figure 3 shows the mechanism 2 with a side-panel or face 12 of the housing 4 removed, to show the inner workings of the mechanism 2. Figure 3 clearly shows that the handle 8 and bolt 6 engage with one another via a rack 14 and pinion 16 arrangement. In this embodiment, the handle 8 is in engagement with the pinion 16, whereas the bolt 6 comprises the rack 14.

Pivotal rotation of the handle 8 will cause rotation of the pinion 16, which will in turn drive linear motion of the rack 14 and bolt 16.

An angle between the first and second handle positions might be 180°.

This might be advantageous, since this gives a very clear indication of the state of the latch mechanism (e.g. latched or unlatched), simply by viewing the state or position of the more visible handle 8. For example, if the handle 8 is pointing towards an opening through which the bolt 6 extends, then the bolt 6 is in the first/latched position. If the handle 8 is pointing away from that opening, then it is clear that the bolt 6 is in the second/unlatched position.

There is thus little or no need to accurately inspect or approach the latch mechanism to determine what latched state it is in.

As described above, the handle 8 is mounted relative to a panel (i.e. a face) 12 of the housing 4. Conveniently, the handle 8 is shaped (which includes sized) such that extremities of the handle 8 remain within outer extremities of the face 12 when the handle is in one or more of the first handle position, the second handle position, and/or in-between the first and second handle positions. This functionality prevents the handle extending beyond those extremities of the face, preventing an object or the like from catching or impinging against the handle 8, which would otherwise cause damage to the handle 8, the mechanism 2 as a whole, and/or the object.

The mechanism 2 comprises a bolt biasing element in the form of a spring 18. The bolt biasing element 18 is arranged to bias the bolt 6 toward the first bolt position -i.e. the latched position. This ensures that the mechanism 2 as a whole is fail-safe, such that if the rack 14 and pinion 16 fails in some way, the latch mechanism 2 ensures that latching is maintained. This also allows the bolt 6 to be pushed back against the spring 18, for example by hand or by an opposing abutment surface, which might allow for at least partial operation of the mechanism 2 without use of the handle 8. This might make use of the mechanism easier. Also, in being biased in this manner, the bolt 6 is able to extend into a recess without user input. For example, when a closure (e.g. a door or gate) provided with the mechanism is moved, the bolt 6 may more across a surface until a recess is encountered, at which point the biased bolt is biased into the recess without user input. Again, this might facilitate easier use of the mechanism. Due to the rack 14 and pinion 16 arrangement, movement of the bolt 6 will cause movement of the handle 8.

The bolt biasing element/spring 18 extends around or between, or the like, one or more surfaces of the bolt 6 and an abutment surface 20 of the housing. The abutment surface might conveniently extend through a slot in the bolt, allowing the biasing element 18 to be located substantially within the extremities of the bolt 6, which might make the mechanism 2 as a whole simpler and/or smaller.

The mechanism 2 further comprises a handle retainer, for use in selectively retaining the handle 8 in the second handle position. In this example, the handle retainer comprises a biased protrusion 22 that protrudes from the housing 4 for engagement or other interaction with the handle 8. The protrusion 22 is conveniently ball-shaped, in order to allow for relatively easy movement of the handle 8 into and out of retained configuration over the surface of the ball 22. An under-side of the handle 8 is provided with a recess 24 for receiving the ball-shaped protrusion 22, and facilitating the retention of the handle 8.

In another example, the retainer might be used to selectively retain the handle in the first handle position, or an additional handle retainer might be provided to facilitate retaining the handle in one or both of the first and/or second handle positions.

It can be seen from the Figures that the housing 2 as a whole presents flush outer surfaces, with the exception of the handle. This might prevent objects impinging or catching on the housing 2. The handle 8 is also relatively close fitting to the housing 4, for much the same reasons. In other embodiments, the housing might be more skeletal in nature, allowing for easy drying and/or wash-down.

One or more elements of the mechanism 2 may be formed form materials typical in a heavy duty environment. For example, the materials might typically be metallic in nature.

Although not shown above, it will be understood that the latch mechanism would typically be used in combination with some form of catch, for example an aperture or other opening or depression capable of receiving the bolt.

The mechanism shown in and described with reference to Figures 1-3 is simple, yet robust and effective. The mechanism might find use in a wide variety of applications, but in particular in heavy duty applications where the mechanism is used frequently, or in a dirty environment, or where simple but effective latch actuation is required. For instance, the latch mechanism might find advantageous use on a door or other opening of a vehicle, and in particular a livestock transporter/trailer which meets the heavy duty and dirty criteria described above. The latch mechanism could be mounted or even retro-fitted to a vehicle, for example to facilitate latching of a closure of the vehicle.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

Claims 1. A latch mechanism, comprising: a housing; a bolt moveable within the housing from a first bolt position to a second bolt position, the first bolt position being when the bolt protrudes further from the housing than when in the second bolt position; a handle, moveable in a pivotal manner from a first handle position to a second handle position, to move the bolt from the first bolt position to the second bolt position, wherein the handle and bolt engage with one another via a rack and pinion arrangement.
2. The latch mechanism of claim 1, wherein the handle is in engagement with or comprises the pinion.
3. The latch mechanism of claim 1 or claim 2, wherein the bolt is in engagement with or comprises the rack.
4. The latch mechanism of any preceding claim, further comprising a bolt biasing element, which is arranged to bias the bolt toward the first bolt position.
5. The latch mechanism of any preceding claim, further comprising a handle retainer, for selectively retaining the handle in the second handle position.
6. The latch mechanism of claim 5, wherein the handle retainer comprises a biased protrusion that protrudes from the housing.
7. The latch mechanism of claim 6, wherein the protrusion is ball-shaped.
8. The latch mechanism of claim 6 or claim 7, wherein the handle comprises a recess for receiving the protrusion.
9. The latch mechanism of any preceding claim, wherein the handle is located on a face of the housing, and wherein the handle is shaped such that the handle remains within outer extremities of the face when in one or more of: the first handle position, the second handle position, in-between the first and second handle positions.
10. The latch mechanism of any preceding claim, wherein an angle between the first and second handle positions is 180°.
11. The latch mechanism of any preceding claim, wherein the second bolt position is when the bolt is retracted within the housing, or is flush with an extremity of the housing.
12. A vehicle comprising the latch mechanism of any preceding claim.
13. A method, the method comprising mounting to a vehicle the latch mechanism of any of claims 1 to 11.
14. A rack and pinion based latch mechanism.
15. A latch mechanism substantially as described herein, substantially as described herein with reference to the accompanying Figures, and/or substantially as shown in the accompanying Figures.