GB2402961A

GB2402961A - Spring biased bonnet latch for motor vehicle

Info

Publication number: GB2402961A
Application number: GB0313853A
Authority: GB
Inventors: Colin Jeffrey Taylor
Original assignee: Bloxwich Engineering Ltd
Current assignee: Bloxwich Engineering Ltd
Priority date: 2003-06-14
Filing date: 2003-06-14
Publication date: 2004-12-22
Anticipated expiration: 2023-06-14
Also published as: ZA200404642B; GB0313853D0; GB2402961B

Abstract

A hood latch has a catch lever 8 co-operable with a striker 2 for securing a vehicle hood (not shown) closed. The catch lever 8 is pivotally mounted on a pivot pin 5 and has a cavity 13 to receive and retain the striker 2. The cavity 13 has an abutment surface 14 engaged by the striker 2 such that the lever 8 is loaded in compression by forces applied to the lever 8 by the striker 2. The catch lever 8 can be made of plastics materials that are strong in compression, light and provide the abutment surface 14 with low sliding friction to facilitate relative movement between the striker 2 and abutment surface 14. An Anti-rattle spring may be provided. In a second embodiment dual or twin bonnet latches may be provided where the two locks are each located adjacent to the wings of the motor vehicle.

Description

HOOD LATCHES FOR VEHICLES

This invention relates to hood latches for vehicles. The term hood is used herein to refer to a closure panel for a compartment in the vehicle body and in particular, but not exclusively, to the closure panel for the front compartment which may house the engine or provide storage space in a rear engine vehicle.

The hood covering the front compartment of a vehicle is usually hinged at its rear end and held down at its front end by a spring-loaded latch.

The latch is usually released by operating a device from within the vehicle. On release of the latch, the hood is still held closed by a secondary safety latch that is released by a handle operated from outside the vehicle. The secondary safety latch prevents the hood from being released and opening while the vehicle is moving and ensures the hood is secured even if the hood is not properly retained by the primary latch during closure of the hood.

One type of latch engages with a headed pin attached to the hood.

Typically, a moveable element of the latch engages behind the head of the pin to retain it in the latch.

Another type of latch engages with a horizontal bar attached to the hood.

Typically, this type of latch comprises a catch lever that co-operates with a separate release lever with a ratchet and pawl action. The catch lever is biased towards a release position to raise the hood on release of the latch and, in a retaining position, is prevented from moving to the release position by the release lever engaging projections on the catch lever. On operation of a device within the vehicle, the release lever is disengaged l from the projections to allow the catch lever to move to the release position.

The catch lever is usually made of steel so as it can withstand the forces that occur during use of the latch. In particular, the catch lever must have high tensile strength because the latch designs rely upon the tensile strength of the catch lever to retain the striker in the latch against forces pulling the striker from the latch, such as those brought about by air pressure under the hood and in crash conditions, and the lifting forces on release of the latch are transmitted through the catch lever. Furthermore, the catch lever must be able to withstand the damage caused by impact of a striker with the catch lever during repeated closure of the hood.

The current market trend is for smaller and lighter latches. Vehicle legislation requires that there are no hard projections beneath the surface of the hood which may cause damage in a pedestrian impact.

Accordingly, there is a trend to mount two latches, one on each wing panel, with a safety hook mounted centrally, released by a selfpresenting handle when the latches are released. Each hood latch must be capable of holding the hood independently and, because of their position on the wing panel, be smaller than known latches that are mounted centrally on the hood.

An object of the invention is to provide a hood latch that overcomes or at least mitigates some of the problems of existing hood latches.

A preferred object of the invention is to provide a hood latch that is suitable for mounting on a wing panel of a vehicle.

Another preferred object of the invention is to provide a hood latch of reduced weight. l i 3

There is provided in a first aspect of the invention a hood latch for a vehicle comprising a latch for receiving and releasably retaining a striker, the latch having a housing with a slot therein arranged to receive the striker, a catch lever pivotally attached to the housing by a pivot pin, means for biasing the lever towards a retaining position in which the catch lever co-operates with the striker to retain the striker in the slot, and means to move the catch lever against the biasing means to a release position in which the striker is released from the catch lever, wherein the catch lever has an abutment surface co-operable with the striker in the retaining position such that the catch lever is loaded in compression by forces urging the striker in a direction out of the slot.

By loading the catch lever in compression, the catch lever can be made of plastics materials, such as polyamide, that are strong in compression and are lighter than steel. The use of plastics provides the abutment surface with low sliding friction that facilitates relative movement between the striker and the abutment surface.

The abutment surface may be a planar surface radially spaced from and substantially tangential to the pivot axis of the pivot pin. The striker may contact the abutment surface on a side of the catch lever opposite the pivot pin such the catch lever is compressed between the striker and the pivot pin by forces urging the striker from the slot.

Preferably, the forces on the catch lever are transmitted to the housing through the pivot pin. The pivot pin may be integral with the housing.

In this way, the loads on the catch lever are shared throughout the latch increasing the loads that the latch can withstand and reducing wear and tear.

I

Preferably, the catch lever has an outwardly facing guide surface that is contacted by the striker when the striker is inserted into the slot causing the catch lever to pivot against the biasing and allow the striker to enter the slot. The outwardly facing guide surface may extend at a small angle relative to the direction of insertion of the striker in the slot when the catch lever is in the retaining position. The angle may be between 10 and 45O.

The low contact angle of the guide surface reduces impact damage to the catch lever caused by engagement of the striker with the catch lever on closure of the hood. This is of particular benefit where the catch lever is made of lightweight materials such as plastics.

The guide surface of the catch lever may lead to a cavity for receiving the striker in the retaining position, the abutment surface being one of the surfaces of the catch lever defining the cavity. Preferably, the cavity is substantially L-shaped. Alternatively, the cavity may be substantially U-shaped.

Preferably, the latch comprises striker biasing means to apply a force to the striker to push the striker from the slot when the catch lever is in the release position. In this way, the hood is lifted to a raised position when the latch is released allowing the vehicle user to access a handle to release a secondary safety latch preventing accidental opening of the hood. As the forces pushing the striker from the slot in the release position are not transmitted through the catch lever, the forces on the catch lever are further reduced.

The striker biasing means may be a lifter spring attached to the housing.

The lifter spring may be made of metal, preferably steel.

The latch may comprise anti-rattle biasing means to apply a force to the striker in the retaining position of the catch lever to urge the striker against the abutment surface in the retaining position. In this way, the striker is trapped against the catch lever to prevent rattling of the striker in the latch.

The anti-rattle biasing means may be a spring of metal, such as steel, or elastic material, such as rubber or urethane.

The lifter spring may provide the anti-rattle biasing means.

The lever biasing means may be a helical spring extending between a wall of the housing and the catch lever. The helical spring may be made of metal, preferably steel.

In one arrangement, the release means is a retractable cable attached to a distal end of the catch lever. The cable may be connected to a release handle operated from inside the vehicle. In particular, the catch lever made of smooth material having low sliding friction facilitates direct operation of the catch lever in this manner.

There is provided in a second aspect of the invention a hood latch for a vehicle comprising a latch for receiving and releasably retaining a striker, the latch having a housing with a slot therein arranged to receive the striker, a pivotal catch lever movable towards and away from a retaining position in which the lever is co-operable with the striker to retain the striker in the slot, lever biasing means to bias the lever towards the retaining position, means to move the catch lever against the biasing to a release position in which the striker is released from the catch lever and anti-rattle biasing means arranged to urge the striker against the catch lever in the retaining position.

There is provided in a third aspect of the invention a hood latch for a vehicle comprising a latch for receiving and releasably retaining a striker, the latch having a housing with a slot therein arranged to receive the striker, a catch lever pivotally attached to the housing and biased towards a retaining position in which the catch lever co-operates with the striker to retain the striker in the slot and release means arranged to directly engage the catch lever to move the catch lever against the biasing to a release position in which the striker is released from the catch lever.

There is provided in a fourth aspect of the invention a vehicle comprising a hood having one or more hood latches according to any one of the first, second or third aspects of the invention, each striker of the one or more hood latches being attached to either one of the hood or the vehicle body and each latch of the one or more hood latches being attached to the other one of the hood or the vehicle body.

The vehicle may comprise two hood latches according to the first, second or third aspects of the invention, each one mounted on a wing of the vehicle. Alternatively, the vehicle comprises one hood latch according to the first, second or third aspects of the invention mounted on the front of the vehicle.

The vehicle may comprise a safety latch for holding the hood closed on release of the one or more hood latches, the safety latch releasable by operation of a device accessible from outside the vehicle when the one or more hood latches are released.

An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 shows a side view of a hood latch according to the invention with one side of the housing removed to reveal the internal mechanism of the latch; Figure 2 shows a side view of the hood latch shown in Figure 1 in a retaining position in which a striker is retained in the latch; and Figure 3 shows a side view of the hood latch shown in Figures 1 and 2 in a release position in which the striker is released from the latch.

Referring to the accompanying drawings, a hood latch for securing a hood of a vehicle in a closed position is shown. The hood latch comprises a latch 1 and a striker 2.

The striker 2 may consist of a substantially U-shaped loop attached to the hood having a bar extending parallel to the hood that can be retained in the latch 1. Alternatively, the striker 2 may be a hook or other open sided shape having a bar parallel to the hood. It will be understood that the invention is not restricted to the bar extending parallel to the hood but the bar could extend at other angles, for example inclined towards the centre of the vehicle at an angle of 10 .

The latch 1 includes a housing consisting of two plastics moulded plates.

In this embodiment, the plates are made of polyamide but it will be understood that other materials may be employed, including other plastics material, pressed steel, die-cast aluminium or zinc. In the Figures, only a first plate 3 is shown. The two plates have co-operating formations (19, 20) so that the plates can be "clipped" together to form the housing.

The plates define a slot 4 for receiving the striker 2. Integral with the plate 3 is a pivot pin 5 located in a direction above the slot 4. When, the plates are clipped together to form the housing, the pivot pin 5 extends between the plates to enter a hole or recess in the plate not shown.

Each plate has bores 6 and 7 therethrough for receiving bolts (not shown) for attaching the housing to the vehicle. The bores 6 and 7 are surrounded by annular strengthening portions comprising walls of the plates of increased thickness that reinforce the housings around the bores 6 and 7.

Contained within the housing is a plastics moulded catch lever 8 pivotally mounted on the pivot pin 5. The catch lever 8 is biased by a steel, helical spring 9 towards the positions shown in Figures 1 and 2. In this embodiment the catch lever 8 is made of polyamide but it will be understood that other plastics material may be employed.

The catch lever 8 has a planar outwardly facing guide surface 10, which obscures the slot 4 from the striker 2 in a rest position, shown in Figure 1, in which the striker 2 is not retained in the slot 4. When the catch lever 8 is in a position shown in Figures 1 and 2, this surface 10 is at an angle of between 10 and 45 to the direction at which the striker 2 is inserted in the slot 4. The exact angle of the surface 10 is dependent upon the overall dimensions of the latch and the diameter of the striker bar 2 and should be as small as possible.

Closing the hood moves the striker 2 to engage the outwardly facing guide surface 10 of the catch lever 8 causing the catch lever 8 to pivot away from the slot 4 against the biasing of the spring 9 such that the striker 2 can enter into the slot 4. r 9

A lifter spring 11 is coiled around one of the strengthening portions of the plates and has an arm 12 that, in the rest position shown in Figures 1, extends across the slot 4 and into a recess 18 in the catch lever 8.

As the striker 2 enters the slot 4, it catches the arm 12 of the lifter spring 11 deflecting the arm 12 away from the open end of the slot 4.

When the striker 2 has moved far enough into the slot 4 to pass the end of guide surface 10, the catch lever 8 is returned back towards the slot 4 under the biasing of the spring 9 to a retaining position as shown in Figure 2.

In this retaining position, the striker 2 is retained in a substantially L shaped cavity 13 defined by walls of the catch lever 8, including an abutment surface 14 that is radially spaced from and substantially tangential to the pivot axis of the catch lever 8. The arm 12 of the spring 11 pushes the striker 2 against abutment surface 14 of the catch lever 8 preventing rattling of the striker 2 in the latch 1. Any loads applied to the lever 8 by forces urging the striker 2 out of the slot 4 are directed towards the pivot pin 5 such that the catch lever 8 is loaded in compression between the abutment surface 14 and the pivot pin 5.

To release the striker 2 from the latch 1, a vehicle user operates a release device from within the vehicle. This retracts a cable 15 attached to a distal end 17 of the catch lever 8. The cable 15 passes through a hole in the end 17 and is attached to a disc 16 of larger diameter than the hole to secure the cable 15 to the catch lever 8.

Retracting the cable 15 causes the catch lever 8 to pivot away from the slot 4 against the biasing of the spring 9 to a release position as shown in Figure 3. This allows the striker 2 to be removed from the slot 4. The lifter spring 11 moves the striker 2 out of the slot 4 lifting the hood of the vehicle. Once the hood has been lifted to this position, the vehicle user can access a handle for releasing a safety latch to allow the hood to be raised uncovering the engine.

A hood latch assembly may comprise a pair of latches 1 attached to each wing of a vehicle and a pair of strikers 2 attached to a hood of the vehicle. A safety latch, as is well known in the art, is attached to the front of the vehicle to provide a safety mechanism to prevent the hood from accidentally opening if the strikers 2 are not properly engaged with the latches 1.

Alternatively, the hood latch could be attached to the front of the vehicle or/and the latch attached to the hood and the striker attached to the body of the vehicle.

It will be understood that the invention is not meant to be limited to the above-described embodiment but includes modifications and alterations that would be envisaged by a person skilled in the art.

For example, the cable 15 could be attached to a portion of the catch lever 8 other than the distal end, although attaching the cable 15 to the distal end is preferable due to the mechanical advantage. The cable 15 can be attached to the distal end of the lever 8 in many different ways.

For example, the cable 15 could be attached to a hook which secures the cable 15 to the distal end by looping over a leg provided at the end of the catch lever 8. A hook may be used for ease of attachment and a compact design. Furthermore, the catch lever 8 could be moved to the release position by some other means, for example a lever mechanism.

Although the invention has been described having a catch lever 8 of plastics it will be understood that the catch lever 8 could be made of other materials including steel.

The lifter spring 11 could be a helical spring that is compressed against the bottom of the housing as the striker 2 enters the slot 4.

The latch could be arranged to retain a headed pin rather than a striker comprising a perpendicular bar.

Claims

1. A hood latch for a vehicle comprising a latch for receiving and releasably retaining a striker, the latch having a housing with a slot therein arranged to receive the striker, a catch lever pivotally attached to the housing by a pivot pin, means for biasing the lever towards a retaining position in which the catch lever co-operates with the striker to retain the striker in the slot, and means to move the catch lever against the biasing means to a release position in which the striker is released from the catch lever, wherein the catch lever has an abutment surface co- operable with the striker in the retaining position such that the catch lever is loaded in compression by forces urging the striker in a direction out of the slot.

2. A hood latch according to claim 1 wherein the catch lever is made of plastics material.

3. A hood latch according to claim 2 wherein the catch lever is made of polyamide.

4. A hood latch according to any one of the preceding claims wherein the abutment surface is a planar surface radially spaced from and substantially tangential to the pivot axis of the pivot pin.

5. A hood latch according to any one of the preceding claims wherein the striker contacts the abutment surface on a side of the catch lever opposite the pivot pin such the catch lever is compressed between the striker and the pivot pin by forces urging the striker from the slot.

6. A hood latch according to any one of the preceding claims wherein the forces on the catch lever are transmitted to the housing through the pivot pin.

7. A hood latch according to any one of the preceding claims wherein the pivot pin is integral with the housing.

8. A hood latch according to any one of the preceding claims wherein the catch lever has an outwardly facing guide surface that is contacted by the striker when the striker is inserted into the slot causing the catch lever to pivot against the biasing and allow the striker to enter the slot.

9. A hood latch according to claim 8 wherein the outwardly facing guide surface may extend at an acute angle relative to the direction of insertion of the striker in the slot when the catch lever is in the retaining position.

10. A hood latch acceding to claim 9 wherein the angle is between 10 and 45 .

11. A hood latch according to any one of claims 8 to 10 wherein the guide surface of the catch lever leads to a cavity for receiving the striker in the retaining position, the abutment surface being one of the surfaces of the catch lever defining the cavity.

12. A hood latch according to claim 11 wherein the cavity is substantially L-shaped.

13. A hood latch according to claim 1 l wherein the cavity is substantially U-shaped.

14. A hood latch according to any one of the preceding claims wherein the latch comprises striker-biasing means to apply a force to the striker to push the striker from the slot when the catch lever is in the release position.

15. A hood latch according to claim 14 wherein the hood is lifted to a raised position when the latch is released and is retained in the raised position by a secondary safety latch.

16. A hood latch according to claim 15 wherein the secondary safety latch is releasable by a user operable handle accessible when the hood is raised to the release position.

17. A hood latch according to any one of claims 14 to 16 wherein the striker biasing means is a lifter spring attached to the housing.

18. A hood latch according to any one of the preceding claims wherein anti-rattle biasing means is provided to apply a force to the striker in the retaining position of the catch lever to urge the striker against the abutment surface in the retaining position to prevent rattling of the striker in the latch. I

19. A hood latch according to claim 18 wherein the anti-rattle biasing means is an anti-rattle spring.

20. A hood latch according to claim 19 as dependent on claim 17 wherein anti-rattle spring and lifter spring comprise a single spring.

21. A hood latch according to any one of the preceding claims wherein the lever biasing means is a helical spring extending between a wall of the housing and the catch lever.

22. A hood latch according to any one of the preceding claims wherein the release means is a retractable cable attached to a distal end of the catch lever.

23. A hood latch according to claim 22 wherein the cable is connectable to a remote release handle.

24. A hood latch for a vehicle substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings.

25. A vehicle comprising a hood having one or more hood latches according to any one of preceding claims, each striker of the one or more hood latches being attached to either one of the hood or the vehicle body and each latch of the one or more hood latches being attached to the other one of the hood or the vehicle body.

26. A vehicle according to claim 25 wherein two hood latches are provided.