EP0806532A2

EP0806532A2 - Latch assemblies for vehicle hoods

Info

Publication number: EP0806532A2
Application number: EP97303132A
Authority: EP
Inventors: Colin Jeffrey Taylor; Nicholas Joycey
Original assignee: Bloxwich Engineering Ltd
Current assignee: Bloxwich Engineering Ltd
Priority date: 1996-05-09
Filing date: 1997-05-08
Publication date: 1997-11-12
Also published as: JPH1046899A; EP0806532A3

Abstract

A latch assembly for a vehicle hood comprises a latch (2) for receiving and releasably retaining a striker pin (3) by the co-operation of a latching member in the latch (2) with a head (4) on the pin (3). The latch (2) comprises a body (10,11) having a bore (13) in which the striker pin (3) is adapted to be received, and the latch member comprises a resilient member (23) which is chordal to the bore (13) at least in a retaining position in which the member (23) co-operates within the head (4) to retain the striker pin (3) in the latch (2).

A release ring (15) rotatable about the axis of the bore (13) carries abutment means (24,25) for co-operation with the member (23) to move it away from the bore (13) and release it from the striker pin (3).

Description

This invention relates to latch assemblies for vehicle hoods. The term hood is used herein to refer to the front luggage boot cover on rear and mid engine vehicles as well as the engine cover on any vehicle, or any similar cover that may be found on a vehicle body. The hood covering the front or engine compartment of a vehicle is usually hinged at its rear end to the scuttle or other part of the vehicle body and is normally held down at its front end by a spring-loaded latch assembly releasable by remote control from inside the vehicle or by an existing release device.
The latch assembly most commonly used comprises a headed striker pin mounted on the hood and adapted, as the hood is closed, to pass through an opening in a catch plate securely to the grill surround or other part of the front end of the body, and to then be engaged by a pivotal or slideable catch lever.
According to our invention in a latch assembly for a vehicle hood comprising a latch for receiving and releasably retaining a striker pin by the co-operation of a latch member in the latch with a head on the pin, the latch comprises a body having a bore in which the striker pin is adapted to be received, and the latch member is chordal to the bore at least in a retaining position in which the member co-operates with the head to retain the striker pin in the latch, and a release ring rotatable about the axis of the bore carries abutment means for co-operation with the latch member to move it away from the bore into a release position in which it is released it from the striker pin.
The latch member may comprise a resilient member which is adapted to be resiliently deflectable between the two positions. Alternatively the latch member may comprise a substantially rigid blade which is displaceable from the retaining position into the release position against a resilient biasing force.
The latch member may comprise a finger defined by the distal end of a wire loop which surrounds the release ring and of which the opposite end comprises a tail connected to a cable pull.
Alternatively the finger may comprise a portion of a flattened wire loop which is accommodated between the abutment means and casing for the latch assembly.
When the latch member comprises the substantially rigid blade it is arranged to pivot about one end on an abutment in the body into the release position against the loading in a leaf spring.
Conveniently the abutment means comprises angularly spaced shoulders which are upstanding from the ring and co-operate with the inner edge of the latch member.
This enables the latch to be released upon angular movement of the release ring in either direction.
In one embodiment the striker pin is moved axially with respect to a cup which forms an abutment for one end of a compression spring of which the opposite end co-operates with the hood, movement of the hood towards the body causing the cup to be received in a counterbore in the body with the striker pin entering the bore against the force in the compression spring, the co-operation of the head with the member deflecting or displacing the latch member to enable the head to pass through the plane of the latch member with the latch member being resiliently biased in the opposite direction for co-operation with the striker pin under the head.
Three embodiments of our invention are illustrated in the accompanying drawings in which:

Figure 1 is a section through a latch assembly for a vehicle hood showing a striker pin assembly in a released position with respect to other latch assembly;
Figure 2 is a plan of the latch assembly;
Figure 3 is a view similar to Figure 2 but showing a modified construction; and
Figure 4 is a plan of another latch assembly with a cover removed for clarity;
Figure 5 is a plan with the cover in position;
Figure 6 is perspective view of the latch assembly with the cover removed.

The latch assembly illustrated in Figures 1 and 2 of the accompanying drawings comprises a striker pin assembly 1 adapted to be attached to the hood of a vehicle, and a latch 2 adapted to be secured to a grill surround or other part of the body of a vehicle.
The striker pin assembly comprises a striker pin 3 provided with the head 4 having a conical leading portion 5 and a latching face 6 and which depends from the hood. A cup 7 forming an abutment for one end of a compression spring 8 of which the opposite end abuts against the hood engages with the latching face 6 to determine its advanced position.
The latch 2 comprises a body defined by a top cover 10 and a base plate 11 which are fastened together to define a chamber 12 therebetween. An axial bore 13 of constant diameter extends through the top cover 10 and the base plate 11, with the portion of the bore in the base plate defined by an internal rim 14. The external cylindrical surface of the rim 14 defines an axis of rotation for a release ring 15 having a central opening 26 of a diameter corresponding to that of the bore, and a pair of upstanding lugs 16 and 17 which project towards the top cover 1.
A wire form spring 20 of skeletal outline is located between the upper end of the release ring 15 and a complementary face 21 on the top cover 10 with the spring located in position in a gap 22 between lugs on the internal face of the top cover 10. The spring 20 comprises a distal end portion comprising a resilient member in the form of a resilient finger 23 which is chordal to the bore 13 and co-operates with abutment faces 24, 25 on the lugs 16 and 17, respectively, and spaced parallel end portions 27 and 28 interconnected by a bridge portion 29 with the end portion 28 being cranked through 90° to be received in the gap 22 whereafter it is wound around the release ring 15 and terminates in a tail 30 secured in a radial lug 31 projecting from, and integral with, the release ring 15.
The radial lug 31 is connected to a cable pull by means of which the release ring 15 is moved angularly about the rim 13 as an axis. This, in turn, causes the face defined by a shoulder 24, 25 on a respective lug 16 or 17 to co-operate with the finger 23 and move it angularly away from the bore against the resilient of the spring 20, from the position shown in Figure 2 in which it is chordal to the bore.
To close the hood the hood is simply moved towards the latch 2 which causes the cup 7 to be received in the counterbore 32 at the adjacent end of the bore. This serves to align the striker pin 3 coaxially with the bore. Further movement of the hood in the same direction causes the striker pin 3 to enter the bore 13 with the spring 8 being compressed by relative movement of the hood towards the latch 2. The conical leading portion 5 co-operates with the finger 23 to displace it angularly against its natural resilient. This enables the head 4 to pass the finger with the finger then automatically returning to its chordal position to engage with the latching face 6. The striker pin 3 is therefore automatically retained by the latch 2.
To release the hood the cable is operated to move the release ring angularly 15 in one direction and the corresponding lug 16, 17 deflects the finger 23 angularly as described above thereby releasing it from the engagement with the latching face 6. Stored energy in the spring 8 is thus released and striker pin 3 is automatically withdrawn from the bore 13, whereafter the hood can be released in conventional manager, for example after release any additional manually releasable safety hood or other device.
In this construction the portion of the spring 20 between the gap 22 and the tail 30 acts as a secondary spring to achieve centering of the release ring 15 and act as a return spring for the cable pull.
In the construction illustrated in Figure 3 of the accompanying drawings the wire form spring 20 is replaced by a primary spring 30 of skeletal outline, and a secondary spring 31 of arcuate outline, and the lugs 16 and 17 are embodied in a single lug 32 subtending an angle exceeding 180°.
The spring 30 comprises a loop constituted by limbs 33 and 34 which are crossed over each other to form a flattened loop of generally "&" outline. An interconnecting bridge portion 35 defining the resilient member co-operates with the outer ends of the lug 32, and the spring is held in position by the co-operation of the ends of limbs 33, 34 with a flange 36 on the top cover 10. The bridge portion 35 comprises outwardly inclined parts which are tangential to the shoulders of the ends of the lug 32.
The secondary spring 31 is anchored at opposite ends 37, 38 in the flange 36 and in the lug 32, and partially encircles the release ring 15.
In operation the bridge portion 35 acts in a similar manner to that of the resilient finger 23, namely to act as a retaining member for the striker pin 3, and the secondary spring 31 acts to achieve centering of the release ring 15 and as a return spring for the cable pull.
In the latch assembly illustrated in Figures 4 to 6 of the accompanying drawings, the latch 2 comprises a body defined by a top cover 50 and a base plate 51 which are fastened together to define a chamber 52 therebetween. An axial bore 53 of constant diameter extends through to cover 50 and the base plate 51, with the portion of the bore in the base plate defined by an internal rim 54. The external cylindrical surface of the rim 54 defines an axis of rotation for a release ring 55 having a central opening 56 of a diameter corresponding to that of the bore 53, and a part annular lug 57 which projects towards the cover 50 and of which the free ends define abutment surfaces 58 and 59 lying on the diameter of the bore 53.
A latch member in the form of a substantially rigid blade 60 extends between opposite ends of the base plate 51 chordal to the bore 53. A blade spring 61 of curved outline is anchored at substantially the mid-point in its length to the base plate and oppositely extending fingers 62 and 63 co-operate with an adjacent edge of the blade 60 to urge the blade 60 into engagement with the abutment surfaces 58,59. In this position curved surfaces 64,65 at opposite ends of the blade 60 co-operate with complementary abutment surfaces in the cover 50 (not shown), and a concave recess 67 at substantially the mid-point into the length of the blade 60 transverses the bore 53 in the retaining position to retain the striker pin within the latch.
A helical spring 70 surrounds the release ring 55 and opposite ends of the spring 70 are anchored against fixed abutments 71,72 projecting from the base 57 towards the cover 50. This holds the release ring 55 in a neutral position in which the abutment surfaces 58 and 59 lie in a diameter of the bore 53 parallel to the side of the base 51.
Cable pulls can be connected to the release ring 55 through anchorage slots 73,74. The slots 76,77 are accessible through complementary slots 75,76 in the cover with the pulls projecting through openings 77,78 in the ends of the cover. Normally only one pull is provided.
In order to release the latch a force in a direction to withdraw the pull from the cover 50, say through the opening 78, acts to move the release ring 55 angularly about the rim 54 as an axis against the force in the spring 70. This, in turn causes the abutment face 59 to cause the curved surface 64 on the blade 60 to pivot about the complementary abutment as an axis with the concave recess 67 withdrawn from the bore 53. The blade 60 therefore acts as a lever pivoting about the abutment face 59 as a fulcrum against the force in the blade spring 61. The hood can then be opened with the striker pin withdrawn from the latch.
Upon release of the pull, the stored energy into the springs 63 and 70 is released to return the blade 60 and the ring 55 to the retaining position illustrated in the drawing.
The latch can be released by the application of a pull in either of the two opposite directions.
To close the hood, the hood is simply moved towards the latch with the striker pin acting on the blade 60 to displace it bodily away from both abutment surfaces in the cover 50 until the head passes the blade leaf with the head retained under it.

Claims

A latch assembly for a vehicle hood comprising a latch (2) for receiving and releasably retaining a striker pin (3) by the co-operation of a latching member in the latch (2) comprises a body (10,11) having a bore (13) in which the striker pin (3) is adapted to be received, and the latch member is chordal to the bore (13) at least in a retaining position in which the member (23) co-operates with the head (4) to retain the striker pin (3) to the latch (2), characterised in that a release ring (15) rotatable about the axis of the bore (13) carries abutment means (24,25) for co-operation with the latch member (23) to move it away from the bore (13) into a release position in which it is released from the striker pin (3).
A latch assembly as claimed in claim 1, in which the latch member (23) comprises a resilient member which is adapted to be resiliently deflectable between the two positions.
A latch assembly as claimed in claim 1, in which the latch member (23) comprises a substantially rigid blade (60) which is displaceable from the retaining position into the release position against a resilient biasing force.
A latch assembly as claimed in claim 1 or claim 2, in which the member comprises a finger (23) defined by the distal end of a wire loop (20) which surrounds the release ring (15) and of which the opposite end comprises a tail (30) connected to a cable pull.
A latch assembly as claimed in claim 1 or claim 2, in which the resilient member comprises a portion of a flattened wire loop (35) which is accommodated between the abutment means (24,25) and casing (10) for the latch assembly.
A latch assembly as claimed in claim 3, in which the blade (60) is adapted to pivot at either end about complementary abutment surfaces on the body against the force in a blade spring (61) in response to rotation of the release ring (55), the blade (60) being freely separable from both abutments to permit the blade (60) to move bodily in response to movement of a striker pin (3) in a closing direction.
A latch assembly as claimed in any preceding claim, in which the abutment means comprises angularly spaced shoulders (24,25) which are upstanding from the ring (15) and co-operate with the inner edge of the latch member (23,25,60).
A latch assembly as claimed in claim 7, in which the latch is adapted to be released upon angular movement of the release ring (15) in either direction.
A latch assembly as claimed in any preceding claim, in which the striker pin (3) is moved axially with respect to a cup (7) which forms an abutment for one end of a compression spring (8) of which the opposite end co-operates with the hood, movement of the hood towards the body causing the cup (7) to be received in a counter-bore (32) in the body with the striker pin (3) entering the bore (13) against the force of the compression spring (8), the co-operation of the head (4) with the member (23) deflecting or displacing the latch member (23,25) to enable the head (4) to pass through the plane of the latch member with the latch member being resiliently biased in the opposite direction for co-operation with the striker pin (3) under the head (4).