GB2031509A

GB2031509A - A safety latch for vehicle bonnet

Info

Publication number: GB2031509A
Application number: GB7930963A
Authority: GB
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 1978-09-25
Filing date: 1979-09-06
Publication date: 1980-04-23
Also published as: DE2937899A1; FR2436702A1; JPS5822626B2; FR2436702B1; GB2031509B; JPS5542973A

Abstract

A safety-latch hook (3) for a vehicle bonnet, is carried on a spindle (4) which is rotatably mounted in, and passes through, a base plate (1) and which has a release lever (5) fixed to its other end. By pushing the end of the release lever, the spindle is rotated, and thereby the latch is rotated so as to release the bonnet. A biasing spring (6) is fitted to the assembly. Other arrangements are described. <IMAGE>

Description

SPECIFICATION A secondary hood latch with an axle and two arms on the axle The present invention relates to a locking device for holding down the bonnet on a vehicle, and more particularly to an improvement in the secondary latching system of such a locking device.

Heretofore, it has been practiced to fit vehicles which have bonnets which can be raised and lowered with locking devices which comprise primary and secondary latching systems, from the point of view of safety, since if the bonnet of a vehicle is suddenly raised by wind while the vehicle is moving at speed it can not only damage the vehicle but also cause a serious accident. In Fig. 1 there is shown the general layout of a vehicle bonnet and of a locking device for holding down this bonnet; this figure of the drawings can be applied both to the present invention and also to the prior art. S denotes a striker fixed to a vehicle bonnet F, and L is a locking device to be fixed to a radiator core holder board, or base plate, R.

In Fig. 2 there is shown in detail a prior art type locking device. Here only the details of the secondary latch, which is generally on the right hand side of the figure, are relevant. It is to be understood that the primary latch, comprising the parts denoted by reference numerals 2, 14, 17, 18, 1 9 etc., engages and disengages when the bonnet is completely pressed down to its lowermost position. The secondary latch, comprising the parts denoted by reference numerals 3, 4, 5, 6, 7, and 21, on the other hand, engages and disengages when the bonnet is pressed down to a position somewhat above the engagement position of the primary latch. Thus, if the primary latch fails or is not properly engaged, the secondary latch provides a fall back capability for holding down the bonnet.It is; normally arranged that the secondary latch is engaged merely by the pressure of the weight of the bonnet, without the bonnet requiring to be pressed down by hand.

In more detail, the secondary latch comprises the latch lever 3, which is pivoted around the spindle 4 to the base plate R, and whose end is formed as a hook 21 which is adapted to engage with a part of the bonnet 1 6. This latch lever 3 is biased clockwise in the figure by the spring 6 so as to keep the hook 21 engaged with the bonnet. A release lever comprising parts 5 and 7 is fixed to the front or outside side of the latch lever 3, and, by raising this lever in the figure, the hook 21 may be disengaged from the bonnet so that the latter may be lifted up.

Fig. 3 shows this secondary latch in a more clearly visible three-dimensional perspective view. The release lever 5 is spot-welded to the front of the latch lever 3 and extends over a notch in the base plate 1 towards the outside of the vehicle. On the end of the release lever 5 is formed the push plate 7. The spring 6 is fitted between this end of the release lever 5 and the base plate 1. Thus, when the operator pushes upwards the push plate 7, the hook 21 formed at the end of the latch lever 3 may be released from its engagement with the bonnet. Here xl shows the length of the effective arm of the lever formed between the push plate 7 and the rotational axis of the spindle 4, and y1 is the offset between the push plate 7 and the hook 21 to which force is to be applied, in the direction along the axis of the spindle 4.

Because the latch lever 3 is conveniently located inside the engine compartment, and the push plate 7 must be located near the front end of the engine bonnet, in order to be operated by hand, it is inevitable that the distance y1 must be considerable. Therefore a strong twisting force is applied to the release lever 5, and therefore it must be formed as a strong channel member. Further, twisting of the latch lever 3 around, i.e., skew to, its axis on the spindle 4 must be prevented by forming the latch lever 3, also, in a channel section, so as to provide a long supporting distance for the latch lever 3 to be held by the spindle 4. All these considerations mean that the structure of the secondary latch must be robust and heavy, and accordingly it is difficult to fabricate, and expensive.

Further, it is to be noted that in view of various considerations it is difficult to make the distance xl very large, and, the larger this distance is, the more screw twisting is applied to the latch lever where it is fixed on the spindle 4.

Therefore, it is the object of the present invention to provide a secondary latch for a vehicle bonnet which is easy and cheap to make.

According to the present invention, this and other objects are accomplished by, in a vehicle incorporating a raising and lowering bonnet, a base plate having an inside side and an outside side, an edge of which abuts an edge of the bonnet when the latter is lowered, and from which the edge of the bonnet rises when it is raised, and a primary latch fixed to the base plate, a secondary latch fixed to the base plate, comprising a latch spindle rotatably mounted through the base plate and generally perpendicular to it, a hook member fixedly mounted on the end of the latch spindle which is on the inside side of the base plate and adapted to engage with the bonnet when the latter is lowered, and a release lever whose one end is fixedly mounted on the end of the latch spindle which is on the outside side of the base plate, and whose other end is adapted to be pushed by hand so as to rotate the latch spindle and hook member in a first rotational direction so as to release the engagement of the hook member from the hood.

In the accompanying drawings: Figure 1 is a schematic perspective view of an engine compartment of a vehicle and a bonnet covering it, provided with a bonnet locking device; Figure 2 is a view from the back, showing a prior art locking device; Figure 3 is a perspective view of the secondary latching mechanism of Fig. 2; Figure 4 is a horizontal section, taken along the line IV-IV in Fig. 2; Figure 5 is a perspective view, showing an embodiment of the present invention; Figure 6 is a horizontal section, taken along the line VI-VI in Fig. 5; and Figure 7 is a perspective view, showing another embodiment of the present invention.

Referring to Figs. 5 and 6, first embodiment of the present invention is shown. A hook member 3 is pivoted to the inside side of the base plate 1, and has a hook 21 formed on its end which engages the bonnet when the bonnet is lowered. In more detail, the hook member 3 is riveted to the end of a latch spindle 4 so that it is fixed thereto, and this spindle 4, as can be better seen in Fig. 6, passes through the base plate 1 from its one side to its other side, and is free to turn with respect to it. The reference numerals 11 and 1 2 in Fig. 6 denote a spacer and a washer, respectively, and these co-operate so as to keep the latch spindle substantially perpendicular to the base plate 1. On the other end of this latch spindle 4 is riveted, so that it is fixed thereto, a release lever 5, whose other end is formed as a push plate 7.In the shown embodiment, this lever is slightly cranked, so as to bring the push plate 7 away from the base plate 1, but the amount of this cranking, denoted by y2, is much less than the necessary amount of offset in the axial direction of the pivot, y1, in the prior art described above.

x2 indicates the effective length of the lever arm of the release lever. Further, formed on the hook member 3 is a secondary arm 9, to which is attached one end of a biasing spring 6, the other end of which is attached to the base plate 1.

It is to be noted that in this device the distance x2, which is the length of the release lever, can be made as large as desired, without any problem of the twisting force on any part of the mechanism being increased. This is in contradistinction to the mechanism of the illustrated prior art, in which the increase of the distance xl increases the twisting forces on the mechanism.

It is clear that, because there is no skewed twisting force on any of the members, the latch shown above can be made simply and of a lighter construction than the prior art latches, and does not need to be made of a channel construction.

Another advantage of the present invention is that, because the motivating force for operating the latch is passed through the base plate, it is not necessary for any member to pass over the base plate, as in the prior art shown. Consequently, this base plate is not constrained in its shape, and can be brought more closely to mate with the bonnet.

In the second embodiment of the present invention which is shown in Fig. 7, the biasing spring 6 is attached to the release lever 5, instead of being attached to the hook member 3. Apart from this, the operation of this embodiment is the same as that of the first embodiment, and the same functions and advantages are derived as in the first embodiment.

Claims

1. A vehicle incorporating a raising and lowering bonnet, a base plate, having an inside side and an outside side, a primary latch mechanism fixed to the base plate, and a secondary latch mechanism fixed to the base plate, said secondary latch mechanism comprising: a latch spindle rotatably mounted through the base plate and generally perpendicular to it; a hook member fixedly mounted on the end of the latch spindle which is on the inside side of the base plate and adapted to engage with the bonnet when the latter is lowered; a release lever whose one end is fixedly mounted on the end of the latch spindle which is on the outside side of the base plate, and whose other end is adapted to be pushed by hand so as to rotate the latch spindle and hook member in a first rotational direction so as to release the engagement of the hook member from the hood.

2. A vehicle as claimed in claim 1, further comprising means for biasing the assembly of the latch spindle, hook member, and release lever in a rotational direction opposite to said first rotational direction.

3. A vehicle as claimed in claim 2, wherein the biasing means comprises a spring connected between the hook member and the base plate.

4. A vehicle as claimed in claim 2, wherein the biasing means comprises a spring connected between the release lever and the base plate.

5. A vehicle having a raising and lowering hood substantially as described with reference to, and as illustrated in, Figs. 5 and 6, or Fig.

7, of the accompanying drawings.