GB2470993A

GB2470993A - A latch device in a vehicle

Info

Publication number: GB2470993A
Application number: GB1008798A
Authority: GB
Inventors: Kiyohiko Kamata; Naoya Seto
Original assignee: Mitsui Mining and Smelting Co Ltd
Current assignee: Mitsui Mining and Smelting Co Ltd
Priority date: 2008-07-08
Filing date: 2009-07-03
Publication date: 2010-12-15
Anticipated expiration: 2029-07-03
Also published as: GB0911606D0; GB2461631A; GB2461631B; GB201008798D0; GB2470993B

Abstract

A latch device comprising a spring 10 biased latch 5 pivotal from a disengaged position in which the latch disengages from a striker to an engaged position in which the latch engages the striker. A pivotal locking plate (pawl) 6 having hook 61 to retain the latch in the engaged position. The latch has a limiting portion 57 which contacts the locking plate at 63 to prevent contact between hook of pawl 6 from contacting the latch 5. Upon engagement with the striker the latch rotates and limiting portion 57 disengages from the pawl 6 to allow rotation of the pawl and hook 61 to engage the latch. The contact portion 63 of locking plate may be on an elongate arm 62; the limiting and contact portions may comprise a pin 57 following an arcuate surface 63; the centre point of the arc being the pivot 9 of the latch such that the force exerted is directed centrifugally. The location of the pin and arc may be interchanged, see fig.15. Ensuring there is no contact and pawl 6 is kept separate from latch 5 during rotation of the latch minimizes any resistance due to friction between the latch and the pawl. A pivotal cam plate 7 may be provided to engage the latch and move the latch into an overrunning position.

Description

LATCH DEVICE INAVEHICLE

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a latch device in a vehicle for locking a seat, a roof or a trunk lid to the vehicle.

[0002] In W02004/069585, a latch device for locking a seat in a vehicle comprises a latch operable to engage with a striker in a vehicle body; a locking plate which engages with the latch to prevent the latch from turning; and a cam member for preventing loosening between the latch and the striker and applying rotational moment toward an overrunning position to the latch. When the striker fits in the latch, the cam member is rotated, so that the latch is forced to turn the overrunning position to allow the striker to engage with the latch firmly.

[0003] In the latch device, when the latch is in a standby position before accepting the striker, a hook of the locking plate and a cam portion of the cam member contact the outer surface of the latch by force of respective spring, applying rotational moment toward the standby position to the latch.

Rotational moment that acts to the latch becomes resistant force for turning the latch for engagement from the standby position, so that load of engagement of the striker with the latch gets larger, which is disadvantageous.

SUMMARY OF THE INVENTION

[0004] In view of the disadvantages, it is a main object of the invention to provide a latch device in a vehicle that reduces resistance when a latch turns for engagement from a standby position thereby carrying out engagement of a striker with the latch by a small force.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Fig. 1 is a front elevational view of a vehicle seat including the present invention.

[0006] Fig. 2 is a side view in which a latch in the first embodiment of a latch device in a vehicle according to the present invention is in a standby or disengagement position.

[0007] Fig. 3 is a side view of the latch device during engagement.

[0008] Fig. 4 is a side view thereof when the latch is in an engagement position.

[0009] Fig. 5 is a side view thereof when the latch is in an overrunning position.

[0010] Fig. 6 is a side view thereof when the latch is released.

[0011] Fig. 7 is an enlarged side view of the main part thereof.

[0012] Fig. 8 is a side view of the second embodiment of a latch device in a vehicle according to the present invention when a latch is in a standby position.

[0013] Fig. 9 is a side view thereof during engagement.

[0014] Fig. lOis a side view thereof when the latch rotates from Fig. 9.

[0015] Fig. 11 is a side view thereof when the latch rotates from Fig. 10.

[0016] Fig. 12 is a side view thereof when the latch is in engagement.

[0017] Fig. 13 is a side view thereof when the latch is in an overrunning position.

[0018] Fig. 14 is a side view thereof when the latch is released.

[0019] Fig. 15 is an enlarged side view of the third embodiment a latch device in a vehicle according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

[0020] In Fig. 1, a seat 1 in a vehicle is normally locked in use shown by solid lines on which one sits and can be moved to a storage position shown by two-dot-dash lines. In order that the seat 1 may be locked in use, a latch device 2 on the lower surface of the seat 1 is engaged with a striker 3 fixed to a vehicle floor. Besides the seat 1, the latch device 2 may be used for a moving roof or a trunk lid.

[0021] In Figs. 2-6, the first embodiment of the present invention will be described. The latch device 2 comprises a base member 4 fixed to the lower surface of the seat 1; a latch 5 which can be engaged with the striker 3; a locking plate 6 which can be engaged with the latch 5 engaged with the striker 3; a cam plate 7 giving rotational moment for turning the latch 5 from an engagement position in Fig. 4 to an overrunning position in Fig. 5; and a release lever 8 for turning the locking plate 6 in a counterclockwise direction in Figs. 4 and 5 for releasing.

[0022] In the middle of the lower end of the base member 4, there is formed a striker-fitting groove 41 in which the striker 3 engages when the seat 1 is locked in the used position.

[0023] The latch 5 is pivotally mounted on a latch shaft 9 above the striker-fitting groove 41 of the base member 4 and turns from a standby or disengagement position in Fig. 2 to the overrunning position in Fig. 5 via the engagement position in Fig. 4 and vice versa. The latch 5 is forced in the disengagement direction or counterclockwise direction in Figs. 2-7 with a first spring 10 wound on the latch shaft 9.

[0024] The latch 5 has a first arm 51 and a second arm 52 between which the striker-fitting groove 53 is formed. The second arm 52 has in the inner edge an engagement portion 54 which engages with a hook 61 at the lower end of the locking plate 6. At the tip end of the second arm 52 or the engagement portion 54, there is formed an input portion 55 which is capable of being in sliding contact with a cam portion 71 of the cam plate 7.

[0025] The standby or disengagement position of the latch 5 stands for a position where the striker 3 does not engage with the striker-fitting groove 53; the engagement position stands for a position where the striker 3 engages in the striker-fitting groove 53 and the hook 61 of the locking plate 6 engages with the engagement portion 54; and the overrunning position stands for a position where there is a gap between the hook 61 of the locking plate 6, by further turning the engagement portion 54 from the engagement position.

[0026] The locking plate 6 is pivotally mounted on a second shaft 11 extending along a width of the vehicle and forced clockwise in Figs. 2-7 or in a direction of engagement of the hook 61 with the engagement portion 54 of the latch 5.

[0027] The hook 61 of the locking plate 6 engages with the engagement portion 54 of the latch 5 preventing the latch 5 from turning from the engagement position to the disengagement position, and the hook 61 leaves the engagement portion 54 allowing the latch 5 to turn to the disengagement position. The first spring 10 engages with the latch 5 at one end and with the locking plate 6 at the other end, applying a force to the latch 5 toward disengagement and a force to the locking plate 6 toward engagement.

[0028] The cam plate 7 is pivotally mounted on a cam shaft 13 extending along the width of the vehicle and forced with a second spring 12 wound on the locking plate shaft 11, in an engagement direction or counterclockwise in Figs. 2-7. On the upper edge of the cam plate 7, there is a cam portion 71 which is capable of contacting the input portion 55 of the latch 5 when the latch 5 is between just before the engagement position and overrunning position of the latch 5.

[0029] The cam portion 71 is formed to increase a distance from the center of the cam shaft 13 as it turns counterclockwise. The cam plate 7 turns in a direction of engagement by the force of the second spring 12 while the cam portion 71 contacts the input portion 55, thereby giving turning moment to the latch 5 for rotating from the engagement position to the overrunning position.

[0030] A force is given to the input portion 55 which contacts the cam portion 71 of the cam plate 7 and the striker 3 is subjected to the force by the first engagement portion 51 of the latch 5 at the point A in Fig. 7. The input portion is more separate than the point A from the latch shaft 9. Increased force is exerted to the point A. [0031] When the latch 5 is between the disengagement position and just before engagement position in Fig. 2, a pressing portion 72 of the cam portion 71 contacts a contact portion 56 at the upper edge of the second arm 52 by force of the second spring 12 giving the latch 5 rotational moment in a direction of disengagement. A contact point of the pressing portion 72 to the contact portion 56 is more separate than the point A from the latch shaft 9 increasing input force and outputting it at the point B. The latch 5 can be rotated more reliably in the disengagement position.

[0032] The locking plate 6 and the cam plate 7 are disposed such that tracks of the hook 61 and the cam 71 cross a straight line between the locking plate shaft 11 and the cam shaft 13 in Fig. 7.

[0033] Timing is set such that the cam portion 71 of the cam plate 7 gets in sliding contact with the input portion 55 of the latch 5 simultaneously with or slightly earlier than engagement of the hook 61 of the locking plate 6 with the engagement portion 54 of the latch 5. In Fig. 7, the cam portion 71 of the cam plate 7 gets in sliding contact with the input portion 55 of the latch 5 just before the latch 5 turns from the disengagement position to the engagement position.

Thus, just before the hook 61 of the locking plate 6 engages with the engagement portion 54 of the latch 5, the cam plate 7 gives the latch 5 rotational moment for rotating it toward the overrunning position, thereby allowing the hook 61 of the locking plate 6 to contact the engagement portion 54 without rubbing the engagement portion 54.

[0034] A release lever 8 is pivotally mounted on a lever shaft 14 over the locking plate 6 on the base member 4. The lower end of the release lever 8 is connected to the upper end of the locking plate 6, and the upper end of the release lever 8 is connected to a strap (not shown) of the seat 1 via a cable or a rod.

[0035] When the seat I is used, the strap is pulled and the release lever 8 turns from the standby position in Fig. 2 clockwise to allow the locking plate 6 to turn from the engagement position in Figs. 4 and 5 for releasing. When the locking plate 6 rotates, the hook 61 of the locking plate 6 leaves the engagement portion 54 of the latch 5. When the locking plate 6 rotates further, the contact portion 62 at the lower end of the locking plate 6 contacts a projection 73 on the cam plate 7 to allow the cam plate 7 to turn clockwise in Figs. 2-7 to allow the cam portion 71 to go away from the input portion 55 of the latch 5. Thus, it is permitted for the latch 5 to turn for disengagement. When the locking plate 6 turns counterclockwise, the gap is formed between the hook 61 and the engagement portion 54 to allow the hook 61 to go away from the engagement portion 54 smoothly without rubbing the engagement portion 54.

Before the hook 61 leaves the engagement portion 54, the cam plate 7 does not turn clockwise, so that releasing is not obstructed. The force of the second spring 12 is not so large and the releasing force does not get larger.

[0036] Then, the operation of the latch device 2 will be described.

When the seat 1 is stored or is not used, the latch 5 leaves the striker 3 and is kept in the disengagement position in Fig. 2. The locking plate 6 and the cam plate 7 contact the contact portion 56 of the latch 5. To use the seat 1, the striker 3 engages in the striker-fitting groove 41 and in the engagement groove 53 of the latch 5 to allow the latch 5 to turn toward the engagement position.

[0037] In Figs. 3 and 7, when the latch 5 turns just before the engagement position, the cam portion 71 of the cam plate 7 contacts the input portion 55 of the latch 5. Thus, the cam plate 7 turns toward engagement by the force of the second spring 12 to allow the latch 5 to turn in the engagement position where the hook 61 of the locking plate 6 engages with the engagement portion 54 of the latch 5 by the force of the first spring 10.

[0038] When the cam plate 7 turns further in the engagement direction, the latch 5 turns in the overrunning position where the striker 3 goes deeply in the striker-fitting groove 41 and is firmly held between the striker-fitting groove 41 and the first arm 51 of the latch 5. As mentioned above, the input portion 55 which contacts the cam portion 71 of the cam plate 7 is more separate from the latch shaft 9 than the point A at which rotational moment is exerted, so that the latch 5 can be rotated reliably by a small force from the engagement position to the overrunning position.

[0039] When the seat is locked in use, the latch 5 is securely rotated by a small force to the overrunning position thereby preventing loosening at the engagement between the latch 5 and the striker 3.

[0040] The second embodiment of the present invention will be described with respect to Figs. 8-14.

In the embodiment, a latch 5 and a locking plate 6 have an upward arm 56 and a sideward arm 62 respectively, which is mainly different from the first embodiment. Description of the same members as those in the first embodiment will be omitted.

A pin 57 is fixed to the upward arm 56 and operable to engage on an arc 63 on the upper edge of the sideward arm 62.

[0041] A first spring 10 is wound on a first pivot shaft 9 of the latch 5. One end of the first spring 10 engages with the latch 5 and the other end engages with the sideward arm 62 of the locking plate 6, so that the latch 5 and the locking plate 6 are forced clockwise.

[0042] While the latch 5 turns from a disengagement position in Fig. 8 to just before an engagement position and vice versa, the arc 63 of the sideward arm 62 contacts the pin 57 of the latch 5.

[0043] When the latch 5 is in a standby or disengagement position in Fig. 8, the arc 63 contacts the pin 57 to allow an end 611 of a hook 61 to go away from the outer edge of the latch 5.

[0044] The arc 63 is part of a circle having the first pivot shaft 9 as center when the locking plate 6 is away from the latch 5.

The point of contact of the arc 63 to the pin 57 is on the line A between the center of the pin 57 and the center of the first pivot shaft 9 centrifugally, so that no rotational moment is applied to the latch 5. So, while the latch 5 turns from the disengagement position to just before the engagement position, a resistant force against the latch 5 comprises only friction between the pin 57 and the arc 63 and a force by the first spring 10, so that the latch 5 is rotated from the disengagement position to the engagement position by a small force.

[0045] A horizontal arm 18 of a release lever 8 is connected to a strap or a knob (not shown) on a seat 1 via a cable 15 or a rod. When the horizontal arm 18 is connected to the knob via the cable 15, the position of the knob is variable depending on the position of the locking plate 6, so that it can be easily found whether or not a hook 61 of the locking plate 6 engage with an engagement portion 54 of the latch 5.

[0046] When the seat 1 is in use, the strap or knob is pulled, and the release lever 8 turns clockwise to allow the locking plate 6 to turn counterclockwise.

The hook 61 of the locking plate 6 leaves the engagement portion 54 of the latch 5. The projection 73 of the latch 7 contacts the locking plate 6 and a cam portion 71 leaves the latch 5, thereby permitting the latch 5 to turn for disengagement. When the hook 61 of the locking plate 6 leaves the engagement portion 54 of the latch 5, there is a gap between the hook 61 of the locking plate 6 and the engagement portion 54 of the latch 5. Thus, the hook 61 can get away from the engagement portion 54 without rubbing the engagement portion 54.

[0047] Engagement of a striker 3 with the latch 5 will be described as below.

When the seat 1 is stored, as shown in Fig. 8, the latch 5 is in a standby position before accepting the striker 3; the locking plate 6 is in a leaving position where the arc 63 contacts the pin 57 of the latch Sand the end 611 of the hook 61 is away from the outer surface of the latch 5; and the cam plate 7 is in a leaving position where the projection 73 contacts the outer edge of the locking plate 6 and the tip end of the cam portion 71 is away from the outer surface of the latch 5.

[0048] When the seat 1 is used, the striker 3 engages in a striker-fitting groove 41 of a base member 4 and also in an engagement groove 53 of the latch 5 in Fig. 8. The latch 5 turns against the force of the first spring 10 from the standby position, and the outer surface of the latch 5 gets in touch with the tip end of the cam portion 71 of the cam plate 7. In Fig. 10, the latch 5 turns further, and then, the outer surface of the latch 5 contacts the end 611 of the hook 61 of the locking plate 6.

[0049] In this embodiment, the arc 63 of the locking plate 6 is part of a circle having the first pivot shaft 9 as center. Thus, until the outer surface of the latch contacts the end 611 of the hook 61 of the locking plate 6, the pin 57 of the latch 5 moves in sliding contact with the arc 63, and the locking plate 6 does not move from the standby position to another position. Until the outer surface of the latch 5 contacts the end of the cam portion 71 of the cam plate 7, the pin 57 of the latch 5 moves in sliding contact with the arc 63 forward, and the cam plate 7 does not move from the standby position to another position.

[0050] In Fig. 11, the latch 5 turns for engagement, and the locking plate 6 and the cam plate 7 which follow rotation of the latch 5 turn counterclockwise and clockwise respectively against the forces of the first and second springs 10,12.

When the locking plate 6 turns, the arc 63 goes away from the pin 57 and simultaneously the pin 57 moves out of the track of the arc 63.

[0051] In Fig. 12, the latch 5 reaches the engagement position, and the pin 57 goes away from the arc 63 to allow the locking plate 6 to turn freely for the engagement. The hook 61 of the locking plate 6 engages with the engagement portion 54 of the latch 5 by force of the first spring 10, and the cam portion 71 of the cam plate 7 contacts the end 55 of the engagement portion 54 of the latch 5. Thus, the cam plate 7 turns toward the engagement by force of the second spring 12 and the cam portion 71 gets in sliding contact with the end of the engagement portion 54 of the latch 5 to allow the latch to turn to the overrunning position in Fig. 8.

[0052] When the latch 5 turns to the overrunning position, the striker 3 is strongly held between the striker-fitting groove 41 and the first arm 51 of the latch 5, preventing loosening between the striker 3 and the latch 5.

[0053] As above, in the initial step in which the latch turns from the standby position to just before the engagement position or until the outer surface of the latch 5 contacts the end of the cam portion 71 of the cam plate 7, resistant force against rotation of the latch 5 from the standby position toward engagement comprises only frictional resistance between the arc 63 and the pin 57 and a force of the first spring 10, thereby reducing the resistance to the latch 5 and allowing the striker 3 to engage with the latch 5 by a small force. Also the end of the cam portion 71 and the end 611 of the hook 61 of the locking plate 6 contact the outer surface of the latch 5 stepwise, preventing load from increasing rapidly when the latch 5 turns toward the engagement.

[0054] Fig. 15 is a side elevational view of the third embodiment of the present invention.

In this embodiment, in a latch, there is provided an arcuate portion 58 which is part of a circle having a first pivot shaft 9 as the center. The upper end of an upward arm 56 is bent to form the arcuate portion 58. A pin 64 is fixed on a horizontal arm 62 to contact the lower surface of the arcuate bent portion 58. Except the bent portion 58 and the pin 64, the structure is the same as that in the foregoing embodiments and its description is omitted.

[0055] When the latch 5 is in a standby position or the like, the pin 64 contacts the bent portion 58 such that a force that exerts the latch 5 is directed centrifugally.

[0056] When the latch 5 is in the standby position in Fig. 15, the pin 6 contacts the bent portion 58 of the latch 5, so that the locking plate 6 is held in a leaving position where the end 611 of the hook 61 does not contact the outer surface of the latch 5. When the latch 5 rotates from the standby position, the bent portion 58 moves in sliding contact with the pin 64 and goes away from the pin 64.

[0057] In the embodiment, when the latch 5 is in the standby position or the like, the end 611 of the hook 61 and the cam portion 71 of the cam 7 are held in a position away from the outer surface of the latch 5 thereby reducing resistance when the latch 5 is rotated from the standby position. While the locking plate 6 and the cam plate 7 are still held in the standby position, the latch 5 can be rotated from the standby position for the engagement.

[0058] The foregoing merely relates to embodiments of the invention.

Various changes and modifications may be made without departing from the scope of claims.

i) The cam plate 7 is omitted. The initial stage for turning the latch 5 from the standby position to the leaving position is defined as period until the outer surface of the latch 5 contacts the end 611 of the hook 61 of the locking plate 6.

ii) The contact portion is provided in the release lever 8 moving together with the locking plate 6. The contact portion may be any part moving together with the locking plate 6 except the hook 61 of the locking plate 6.

Other embodiments of the invention can be seen in the following paragraphs: 1. A latch device in a vehicle, comprising: a base member fixed to one of a vehicle body and an object supported on the vehicle body; a first pivot shaft fixed to the base member; a first spring wound on the first pivot shaft; a latch pivotally mounted to the base plate on the first pivot shaft and being capable of turning against a force of the first spring from a disengagement position in which the latch disengages from a striker fixed to the other of the vehicle body and the object, to an engagement portion in which the latch engages with the striker; a second pivot shaft fixed to the base member; a second spring wound on the second pivot shaft; and a locking plate pivotally mounted to the base member on the second pivot shaft and having a hook that engages with the latch to prevent the latch from turning from the engagement position to the disengagement position, a contact portion being provided on the locking plate; said latch comprising a limiting portion operable to contact the contact portion of the locking plate to prevent the hook of the locking plate from contacting the latch, the latch turning to allow the limiting portion to leave the contact portion, enabling the hook to turn and engage with the latch.

2. The latch device of paragraph 1, further comprising a cam plate pivotally mounted to the base member, the cam plate having a cam portion allowing the latch to turn to an overrunning position beyond the engagement position by a force of the second spring.

3. The latch device of paragraph 1 wherein the contact portion contacts the limiting portion such that force which acts to the latch directs centrifugally.

4. The latch device of paragraph 1 wherein the limiting portion comprises a pin projecting on the latch, the contact portion comprising an arc of a horizontal arm of the locking plate.

5. The latch device of paragraph 1 wherein the limiting portion comprises an arcuate portion, the contact portion of the locking plate comprising a pin fixed on a horizontal arm of the locking plate.

Claims

CLAIMS: 1. A latch device in a vehicle, comprising: a base member fixed to one of a vehicle body and an object supported on the vehicle body; a first pivot shaft fixed to the base member; a first spring wound on the first pivot shaft; a latch pivotally mounted on the first pivot shaft to the base plate and being capable of turning against a force of the first spring from a disengagement position in which the latch disengages from a striker fixed to the other of the vehicle body and the object, to an engagement portion in which the latch engages with the striker; a second pivot shaft fixed to the base member; and a locking plate pivotally mounted on the second pivot shaft to the base member and having a hook that engages with the latch to prevent the latch from turning from the engagement position to the disengagement position, a contact portion being provided on the locking plate; said latch comprising a limiting portion operable to contact the contact portion of the locking plate to prevent the hook of the locking plate from contacting the latch, the latch turning to allow the limiting portion to leave the contact portion, enabling the hook to turn and engage with the latch.
2. The latch device of claim 1, further comprising a cam plate pivotally mounted to the base member and a second spring wound on the second pivot shaft, the cam plate having a cam portion allowing the latch to turn to an overrunning position beyond the engagement position by a force of the second spring.
3. The latch device of claim 1 wherein the contact portion contacts the limiting portion such that force which acts to the latch directs centrifugally.
4. The latch device of claim 1 wherein the limiting portion comprises a pin projecting on the latch, the contact portion comprising an arc of a horizontal arm of the locking plate.
5. The latch device of claim 1 wherein the limiting portion comprises an arcuate portion, the contact portion of the locking plate comprising a pin fixed on a horizontal arm of the locking plate.