Background of the Invention
The present invention relates to a latch, in particular for a motor vehicle.
More particularly, the invention concerns a latch of the type comprising a case integral with a first part of the vehicle, and in which is disposed a bolt, and a keeper integral with a second part of the vehicle and adapted to cooperate with said bolt, said first and second parts of the vehicle being movable relative to each other, and the bolt being mounted to be movable between a position for releasing the keeper and a position for locking the latter in the case.
The latches of the prior art have a certain number of drawbacks, in particular as concerns the locking of the keeper by the bolt which requires a large effort resulting for example in the necessity to close the rear door of the vehicle vigourously.
Summary of the Invention
An object of the invention is therefore to overcome this problem by providing a latch which permits the gentle locking of the keeper in the case, while retaining the effectiveness of the locking and enabling the user to actuate at any moment the means for unlocking the keeper.
The invention therefore provides a latch of the type described hereinbefore, wherein the bolt comprises means for hooking the keeper and is mounted to be movable along a path roughly parallel to the path of the displacement of the keeper in the vicinity of the case, between a keeper hooking position, the hooking being achieved by the shifting of said movable part of the vehicle by the user and the keeper locking position by actuating means controlled in one direction by means detecting the presence of the keeper in the hooking position and in the other direction by means detecting the actuation of the bolt unlocking means.
Advantageously, the hooking means comprise a hook which is movable between an active position, to which it is elastically biased and in which it extends into the path of the displacement of the keeper, and a retracted position for permitting the hooking or the release of the keeper.
Brief Description of the Drawing
A better understanding of the invention will be had from the following description which is given solely by way of example with reference to the accompanying drawing, in which FIG. 1 represents a sectional view of a latch according to the one embodiment of invention, the keeper being shown in several of its positions.
Detailed Description of a Preferred Embodiment
As has been shown in FIG. 1 of this drawing, a latch according to the invention for a motor vehicle comprises a case 1 mounted on a first part 2 of the vehicle and in which is disposed a bolt 3. The latch further comprises a keeper 4 adapted to cooperate with the bolt and mounted on a second part 5 (e.g. door) of the vehicle, for example mounted to be movable relative to the first part 2 of the vehicle, and movable by the user.
The bolt 3 comprises keeper hooking means 6 and is mounted to be movable along a path which is roughly parallel to the path of the displacement of the keeper in the vicinity of the case, between a keeper hooking position, illustrated by the arrow A in said Figure, the hooking being achieved by a shifting of said movable part of the vehicle by the user, and a keeper locking position, illustrated by the arrow B by actuating means 7 operated in one direction, i.e. from the hooking position A to the locking position B, by means detecting the presence of the keeper in the hooking position.
These detecting means are, for example, constituted by a switch 20 actuated by the keeper or the bolt when the keeper reaches the position in which it has just been hooked by the hooking means 6, as shown in FIG. 1. An unlocking switch (not shown), actuated by the user when he desires to unlock the latch, causes operation of the actuating means in the opposite direction. A switch 21 actuated by the user when he desires.
Note moreover that end-of-travel switches 18 and 19 are provided in the bolt hooking position A and locking position B, respectively, for cutting off the supply of power to the actuating means 7 and stop the displacement of the bolt.
The hooking means 6 comprise a hook which is movable between a first or active position to which it is elastically biased and in which it extends into the path of displacement of the keeper, and a second or retracted position for permitting the unhooking or the release of the keeper.
The hook 6 has for example an inclined camming surface 6a, with which cooperates the keeper 4 for shifting the hook to its retracted position upon the hooking of the keeper.
Means 8 for retracting the bolt from the keeper 4 upon actuation of the bolt unlocking means are also provided. These means will be described in more detail hereinafter.
The bolt 3 has a generally S shape. One of the ends of this bolt includes the aforementioned hooking means 6 and its central portion is pivotally mounted on a slide or support 10 which is movable in the case 1 by the actuating means 7 so as to cause the bolt to be displaced between its two positions.
At the other of its ends, the bolt has bearing surfaces 3a, 3b adapted to cooperate with a first abutment surface 1a of the case and the aforementioned retracting means 8 for locking the bolt in the locking position and retracting it upon its return to the hooking position respectively.
For this purpose, the retracting means 8 comprise an abutment element 9 pivotally mounted in the case to move between an active position to which it is elastically biased and a retracted position. This abutment element has bearing surfaces 9a, 9b adapted to cooperate with the bearing surfaces 3a, 3b of the bolt for shifting the abutment element to its retracted position when the bolt moves towards its locking position in opposition to the action of elastically yieldable means 11 which biases the abutment element to its active position. Thus, when the bolt is shifted from its hooking position A to its locking position B, the corresponding end of the bolt causes the abutment element to retract until this end of the bolt has completely passed beyond the abutment element. The latter then returns to its active position. In this position, the abutment element bears against a second abutment surface 1b of the case, and the first abutment surface 1a of the latter locks the bolt in the locking position.
When the actuating means 7 are operated in such manner as to ensure a displacement of the bolt 3 from the locking position B to the hooking position A, the corresponding end of the bolt, and more particularly the bearing surface 3a of the latter, bears against the support surface 9b of the abutment element whose support surface 9a is itself bearing against the abutment surface 1b of the case. The bolt is then caused to swing about its pivot axis in such manner as to retract from and release the keeper. As soon as this abutment element has been passed through, the corresponding end of the bolt is then released and the bolt returns to its active hooking position under the action of the elastically yieldable means biasing it to this position. For this purpose, it should be noted that this bolt is elastically biased to its active position by a spring 12 having one end bearing against the slide 10 and the other end against the bolt 3.
The aforementioned actuating means 7 comprises, for example, a motor/speed-reducer 13 whose output shaft cooperates with driving means 14 constituted, for example, by an irreversible worm and worm wheel system 15 connected to a driving strip 16 mounted to be movable in a slideway 17 mounted on the case and having one end connected to the slide 10. Also note that the slide 10 is movably mounted in this slideway 17.
It will be understood that other embodiments are possible. Thus, for example, the driving strip 16 may be dispensed with in the case where there is used a driving system including a link and crank connected to the slide 10 and to the motor speed-reducer unit 13 to ensure the shifting of the slide carrying the bolt 3. This permits the use of a motor.
The latch according to the invention:
When the user shifts the movable part of the vehicle on which the keeper is mounted to the hooking position A, this keeper 4 cooperates with the inclined surface 6a of the means 6 for hooking the bolt 3 so as to shift the latter to its retracted position and permit the keeper to pass beyond the hooking means and reach the hooking position A.
In this position, the means detecting the presence of the keeper in the hooking position supply power to the motor speed-reducer 13 in a certain direction so that the latter results in the displacement of the driving strip 16, and therefore of the slide 10 and the bolt 3, to the position B in which the bolt locks the keeper.
Upon this displacement, the corresponding end of the bolt constrains the abutment element 9 to retract until the end has passed beyond this element.
In the keeper locking position B, the supply of power to the motor speed-reducer unit is cut off by the corresponding end-of-travel switch 18 and the corresponding end of the bolt is then disposed below the abutment element where it bears against the first abutment surface 1a of the case, which prevents the bolt from pivoting, bearing in mind that the irreversible worm and worm wheel system locks the slide in position.
When the user desires to unlock the keeper, he actuates the unlocking switch which supplies power to the motor speed-reducer unit in such manner that the slide, and therefore the bolt, are shifted to the hooking position A. Upon this displacement, the corresponding end of the bolt comes to bear against the abutment element which is itself bearing against the second abutment 1b of the case, which causes the bolt to pivot to its retracted position for releasing the keeper. The displacement of the bolt continues so long as its corresponding end has not completely passed beyond the abutment element and the end-of-travel switch 19 detecting the presence of the bolt in the keeper hooking position has not been actuated. When the latter is actuated, it cuts off the supply of power to the motor speed-reducer unit and stops the displacement of the bolt which is then ready for another locking cycle.
In the description, the various detecting and end-of-travel switches have been only schematically illustrated and have not been described in detail since these types of switches are well known in the art and present no particular difficulty as concerns their use.
Thus, the latch according to the invention permits a gentle locking of the keeper, the bolt ensuring an automatic locking of the keeper.