CROSS REFERENCE TO RELATED APPLICATION

This PCT Patent Application claims the benefit of U.S. provisional application serial number 61/589,589 filed January 23, 2012, the entire disclosure of the application being considered part of the disclosure of this application, and hereby incorporated by reference. Field of the Invention

This disclosure generally relates to the field of vehicle latches. Background of the Invention

Vehicle doors use latches as part of the vehicle door locking system. Such systems typically provide a number of functions whilst striving to minimize costs to the end consumer. For example, the door locking system may lock the door by making the inner and/or outer door handle inoperative. The door locking system also has to be able release the latch to allow the person to open door once the door is unlocked. It is typically desired to decouple the locking and releasing functions, that is, to allow the user to unlock the door and only then to release it. Thus, for example, a passenger inside the vehicle can unlock the door allowing a person outside the vehicle to release the latch and open the door. One known type of conventional latch, called an "override" latch, has a dedicated inside lock button to control the inside lock/unlock function and a separate inside door handle to provide the inside release function.

Summary of the Invention

An "override" latch is provided with a push-pull system in which an inside door handle carries out both functions (lock/unlock and release) independently. According to one aspect a push-pull latch for a vehicle door is provided. The latch includes a housing, a ratchet and a pawl, an outside release lever, an inside release lever, a locking mechanism and an inside link lever. The ratchet is movable between a closed position to retain a striker and an open position to permit release of the striker, and is biased towards the open position. The pawl is movable between a locking position in which the pawl keeps the ratchet in the closed position, and an unlocked position wherein the pawl permits the movement of the ratchet out of the closed position. The pawl is biased towards the locking position. The outside release lever is pivotally mounted in the housing for movement between a rest position and an actuated position. The locking mechanism is configured for selectively locking and unlocking the latch by respectively disabling and enabling the outside release lever from actuating the pawl. The inside release lever is pivotally mounted in the housing and is movable between a locked position, an unlocked position and a release position. The inside link lever is pivotally mounted in the housing and positioned for operatively connecting the inside release lever to the locking mechanism. The inside release lever is connected to the inside link lever by a transfer spring and a lost motion connection. Pivotal movement of the inside release lever in a first directional sense from the unlocked position to the locked position transfers movement of the inside release lever to the inside link lever via the lost motion connection thereby locking the locking mechanism. Pivotal movement of the inside release lever in a second directional sense from the locked position to the unlocked position transfers movement of the inside release lever to the inside link lever solely via the transfer spring, thereby urging the inside link lever to unlock the locking mechanism. Movement of the inside release lever in the second directional sense from the unlocked position to the release position drives the pawl to the unlocked position thereby permitting the ratchet to move to the open position to release the striker, and the lost motion connection prevents a transfer of movement from the inside release lever to the inside link lever during pivotal movement of the inside release lever in the second directional sense from the unlocked position to the release position. Brief Description of the Drawings

The foregoing and other aspects will be more readily appreciated by reference to the accompanying drawings, wherein:

Figure la is a perspective view of a vehicle; Figure lb is a side view of major operating levers in an embodiment of a push-pull latch;

Figure 2 is a side view of the major operating levers of the push-pull latch shown in Figure lb in a view orthogonal to that of Figure lb;

Figure 3 is a perspective view of the major operating levers of the push-pull latch shown in Figure lb; Figure 4 is a perspective view of the major operating levers of the push-pull latch from a reverse angle compared to Figure 3;

Figure 5 is an exploded view of the major operating levers of the push-pull latch shown in Figure lb;

Figure 6A is a side view of the major operating levers of the push-pull latch shown in Figure lb showing the state of the levers when an inside release lever is moved to a locked position;

Figure 6B is a side view of the major operating levers of the push-pull latch shown in Figure lb showing the state of the levers when the inside release lever is moved to an unlocked position; and Figure 6C is a side view of the major operating levers of the push-pull latch shown in Figure lb showing the state of the levers when the inside release lever is moved to a release position. Detailed Description of Embodiments

Referring to Figure la, an embodiment of a push-pull automotive latch 10 is provided for a vehicle 1 1. The vehicle 1 1 includes a body 13, having a door 15 hingedly connected thereto and movable between an open position and a closed position. The latch 10 includes a housing 12 (partially shown in Figures 6a-6c) in which a ratchet 14 (Figure 2) is pivotally mounted for rotation between a closed position (as seen in Figure 2) and an open position. In the view shown in Figure 2, the ratchet 14 would be rotated approximately 90 degrees clockwise to reach the open position. In the closed position the ratchet 14 is positioned to securely retain a striker 17 mounted to the vehicle body 13 thereby securing the door 15 against the vehicle body 13. In the open position the ratchet 14 permits the striker 17 to enter or exit the latch 10. The ratchet 14 is biased towards the open position by a ratchet biasing member 19 (e.g. a torsion spring).

A pawl 16 is pivotally mounted for rotation in the housing 12 (Figure 6a-6c) between a locked position (shown in Figure 2) and an unlocked position. In the view shown in Figure 2, the pawl 16 would be rotated approximately 10 degrees clockwise to reach the open position. The pawl 16 is mounted in the same plane as the ratchet 14 and in the locked position a shoulder 18 of the pawl 16 abuts against a tooth 20 of the ratchet 14. In the unlocked position the pawl 16 moves out of the way of the ratchet 14 (where, in Figure 2 for example, the pawl 16 moves counterclockwise to the open position) thereby allowing the bias force on the ratchet 14 to move the ratchet into the open position. The pawl 16 is biased towards the locked position by a pawl biasing member 21 (e.g. a torsion spring).

A pawl extension 24 (Figure 3) is part of the pawl 16 and moves in a plane that is parallel to the plane in which the rest of the pawl 16 and the ratchet 14 move. As seen in Figure 5 the pawl extension 24 has a projecting tab 24A that interfaces with a cavity 28 in the pawl 16. The pawl extension 24 and the rest of the pawl 16 move together as one unit. In the illustrated embodiment the ratchet 14 and pawl 16 are ensconced in a sub-compartment (not shown) of the housing and the pawl extension 24 is provided as a means to access the pawl 16 in the sub-compartment.

The pawl extension 24 also features a second tab 24B (Figure 5) that projects in an opposite direction to that of tab 24A, and a lug 24C. A slot 25 is also formed in the pawl extension 25 and is described further below.

An outside release lever 30 is pivotally mounted in the housing 12 for rotation between a rest position (as seen in Figure 2) and an actuated position. The outside release lever 30 may be connected via any suitable means, such as a cable, to an outside door handle 31 (Figure la) located on the exterior of the vehicle door 15. The outside release lever 30 is biased towards the rest position via an outside release lever biasing member 33, (e.g. a torsion spring) acting against an arm 34.

The outside release lever 30 is selectively coupled to or uncoupled with the pawl extension 24 through a sliding lock link 40 that slides between a coupled position (as seen in Figure 4) and an uncoupled position. As seen in Figure 4, when the sliding lock link 40 is in the coupled position and the outside release lever 30 is actuated, a thumb 32 of the outside release lever 30 engages a block 42 of the sliding lock link 40. As seen in Figure 4 and the sliding lock link 40 is slidingly connected to the pawl extension 24 via a captive pin 48 (Figure 5) that projects laterally from the block 42 and rides in the slot 25 of the pawl extension 24. Thus, when the sliding lock link 40 is in the coupled position, actuating the outside release lever 30 actuates the pawl 16 into the unlocked position and the ratchet 14 into the open position.

The sliding lock link 40 may also be moved to the uncoupled position in which case the block 42 is withdrawn from the path of the outside release lever 30 (and specifically from the path of the outside release lever thumb 32) so that actuating the outside release lever 30 does not actuate the pawl 24 and open the latch 10. The sliding lock link 40 interfaces with a lock lever 50 that is mounted in the housing 12 for pivotal rotation between a locked position and an unlocked position (as seen in Figure 4). The sliding lock link 40 includes a raised lip 44 and a slot 46. The lock lever 50 has a tri-lobed configuration featuring three lobes 52, 54 and 56. Lobe 52 features a projecting pin 58, a post 60 and a tab 62. The projecting pin 58 rides in the sliding lock link slot 46 on the sliding lock link 40. A torsion spring 64 is mounted about the post 60 and is connected between the lock lever 50 and the sliding lock link 40 via a first tang 64A wrapped around tab 62 and a second tang 64B fitted into the raised lip 44. Accordingly, when the lock lever 50 moves to the locked position (moving clockwise in the view shown in Figure 4) the lock lever projecting pin 58 rides against an end 65 of the sliding lock link slot 46 to move the sliding lock link 40 to the uncoupled position (moving to the left in the view shown in Figure 4). When the lock lever 50 returns to the unlocked position (as seen in Figure 4) the torsion spring tang 64B pushes against the rear raised lip 44 of the sliding lock link 40 to return the sliding lock link 40 to the coupled position.

In the event the lock lever 50 returns to the unlocked position when the outside release lever 30 is in the actuated position so as to interfere with the movement of the sliding lock link 40, the pin and slot connection between the lock lever 50 and the sliding lock link 40 permits the lock lever 50 to move first into the unlocked position and permits the sliding lock link 40, under the influence of the loaded torsion spring 64, to move later into the coupled position when the outside release lever 30 returns to the rest position and no longer obstructs the movement of the lock link 40.

As shown in Figures 3 and 4, the lock lever 50 may be controlled by three levers: an inside release lever 70; an inside link lever 80; and an auxiliary lock lever 90. The three levers 70, 80, 90 are situated in a plane transverse to the plane of the ratchet 14 and pawl 24.

The inside release lever 70 is pivotally mounted to the housing 12 for rotation about a rotational axis 75 between a locked position, an unlocked position, and a released position. More particularly, the inside release lever 70 includes a lever arm 72 that is connected via a stiff linkage such as a rod (shown at 71 in Figure 3) to an inside door handle (shown at 73 in Figure la). The inside release lever 70 also has an arcuate slot 74 with first and second ends 74A, 74B formed about the rotational axis 75 and a lug 76 that is radially offset from the rotational axis 75. The lug 76 interacts with the lug 24C of the pawl extension 24 as explained below.

The inside link lever 80 is pivotally mounted to the housing 12 about the same rotational axis 75. The inside link lever 80 features an aperture 82 (Figure 3), a projecting cam member 84 and a raised tab 86. The tab 86 is radially offset from the rotational axis 75 and is disposed within the arcuate slot 74 of the inside release lever 70. A torsion spring 78 is installed between the inside release lever 70 and the inside link lever 80. The torsion spring 78 has a first tang 78A abutting the lever 70 adjacent lug 76 and a second end 78B fitted into the aperture 82 of lever 80.

Referring to Figure 3, the auxiliary lock lever 90 is pivotally mounted to the housing 12 about a second rotational axis 95 that is offset from the first rotational axis 75. The auxiliary lock lever 90 features a cam follower slot 92 that receives the projecting cam member 84 of the inside lock link 80. The cam follower slot 92 has first and second ends 92 A, 92B. The auxiliary lock lever 90 also includes a forked connector 94 that interacts with a ball 66 disposed at the end of the lock lever lobe 56. As a result of engagement of the ball 66 with the connector 94, movement of either of the auxiliary lock lever 90 and the lock lever 50 between locked and unlocked positions causes movement of the other of the auxiliary lock lever 90 and the lock lever 50 between locked and unlocked positions. In embodiments wherein the auxiliary lock lever 90 is provided, the lock lever 50 may be referred to as a primary lock lever 50.

The inside release lever 70 has an operative lost motion connection with the auxiliary lock lever 90 which is described further below.

To lock the latch the inside door handle 73 is moved in a first direction (e.g. by pushing the handle tip shown at 91 to the left in Figure la) which moves the inside release lever 70 in a first directional sense (clockwise in the views shown in Figures 6A, 6B and 6C) from the unlocked position (Figure 6B) to the locked position (Figure 6A). When the inside release lever 70 is in the unlocked position the inside lock link tab 86 is situated immediately adjacent the first end 74A of the inside release lever arcuate slot 74 so that movement of the inside release lever 70 towards the locked position (i.e. clockwise in the views shown in Figures 6A, 6B and 6C) causes an immediate clockwise movement of the inside lock link 80 due to engagement between the inside lock link tab 86 and the first slot end 74A. The motion of the inside lock link 80 is, in turn, transferred by the projecting cam member 84 to the auxiliary lock lever 90 causing the auxiliary lock lever 90 to also rotate clockwise which, in turn, moves the lock lever 50 to the locked position. In the process the projecting cam member 84 moves from the first end 92A to the second end 92B of the cam follower slot 92.

To unlock the latch from inside the passenger compartment the inside door handle 73 is manipulated in an opposite sense to the first sense (i.e. by pulling the handle tip 91 towards the right in the view shown in Figure la) to move the inside release lever 70 from the locked position (Figure 6A) to the unlocked position (Figure 6B). In the locked position the inside lock link tab 86 is situated immediately adjacent the first end 74 A of the inside release lever arcuate slot 74 so that movement of the inside release lever 70 counterclockwise is not transferred to the inside lock link 80 via the arcuate slot 74. Instead, the inside release lever 70 presses on the spring tang 78A causing a reaction on the other spring tang 78B to thereby move the inside lock link 80 counterclockwise. The motion of the inside lock link 80 is, in turn, transferred by the projecting cam member 84 to the auxiliary lock lever 90 causing the auxiliary lock lever 90 to also move counterclockwise and, in turn, to move the lock lever 50 to the unlocked position. In the process the projecting cam member 84 moves from the second end 92B to the first end 92 A of the cam follower slot 92. It will be noted, however, that, because the counterclockwise movement of the inside release lever 70 is transferred to the inside lock link 80 by the torsion spring 78, the position of the inside lock link tab 86 does not change relative to the inside release lever, and remains adjacent to the first end 74 A of the arcuate slot 74. When the inside release lever 70 is in the unlocked position as shown in Figure 6B the pawl extension 24 is not yet actuated because the inside release lever lug 76 does not yet engage the pawl extension lug 24C. To release the latch, the inside release lever 70 is moved further clockwise to the position shown in Figure 6C. In this position (referred to as the release position) the inside release lever lug 76 engages the pawl extension lug 24C to move the pawl extension 24 and pawl 16 to the unlocked position and move the ratchet 14 to the open position. Note also that the motion of the inside release lever 70 is not transferred to the inside lock link 80 because the inside release lever arcuate slot 74 is sized such that the inside lock link tab 86 does not contact the second end 74B of the inside release lever arcuate slot 74 until the inside release lever 70 has reached its end of travel. This lost motion connection between the inside release lever 70 and the inside lock link 80 thus enables an over-travel of the inside release lever 70 in comparison to the prior art without effecting a change in the travel of the auxiliary lock lever 90.

In the process of moving between the unlocked position and the release position the inside release lever 70 loads the torsion spring 78. Once the user releases the inside door handle 73 the inside release lever 70 moves back to the unlocked position due to the release of the stored energy in the torsion spring 78.

Those skilled in the art will understand that while the lost motion connection between the inside release lever 70 and the inside link lever 80 has been provided in the illustrated embodiment by an arcuate slot disposed on the inside release lever and a tab disposed on the inside link lever 80 the reverse configuration is also possible where the inside release lever 70 has a tab and the inside link lever 80 is configured with an arcuate slot.

A variety of other alterations and modifications may be made to the embodiments described herein without departing from the fair meaning of the accompanying claims.