Park lock apparatus

Patent metadata

Field	Value
Publication number	US-10024430-B2
Application number	US-201515519193-A
Country	US
Kind code	B2
Filing date	Oct 8, 2015
Priority date	Oct 17, 2014
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

A park lock apparatus and control unit for a vehicle, the apparatus comprising: a locking member (28, 30; 50) having: a first state arranged to permit independent rotational movement of front and rear drive shafts (20, 22) of the vehicle relative to a fixed position on the vehicle; a second state arranged to prevent independent rotational movement of the front and rear drive shafts of the vehicle relative to the fixed position on the vehicle; and a third state arranged to prevent rotational movement of the front and rear drive shafts of the vehicle relative to the fixed position on the vehicle, and an actuation member (36; 64) for moving the locking member between the first, second and third states.

First claim

The invention claimed is:

1. A vehicle park lock apparatus, the apparatus comprising:
at least one locking member having:
a first state in which the at least one locking member is arranged such that a differential is unlocked and a park lock is disengaged to permit independent rotational movement of front and rear drive shafts relative to a fixed reference position;
a second state in which the at least one locking member is arranged to lock the differential to prevent independent rotational movement of the front and rear drive shafts relative to the fixed reference position, and in which the park lock is disengaged; and
a third state in which the at least one locking member is arranged such that the differential is locked and the park lock is engaged to prevent rotational movement of the front and rear drive shafts relative to the fixed reference position, and

an actuation member for moving the at least one locking member between the first, second and third states, the actuation member being movable between three positions, each position associated with one of the first state, the second state, and the third state, wherein the at least one locking member cannot be moved from the first state to the third state without first being moved to the second state to lock the differential.

2. A vehicle park lock apparatus as claimed in claim 1 , wherein each of the first and second states permits motive power to be transferred from a transmission to both of the front and rear drive shafts of the vehicle.

3. A vehicle park lock apparatus as claimed in claim 1 , wherein the actuation member comprises a lever.

4. A vehicle park lock apparatus as claimed in claim 1 , comprising
a gearbox connected to the differential for transferring rotational movement from the gearbox to at least one of the front and rear drive shafts;
the at least one locking member comprising a dog gear movable between a first position and a second position to permit and prevent relative movement of the front and rear drive shafts to move between the first and second states, respectively; and
a park pawl movable between a first position and a second position to permit and prevent rotational movement of the differential relative to the gearbox to move between the first or second state and the third state, respectively.

5. A vehicle park lock apparatus as claimed in claim 1 , comprising
a gearbox connected to the differential for transferring rotational movement from the gearbox to at least one of the front and rear drive shafts,
the at least one locking member comprising a dog gear movable between a first, second and third position each corresponding to the first, second and third states respectively, wherein:
in the first position the dog gear permits relative movement of the front and rear drive shafts;
in the second position the dog gear prevents relative movement of the front and rear drive shafts;

in the third position the dog gear prevents:
relative movement of the front and rear drive shafts; and
relative movement of the differential and the gearbox.

6. A vehicle park lock apparatus as claimed in claim 1 , wherein the actuation member comprises an actuator connected by a connection to the at least one locking member.

7. A vehicle park lock apparatus as claimed in claim 6 , wherein the connection comprises a Bowden cable.

8. A vehicle park lock apparatus as claimed in claim 1 , comprising
a gearbox connected to the differential for transferring rotational movement from the gearbox to at least one of the front and rear drive shafts, the apparatus comprising a control unit configured to:
determine relative movement of the front and rear drive shafts;
permit movement of the at least one locking member from the first to the second state in dependence on the determined relative movement of the front and rear drive shafts;
determine relative movement of the differential to the gearbox;
permit movement of the at least one locking member from the second state to the third state in dependence on the determined relative movement of the differential to the gearbox.

9. A vehicle park lock apparatus as claimed in claim 8 , wherein movement of the at least one locking member from the first state to the second state is permitted when there is substantially no relative movement of the front and rear drive shafts.

10. A vehicle park lock apparatus as claimed in claim 8 , wherein movement of the at least one locking member from the second state to the third state is permitted when there is substantially no relative movement of the differential and the gearbox.

11. A control unit arranged to control the vehicle park lock apparatus as claimed in claim 1 , the control unit being operable to control movement of the at least one locking member between the first, second and third states, in response to user actuation of the actuation member.

12. A vehicle comprising the vehicle park lock apparatus as claimed in claim 1 and a gearbox connected to the differential for transferring rotational movement from the gearbox to at least one of the front and rear drive shafts.

13. A vehicle comprising the control unit of claim 11 and a gearbox connected to the differential for transferring rotational movement from the gearbox to at least one of the front and rear drive shafts.

Assignees

• Jaguar Land Rover Ltd

Inventors

• Spooner John
• Pybus Ged

Classifications

• B60K17/346 Primary

  the transfer gear being a differential gear · CPC title

• B60T1/005

  by locking of wheel or transmission rotation · CPC title

• F16H63/3416 Primary

  Parking lock mechanisms or brakes in the transmission · CPC title

• F16H63/3425

  characterised by pawls or wheels · CPC title

• B60K17/3467

  combined with a change speed gearing, e.g. range gear · CPC title