Claims:We claim:

1. A parking mode interlock mechanism (100) for auto-transmission vehicles, the parking mode interlock mechanism (100) comprising:
an actuator (10) fastened with a housing (50) of a steering lock;
a plunger (30) anchored with the actuator (10) using a T-slot (25), the plunger (30) capable of moving in any one of a locking position and an unlock position;
a spring (20) provided between the plunger (20) and the actuator (10) to provide a return motion to the plunger (30); and
a cam (40) having a protrusion (35) configured thereon, the cam (40) engages with the plunger (30) to incorporate an interlock function,
wherein, once a mode shifter of the vehicle is brought out of the parking mode, the actuator (10) gets activated and pulls the plunger (30) against force of the spring (20) thereby restricting motion of the cam (40) between an accessories position to a lock position of the steering lock as the plunger (30) and protrusion (35) of the cam (40) create a stopper thereby making a key inaccessible.

2. The parking mode interlock mechanism (100), wherein the actuator (10) is a low power actuator having 7 gm lifting force and a compact packaging size. , Description:Parking Mode Interlock Mechanism for Auto-Transmission Vehicles

Field of the invention

The present invention generally relates to an interlock mechanism of a vehicle and more particularly, to a parking mode interlock mechanism for auto-transmission vehicles.

Background of the invention

A parking mode interlock mechanism ensures that the driver leave the car always in a parking mode. This is done by linking a steering lock and a mode shifter. However, the key withdrawal is not possible until the mode shifter in auto-transmission vehicle is in the park mode.

Current interlock mechanisms have any one of a lever type mechanism and a pin type mechanism. The lever type mechanism requires more packaging space and involves more number of links. Further, the lever type mechanisms have more number of child parts that invites more quality issues. Whereas, the pin type mechanism takes less space but the load sustainability of this mechanism is less. Further, the current interlock mechanisms heats up the whole lock and key, leaving the user uncomfortable.

Reference may be made to Chinese patent application no. CN106314357 (A) that discloses a steering lock solenoid valve structure for a vehicle. However, the structure disclosed in this patent requires high power solenoids that require 1~2 kg lifting force. Further, a high power actuator utilized in this patent is larger in size and costlier.

Accordingly, there exists a need to provide a compact and low cost parking mode interlock mechanism for auto-transmission vehicles that overcomes the above mentioned drawbacks of the prior art.

Objects of the invention

An object of the present invention is to provide a compact and low cost parking mode interlock mechanism for auto-transmission vehicles.

Another object of the present invention is to provide a parking mode interlock mechanism that is operable with a low power actuator and sustain abuse operations.

Summary of the invention

Accordingly, the present invention provides a parking mode interlock mechanism (hereinafter, “the mechanism”) for auto-transmission vehicles. The mechanism comprises an actuator, a spring, a plunger and a cam.

The actuator is fastened with a housing of a steering lock. Specifically, the actuator is a low power actuator having 7 gm lifting force and a compact packaging size. The plunger is anchored with the actuator using a T-slot. The plunger is capable of moving in any one of a locking position and an unlock position. The spring is provided between the plunger and the actuator to provide a return motion to the plunger. The cam includes a protrusion configured thereon. The cam engages with the plunger to incorporate an interlock function. In accordance with the present invention, once a mode shifter of the vehicle is brought out of the parking mode, the actuator gets activated and pulls the plunger against force of the spring thereby restricting motion of the cam between an accessories position to a lock position of the steering lock as the plunger and protrusion of the cam create a stopper thereby making a key inaccessible.

Brief description of the drawings

Figure 1 shows a parking mode interlock mechanism for auto-transmission vehicles, in accordance with the present invention;

Figure 2 shows an exploded view of the parking mode interlock mechanism of figure 1;

Figure 3 shows a section view of a housing of a steering lock, in accordance with the present invention;

Figure 4 shows a T-slot in a plunger of the parking mode interlock mechanism, in accordance with the present invention;

Figure 5 shows a protrusion of a cam of the parking mode interlock mechanism, in accordance with the present invention; and

Figure 6 shows various steering lock positions, in accordance with the present invention.

Detailed description of the invention

The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.

The present invention provides a parking mode interlock mechanism for auto-transmission vehicles. The parking mode interlock mechanism is compact and low cost mechanism. The parking mode interlock mechanism utilizes small parts and actuator so overall weight of the mechanism is less. The parking mode interlock mechanism reduces the quality issues.

This present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.
Table:

Ref. No. Component name
100 Parking mode interlock mechanism
10 Actuator
20 Spring
25 T-slot
30 Plunger
35 Protrusion
40 Cam
50 Housing

Referring to figures 1-6, a parking mode interlock mechanism (100) (hereinafter, “the mechanism (100)”) for auto-transmission vehicles in accordance with the present invention is shown. Specifically, the mechanism (100) is used in a mechanical steering column lock of the auto-transmission vehicles.

As shown in figure 2, the mechanism (100) comprises an actuator (10), a spring (20), a plunger (30) and a cam (40).

The actuator (10) is fastened with a housing (50) of a steering lock (not shown). The plunger (30) is anchored with the actuator (10) using a T-slot (25). The plunger (30) is capable of moving between any one of a locking position and a normal/unlock position. The spring (20) is provided between the plunger (30) and the actuator (10) to provide a return motion to the plunger (30). The cam (40) includes a protrusion (35) configured thereon. In the housing (50), the plunger (30) engages with the cam (40) to incorporate an interlock function.
Again referring to figures 1-6, in an operation, once a mode shifter (not shown) of the vehicle is brought out of the parking mode, the actuator (10) gets activated and pulls the plunger (30) against force of the spring (20) thereby restricting motion of the cam (40) between an accessories position to a lock position (ACC~LOCK position) of the steering lock as shown in figure 6 as the plunger (30) and protrusion (35) of the cam (40) create a stopper thereby making a key inaccessible. When the vehicle mode shifter is brought in the parking mode, the actuator (10) gets deactivated causing the plunger (30) to come back to the normal position with the help of force of the spring (20) thereby freeing motion of the cam (40) and allowing the key to move to a lock position and withdrawal of the key.

The unique mechanism (100) comprises only two moving links and one fixed link. The mechanism (100) is designed to sustain abuse operations and abusive loads of more than 50 kgf-cm. In an embodiment, the mechanism (100) is operable with a low power actuator (10) i.e. works with 7 gm lifting force actuator (10) whose packaging size is very compact. However, it is understood here that the mechanism (100) can be customized to work on any suitable power actuator (10) in other alternative embodiments of the present invention. The mounting scheme of the mechanism (100) allows very less metal to metal contact between a coil of the actuator (10) and the lock housing (50) resulting in less temperature rise of lockset and the key.

Advantages of the invention:

1. The mechanism (100) is compact and low cost mechanism.
2. The mechanism (100) utilizes small parts and the actuator (10) so overall weight of the mechanism (100) is less.
3. The mechanism (100) reduces quality issues.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the scope of the present invention.