CLIAMS:We claim:
1. A device (100) for introducing delay in manual transmission system in a vehicle, said device comprising,
a first piston element (101) connected to a gear shift lever (103) of the vehicle;
a second piston element (102) connected to a gear box (104) of the vehicle;
a first spring element (105) positioned between said first piston element (101) and said second piston element (102) on side of said gear shift lever (103);
a second spring element (106) positioned between said first piston element (101) and said second piston element (102) on side of said gear box (104); and
at least one force transmission element (107) provided between said first piston element (101) and said second piston element (102) to transmit force from said first piston element (101) to said second piston element (102).
2. A device as claimed in claim (1) wherein said transmission system is provided with an electronic control for clutch operation.
3. A device as claimed in claim (1) wherein said first piston element (101) and said second piston element (102) are connected with each other with an interface of bearings (108) to achieve relative motion with respect to each other.
4. A device as claimed in claim (1) wherein the compression characteristics of said first spring element (105) and said second spring element (106) are determined based on a desired time delay between the motion of the gear shift lever (103) and the gear box (104).
5. A device as claimed in claim (1) wherein the relative displacement between said first piston element (101) and said second piston element (102) is determined based on the desired time delay for transmitting the force from the gear shift lever (103) and the gear box (104).
6. A device as claimed in claim (1) wherein two force transmission elements are provided between said first piston element (101) and said second piston element (102).
7. A device as claimed in claim (1) wherein said force transmission element (107) is provided on said first piston element (101).
8. A device as claimed in claim (1) wherein said force transmission element (107) is provided on said second piston element (102).
9. A device as claimed in claim (1) is fitted with a sensor to detect motion of the device and intention of a gear shift. ,TagSPECI:The following specification particularly describes the invention and the manner in which it is to be performed.

Field of the invention:
[001] The invention relates to transmission systems in a vehicle. Particularly the invention relates to a transmission system with an electronic clutch.

Background of the invention:
[002] In a transmission system when the gear is up shifted or downshifted, the clutch should be opened before the gear gets changed. In manual transmission systems the driver presses the clutch physically to open the clutch. However in a transmission system with an electronic clutch, when the gear is shifted, the clutch needs to be opened by means of an actuator. On detecting the intention of the driver to shift the gear position, the transmission control unit sends a signal to the clutch actuator to open the clutch. The clutch actuator requires certain time to open the clutch. In the existing push pull cable type clutch systems, the actuator will get less time to respond and the clutch may not be completely opened by the time the user has initiated the gear shift. In such a situation the driver will experience a resistance to the change of gear position and it will lead to improper disengagement of gears.

Brief description of the invention:
[003] To prevent the driver from facing resistance during shifting of gear position in an electronic clutch transmission system, the clutch should be opened by the actuator only when the gear shift takes place. Since the actuator has an inherent time delay in operation to actuate the gear, it is necessary to delay the shifting of clutch by a similar time period. Thus, it is envisaged that a mechanical time delay element is introduced between the gear shift lever (103) and the gear box (104) such that the shift at the gear shift lever (103) is transmitted to the gear box (104) with a suitable delay.

[004] A device for introducing delay in manual transmission system in a vehicle is described in the present disclosure. The device comprises a first piston element (101) connected to a gear shift lever (103) of the vehicle and a second piston element (102) connected to a gear box (104) of the vehicle. A first spring element (105)is positioned between the first piston element (101) and the second piston element (102) on side of the gear shift lever (103) and a second spring element (106) positioned between the first piston element (101) and the second piston element (102) on side of the gear box (104). At least one force transmission element (107) provided between said first piston element (101) and said second piston element (102) to transmit force from said first piston element (101) to said second piston element (102) or vice versa.

Brief description of the drawing:
[005] The different embodiments of the invention are described with reference to the following accompanying drawing,
[006] Fig. 1 illustrates a device for introducing delay in manual transmission system in a vehicle in accordance with one embodiment of the invention.

Detailed description of the embodiments:
[007] Fig. 1 illustrates a device for introducing delay in manual transmission system in a vehicle in accordance with one embodiment of the invention.

[008] In accordance with one embodiment of the invention the device for introducing delay in manual transmission system in a vehicle comprises a first piston element (101) connected to a gear shift lever (103) of the vehicle and a second piston element (102) connected to a gear box (104) of the vehicle. A first spring element (105) is positioned between the first piston element (101) and the second piston element (102) on side of the gear shift lever (103). A second spring element (106) positioned between the first piston element (101) and the second piston element (102) on side of said gear box (104). At least one force transmission element (107) is provided between the first piston element (101) and the second piston element (102) to transmit force from the first piston element (101) to the second piston element (102) and vice versa.
[009] The device for introducing delay in manual transmission system is envisaged wherein the clutch operation is with electronic control.

[0010] In accordance with one embodiment of the invention the first piston element (101) and the second piston element (102) are connected with each other with an interface of bearings (108) to achieve relative motion with respect to each other.

[0011] The compression characteristics of the first spring element (105) and the second spring element (106) are determined based on a desired time delay between the motion of the gear shift lever (103) and the gear box (104). The relative displacement between the first piston element (101) and the second piston element (102) is determined based on the desired time delay for transmitting a force from the gear shift lever (103) to the gear box (104).

[0012] The force transmission element (107) is in form of a rod or protrusion on the surface of the first piston element (101) and or the second piston element (102). In one embodiment of the invention there are two force transmission elements are provided between the first piston element (101) and the second piston element (102). In another embodiment both force transmission elements may be provided on the first piston element (101) or the second piston element (102). In yet another embodiment one of the force transmission elements is provided on the first piston element (101) and the second is provided on the second piston element (102).

[0013] In a manual transmission system the driver needs to shift the gear shift lever (103) to select a suitable gear for driving based on the driving conditions. In vehicles with manual clutch, before shifting the lever (103) the driver needs to press the clutch pedal to disengage the clutch. In transmission systems which have electronic clutch control, the driver intention to change the gear is detected. On detection of the intention to change the gear, the transmission control unit is adapted to disengage the clutch by operating an actuator. The actuator has an inherent delay in operation due to which the clutch opening is delayed. To overcome this delay and ensure that the clutch is opened when a driver intention to shift gear is detected, the device in accordance with this invention is used. The device in accordance with this invention introduces a delay between the gear shift by the driver at the gear shift lever (103) and the gear shift at the gear box (104). The device comprises a first piston element (101) and a second piston element (102). In one embodiment of the invention one of said piston elements (101) is in form of a piston housing and the other piston element (102) is in form of a piston adapted to reciprocate in the piston housing. The first piston element (101) is connected to the gear shift lever (103) by mechanical linkages. As the driver moves the gear shift lever (103) to shift the gear position, the first piston element (101) is displaced linearly. Bearing is provided between the first piston element (101) and the second piston element (102). The bearing enables relative movement between the first piston element (101) and the second piston element (102). A first spring element (105) is positioned between the first piston element (101) and the second piston element (102) on the side of the gear shift lever (103). A second spring element (106) is positioned between the second piston element (102) and the first piston element (101) on the side of the gear box (104). In a first direction of movement, the second spring element (106) gets compressed between the first piston element (101) and the second piston element (102). The force applied by the driver on the gear shift lever (103) is not transferred to the gear box (104) until one of the spring elements (105 or 106) is being compressed. When a force transmission element (107) connects the first piston element (101) to the second piston element (102), the force is transferred from the first piston element (101) to the second piston element (102). The second piston element (102) further transfers the force to the gear box (104) with a time delay equal to the time required to compress the second spring element (106) resulting in the desired shift in the gear position. Due to the two spring elements opposing each other, the first element once again come to an initial rest position after transferring of the force. In another situation, the first piston element (101) moves in a second direction such that the first piston element (101) is compressed until the force transferring element transfers the force from first piston element (101) to the second piston element (102). The second piston element (102) further transfers the force to the gear box (104) resulting in the desired shift in the gear position. The device in accordance with this invention is designed such that the relative displacement (l) between the first piston element (101) and the second piston element (102) is proportional to the time delay required to be introduced in a transmission system based on the time take for operation of the actuator. The compression characteristics of the spring are also designed as per the need for the time delay in transmission of the force. The time delay also depends upon the force required for up shifting or downshifting of the gears.

[0014] Due to the delay introduced by a device as envisaged in this disclosure, the clutch which is disengaged by means of an actuator will be in open state when the actual gear shift takes place in the gear box (104). Thus, the driver does not experience any resistance while changing the gear position. This enhances the driving experience.

[0015] In accordance with one embodiment of the invention, the device is fitted with a sensor to detect motion of the device and thus, intention of a gear shift. As the driver applies force to the gear shift lever (103), the first piston element (101) is displaced. When a sensor is fitted to the device in accordance with this invention, the sensor will detect the motion which indicates the intention of shifting gear position and thus the clutch can be opened when the gear shift takes place at the transmission.

[0016] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.