This invention relates to a reverse gear shift control device for a motor vehicle, more particularly, though not exclusively, a motor vehicle, such as, for example, an autorickshaw having handle bar steering control-
In the conventional type of three wheelers having handle bar steering control the controlrsystem for gear shifting is a twist grip type in conjunction with clutch control. The said control system is meant for controlling the gearshift position for only forward motion of the vehicle with different speeds. Initially, the twist grip is maintained in neutral gear and the vehicle does not move. As the clutch is disengaged and the twist grip is rotated to the first gear position and the clutch is engaged, the vehicle picks up forward motion. The speed of the vehicle can be increased by repeating the operation of second gear, third gear and so on.
In order to obtain reverse motion of the vehicle in the conventional known type of three wheeler, a reversing gear lever is provided near dash board which when operated enables the vehicle to be driven in the reverse direction. It is necessary to engage the first forward gear with reversing gear lever in the engaged position to make such vehicle travel in the reverse direction. The above system of operation and control has the following disadvantages.

The driver of the vehicle has to operate the reverse gear lever on the dashboard followed by operating the first forward gear by twisting the grip on the handle bar. If the driver drives the vehicle inadvertently by engaging any one of the other forward gears for example second, third and so on, the vehicle will move in the reverse direction with more speed than intended.
Hence objective of the present invention is to overcome the above problem by integrating the above control device without causing any increase in the reversing speed.

This invention will now be described with reference to the accompanying drawings which illustrate by way of example and not by way of limitation one of various possible embodiments of the gear shift device proposed herein,

Fig 1 illustrating the handlebar of the known three-wheeler vehicle

Fig 2 illustrating cross section of gear box

Fig 3 illustrating a sectional view of the reverse gear arrangement; and

Fig 4 illustrating an enlarged view of reverse stopper.

The present invention provides a reverse gear shift control device for a motor vehicle, such as, for example, a three wheeled motor vehicle comprising a left hand operated twist gripj^a cam gearshift^operated by said twist grip through control cable3 means, said cam gear shift having circumferential slots to hold the gear shift forks. The gearshift forks move on the circumferential slots of cam gear shift, which in turn moves the pair of forward moving gears to select the desired gear pair to engage and transmit rotary motion of speed gears to the drive shaft and further to wheel, to achieve vehicle -forward motion while said twist grip markings 1,2,3,& 4 aligns witha marking on the handle bar. The vehicle will be in neutral when the twist grip marking N aligns with the said marking on the handle bar. The said reverse gear shift control device also comprises of a plate reverse stopper mounted on the face of the cam gear shift operated by said twist grip through the said control cable means. The said plate reverse stopper has a pre¬determined notch positioned on the periphery of the said plate reverse stopper. A spring loaded arm stopper mounted on the drive shaft locks the said plate reverse stopper in predetermined position with the help of plate lock arm spring reverse provided on the drive shaft. The said plate arm spring reverse lifts the arm stopper reverse when the drive shaft starts rotating in forward motion. The said plate arm spring engages with the said notch in the periphery of said plate reverse stopper against the said lock arm spring force reverse stopper. When the twist grip marking A aligns with said marking on the handle bar, said arm stopper reverse engages on the pre-determined notch position of said plate reverse stopper while drive shaft is in forward motion, thereby stopping the rotation of said cam gear shift. The said position A will not permit any transmission of vehicle motion under which circumstance the drive shaft rotation comes to halt. In this particular condition the said plate reverse stopper disengages from the said arm stopper reverse allowing to rotate the said twist grip marking R to align with said marking on the handle bar. When the twist grip marking R aligns with marking on the handle bar said arm stopper reverse enables the movement of the said cam gear shift by control cable means making the said gear shift forks move to select the reverse gear pair to set the vehicle in reverse motion. When the twist grip marking A aligns with the said marking on the handle bar, a beep sound commences to caution the driver for readiness for reverse motion of the vehicle. When the twist grip marking R align with the said marking on the handle bar the vehicle moves in reverse direction. All the said markings 1,2,3,4,N,A,& R are provided on the body of the said twist grip. The said motion in both forward and reverse direction is achieved in conjunction with any known type of clutch control means.

It will be appreciated from the foregoing description that various other embodiments of the above mentioned device are possible without departing from the scope and ambit of this invention.

We Claim

1. A reverse gear shift control device for a motor vehicle comprising a twist grip with a control cable; a cam gear shift operated by the twist grip and cable, said cam gear shift having circumferential slots to hold the gear shift forks on the said slots, for selecting the desired gear pair; a plate reverse stopper mounted on the face of the said cam gear shift, having a notch; a spring loaded arm stopper mounted on the drive shaft for locking the said plate reverse stopper with the help of plate lock arm spring reverse provided on the drive shaft, whereby when the twist grip marking A aligns with the marking on the handle bar, the arm stopper reverse engages with the notch while drive shaft is in forward motion, thereby stopping the rotation of the cam gear shift, and when the twist grip marking R aligns with the marking on the handle bar, the arm stopper reverse enables the movement of the cam gear shift to select the reverse gear pair to set the vehicle in reverse motion, all the said markings 1,2,3,4,N,A & R being provided on the body of the said twist grip.

2. A reverse gear shift control device as claimed in claim 1 wherein a circuit is incorporated to caution the driver

visually or aurally for readiness for the reverse motion of the vehicle.

3. A reverse gear shift device as claimed in any one of the preceding Claims operating in conjunction with known clutch control means.

4. A reverse gear shift control device for a motor vehicle substantially as herein described with reference to and as illustrated in the accompanying drawings.