Automated inter-axle differential locking system
The present invention relates to an automatic inter-axle differential (IAD) locking system for a vehicle having a tandem drive axle. The IAD lock system comprises a vehicle IAD having a rotating sliding clutch mechanism and a rotating side helical gear. If the absolute difference between the sliding clutch revolutions per minute (RPM) and the side helical gear RPM is greater than a minimum limit, and if the absolute difference between the sliding clutch RPM and the side helical gear RPM is less than a maximum limit, and the speed of the vehicle is less than a third limit, then a microprocessor engages the IAD lock mechanism.
1 . An inter-axle differential locking system for a vehicle having a tandem drive axle, comprising:
an inter-axle differential of a vehicle having a rotating sliding clutch and a rotating side helical gear;
at least one speed sensor adjacent said sliding clutch for sensing the revolutions per minute of said sliding clutch;
at least one speed sensor adjacent said side helical gear for sensing the revolutions per minute of said side helical gear; and
a mechanism for measuring the speed of said vehicle;
wherein if the absolute difference between the sliding clutch revolutions per minute and the side helical gear revolutions per minute is greater than a minimum limit, and if the absolute difference between the sliding clutch revolutions per minute and the side helical gear revolutions per minute is less than a maximum limit, and the speed of said vehicle is less than a third limit, then a microprocessor engages said inter-axle differential.
2 . The inter-axle differential locking system of claim 1 , further comprising a solenoid which is in communications with said microprocessor for controlling the engagement and disengagement of said inter-axle differential.
3 . The inter-axle differential locking system of claim 1 , wherein said microprocessor is an MC9S12D64.
4 . The inter-axle differential locking system of claim 1 , wherein said microprocessor is capable of turning on and flashing on and off vehicle lamps.
5 . The inter-axle differential locking system of claim 1 , further comprising a pneumatic port.
6 . The inter-axle differential locking system of claim 1 , further comprising a shift fork.
7 . The inter-axle differential locking system of claim 1 , further comprising a push rod.
8 . The inter-axle differential locking system of claim 1 , further comprising a piston.
9 . The inter-axle differential locking system of claim 1 , further comprising a shift cylinder.
10 . An inter-axle differential locking system for a vehicle having a tandem drive axle, comprising:
an inter-axle differential of a vehicle having a rotating sliding clutch and a rotating side helical gear;
a speed sensor adjacent said sliding clutch for sensing the revolutions per minute of said sliding clutch;
a speed sensor adjacent said side helical gear for sensing the revolutions per minute of said side helical gear;
a microprocessor;
a solenoid;
vehicle compartment lamps; and
a connection to vehicle communication links;
wherein if the absolute difference between the sliding clutch revolutions per minute and the side helical gear revolutions per minute is greater than a minimum limit, and if the absolute difference between the sliding clutch revolutions per minute and the side helical gear revolutions per minute is less than a maximum limit, and the speed of said vehicle is less than a third limit, and in an absence of an expiration of a relock timer, and in an absence of a manual unlock and hold request from a vehicle operator, then the microprocessor engages said inter-axle differential.