Automatic electric power parking brake for a motor vehicle

Abstract

Automatic electric power parking brake system for motor vehicle automatically sets the parking brake when the driver leaves the seat or turns off the engine. It releases the parking brake automatically when the driver sits down and turns on the engine, The device for releasing parking brake includes a driver seat sensor and a double pole double throw igniting switch latching relay to provide a signal causing a motor-operated or coils-operated parking brake to release. The device for setting parking brake is different in an automatic transmission vehicle or in a manual transmission vehicle. A parking shift switch is separately connected to the driver seat sensor and the igniting switch latching relay causing parking brake to be set in an automatic transmission vehicle. A driver's seat belt buckle switch connects with the driver seat sensor, or the igniting switch latching relay, to set the parking brake in a manual transmission vehicle. A neutral shift switch in an automatic transmission vehicle or a button switch in a manual transmission vehicle can release the parking brake for manual vehicle pushing and towing.

I claim:  
     
         1 . An automatic electric power parking brake system for a motor vehicle with an electrically operated mechanical parking brake, a driver sensor for generating a driver present signal in response to a driver seat being occupied and a driver absent signal in response to a driver seat being unoccupied, and a double pole double throw igniting switch latching relay, comprising: 
 means to provide a signal causing said parking brake being set in response to either said driver sensor generating a driver absent signal or said latching relay being conditioned to turn off engine,    electric power means being mechanically connected to said parking brake being electrically connected to said driver sensor by generating said driver present signal, through said latching relay being conditioned to turn engine on to provide a signal causing said parking brake to be release, and said means being connected to set electric power means to provide a signal causing said parking brake to be set.    
     
     
         2 . The system of  claim 1  wherein said electric power means includes a motor rotated in two directions with a worm wheel assembly being fastened to a sector gear, said sector gear being connected to a lift arm that is fastened to brake discs or drums through a fork parking brake cable;  
     
     
         3 . The system of  claim 1  wherein said electric power means additionally includes a coil-operated electric power means;  
     
     
         4 . The system of  claim 3  wherein said electric power means comprises: 
 a lift plate with several parallel ditches on its surface being fastened to brake discs or drums,  
 a coil being electrically connected to said means to pull said lift plate forward to set said parking brake,  
 a panel with several popped out piston cylinders being pressed to said plate by two springs, said cylinders being popped into said ditches one by one,  
 a coil being connected to said means to pull said panel with said cylinders out of said ditches, and  
 a spring pulling said lift plate backward to release said parking brake;  
 
     
     
         5 . The system of  claim 1  wherein said means to provide a signal causing said parking brake being set includes a switch being normally electrically closed but opened while transmission lever being on parking shift, said switch being separately electrically connected to said driver sensor by generating driver absent signal, and to said latching relay being conditioned to turn off engine in an automatic transmission vehicle;  
     
     
         6 . The system of  claim 5  wherein a switch being normally opened but being electrically closed while transmission lever being on neutral shift is additionally connected with Vcc and said electric power means to provide a signal causing said parking brake to release;  
     
     
         7 . The system of  claim 1  wherein said means to provide a signal causing said parking brake being set includes said electric power means being connected with seat sensor generating a driver absent signal or said latching relay being conditioned to turn off engine in a manual transmission vehicle;  
     
     
         8 . The system of  claim 7  wherein said means also additionally includes a driver's seat belt switch being normally electrically closed but being opened while driver seat belt being buckled;  
     
     
         9 . The system of  claim 7  wherein a single pole double throw 2-way switch being normally electrically closed to said driver sensor and said latching relay, and normally opened to said electric power means, but conversely being opened to said driver sensor and said latching relay, and being electrically closed to said electric power means, is additionally connected with Vcc and said electric power means to cause said parking brake to release;  
     
     
         10 . The system of  claim 1  wherein an additional spare handbrake system comprises: 
 a handbrake lever being connected with a cable to fasten said parking brake,  
 a single pole single throw handbrake lever switch being normally electrically closed to said automatic electric power system while said handbrake lever being pushed fully down, but being opened while said parking brake being set by said handbrake lever;  
 
     
     
         11 . The system of  claim 10  wherein said spare handbrake system includes an indicator to indicate the condition of said automatic electric power system;  
     
     
         12 . The system of  claim 10  in connection with  claim 7  wherein a single pole double throw handbrake lever switch with a side off position of a manual transmission vehicle additionally comprises: 
 a leading-in electric contact being connected with Vcc,  
 a first outgoing electric contact being connected to said driver sensor and said latching relay,  
 a second outgoing electric contact being connected to said electric power means to release said parking brake,  
 a switch operated by said handbrake lever electrically connecting said leading-in contact to said first contact but disconnecting said leading-in contact to said second contact while said handbrake lever being pulled to a releasing said handbrake position, said switch electrically connecting said leading-in contact to said second contact but disconnecting said leading-in contact to said first contact while said handbrake lever being pulled to a different releasing said handbrake position, and said switch disconnecting said leading-in contact to said first contact and said second contact while said handbrake lever being pulled to set said handbrake.