Robert M Berdahl, Age 875310 Connecticut Ave, Washington, DC 20015

4709771, Dec 1, 1987

Apr 21, 1986

6/853865

Michael T. Basham - Maple Grove MN
Robert M. Berdahl - Plymouth MN
Bruce E. Field - Minneapolis MN

Tennant Company - Minneapolis MN

B62D 5104
B62D 1104

180 65

A drive control for a vehicle such as a floor scrubber, a floor sweeper, a pallet truck or the like, operated by a person walking or riding on a sulky behind it, includes first and second drive motors each arranged to drive a vehicle wheel. Manual means are provided whereby an operator by manipulation of a control may determine vehicle speed; forward and reverse direction; and turning right or left. A variable voltage is responsive to the operator's movements for providing an electrical signal representative of the desired speed in either the forward or reverse direction. Other movements by the operator of the control provide turning in the right or left direction. The means for detecting a turning control signal from the operator is effective to reduce the motor drive signal to the motor on the inside of the desired turn, from the level representative of the existing speed toward a no-speed level at a programmed rate. The control further includes a proximity reverse sensing means effective to stop reverse movement of the vehicle upon sensing the presence of an operator closely adjacent the rear of the vehicle and for providing a short burst of forward movement of the vehicle upon such detection. The control further can provide signals to control operative functions of the controlled vehicle which may be affected by speed or direction of the vehicle.

5044043, Sep 3, 1991

Feb 6, 1989

7/307258

Michael T. Basham - Maple Grove MN
Robert M. Berdahl - Plymouth MN
Bruce E. Field - Minneapolis MN

Tennant Company - Minneapolis MN

A47L 512

15319

A drive control for a vehicle such as a floor scrubber, a floor sweeper, a pallet truck or the like, operated by a person walking or riding on a sulky behind it, includes first and second drive motors each arranged to drive a vehicle wheel. Manual means are provided whereby an operator by manipulation of a control may determine vehicle speed; forward and reverse direction; and turning right or left. A variable voltage is responsive to the operator's movements for providing an electrical signal representative of the desired speed in either the forward or reverse direction. Other movements by the operator of the control provide turning in the right or left direction. The means for detecting a turning control signal from the operator is effective to reduce the motor drive signal to the motor on the inside of the desired turn, from the level representative of the existing speed toward a no-speed level at a programmed rate. The control further includes a proximity reverse sensing means effective to stop reverse movement of the vehicle upon sensing the presence of an operator closely adjacent the rear of the vehicle and for providing a short burst of forward movement of the vehicle upon such detection. The control further can provide signals to control operative functions of the controlled vehicle which may be affected by speed or direction of the vehicle.

4825500, May 2, 1989

Aug 17, 1987

7/086492

Michael T. Basham - Maple Grove MN
Robert M. Berdahl - Plymouth MN
Bruce F. Field - Minneapolis MN

Tennant Company - Minneapolis MN

A47L 1103

15319

A drive control for a vehicle such as a floor scrubber, a floor sweeper, a pallet truck or the like, operated by a person walking or riding on a sulky behind it, includes first and second drive motors each arranged to drive a vehicle wheel. Manual means are provided whereby an operator by manipulation of a control may determine vehicle speed; forward and reverse direction; and turning right or left. A variable voltage is responsive to the operator's movements for providing an electrical signal representative of the desired speed in either the forward or reverse direction. Other movements by the operator of the control provide turning in the right or left direction. The means for detecting a turning control signal from the operator is effective to reduce the motor drive signal to the motor on the inside of the desired turn, from the level representative of the existing speed toward a no-speed level at a programmed rate. The control further includes a proximity reverse sensing means effective to stop reverse movement of the vehicle upon sensing the presence of an operator closely adjacent the rear of the vehicle and for providing a short burst of forward movement of the vehicle upon such detection. The control further can provide signals to control operative functions of the controlled vehicle which may be affected by speed or direction of the vehicle.