Speed and steering control for a floor maintenance machine

• US 4,709,771 A
• Filed: 04/21/1986
• Issued: 12/01/1987
• Est. Priority Date: 04/21/1986
• Status: Expired due to Fees

• Current Assignee: Tennant Company
• Original Assignee: Tennant Company
• Inventors: Basham, Michael T., Field, Bruce E., Berdahl, Robert M.
• Primary Examiner(s): Love, John J.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/853,865
• Time in Patent Office: 589 Days
• Field of Search: 180/6.5, 180/19.3, 180/65.1, 180/65.5, 180/65.8, 180/332
• US Class Current: 180/6.5
• CPC Class Codes: A47L 11/28 Floor-scrubbing machines, motor-driven A47L11/29 takes precedence
• CPC Class Codes: A47L 11/4011 Regulation of the cleaning machine by electric means; Control systems and remote control systems therefor
• CPC Class Codes: A47L 11/4061 Steering means; Means for avoiding obstacles; Details related to the place where the driver is accommodated
• CPC Class Codes: A47L 11/4066 Propulsion of the whole machine
• CPC Class Codes: A47L 11/4075 Handles; levers
• CPC Class Codes: B62D 51/00 Motor vehicles characterised by the driver not being seated wheeled carriers for golf bags A63B55/60
• CPC Class Codes: B62D 51/001 characterised by the vehicle control device mechanical features of control devices in general G05G; arrangements of vehicle control devices in general B60K20/00, B60K23/00, B60K26/00
• CPC Class Codes: B62D 51/002 comprising safety arrangements safety devices for vehicle propulsion unit control B60K28/00
• CPC Class Codes: B62D 51/04 the driver walking
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

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.

Claims

1. A drive control for a vehicle including,

first and second drive motors, each arranged to drive a vehicle wheel, means responsive to an operator command for providing an electrical signal representative of a desired speed for the vehicle, means for translating the speed signal into drive signals for each motor,

binary means for detecting an operator turning command, and means for changing one of the motor drive signals in response thereto, selected in accordance with the turning command, from its level representative of the motor speed just prior to the turning command toward a no-speed level at a programmed rate in accordance with a voltage ramp, with the initial point for the ramp being the motor drive signal representative of the motor current just prior to the turning command and the end point of the ramp being a signal representative of no motor current, and wherein said means for changing the motor drive signal includes means for progressively restoring said one of the motor drive signals when the operator turning command is terminated.

2. The drive control of claim 1 further characterized in that said voltage ramp is defined by a resistance and a capacitance.

3. The drive control of claim 1 further characterized in that the means for detecting an operator turning command includes spaced proximity switches.

4. The drive control of claim 1 further characterized in that the means responsive to an operator command for providing an electrical signal representative of a desired speed for the vehicle further provides a signal representative of the desired forward/reverse direction for the vehicle.

5. The drive control of claim 4 further characterized by and including an inverter circuit connected to the means for detecting an operator turning command for inverting the turning command signal when the vehicle direction is reverse.

6. The drive control of claim 4 further characterized by and including a speed signal limit circuit connected to the means responsive to an operator command for providing a signal representative of the desired speed and the desired direction of the vehicle for limiting the speed signal in the reverse direction.

7. The drive control of claim 4 further characterized in that the means responsive to an operator command for providing an electrical signal representative of a desired speed and a desired direction for the vehicle include a variable voltage, with one portion of the variable voltage range being indicative of a forward speed and another portion of the voltage range being indicative of a reverse speed.

8. The drive control of claim 7 further characterized by and including a converter circuit connected to said variable voltage for converting either a signal representative of a forward speed or a signal representative of a reverse speed to the same analog signal range, and a selector circuit connected to said converter for selecting either the forward or reverse speed signal.

9. The drive control of claim 4 further characterized by and including an analog to digital converter connected at the input of each drive motor to convert the speed, direction and turning control signals from analog to digital form.

10. The drive control of claim 1 further characterized in that said vehicle is operated by an operator walking behind it.

11. The drive control of claim 1 further characterized in that said vehicle includes an articulated sulky for supporting the operator.