Brush head positioning system

Abstract

An apparatus for use on comprising a vehicle adapted to move across a surface and responsive to an operator. A head assembly connected to a support on the vehicle is adapted to carry a device for engaging the surface. An actuator on the vehicle raises and lowers the head assembly support relative to the surface. A position control responsive to operator input indicates a head position of the device relative to the surface or range of head positions of the device head assembly relative to the surface support. The head position or the range of head positions indicates a distance or range of distances, respectively, between the device and the surface. A controller responsive to the position control selectively actuates the actuator or maintain the device head assembly in the head position or within the range of head positions as indicated by the position control. As a result, a repeatable position or range of positions of the brush head assembly is obtained, the relative engagement between the head assembly and surface is controlled and the treatment of the surface by the head assembly is controlled. Position control may be used in combination with torque control of motors driving brushes for engaging the surface. Position control may also be used in combination with a pressure control measuring the pressure between of the brush head and assembly on the surface.

1. An apparatus for use on a surface and responsive to an operator, said apparatus comprising:
 a vehicle adapted to ride on the surface;  
 a head assembly adapted to carry a device for engaging and treating the surface;  
 a support;  
 a connector assembly interconnecting the head assembly and the support;  
 an actuator on the vehicle for raising and lowering the support relative to the surface;  
 a sensor detecting a distance between the support and the head assembly;  
 a head position control, responsive to input from the operator, indicating a desired position of the head assembly relative to the support; and  
 a driving circuit responsive to the head position control and responsive to the sensor for energizing the actuator to raise and lower the support so that the distance between the support and the head assembly as detected by the sensor corresponds to the desired position as indicated by the head position control thereby controlling the relative engagement between the head assembly and the surface and thereby controlling the treatment of the surface by the head assembly.  
 
     
     
       2. The apparatus of  claim 1  wherein the sensor comprises a linear potentiometer. 
     
     
       3. The apparatus of  claim 2  wherein the head position control is a opertor-controlled potentiometer and further comprising a comparator for comparing a voltage signal generated by the operator-controlled potentiometer to a voltage signal generated by the linear potentiometer, said comparator providing an output signal corresponding to the comparison to the driving circuit. 
     
     
       4. The apparatus of  claim 1  further comprising an up/down switch responsive to the operator and connected to the driving circuit for selectively controlling the actuator such that when the switch is in an UP position, the actuator is energized to raise the support and such that when the switch is in a DOWN position, the actuator is energized to lower the support. 
     
     
       5. The apparatus of  claim 1  wherein the connector assembly has a first end engaging the head assembly and having a second end engaging the support wherein a distance between the first end and the second end is variable. 
     
     
       6. The apparatus of  claim 5  wherein the support is  comprises a traveling  nut, wherein the actuator comprises a motor rotating a screw which engages and drives the traveling  nut, said nut being raised and lowered by rotation of the screw, and wherein the connector assembly comprises:
 a slotted tube having a slot at one end receiving a pin sliding within the slot, the pin connected to the traveling  nut, the tube supporting the head assembly at its other end; and  
 a compressible member within the tube having one end engaging the nut and having another end engaging the tube  between the support and the head assembly; and  
 wherein the sensor comprises a linear sensor detecting a length of the compressible member.  
 
     
     
       7. An apparatus for use on a surface and responsive to an operator, said apparatus comprising:
 a vehicle adapted to ride on the surface;  
 a head assembly on the vehicle adapted to carry a device for engaging and treating the surface;  
 a support on the vehicle connected to the head assembly; 
 an actuator on the vehicle supporting the head assembly over the surface and  adapted to raise and lower the head assembly relative to the surface  support;  
 a sensor detecting a position of the head assembly relative to the surface  support;  
 a head  position control, responsive to input from the operator, indicating a desired position of the head assembly relative to the surface  support; and  
 a driving circuit responsive to the head  position control and responsive to the sensor for energizing the actuator to raise and lower the head assembly  support so that the position of the head assembly relative to thesurface  support as detected by the sensor corresponds to the desired position as indicated by the head  position control thereby controlling the relative engagement between the head assembly and the surface independent of the brush length or stiffness and thereby controlling the treatment of the surface by the head assembly.  
 
     
     
       8. The apparatus of  claim 7  further comprising a vehicle having pneumatic tires for riding on the surface, said vehicle supporting the actuator such that the head assembly is above or on the surface. 
     
     
       9. An apparatus for use on a surface and responsive to an operator, said apparatus comprising:
 a vehicle adapted to ride on the surface;  
 a head assembly on the vehicle adapted to carry a device for engaging and treating the surface;  
 a support on the vehicle connected to the head assembly; 
 an actuator on the vehicle supporting the head assembly over the surface and  adapted to raise and lower the head assembly relative to the surface  support;  
 a head  position control, responsive to input from the operator, indicating a desired position of the head assembly relative to the surface  support; and 
 a driving circuit responsive to the head  position control and responsive to the sensor for energizing the actuator to raise and lower the head assembly  support so that the position of the head assembly relative to the surface  support as detected by the sensor corresponds to the desired position as indicated by the head position control thereby controlling the relative engagement between the head assembly and the surface and thereby controlling the treatment of the surface by the head assembly;  
 a support connected to the actuator and being raised and lowered by the actuator; and  
 a connector assembly including a compressible member between the support and the head assembly;  
 wherein the sensor comprises a distance sensor connected between the support and the head assembly for detecting a distance between the support and the head assembly; and  
 wherein the driving circuit responds to the distance sensor to control the head position of the head assembly relative to the surface to maintain contact between the head assembly and the surface .  
 
     
     
       10. The apparatus of  claim 9  wherein the distance sensor is a linear potentiometer. 
     
     
       11. An apparatus for use on a surface and responsive to an operator, said apparatus comprising:
 a vehicle adapted to ride on the surface;  
 a head assembly on the vehicle adapted to carry a device for engaging and treating the surface;  
 a support on the vehicle connected to the head assembly; 
 an actuator on the vehicle supporting the head assembly over the surface and  adapted to raise and lower the head assembly relative to the surface  support;  
 a sensor detecting a position of the head assembly relative to the surface  support;  
 a head  position control, responsive to input from the operator, indicating a desired position of the head assembly relative to the surface  support;  
 a driving circuit responsive to the head  position control and responsive to the sensor for energizing the actuator to raise and lower the head assembly  support so that the position of the head assembly relative to the surface  support as detected by the sensor corresponds to the desired position as indicated by the head  position control thereby controlling the relative engagement between the head assembly and the surface and thereby controlling the treatment of the surface by the head assembly;  
 a support adapted to be raised and lowered by the actuator;  and  
 a compressible member of variable length between the support and the head assembly;  
 wherein the sensor comprises a linear sensor detecting a length of the compressible member.  
 
     
     
       12. An apparatus for use on a surface and responsive to an operator, said apparatus comprising:
 a vehicle adapted to ride on the surface;  
 a head assembly on the vehicle adapted to carry a device for engaging and treating the surface;  
 a support on the vehicle connected to the head assembly; 
 an actuator on the vehicle supporting the head assembly over the surface and  adapted to raise and lower the head assembly relative to the surface  support wherein the actuator comprises a motor rotating a screw driving  in threaded engagement with a traveling  nut engaging the screw  of the support, said nut  support being raised and lowered by rotation of the screw;  
 a sensor detecting a position of the head assembly relative to the surface  support;  
 a head  position control, responsive to input from the operator, indicating a desired position of the head assembly relative to the surface  support;  
 a driving circuit responsive to the head  position control and responsive to the sensor for energizing the actuator to raise and lower the head assembly  support so that the position of the head assembly relative to the surface  support as detected by the sensor corresponds to the desired position as indicating by the head  position control thereby controlling the relative engagement between the head assembly and the surface and thereby controlling the treatment of the surface by the head assembly;  
 a slotted tube having a slot at one end receiving a pin sliding within the slot, the pin connected to the traveling  nut, the tube supporting the head assembly at its other end; and  
 a compressible member within the tube having one end engaging the nut and having another end engaging the tube  between the support and the head assembly;  
 wherein the sensor comprises a linear sensor detecting a length of the compressible member.  
 
     
     
       13. The apparatus of  claim 12  further comprising an inner tube coaxial with and slidable within the slotted tube, the inner tube connected to and moving with the support. 
     
     
       14. The apparatus of  claim 12  wherein the sensor comprises a switch on the tube for detecting compression of the compressible member wherein the repeatable position corresponds to the position of the device  when it  the head assembly engages the surface. 
     
     
       15. An apparatus for use on a surface and responsive to an operator, said apparatus comprising:
 a vehicle adapted to ride on the surface;  
 a head assembly on the vehicle adapted to carry a device for engaging and treating the surface;  
 a support on the vehicle connected to the head assembly; 
 an actuator on the vehicle supporting the head assembly over the surface and  adapted to raise and lower the head assembly relative to the surface  support;  
 a sensor detecting  detector providing a count corresponding to a position of the head assembly  support relative to the surface  actuator;  
 a head  position control, responsive to input from the operator, indicating a desired position of the head assembly relative to the surface  support;  
 a driving circuit responsive to the head  position control and responsive to the sensor  detector for energizing the actuator to raise and lower the head assembly  support so that the position of the head assembly relative to the surface  actuator as detected by the sensor  detector corresponds to the desired position as indicated by the head  position control thereby controlling the relative engagement between the head assembly and the surface and thereby controlling the treatment of the surface by the head assembly;  
 wherein the actuator comprises a motor rotating a screw driving  in threaded engagement with a traveling  nut engaging the screw  of the support, said nut  support being raised and lowered by rotation of the screw;  
 wherein the sensor comprises a detector for providing a count corresponding to the position of the head; 
 wherein the head  position control is set by the operator to indicate the  an additional preset amount the support is to be lowered below a repeatable position; and  
 a comparator for comparing the count to the additional preset amount, said driving circuit being responsive to comparator to lower the traveling nut  support below a  the repeatable position when the count corresponds to a position which is higher than  the additional preset amount as indicated by the head  position control.  
 
     
     
       16. The apparatus of  claim 15  wherein the detector comprises a magnet adapted to rotate in synchronism with the screw, a Hall sensor detecting rotation of the magnet and providing a pulse, and a counter for counting the pulses of the Hall sensor, and wherein the comparator compares the count of the counter to the additional preset amount. 
     
     
       17. The apparatus of  claim 16  further comprising a switch for detecting when the nut  support is in the repeatable position, and wherein the switch resets the counter and wherein the driving circuit is responsive to the comparator to lower the traveling nut  support a number of counts corresponding to the addtional preset amount. 
     
     
       18. An apparatus for use on a surface and responsive to an operator, said apparatus comprising:
 a vehicle adapted to ride on the surface;  
 a head assembly on the vehicle adapted to carry a device for engaging and treating the surface;  
 a support on the vehicle connected to the head assembly; 
 an actuator on the vehicle supporting the head assembly over the surface and  adapted to raise and lower the head assembly relative to the surface  support;  
 a sensor comprising a switch on the actuator for detecting a position of the head assembly relative to the surface  support;  
 a head  position control, responsive to input from the operator, indicating a desired position of the head assembly relative to the surface  support; and  
 a driving circuit responsive to the head  position control and responsive to the sensor for energizing the actuator to raise and lower the head assembly  support so that the position of the head assembly relative to the surface  support as detected by the sensor corresponds to the desired position as indicated by the head  position control thereby controlling the relative engagement between the head assembly and the surface and thereby controlling the treatment of the surface by the head assembly;  
 wherein the sensor comprises a switch on the actuator for detecting a position of the head assembly .  
 
     
     
       19. An apparatus for use on a surface and responsive to an operator, said apparatus comprising:
 a head assembly adapted to carry a device for engaging the surface;  
 a support connected to the head assembly; 
 an actuator raising and lowering the head assembly relative to the surface  support;  
 a position control responsive to operator input for indicating a head position of the device  head assembly relative to the surface  support or range of head positions of the device  head assembly relative to the surface  support, said head position or said range of head positions indicating a distance or range of distances, respectively, between the device  head assembly and the surface  support; and  
 a controller responsive to the position control for selectively actuating the actuator to maintain the device  head assembly in the head position or within the range of head positions as indicated by the position control independent of the brush length or stiffness.  
 
     
     
       20. The apparatus of  claim 19  further comprising:
 a pressure sensor detecting the pressure of device  the head assembly on the surface;  
 a pressure control responsive to operator input for indicating a desired pressure or a desired range of pressures for the device  head assembly on the surface; and  
 wherein the controller is responsive to the pressure control and the pressure sensor for selectively actuating the actuator to maintain the pressure of the device on the surface at the desired pressure or within the desired range of pressures.  
 
     
     
       21. An apparatus for use on a surface and responsive to an operator, said apparatus comprising:
 a head assembly adapted to carry a device for engaging the surface;  
 a support connected to the head assembly; 
 an actuator raising and lowering the head assembly relative to the surface  support;  
 a position control responsive to operator input for indicating a head  desired position of the device  head assembly relative to the surface  support or range of head  desired positions of the device  head assembly relative to the surface  support, said head  desired position or said range of head  desired positions indicating a distance or range of distances, respectively, between the device  head assembly and the surface  support;  
 a controller responsive to the position control for selectively actuating the actuator to maintain the device  head assembly in the head  desired position or within the range of head  desired positions as indicated by the position control;  
 a motor on the head assembly for rotating the device;  
 a torque control circuit having an input receiving a signal for controlling the torque of the motor; and  
 a torque control responsive to operator input for indicating a desired torque or a desired range of torques for the motor;  
 wherein the controller is responsive to the torque control for providing a torque control signal to the input of the torque control circuit to maintain the motor at the desired torque or within the desired range of torques.  
 
     
     
       22. The apparatus of  claim 21  further comprising:
 a pressure sensor detecting the pressure of device  the head assembly on the surface;  
 a pressure control responsive to operator input for indicating a desired pressure or a desired range of pressures for the device  head assembly on the surface; and  
 wherein the controller is responsive to the pressure control and the pressure sensor for selectively actuating the actuator to maintain the pressure of the device on the surface at the desired pressure or within the desired range of pressures.  
 
     
     
       23. An apparatus for use on a surface and responsive to an operator, said apparatus comprising:
 a head assembly adapted to carry a device for engaging the surface;  
 a support connected to the head assembly; 
 an actuator raising and lowering the head assembly relative to the surface  support;  
 a position control responsive to operator input for indicating a repeatable head  position of the device  head assembly relative to the surface  support or a repeatable range of head  positions of the device  head assembly relative to the surface  support, said repeatable head  position or said repeatable range of head  positions indicating a distance or range of distances, respectively, between the device  head assembly and the surface  support; and  
 a controller responsive to the position control for selectively actuating the actuator to maintain the device in the repeatable head  position or within the repeatable range of head  positions as indicated by the position control independent of the brush length or stiffness.  
 
     
     
       24. Apparatus for use by an operator on a surface comprising:
   a vehicle adapted to move across the surface;        a head assembly on the vehicle for treating the surface;        a support on the vehicle connected to the head assembly;        an actuator on the vehicle for raising and lowering the support and the head assembly;        a resiliently compressible member interposed between the support and the head assembly;        a sensor for sensing a repeatable position of the support; and        a control responsive to user input and the sensor for controlling the actuator to drive the support downward from said repeatable position an additional distance corresponding to said user input to compress said compressible member.     
     
     
       25. The apparatus of  claim 24  wherein said repeatable position of the support corresponds to a position in which the head assembly is in contact with the surface. 
     
     
       26. The apparatus of  claim 25  wherein the sensor comprises a switch on the vehicle for sensing when the support is lowered to said repeatable position, and wherein the control is responsive to the switch for controlling the actuator to drive the support downward from said repeatable position the additional distance to compress the compressible member. 
     
     
       27. The apparatus of  claim 25  wherein the sensor comprises a linear potentiometer between the head assembly and the support for sensing when the support is lowered to the repeatable position, and wherein the control is responsive to the linear potentiometer for controlling the actuator to drive the support downward from said repeatable position the additional distance to compress the compressible member. 
     
     
       28. Apparatus for use by an operator on a surface comprising:
   a vehicle adapted to move across the surface;        a head assembly on the vehicle for treating the surface;        a support on the vehicle connected to the head assembly;        an actuator on the vehicle for raising and lowering the support and the head assembly;        a resiliently compressible member interposed between the support and the head assembly;        a sensor for sensing when the head assembly is lowered to a position corresponding to contact of the head assembly with the surface, and for generating a signal in response thereto; and        a control responsive to user input and the sensor for controlling the actuator to drive the support down to lower the head assembly until said signal is received and thereafter to drive the support down an additional distance to compress the compressible member an amount corresponding to said user input.     
     
     
       29. The apparatus of  claim 28  wherein the sensor comprises a switch on the vehicle for sensing when the support is lowered to a position corresponding to contact of the head assembly with the surface and for generating a signal in response thereto, and wherein the control is generating a signal in response thereto, and wherein the control is responsive to the switch for controlling the actuator to drive the support down the additional distance to compress the compressible member. 
     
     
       30. The apparatus of  claim 28  wherein the sensor comprises a linear potentiometer between the head assembly and the support for sensing when the support is lowered to a position corresponding to contact of the head assembly with the surface and for generating a signal in response thereto, and wherein the control is responsive to the linear potentiometer for controlling 
     
     
       31. Apparatus for use by an operator on a surface comprising:
   a vehicle adapted to move across the surface;        a head assembly on the vehicle for treating the surface;        a support connected to the head assembly;        an actuator on the vehicle comprising a screw in threaded engagement with the support, and a motor for rotating the screw to raise and lower the support and the head assembly connected thereto;        a spring co - axial with the screw interposed between the support and the head assembly;        a control responsive to user input for controlling the actuator to lower the support until the head assembly is in contact with the surface and the spring is compressed a preset amount corresponding to the user input; and        a switch on the vehicle for sensing when the head assembly is in contact with the surface, and wherein the control is responsive to the switch for controlling the actuator to lower the support and compress the spring the preset amount.     
     
     
       32. Apparatus for use by an operator on a surface comprising:
   a vehicle adapted to move across the surface;        a head assembly on the vehicle for treating the surface;        a support connected to the head assembly;        an actuator on the vehicle comprising a screw in threaded engagement with the support, and a motor for rotating the screw to raise and lower the support and the head assembly connected thereto;        a spring co - axial with the screw interposed between the support and the head assembly;        a control responsive to user input for controlling the actuator to lower the support until the head assembly is in contact with the surface and the spring is compressed a preset amount corresponding to the user input; and        a linear potentiometer between the head assembly and the support for sensing a length of the spring, and wherein the control is responsive to the linear potentiometer for controlling the actuator to lower the support and compress the spring the preset amount.     
     
     
       33. Apparatus for use by an operator on a surface comprising:
   a vehicle adapted to move across the surface;        a head assembly on the vehicle for treating the surface;        a support connected to the head assembly;        an actuator on the vehicle comprising a screw in threaded engagement with the support, and a motor for rotating the screw to raise and lower the support and the head assembly connected thereto;        a spring co - axial with the screw interposed between the support and the head assembly; and        a control responsive to user input for controlling the actuator to lower the support until the head assembly is in contact with the surface and the spring is compressed a preset amount corresponding to the user input;        wherein the support comprises a nut and wherein the actuator comprises a screw in threaded engagement with the nut and a motor for rotating the screw to raise and lower the nut, said apparatus further comprising a connector assembly connecting the head assembly and the support; and        wherein the connector assembly comprises an outer tube containing said spring and connected to the head assembly, said support further comprising an inner tube secured to the nut and slidable inside the outer tube, and a pin connected to the inner tube slidable in a slot in the outer tube.     
     
     
       34. Apparatus for use by an operator on a surface comprising:
   a vehicle adapted to move across the surface;        a head assembly on the vehicle for treating the surface;        a support connected to the head assembly;        an actuator on the vehicle comprising a screw in threaded engagement with the support, and a motor for rotating the screw to raise and lower the support and the head assembly connected thereto;        a spring co - axial with the screw interposed between the support and the head assembly;        a control responsive to user input for controlling the actuator to lower the support until the head assembly is in contact with the surface and the spring is compressed a preset amount corresponding to the user input; and        a linear sensor for detecting a length of the spring, the control being responsive to the linear sensor to operate the actuator to raise and lower the support.     
     
     
       35. Apparatus for use by an operator on a surface comprising:
   a vehicle adapted to move across the surface;        a head assembly on the vehicle for treating the surface;        a support connected to the head assembly;        an actuator on the vehicle comprising a screw in threaded engagement with the support, and a motor for rotating the screw to raise and lower the support and the head assembly connected thereto;        a spring co - axial with the screw interposed between the support and the head assembly; and        a control responsive to user input for controlling the actuator to lower the support until the head assembly is in contact with the surface and the spring is compressed a preset amount corresponding to the user input,        wherein the support comprises a nut and wherein the actuator comprises a screw in threaded engagement with the nut and a motor for rotating the screw to raise and lower the nut, said apparatus further comprising:      a detector for providing a count corresponding to the position of the support relative to the actuator;        a position control set by an operator to indicate a preset amount; and        a comparator for comparing the count to the preset amount, said control being responsive to the comparator to lower the support the preset amount below a position at which the head assembly is in contact with the surface.       
     
     
       36. The apparatus of  claim 35  wherein the detector comprises a magnet adapted to rotate in synchronism with the screw, a Hall sensor detecting rotation of the magnet and providing a pulse, and a counter for counting the pulses of the Hall sensor, the comparator being operable to compare the count of the counter to the preset amount.