Automated lawn mower or floor polisher

• US 4,887,415 A
• Filed: 06/10/1988
• Issued: 12/19/1989
• Est. Priority Date: 06/10/1988
• Status: Expired due to Fees

• Current Assignee: Martin, Robert L.
• Original Assignee: Martin, Robert L.
• Inventors: Martin, Robert L.
• Primary Examiner(s): Neuder, William P.
• Application Number:
  US07/204,886
• Time in Patent Office: 557 Days
• Field of Search: 56/10.2, 56/DIG. 15, 180/131, 180/140, 250/202
• US Class Current: 56/10.20R
• CPC Class Codes: A01D 2101/00 Lawn-mowers
• CPC Class Codes: A01D 34/008 for automated or remotely controlled operation
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00
• CPC Class Codes: G05D 2201/0208 Lawn mower
• CPC Class Codes: Y10S 56/15 Condition responsive

Abstract

An automated self propelled lawn mower utilizes a pair of drive motors for independently driving left and right hand drive wheels. Each drive motor is coupled to the respective drive wheel by a double output gear reduction unit. One side of the output shaft from each gear reduction unit is provided with a rotary photo encoder for providing speed and position information relating to each drive wheel. This information from each rotary photo encoder is fed to a computer control via a computer interface. Each independent wheel drive motor is computer controlled through an interface and motor drive relays. An infrared obstacle detector is mounted on each corner of the mower frame for detecting obstructions. Grass touch detection switches on the rear of the mower frame provide an indication of the relative position of the cut or uncut grass which is fed through the computer via the interface circuit for providing computer directional control to the independent wheel drive motors which steer the mower along the proper track. A separate blade drive motor is turned on or off by a photo switch which detects uncut grass. The speed of the blade drive motor is controlled by a manual switch. A floor polishing pad may be substituted for the lawn mower blade to enable use of the device as an automated floor polisher.

Claims

1. A new and improved automated lawn mower, comprising:

a frame having top and bottom surfaces;

a pair of drive wheels mounted for rotation on opposite sides of said frame, adjacent a front portion of said frame;

each of said wheels mounted for rotation with an axle;

each of said axles connected by a clutch to a gear reduction unit;

each of said gear reduction units having dual output shafts with one output shaft connected to said clutch;

a second output shaft of each of said gear reduction units mounted by a bearing block on said frame;

a rotary photo encoder on each of said second gear reduction output shafts;

a wheel drive motor connected to an input shaft of each of said gear reduction units;

a photo switch at a front edge of said frame for detecting uncut grass;

a vertically extending shaft extending through a central portion of said frame;

a variable speed blade drive motor on said upper frame surface connected to said vertically extending shaft;

switch means for manually regulating the speed of said blade drive motor;

a mower blade mounted for rotation with said vertically extending shaft beneath said frame;

a castor wheel centrally mounted adjacent a rear side of said frame;

a touch grass sensor formed from three metallic strips mounted on a rear side edge of said frame for detecting cut and uncut grass;

battery means operably connected for powering both of said wheel drive motors and said blade drive motor;

an infrared obstacle detector mounted at each corner on the upper surface of said frame;

control means operably connected for stopping said blade drive motor in response to said photo switch; and

computer control means operably connected for independently controlling each of said wheel drive motors in accordance with signals received from said touch grass sensor, said rotary photo encoders and said infrared obstacle detectors for steering said motor along a boundary line between cut and uncut grass.