Method and apparatus for mowing lawns

Abstract

The present invention discloses an unattended lawn mowing system in which multiple solar powered self propelled, random motion lawn mowers are used singly or in combination to mow a pre-defined lawn area. The mowing zone is defined as a region of grass bounded by naturally occurring or man made obstacles of infinite variation including, but not limited to, high grass, flowers, trees, fences and lawn edging. Each mowing unit is a solar powered, self-propelled, random motion lawn mower which comprises a frame with a set of drive and coaster wheels on the frame. A set of batteries and battery powered electric motors are mounted on said frame with output means from the motors to power drive wheels and a cutting mechanism on the frame. Photovoltaic panels are mounted on said frame to receive solar rays and convert them into electrical power to charge the batteries with means for controlling the orientation of the solar panels so as to face the direction of greatest solar intensity. The actuation of the mower is controlled by monitoring means that detects the battery charge level and the solar energy output of the panels. Such actuation modes include starting the mower, stopping the mower, altering the direction of travel of the mower and re-charging the batteries of the mower. Random motion of the mowers is accommodated by providing contact switches on the outer periphery of the frame of the mower so that direction of the mowers is changed by more than 90 degrees when the contact switches impact a physical barrier surrounding or within the area to be cut. The mower further includes switch means so constructed that the solar cells are connected to said batteries in a manner that allows for automatic switching between batteries for optimum use and re-charging.

Dependencies are inferred from the claim text.