Abstract: A device is provided for preventing accidental operation of a switch including a body having a surface with an opening and a cavity extending from the opening at an angle for receiving and releasably engaging the actuator member of a switch. With the switch in the desired on or off position, its actuator member is mounted into the cavity to engage the device, via the opening, such that the surface of the body lies adjacent the switch plate. Operation of the switch is prevented by the surface of the body providing a stop against the switch plate without physically anchoring the device to the switch plate.

Abstract: A blade cutting apparatus for a rotary lawn mower. The blade cutting apparatus is defined by a plurality of blades projecting radially outward from a central hub. Each blade is defined by a first portion and a second portion, the first portion being defined by a first edge and a second edge and the second portion being defined by a third edge and a fourth edge. The first and third edges are each sharpened for enabling each blade to cut grass in two separate locations along the length of each strand of grass. Each blade is further defined by an elongated slot formed therein between the first portion and the second portion for allowing cut grass and debris to pass through each blade.

Abstract: A vertical leap measuring apparatus and method is illustrated including a series of vertically spaced electric pressure-sensitive switches and a device for recording an indication reflecting height reached both from a standing position and subsequently from a vertical leap, wherein the difference between the two indications of height reached is calculated to determine the height of the vertical leap.