Abstract: A safe-zone sensing system for a lift having a base, a lift platform, and a driving system for raising and lowering the lift platform. The safe-zone sensing system includes a sensor system having a plurality of sensors mounted to the base of the lift. The sensors collectively defining a safe-zone around the base of the lift and detecting motion or obstructions within the safe zone, a controller fires the sensors in a preselected sequence for continuously scanning the safe zone. Scanning is started when the platform raises above a preselected height. The sensor controller generates an alert which initiates a safety sequence when motion or obstructions are sensed by at least one of the plurality of sensors.

Abstract: A step sensor for mounting on a ladder having a step. The step sensor adapted to be mounted to the ladder. The step sensor includes a housing that holds a power source and electronic circuitry. An emitter is connected to the electronic circuitry and emits a light source over a top surface of the step. A sensor is also connected to the electronic circuitry and receives reflected light from the light source that is reflected by an object on the step. A noise generator generates an alert noise in response to the reflected light being detected by the light sensor, whereby the presence of an object is detected on the step and the alert is generated by the noise generator. A ladder including such a step sensor.

Abstract: A safe-zone sensing system for a lift having a base, a lift platform, and a driving system for raising and lowering the lift platform. The safe-zone sensing system comprises a sensor system having a plurality of sensors mounted to the base of the lift. The sensors collectively defining a safe-zone around the base of the lift and detecting motion or obstructions within the safe zone, a controller fires the sensors in a preselected sequence for continuously scanning the safe zone. Scanning is started when the platform raises above a preselected height. The sensor controller generates an alert which initiates a safety sequence when motion or obstructions are sensed by at least one of the plurality of sensors.

Abstract: A novel lockstep mechanism for a rolling ladder is described. The weight-releasing ladder lockstep allows a ladder to be relocated on wheels but when a person climbs the ladder, the front wheels are automatically retracted and the ladder rests firmly with its front feet on the floor. When in the climbing (stationary) position the front wheels of the lockstep are retracted and the ladder rests on the lockstep's feet. When in the rolling position, the ladder is tilted slightly back on its rear wheels and the wheels of the lockstep are pushed down to allow the ladder to roll. When in the rolling position, the lockstep wheels are held in place via a latch which is isolated from rolling vibrations through pivoting shock links and springs.

Abstract: A novel lockstep mechanism for a rolling ladder is described. The weight-releasing ladder lockstep allows a ladder to be relocated on wheels but when a person climbs the ladder, the front wheels are automatically retracted and the ladder rests firmly with its front feet on the floor. When in the climbing (stationary) position the front wheels of the lockstep are retracted and the ladder rests on the lockstep's feet. When in the rolling position, the ladder is tilted slightly back on its rear wheels and the wheels of the lockstep are pushed down to allow the ladder to roll. When in the rolling position, the lockstep wheels are held in place via a latch which is isolated from rolling vibrations through pivoting shock links and springs.