Abstract: A power saw includes a motor for driving a saw blade or the like around its rotational axis to cut a workpiece. The position of the rotational axis with respect to a reference position is sensed and a manually operated keyboard is provided for entering a desired change in the position of the rotational axis. Positioning motors are provided along with circuitry which is responsive to the entering of a desired change in the position of the rotational axis of the saw blade for moving the axis correspondingly.

Abstract: A whole house ventilator which can be installed without framing and cutting joists. Struts below the fan blade serve as a support for a fan motor and for a venturi. Adjustable pre-cut sleeving fits over the joists and around the fan to eliminate framing. A shutter assembly may be surface-mounted to the ceiling below the joists.

Abstract: A whole house ventilator which can be installed without framing and cutting joists. Struts below the fan blade serve as a support for a fan motor and for a venturi. Adjustable pre-cut sleeving fits over the joists and around the fan to eliminate framing. A shutter assembly may be surface-mounted to the ceiling below the joists.

Abstract: A whole house ventillator which can be installed without framing and cutting joists. Struts below the fan blade serve as a support for a fan motor and for a venturi. Adjustable pre-cut sleeving fits over the joists and around the fan to eliminate framing. A shutter assembly may be surface-mounted to the ceiling below the joists.

Abstract: A baseboard heater for mounting against a wall and spaced from the floor comprises a casing having an open bottom and upper front side which permits the free upward and then forward free flow of air therethrough. An elongated electrical heating element mounted therein adjacent the open bottom thereof is provided with a high temperature cut-off switch. A switch actuator including a sensing tube coextending alongside the heating element is cooled by incoming air to preclude switch actuation but is quickly heated by the heating element to effect cut-off when airflow is blocked.

Abstract: A solar energy conversion device is provided with simplified means for tracking a source of solar energy. In the preferred embodiment, the tracking means is a predeterminedly shaped, heat expandable device operatively connected to an energy concentrator. The energy concentrator is movably mounted and is adapted to direct concentrated energy either towards a suitable energy conversion means in those positions in which the concentration is aligned with respect to the solar energy source, or towards the expandable device in those positions in which the concentrator is disaligned with respect to the solar energy source. Application of concentrated solar energy to the expandable device causes its expansion, which expansion is utilized to move the concentrator into alignment with the energy source. At alignment, concentrated energy is directed from the expandable device toward the energy conversion means.