Abstract: An air curtain providing an air stream across a doorway between areas of relatively cool and warm air masses and continuously monitoring the condition, e.g., temperature, pressure and flow rate, of one or both air masses and the air stream. The air curtain has a control system including an electronic controller operating a heater and fan and receiving air characteristic inputs from temperature, pressure and flow rate sensors. The controller monitors these inputs continuously and processes them to operate the heater and fan according to algorithms designed to minimize air cross-filtration and energy consumption while maintaining the temperature and humidity of the air stream at a point substantially along a line representing the mixing of anteroom air and the air stream that is substantially tangent to the psychrometric saturation curve.

Abstract: An industrial door comprising a pair of side panels and a pair of central panels with each central panel having approximately twice the horizontal width of a side panel. The upper end of one side edge of each side panel is pivoted to the jamb of a doorway, while the upper end of the opposite side edge of each said panel is pivoted to the adjacent side edge of a center panel. A track is located above the doorway and a pair of trolleys are mounted for movement on the track. Each trolley includes a vertical pivot shaft which is connected to a center panel at a location midway of the width of the panel. A drive mechanism is mounted in the header and includes an endless cable which is connected through a torque arm to the shaft of each trolley.

Abstract: An arrow and method of making it. The arrow has a hollow arrow shaft, a single piece adaptor having one end with an outer diameter and a cylindrical bore with an inner surface adhesively engageable about a first end of the shaft and an externally threaded opposite end. An inclined surface surrounds the externally threaded end and tapers inwardly from the outer diameter of the one end towards the bore. The inclined surface has a diameter greater than that of the external threads. The external threads and inclined surface receive and retain an arrow point with internal threads and inclined surface so that impact forces are not transmitted to the inner surface of the shaft. A balance pin has a shaft portion received in the arrow shaft, and a head portion interconnected to one end of the balance pin shaft portion. The head portion has a diameter greater than the shaft portion outer diameter and smaller than the inner diameter of the cylindrical bore.

Abstract: An arrow end adaptor and a balance pin for an arrow and a method for making the same. The arrow comprising a ferrule having a large enough inner diameter to be placed over the arrow shaft, and further having an exterior threaded end whose diameter is smaller than the diameter of the arrow shaft. The point cap is designed such that an arrow point having interior threads may be attached to the exterior threaded end of the point cap. The balance pin is designed to have a head at one end that may be affixed to either a target point or a point cap and a shaft end that may be inserted into the arrow shaft.

Abstract: A vehicle restraint for preventing a vehicle or truck from accidentally pulling away from a loading dock. The truck restraint comprises a frame to be mounted on the vertical front face of the loading dock and a restraining member is mounted for pivotal movement in a generally vertical plane parallel to the dock face between a first lower storage position and a second operative position where the restraining member will prevent outward movement of the truck away from the dock. A curved plate or abutment is mounted in spaced relation to the frame and extends throughout the length of the path of pivotal movement of the restraining means. The restraining member is normally disposed out of contact with the abutment as the restraining member pivots between the storage and operative positions.

Abstract: A semi-rigid elastomeric cover for a roller chain coupling which comprises a generally cylindrical center portion having its radial interior contoured to relatively tightly fit the contour of the roller chain and two opposed axially extending flanges connected to the center portion each flange terminating in a circular beaded portion dimensioned for a compression fit with the hub of the coupling.

Abstract: An industrial door comprising a pair of side panels and a pair of central panels with each central panel having approximately twice the horizontal width of a side panel. The upper end of one side edge of each side panel is pivoted to the jamb of a doorway, while the upper end of the opposite side edge of each said panel is pivoted to the adjacent side edge of a center panel. A track is located above the doorway and a pair of trolleys are mounted for movement on the track. Each trolley includes a vertical pivot shaft which is connected to a center panel at a location midway of the width of the panel. A drive mechanism is mounted in the header and includes an endless cable which is connected through a torque arm to the shaft of each trolley.