Abstract: This invention relates to a system for the control of electrical apparatus with particular reference to control by electric sensors, and with special reference to a control system for domestic appliances, such as refrigerators. The system may be adapted to control of appliances such as dishwashers, dryers, washers, stoves, etc. The preferred embodiment is microcomputer based. Thus, the system enables lower energy consumption, more accurate temperature maintenance and more effective servicing and monitoring of the mechanical condition of the apparatus to which it is applied.

Abstract: An improved seat belt retractor has a rotatable reel around which a safety belt may be wound. A locking pawl is movable between a disengaged condition and an engaged condition engaging ratchet wheel teeth on the reel to hold the reel against rotation. To move the locking pawl into engagement with the ratchet wheel teeth, a pilot pawl is moved from a disengaged condition toward an engaged condition. As the pilot pawl moves toward the engaged condition, it engages a pilot pawl gear and moves the locking pawl toward its engaged condition. A releasable connector assembly or clutch is connected with the ratchet wheel and pilot pawl gear to allow relative rotation to occur between them after movement of the pilot pawl to the engaged condition. The relative rotation results in a change in the angular relationship between the teeth on the ratchet wheel and the teeth on the pilot pawl gear.

Abstract: An improved low cost relay which comprises a one-piece spool/base, a one-piece core/terminal and a one-piece yoke/armature (yokarm). A coil wound on the spool has one of its leads led to a wire which passes through the hollow stem of the spool for contact with the core upon its insertion into the stem. The stem also retains the yokarm in position with respect to the core and spool. A contact area on the yokarm moves against a contact area on a press-fit terminal mounted in the base with excellent wiping action. The other coil lead is led to a second wire mounted in the spool, and which is captured by a lanced split in a further terminal, which is also a press-fit in the base. A suppressor diode is received in the base and has one of its leads captured by the further terminal when inserted into the base, and its other lead received and captured between the yokarm and the base when the core/terminal is inserted. A backstop for the yokarm is provided by a cover for the device which is mounted on the base.

Abstract: A percussive drill extension rod having first and second externally threaded ends, a rod zone therebetween, and a substantially round, internal bore in the threaded ends and rod zone along the longitudinal axis of the extension rod, with particular relative dimensions designed to improve performance and reduce costs. The first threaded end of the extension rod has an outside diameter (TD) in the range of about 1.25 to about 2.5 inches, and the rod zone has an outside diameter (RD) within a range from about equal to the outside diameter (TD) of the first threaded end to about 1.1 times the outside diameter (TD) of the first threaded end. The first threaded end has a cross-sectional area (TDX) derived from the specific outside diameter of the threaded end (TD) selected from the given range of about 1.25 to about 2.5 inches. The rod zone has an annular cross-sectional area (RX) equal from about 0.64 to about 0.

Abstract: A thread structure for use in coupling percussion drilling extension rods minimizes the torque necessary to disconnect such extension rods. This is accomplished by beveling the crest portions of the cooperating thread structures. The direction of the bevel is such that the greatest intrusion of the crest portions into the complementary portions of the cooperating thread structure occurs immediately adjacent the abutting flanks thereof. The abutting flanks then wear in such a way that wedging is substantially avoided. Additionally, the root portions are defined by a continuously curved surface that smoothly extends into a flat surface defining the thread flanks so that fatigue stresses are minimized.