Abstract:
A variable pitch screw is manufactured by twisting a prepared blank to the desired shape. The blank varies along its length such that it naturally twists to the desired shape.
Abstract:
A motor driven power door control system for a vehicle door includes a door position sensor that generates a door position signal for each predetermined distance of door movement so that the period of the door position signal is a measure of door speed. The motor control voltage is variably controlled to a controlled value to establish the door speed at a desired speed value. A door position signal period stall time is determined that is a predetermined function of the controlled value of the motor control voltage so that the stall time is adapted to the motor torque. An obstructive load is indicated when the period of the door position signal exceeds the stall time.
Abstract:
A drum for winding a cable attached to an overhead door includes a hub having a central aperture for accepting a shaft, a radially extending boss formed on the hub and a threaded aperture extending through the boss for retaining a threaded fastener for releasably attaching the hub to a shaft extending through the central aperture, a web attached in a central portion of the hub, the web extending radially outwardly at an angle of approximately 60.degree. with respect to the longitudinal axis of the hub, and a cable support extending about and being attached to the web, the cable support having a multiturn generally helical cable winding groove formed in an outer surface thereof. The cable winding groove includes a first portion spaced a first predetermined constant radius from the longitudinal axis of the hub, a second portion extending from the first portion and a third portion extending from the second portion, the third portion being spaced a second predetermined constant radius from the longitudinal axis of the hub, the first radius being larger than the second radius and the second portion being spaced from the longitudinal axis by a variable radius uniformly decreasing from the first radius to the second radius. A cable entry slot is formed adjacent one end of the first groove portion and includes a cavity having a pair of generally parallel side walls extending at an angle of approximately 2.degree. 30' with respect to a pair of side walls of the groove.
Abstract:
A compound counterbalance system for window sashes and the like, comprising: a biasing mechanism for easing operation of a window sash and the like, the biasing mechanism being movable at an inherently variable of force; a first biasing force transmission, connected intermediately of the window sash and the like and the biasing mechanism, for increasing the effective range of movement of the biasing mechanism; and, a second biasing force transmission connected intermediately of the first biasing force transmission and the biasing mechanism, the second biasing force transmission having a variable rate of operation predetermined to automatically compensate for the variability of the biasing mechanism, to provide substantial constancy of the biasing force. The biasing mechanism preferably comprises a linearly extensible and contractible spring. In one embodiment, both the first and second biasing force transmissions comprise pulley and cable systems. In another embodiment, only the second biasing force transmission comprises a cable and pulley system and the first biasing force transmission comprises a reduction gear assembly. In each embodiment, the variable rate of the second biasing force transmission comprises a generally conical, spiral-grooved pulley and a cable means affixed at one end to the pulley, affixed at the other end to the biasing mechanism and adapted to wind into and out of the groove.
Abstract:
A door closer or operator includes a pivoting pinion on the door closer housing for transmitting door motion, and a cam connected thereto. A connecting member extends along a spring and engages the peripheral edge of the cam. Rotation of the cam causes a change in length of the portion of the connecting member between the position tangent to the cam peripheral edge and the spring second end to expand or compress the spring, resulting in a force transmitted along a longitudinal axis of the connecting member as a result of spring deflection. The cam peripheral edge has a profile with a varying radial distance between the cam axis and the connecting member at the position tangent to the cam peripheral edge such that the radial distance is changed as the spring expands or compresses to maintain a desired constant torque about the axis of the cam and pinion.
Abstract:
A hinge assembly is provided comprising a toggle type hinge (10) with a linear damping device (13) arranged with its longitudinal axis parallel to the axis of movement of the hinge. First and second actuating devices (19, 30) are provided for operating the damping device. Means (20, 32, 55) are provided for activating the first and second actuating devices in response to movement of the hinge.