Abstract:
An improved load compensator for a spring counter-weighting mechanism including a snail cam to provide a constant counter-weight force is described. The cam provides a constant torque to a drum on which are wound cables for exerting a constant counter-weighting force. A manually operable device for altering the relative radial positions of the cam and drum varies the amount of the constant counter-weighting force. The cam is rotated with respect to the drum by a spur gear fitting within a ring gear fixed to the drum and rotated by a knob connected to an axle carrying a pinion gear engaging the spur gear.
Abstract:
An overhead door system employs counterweights which operate through cables connected to a drum which tapers from one end to the other so that the effective force acting on the door in the opening direction is reduced as the proportion of the weight of the door to be supported reduces. The system is adjustable readily to accommodate different types of doors having different opening characteristics in terms of the proportion of the doors weight that must be counterbalanced at different stages of the door opening movement. The drum has a pair of continuous grooves extending side-by-side throughout its length, the counterweight being independently supported by each of a pair of cables laid in these grooves.
Abstract:
A compound counterbalance system for window sashes and the like, comprising: a biasing spring for easing operation of a window sash and the like, the biasing spring being movable at an inherently variable rate of force; a first biasing force transmission having a fixed rate of movement transmission part connected to the biasing spring and a variable rate of movement transmission part connected to the window sash and the like, the variable rate of movement transmission part having a variable rate of operation predetermined to automatically compensate for the variability of the biasing spring to provide substantial constancy of the biasing force throughout an operating range; and, a cable for interconnecting the biasing spring, the first biasing force transmission, and the window sash and the like, whereby loading forces on the first biasing force transmission are substantially constant throughout the operating range. The system may further comprise one or both of a second biasing force transmission connected intermediately of the variable rate of movement transmission part and the window sash and the like, for increasing the effective range of movement of the biasing spring; and, an adjuster for changing the effective magnitude of the biasing force throughout the operating range.
Abstract:
A counterbalance assembly for an appliance has a guide member with a rotatable pulley with a fixed radius and a cam affixed to one side of the pulley and having a varying radius. The cam and the pulley rotate about a pulley axis of rotation as a single unit. The counterbalance has a force applicator that applies a counterbalance force to one of the pulley or cam, and the counterbalance has a connector that couples the other of the pulley or cam to the door. The counterbalance force applies a varying counterbalance torque to the door that is a function of the ratio between the fixed radius and the varying radius over the pivotal range of the door.
Abstract:
Disclosed are apparatus for a block and tackle window balance to be incorporated in single and double hung window assemblies. In one embodiment the block and tackle window balance includes a roller secured within a bottom guide to increase range of travel of a window sash.
Abstract:
The present invention provides for apparatus and methods for operating a garage door. An embodiment of an operating assembly for a door includes a shaft, a graduated drum, and an energy storing member. The shaft is coupled to the door such that the shaft rotates in a first direction as the door is opened and rotates in a second direction as the door is closed. The coupling of the shaft to the door is typically accomplished by a cable. The graduated drum is coupled to the shaft and the energy storing member is coupled to the graduated drum by another cable. The energy storing member is arranged such that the energy storing member stores energy as the door is closed and releases stored energy as the door is opened to assist in the raising and lowering of the door.
Abstract:
Disclosed are apparatus for a block and tackle window balance to be incorporated in single and double hung window assemblies. In one embodiment the block and tackle window balance includes a roller secured within a bottom guide to increase range of travel of a window sash.
Abstract:
A mechanism and method for operating a track-mounted door is disclosed. The mechanism includes a pair of side drums that are connected by first cables to the bottom of the door. The side drums are coaxially mounted on a shaft for simultaneous rotation with a pair of cable drums. The cable drums are connected to high pressure gas struts by second cables. Each second cable is carried around a shiv wheel that slides along a guide track as the second cable moves. Each shiv wheel is operatively connected to one of the gas struts. As the shiv wheel moves along the guide track toward the cable drum, the gas strut is charged. As the shiv wheel moves away from the cable drum, the gas strut is discharged. A standard electric motor and screw driven lift-arm is used to initiate the opening and closing of the door. The charged gas strut stores sufficient energy to overcome friction and gravity to assist the electric motor and lift-arm to open the door.