An example cable tension device is provided. The cable tension device includes a bracket, an arm, and a spring. The arm is rotatably coupled to the bracket and comprises a roller bar to receive a cable of an overhead door. The spring is coupled to the arm. The spring is under a load to cause the arm to rotate away from the bracket to maintain a tension on the cable.

A system for exerting torque on a shaft includes: a spring assembly having; a spring; a companion member to the spring, wherein at least one of the spring and the companion member is in compression and the other of the spring and companion member is in tension; connecting structure for transmitting a force associated with the spring outside of the gear assembly; and a gear train for connecting the connecting structure to the shaft to apply torque to the shaft. A method of exerting torque on a shaft includes: arranging a plurality of spring assemblies arranged in an array around the shaft, each spring assembly having; a spring; connecting structure for transmitting a force associated with the spring; attaching a gear train to the connecting structure; and configuring the gear train to apply the force associated with the spring to the shaft in the form of torque on the shaft.

The invention relates to an overhead door for covering a door opening comprising a door blade (11) with a plurality of panels (17), said door blade (11) being movable between a vertical, closed position and a horizontal, opened or overhead position within a side frame (12) comprising double-sided a vertical track (13) and a horizontal track (14), connected by a connecting portion (15), respectively, and with a belt (20) or a chain associated with one side each of the said side frame (12) to lift the panels (17) from said vertical position to said horizontal position. To develop the stated overhead door in a way that the advantages of a high speed rollup door and an overhead door are combined, to offer an overhead door with a low space requirement, low maintenance requirements and a high speed closing possibility, the stated overhead door comprises driving means (27) for simultaneously driving a plurality of said panels (17).

In example implementations, a track of a vertically stacking door is provided. The track includes a vertical track, a track coupling coupled to the vertical track, a first curved track portion coupled to the track coupling, a second curved track portion coupled to the track coupling, and a ramp coupled to the vertical track before the track coupling.

A counterbalance system for balancing an overhead door installed against a structure of a vehicle or a house, the door having at least one door panel, the system has a longitude pipe with non-circular section cut; a pair of U-brackets having two side walls with one center hole on each side; a pair of torsion spring assemblies received within the pipe, and the inboard end of the assembly being slidingly engaged within the pipe; a pair of connecting shaft, with inboard side connected with the outboard end of each of the spring assemblies; the shaft passing through the center holes of the U-bracket; the outboard end of each shaft being fixed with the side wall on the outboard end of each of the U-brackets; a pair of drums each having a center hole received by the shaft, and each of the drums located between two side walls of the U-bracket.

A dock door assembly and a dock door assembly kit are provided for use in a dock door opening for installation in a warehouse. The dock door assembly comprises a pair of vertical tracks, with each vertical track configured to be attached to a wall along opposing lateral sides of the dock door opening. The dock door assembly also comprises a multiple, horizontal section door characterized by a vertical height when closed and mounted on the pair of vertical tracks. The dock door assembly further comprises a spring shaft assembly and a pair of headplates with each headplate having a U-shaped opening to receive each end of a torsion shaft. Further, the dock door assembly may comprise a pair of door cables and a pair of corner cable attachments connecting each door cable to the spring shaft assembly.

A door control system is provided. The control system includes a controller configured to control a door via a motor. The motor is powered by a battery and bypasses the controller via relays and/or switches when power to the controller is disconnected. The current of the motor may be monitored and/or displayed to confirm that the door is balanced.

A high-speed sectional overhead door covers a door opening with panels stacked in a single plane and lifted from the bottom-most panel. As panels are lifted, each rolls in its own individual track. As the panels move into the head area, they run through curved tracks and are nested there. The stored panels stacked horizontally one atop another with the door open. This design utilizes a dedicated panel-track pairing as well as a unique hook/cam device which allows for the upper panel to be both locked in the closed position and pushed away for separation and storage in the open position. The design also provides a sectional door with low headroom clearance, high speed closing/opening and a multitude of panel heights without hinges joining the adjacent panels

A retractable dual screen system provides auxiliary environmental protection for garage door openings. An upper housing is mounted on an exterior of a garage door, including two rollers and is accessible for maintenance or repair by a removable cover. A first roller is a vinyl insect screening, and a second roller contains polyolefin material to provide an additional layer of insulation to help reduce heat loss and gain through the garage door. The second roller also provides a vapor barrier to help protect the garage door against high winds. A dual track system selectively allows both rollers to be independently deployed over the garage door opening.

An overhead door using a cable tensioning device that is an enclosed drawbar spring that is located in-line with the cable of a counterbalance system, the cable tensioning device maintains the tension on the cable of the counterbalance systems while not interfering with the overhead door hardware, counterbalance system and tracks located to the sides of the overhead door and the cables of the counterbalance system.