Abstract: The overhead door lift assembly integrates a traditional torsion spring and an electrically powered operator into a small package mountable in the available head space of conventional tractor trailers, cargo vehicles or other structures. The lift assembly includes a torsion spring counterbalance, electrical operator, and back tension mechanism. The electrical operator uses an electromagnetic clutch and gearbox that couples directly to the cable drums of the counterbalance. The electromagnetic clutch allows the overhead door to be manually raised and lowered in the event of a power interruption or operator malfunction. The back tension mechanism prevents cables from inadvertently unspooling from cable drums as the operator starts to move the overhead door from its horizontal open position to its vertical closed position.

Abstract: The overhead door lift assembly integrates a traditional torsion spring and an electrically powered operator into a small package mountable in the available head space of conventional tractor trailers, cargo vehicles or other structures. The lift assembly includes a torsion spring counterbalance, electrical operator, and back tension mechanism. The electrical operator uses an electromagnetic clutch and gearbox that couples directly to the cable drums of the counterbalance. The electromagnetic clutch allows the overhead door to be manually raised and lowered in the event of a power interruption or operator malfunction. The back tension mechanism prevents cables from inadvertently unspooling from cable drums as the operator starts to move the overhead door from its horizontal open position to its vertical closed position.

Abstract: The overhead door lift assembly integrates a traditional torsion spring and an electrically powered operator into a small package mountable in the available head space of conventional tractor trailers, cargo vehicles or other structures. The lift assembly includes a torsion spring counterbalance, electrical operator, and back tension mechanism. The electrical operator uses an electromagnetic clutch and gearbox that couples directly to the cable drums of the counterbalance. The electromagnetic clutch allows the overhead door to be manually raised and lowered in the event of a power interruption or operator malfunction. The back tension mechanism prevents cables from inadvertently unspooling from cable drums as the operator starts to move the overhead door from its horizontal open position to its vertical closed position.

Abstract: The strap spool is mountable to drive shafts in various strap winding apparatus, such as winches and torsion spring counterbalances. The strap spool has a two piece design where two symmetrical spool halves slidably mate to form a drum around which the strap is wound. Each spool half has a central hub with an axial opening, which allows the spool halves to mount onto a drive shaft. An annular flange extending radially around the hub and a barrel sleeve extends from the hub perpendicular to the flange. When spool halves are mated together on a drive shaft, the barrel sleeves slidably extend into axial openings in the hub of the opposite spool half and form a tubular drum overlying the drive shaft around which the strap is wound.

Abstract: The strap spool is mountable to drive shafts in various strap winding apparatus, such as winches and torsion spring counterbalances. The strap spool has a two piece design where two symmetrical spool halves slidably mate to form a drum around which the strap is wound. Each spool half has a central hub with an axial opening, which allows the spool halves to mount onto a drive shaft. An annular flange extending radially around the hub and a barrel sleeve extends from the hub perpendicular to the flange. When spool halves are mated together on a drive shaft, the barrel sleeves slidably extend into axial openings in the hub of the opposite spool half and form a tubular drum overlying the drive shaft around which the strap is wound.

Abstract: The powered ramp door lift is used in cargo trailers and other ramp door applications and includes a powered winch assembly, a pair of wire cables or nylon straps connecting the winch assembly to the ramp door, and a “pusher” mechanism. The winch assembly mounted to the trailer header winds and unwinds the cables onto a pair of spools mounted to a drive shaft, which is driven by an electric motor. The “pusher” mechanism prevents the “unspooling” problems that effect the operation of winches in automated ramp door applications. The pusher mechanism engages the ramp door in the closed position and applies an outward force to the ramp door over a small portion of its travel to assist in the initial lowering of the ramp door from the closed position. The winch assembly also includes a cable tension winch shut off mechanism, which deactivates the winch motor in the absence of any tension on cables.

Abstract: The powered ramp door lift is used in cargo trailers and other ramp door applications and includes a powered winch assembly, a pair of wire cables or nylon straps connecting the winch assembly to the ramp door, and a “pusher” mechanism. The winch assembly mounted to the trailer header winds and unwinds the cables onto a pair of spools mounted to a drive shaft, which is driven by an electric motor. The “pusher” mechanism prevents the “unspooling” problems that effect the operation of winches in automated ramp door applications. The pusher mechanism engages the ramp door in the closed position and applies an outward force to the ramp door over a small portion of its travel to assist in the initial lowering of the ramp door from the closed position. The winch assembly also includes a cable tension winch shut off mechanism, which deactivates the winch motor in the absence of any tension on cables.