US 6,134,835 A · Counterbalance system for upward acting door

Abstract

A counterbalance system for an upward-acting door includes spaced-apart wall brackets and cable drums supported on the brackets and connected to flexible cables which depend from the drums and connected to the lower side edges of an upward-acting sectional garage door. One or both of the cable drums may be connected to one end of a torsion coil spring and the opposite end of each spring is connected to a hub assembly. Elongated spring winding and protective cover tubes are sleeved over the springs and are connected to the brackets by worm-gear drive winding mechanisms, respectively, for rotating the tubes to effect winding of the torsion coil springs through the hub assemblies but preventing rotation of the tubes during normal operation of the counterbalance system. The cable drums and spring hub assemblies may be supported on an elongated synchronizing shaft or a torque transfer shaft extending between and supported on the wall brackets.

Claims33

Dependent claims

A counterbalance system for an upward acting door for counterbalancing at least part of the weight of said door when said door is moved between open and closed positions, said system comprising:

rotatable drums interconnected by an elongated shaft and supported on spaced-apart brackets adapted to be supported, respectively, generally above and adjacent to said door, said drums having flexible members wound thereon, respectively, the free ends of said flexible members depending from said drums and adapted to be connected to said door, respectively;
a torsion spring mounted on said shaft between said drums having opposed end portions, one of said end portions being connected to one of said drums;
an elongated tube disposed in sleeved relationship over said spring and operably connected to the other end portion of said spring;
and
a winding mechanism including a part held stationary with respect to said bracket and operatively connected to said tube and operable to hold said tube stationary during normal operation of said counterbalance system, said winding mechanism being operable to rotate said tube, which rotates said other end portion of said spring to adjust the torque applied by said spring to said one drum.

2 more elements

A counterbalance system for counterbalancing at least part of the weight of an upward acting door when said door is moved between open and closed positions, said counterbalance system comprising:

spaced-apart brackets adapted to be mounted generally above and adjacent to said door;
an elongated shaft extending between and supported on said brackets;
opposed drums supported on said shaft, respectively, and releasably securable to said shaft for rotation in synchronization with each other, each of said drums including a flexible member wound thereon, said flexible members being adapted to be connected at a free end depending from said drums to said door, respectively;
each of said drums including a hub portion connected to one end of a torsion coil spring, each of said springs extending axially from said hub portions of said drums toward each other;
opposed hub assemblies connected to the ends of said springs, respectively, opposite the ends connected to said drums and mounted in sleeved relationship over said shaft for rotation relative to said shaft;
elongated spring winding tubes operably supported by said brackets and disposed in sleeved relationship over said springs and said shaft, respectively, said tubes extending toward each other between said brackets, each of said tubes being connected to a respective one of said hub assemblies nonrotatably and for holding said ends of said springs nonrotatable with respect to said brackets, respectively;
and
spring winding mechanisms operably connected to each of said tubes and to one of said brackets, respectively, for holding said tubes, respectively, stationary during operation of said counterbalance system to counterbalance the weight of said door and for adjusting the torsional windup of said springs by selectively rotating respective ones of said tubes to rotate said hub assemblies and said ends of said springs, respectively, opposite the ends connected to said drums.

5 more elements

Dependencies are inferred from the claim text.

Counterbalance system for upward acting door

Life of this patent

Counterbalance system for upward acting door

Life of this patent

Abstract

Claims33