Counterbalance mechanism for vertical opening door

A counterbalance mechanism for a vertical opening, sectional garage door for counterbalancing at least part of the weight of said door when said door is moved between open and closed positions, said mechanism comprising:

• spaced apart brackets disposed generally above and adjacent to said door;
• an elongated shaft extending between said brackets and supported by said brackets, respectively;
• a pair of opposed hub members disposed on said shaft for rotation therewith;
• opposed torsion coil springs disposed around said shaft and each connected at one end to said hub members, respectively;
• opposed cable drums supported on said shaft spaced apart, said cable drums being connected to respective hub portions engaged with opposite ends of said torsion springs, respectively, each of said cable drums being supported on bearing means for rotation relative to said shaft and operable to deflect said torsion springs, respectively;
• elongated, flexible cable members disposed around said cable drums, respectively, and having depending free ends connected to opposite sides of said door;
• and
• a drive mechanism connected to said shaft adjacent to one side of said door, said drive mechanism including cooperating gears operable to selectively rotate said shaft to deflect said torsion springs, respectively, to exert a counterbalance torque on said cable drums to tension said cables to counterbalance at least part of the weight of said door, one of said gears having drive means connected thereto for rotating said gears to rotate said shaft, at will, to adjust the counterbalance torque exerted by said springs on said cable drums, respectively.

A counterbalance mechanism for counterbalancing at least part of the weight of a vertical opening sectional garage door when moving said door between open and closed positions, said mechanism comprising:

• opposed spaced apart wall brackets adapted to be disposed generally above and adjacent to said door;
• an elongated shaft extending between and supported by said brackets, respectively;
• opposed hub members disposed on said shaft and engageable with said shaft for rotation therewith, said hub members being axially slidable on said shaft;
• opposed torsion coil springs disposed around said shaft and each connected at one end to said hub members, respectively;
• opposed cable drums spaced apart from each other, said cable drums each being connected to respective hub portions engaged with opposite ends of said torsion springs, respectively, each of said cable drums being supported on a bearing assembly and providing for rotation of said cable drums relative to said shaft in response to deflection of said torsion springs, respectively;
• bushing means interconnecting said cable drums with said brackets, respectively;
• elongated flexible cable members disposed around said cable drums, respectively, and having depending free ends connected to said door, respectively;
• and
• a drive mechanism mountable on one of said brackets including a housing, gear means mounted in said housing for rotation in response to a drive force means, said gear means being operable to be connected to said shaft for rotating said shaft to deflect said torsion springs in response to rotation of said gear means for adjusting a counterbalance torque exerted on said cable drums to tension said cables for counterbalancing at least part of the weight of said door.

A counterbalance mechanism for a vertical opening door for counterbalancing at least part of the weight of said door when said door is moved between open and closed positions, said mechanism comprising:

• spaced apart bracket means disposed generally above and adjacent to said door;
• elongated shaft means extending between and supported on said bracket means;
• torsion spring means operably connected to said shaft means;
• opposed cable drums disposed on said shaft means and connected to one end of said torsion spring means, respectively, said cable drums having flexible cables wound thereon and connected at a free end depending from said cable drums to said door, respectively;
• drive means including one way drive gear means drivably connected to said shaft means adjacent one of said bracket means for rotating said shaft means in one direction, at will, to adjust the torsional deflection of said torsion spring means to provide a counterbalance force exerted by said cables, said drive means including means operable to prevent rotation of said shaft means in an opposite direction in response to a torsional effort exerted on said shaft means by said torsion spring means, said drive gear means being connected to means for rotating said drive gear means to adjust the deflection of said torsion spring means, respectively, said drive means including a housing detachably mountable on one of said bracket means and including a portion engageable with said one of said bracket means;
• and
• a lock member engageable with said shaft means and with said one of said bracket means for retaining said shaft means stationary with respect to said one of said bracket means upon removal of said drive means from said one of said bracket means.

A counterbalance mechanism for a vertical opening door for counterbalancing at least part of the weight of said door when said door is moved between open and closed positions, said mechanism comprising:

• spaced apart bracket means disposed generally above and adjacent to said door;
• elongated shaft means extending between and supported on said bracket means;
• torsion spring means operably connected to said shaft means;
• opposed cable drums disposed on said shaft means and connected to one end of said torsion spring means, respectively, said cable drums having flexible cables wound thereon and connected at a free end depending from said cable drums to said door, respectively, said cable drums are mounted on bearing means supported on said shaft means and include respective opposed hub members engageable with said torsion spring means, respectively, said bearing means are each engaged with means connected to said bracket means, respectively, for retaining said bearing means and said cable drums secured to said bracket means, respectively;
• and
• drive means operably connected to said shaft means adjacent one of said bracket means for rotating said shaft means in one direction, at will, to adjust the torsional deflection of said torsion spring means to provide a counterbalance force exerted by said cables, said drive means including means operable to prevent rotation of said shaft means in an opposite direction in response to a torsional effort exerted on said shaft means by said torsion spring means.

In a counterbalancing mechanism for a vertical opening door for counterbalancing at least part of the weight of said door when said door is moved between open and closed positions, spaced apart bracket means disposed generally above and adjacent to said door, elongated shaft means extending between and supported on said bracket means, torsion spring means operably connected to said shaft means and opposed cable drums disposed around said shaft means and connected to one end of said torsion spring means, respectively and having flexible cables wound thereon and connected at a free end to said door, and the improvement characterized by:

• a hub connected to one end of said torsion spring means and supported on said shaft for axial sliding movement along said shaft but nonrotatable relative to said shaft, said hub comprising a hub member including groove means formed thereon for engagement with said torsion spring means, and said hub member including means forming a generally circular segment shaped bore for receiving said shaft, said bore having a planar surface cooperable with a corresponding planar surface on said shaft and for engaging said shaft to permit axial sliding movement of said hub relative to said shaft but preventing rotation of said hub relative to said shaft, and at least part of said hub is formed of a molded polymer and includes a reinforcing member for reinforcing said part of said hub at said bore.

A counterbalance mechanism for a vertical opening door for counterbalancing at least part of the weight of said door when said door is moved between open and closed positions, said mechanism comprising:

• spaced apart brackets disposed generally above and adjacent to said door;
• an elongated shaft extending between and supported on said brackets;
• spaced apart torsion springs each having one end operably connected to said shaft for rotation therewith;
• opposed cable drums spaced apart on said shaft between said brackets, said drums each being connected to another end of each of said torsion springs, respectively, said cable drums having flexible cables wound thereon and connected at a free end depending from said cable drums to said door, respectively;
• and
• drive means operably connected to one end of said shaft and mounted on one of said brackets for rotating said shaft in one direction, at will, to adjust the torsional deflection of said torsion springs to provide a counterbalance force exerted by said cables, said drive means including means operable to prevent rotation of said shaft in an opposite direction in response to a torsional effort exerted on said shaft by said torsion springs.