Door, preferably for industrial buildings

Claim 2

A release and lock mechanism for use in a door having a leaf of flexible material and held in suspension for raising and lowering within an opening by at two lines attached one to each end of the lower portion of the door leaf and connected to a hoist means, the ends of the leaf being guided in substantially U-shaped guide bars having lateral flanges, the guide bars being attached to the vertical defining surfaces of the door opening and the two lines extending to the hoist means each within a guide bar, said release and lock mechanism being connected intermediate the end of each line and the respective end of the lower portion of the door leaf and comprising: a vertically movable rod for connection to a respective line, a spring disposed in surrounding relation to said rod, and a locking mechanism in operable connection with said rod and actuated by said spring to a locking position in response to a predetermined decrease in load on the respective line, said mechanism being released from said locking position when the load on the respective line overcomes the force of the spring, said locking mechanism including at least two dogs pivoted in crosswise arrangement on a common shaft for disposition intermediate the lateral flanges of the associated guide bar and connected by links to the rod in movable relation to said shaft, said locking mechanism upon actuation providing an opposing outward expansion of both ends of each dog for creating two vertically spaced apart points of frictional engagement with each of the lateral flanges of the associated guide bars at any vertical position of the lower portion of the door leaf relative to the guide bars when the door leaf is mounted therein, said outward expansion of both ends of each dog thereby causing a fast condition of the door leaf against movement either up or down relative to the guide bars.

Claim 3

A door assembly dependent on a supporting structure for holding the door in suspension for raising and lowering within an opening having vertical defining surfaces, said door assembly comprising: a door having a leaf of flexible material; two lines attached one to each end of the lower portion of the door leaf; hoist means having connections for a power circuit and receiving the two lines for the winding and unwinding of same; a pair of U-shaped guide bars having lateral flanges for attachment to the vertical defining surfaces of the door opening, the guide bars receiving the ends of the door leaf and guiding the same when so attached and the door is held in suspension, said two lines extending to the hoist means each within a guide bar; and release and lock means connected intermediate the end of each line and the respective end of the lower portion of the door leaf, said release and lock means being actuated to lock the door leaf to the guide bar in response to a predetermined decrease in load on the respective line when the door is held in suspension and being released from the locking position when a predetermined load on the respective line is reinstated, each said release and lock means including a rod movable with respect to the door leaf and connected to the respective line, a spring in surrounding relation to the rod responsive to the decrease in load, and a locking mechanism in operable connection with said rod, said locking mechanism including at least two dogs pivoted in crosswise arrangement on a common shaft and disposed intermediate the lateral flanges of the associated guide bar and connected by links to the rod in movable relation to said shaft, said locking mechanism being actuated by said spring upon the respective line receiving the predetermined decrease in load and when so actuated providing an opposing outward expansion of both ends of each dog and creating two vertically spaced apart points of frictional engagement with each of the lateral flanges of the associated guide bar at any vertical position of the lower portion of the door leaf relative to the guide bars and causing thereby a fast condition of the door leaf against movement either up or down relative to the guide bars when said door and guide bars are mounted for operation, said locking mechanism releasing the fast condition only when the load on the respective line overcomes the force of said spring.

Claim 4

A door assembly dependent on a supporting structure for holding the door in suspension for raising and lowering within an opening having vertical defining surfaces, said door assembly comprising: a door having a leaf of flexible material; two lines attached one to each end of the lower portion of the door leaf; hoist means having connections for a power circuit and receiving the two lines for the winding and unwinding of same; a pair of U-shaped guide bars having lateral flanges for attachment to the vertical defining surfaces of the door opening, the guide bars receiving the ends of the door leaf and guiding the same when so attached and the door is held in suspension, said two lines extending to the hoist means each within a guide bar; and release and lock means connected intermediate the end of each line and the respective end of the lower portion of the door leaf, said release and lock means being actuated to lock the door leaf to the guide bar in response to a predetermined decrease in load on the respective line when the door is held in suspension and being released from the locking position when a predetermined load on the respective line is reinstated, each said release and lock means including a rod movable with respect to the door leaf and connected to the respective line, a spring in surrounding relation to the rod responsive to the decrease in load, and a locking mechanism in operable connection with said rod, said locking mechanism including at least two dogs pivoted in crosswise arrangement on a common shaft and disposed intermediate the lateral flanges of the associated guide bar and connected by links to the rod in movable relation to said shaft, said locking mechanism being actuated by said spring upon the respective line receiving the predetermined decrease in load and when so actuated providing an opposing outward expansion of both ends of each dog and creating two vertically spaced apart points of frictional engagement with each of the lateral flanges of the associated guide bar at any vertical position of the lower portion of the door leaf relative to the guide bars and causing thereby a fast condition of the door leaf against movement either up or down relative to the guide bars when said door and guide bars are mounted for operation, said locking mechanism releasing the fast condition only when the load on the respective line overcomes the force of said spring.

Claim 5

A door according to claim 2 wherein said lines are each drawn over a guide wheel at the upper portion of the door to a common drum in the hoist means onto and from which the lines are wound and unwound respectively, one line connected for extension over the drum and the other under the drum.

Claim 6

A door according to claim 2 or 3 further comprising electrical stop means provided in operable contact with each line and actuated also in response to the predetermined decrease in load on the respective line, the stop means when so actuated stopping operation of the hoist by interrupting the hoist means power circuit.

Claim 7

A door according to claim 2 or 3 further comprising electrical stop means actuated when the lower portion of the door leaf reaches a predetermined upper limit position or a predetermined lower limit position when said door is suspended for operation, said stop means when so actuated stopping operation of the hoist by interrupting the hoist means power circuit, rotating the drive motor in the given direction, the hoist means being thereafter reactivated only by electrically energizing the control circuit for reversing the direction of drive motor rotation.