Device for lifting a vertically movable door

The invention relates to a vertically moving door lifting device and more particularly relates to a safety system for such a facility.

vertical movement the doors are particularly appreciated in industrial premises, warehouses, etc ... Such a door can indeed be easily motorized and remote controlled. A door of the kind concerned by the invention comprises a panel guided between two parallel rails respectively extending along the sides of the doorway and attached to the wall. The panel comprises guide wheels subject to move in the grooves of these rails. The panel is operated by two flexible connections (typically straps, but optionally, cables, chains or the like) extending opposite rails respectively, on either side of the panel. Each actuating link and is attached between a fixed anchor point of the panel (usually located at the bottom thereof) and a winder, or similar actuating means, usually installed in height, above the door . operating the links are normally always stretched at least by the weight of the panel itself. This panel can be balanced, at least in part, by springs arranged coaxially to the shaft of the retractor.

The safe operation of such a door must be blameless. in particular, must ensure that it can fall sharply in the manner of a guillotine, especially in case of failure of one of the elements ensuring retention of the door, such as a spring breakage or disappearance torque motor for any reason whatsoever.

The invention achieves this objective by triggering a safety mechanism, when the holding torque disappears.

More specifically, the invention relates to a lifting device of door to vertical movement of the type comprising a winder driven by an electric motor and adapted to actuate maneuvering links attached to said door, characterized in that said motor is coupled to a intermediate piece mounted with predetermined rotary play on a fixed support of said winder and in that a pivoting catch is mounted in the vicinity of said winder to be pivotable into a predetermined position, able to do cooperate with an abutment of said reel when said workpiece intermediate moves rotationally subsequent to a failure in the retaining of the door.

In one embodiment of a preferred example embodiment, the pawl is mounted on the fixed support and is coupled by a pin or the like to the intermediate piece. The latter is situated in the axial extension of the shaft of the reel and the axis of rotation thereof coincides with that of said shaft. The intermediate piece or said fixed support has oblong holes substantially equidistant from the axis of said drum, while the fixed support or said intermediate piece, respectively, has guide elements, for example consisting of bolts or the like, engaged in said oblong holes. According to a preferred embodiment, the intermediate part comprises oblong holes, whereas the fixed support comprises the guide elements. In addition, the pivotable pawl is mounted on a pin fixed to the stationary support and its lug is engaged in a hole of the intermediate piece, so that the rotation of the intermediate member causes pivoting of the lug in the direction of the stop provided on the shaft of the reel.

The invention will be better understood and other advantages thereof will appear more clearly in light of the following description of a vertically moving door lifter according to its principle, given solely by way of example and with reference to the non-limiting accompanying drawings in which:<ul><li>Figure 1 is a view of one end of the lifting device according to the invention;</li><li>Figure 2 is a top view of Figure 1; and</li><li>Figure 3 is a schematic view illustrating the coupling between the motor and the shaft of the retractor.</li></ul>

In the drawings, a lifting device is shown for a vertical movement type door wherein said door (not visible in the drawings) moves between vertical rails under the action of actuating links, here straps 11. the lifting device is shown only in part, and more in particular one end thereof showing the reel and its drive shaft. Each strap is wound on itself in a grooved pulley 12 of the reel 14 secured to a horizontal shaft 16 installed above the door and driven by an electric motor 17. Each strap is normally tensioned between and the door and the retractor 14. in the vicinity of each of its ends, the shaft is provided with a cylindrical bearing 18 freely rotatably mounted in a bearing 19, itself secured to a stationary support 20. the shaft 16 is advantageously a hollow shaft that houses the electric motor 17 and a gear box 22, a relatively irreversible type. As illustrated schematically in Figure 3, the engine body 17 is mounted on the gear 22 (these two elements are mounted in the extension of one another) and the motor shaft is provided with a square section rod 24 which projects axially beyond the end of the hollow shaft. The engine body is not bound to the wall of the shaft 16. However, the gear unit is coupled to this shaft, internally. More specifically, the shaft 16 is shaped so as to present longitudinally extending wide grooves. These grooves thus define internal abutments 26 by which the mechanical coupling is effected with the gear 28 and outer stops (here four in number) whose role will be explained later.

According to an important characteristic of the invention, the motor 17 is coupled (by its square section shaft 24 by means of a pin 30) to an intermediate piece 34 mounted with predetermined rotary play on the fixed support 20 of the retractor 14. A pawl pivot 36 is mounted near said reel. It is arranged to be pivotable within a predetermined own to do cooperate with one of the abutment position 28 of said drum, when said intermediate part 34 moves rotationally subsequent to a failure of the door retaining means, for example a disappearance the torque motor or break in the balancing systems. In the example shown, the pawl 36 is mounted on the fixed support 20 through a pin 42 formed from a bolt fixed to the fixed support 20. It is coupled to the intermediate part 34 to rotate, when the latter is rotated in case of damage. Specifically, the pivotable pawl 36 includes a lug 44 engaged in a hole 45 of said intermediate piece. The latter has a generally trapezoidal shape; it is constituted by a metal sheet having a plurality of parallel folds at 90 ° relative to each other. It is located in the axial extension of the hollow shaft 16 so that the axis of rotation of said intermediate piece is coincident with that of the hollow shaft and therefore also that of the square-section rod. This is achieved by the fact that the intermediate part comprises oblong holes 38, while the fixed support comprises guide elements 40, here constituted by simple bolts engaged in the oblong 38 matching holes. The guide elements 40 and the holes 38 are equidistant from the axis of the retractor. The electric motor is also secured to the intermediate piece, the connection being made at the center of rotation thereof by the mounting described above, including the square section spindle and 30 activate the pin between two parallel parts of the room intermediate 34.

The pin 42 crosses itself a slot 43 of the intermediate part, not to hinder the movement of it. A spring 48 is mounted between said fixed support 20 and the intermediate part 34. As shown in Figure 1, the spring normally keeps the intermediate piece in a stable position in which the guide elements 40 are abutted to ends of certain 38 oblong corresponding holes. In this position illustrated in Figure 1, the pawl 36 is spaced from the hollow shaft 16, its position being determined by cooperation between the pin 44 and the hole 45 of the intermediate part 34. In contrast, if an incident operation, of the kind mentioned above, occurs, a reverse torque is immediately generated by the weight of the door, causing the limited rotation of the intermediate piece, anticlockwise when considering Figure 1, until the guide elements 40 again come into abutment at the other ends of the elongated holes 38. in this rotational movement, the intermediate member 34 causes pivoting of the lug 36 which instantly comes into contact with the one of the stops 28 and lock the hollow shaft 16. the fall of the door is immediately stopped.