Patent Application
20120055095
This invention relates to doors which are subject to operation in high winds and, more particularly, to a door stay that automatically locks the door in an open position when the door swings through a predetermined angle.
Specifications provided by customers often state that doors must remain open at a certain angle under all conditions. Conventional door stays, some of which are described below, are not suitable and could thus result in non-compliance with the customer specifications.
Current door stay designs that lock automatically after a predetermined movement of the door in the opening direction often rely on further door movement in the same direction to unlock the stay, allowing the door to close, for example, under a conventional biasing force in the closing direction. This is unsuitable in high wind areas where the door may unlatch inadvertently due to further movement of the door caused by the wind, and thus cause the door to close.
Conventional scissor-type automatic latching devices are also unsuitable for operation under high wind conditions where external forces are present.
There remains a need therefore, for a door stay that enables the door to automatically lock in the open position upon movement of the door through a predetermined angle, e.g. 80-130 degrees or more, but that will not unlatch due to unintended further movement of the door in either direction.
In an exemplary but non-limiting embodiment, the present invention provides a door stay device for automatically locking a door in an open position comprising a first component adapted to be attached to a stationary support, the first component including a plate having a curved cam edge with a radius substantially matched to a swinging movement of the door between closed and open positions, the plate having a first slot open at the curved cam edge at a location corresponding to the open position of the door; a second component adapted to be secured at a lower or upper edge of the door, the second component having a lock bar arranged to slide along the cam edge and move into the first slot when the lock bar is aligned with the slot.
In another aspect the invention provides a door stay device for automatically locking a door in an open position comprising a first component adapted to be attached to a stationary support, the first component including a plate having a curved cam edge with a radius substantially matched to a swinging movement of the door between closed and open positions, the plate having a first slot open at the curved cam edge at a location corresponding to the open position of the door; a second component adapted to be secured at a lower or upper edge of the door, the second component comprising a member in which a lock bar is spring-biased for sliding movement into the slot when the lock bar is aligned with the first slot and the door is in the open position, and wherein the lock bar is provided with a handle permitting a user to manually withdraw the lock bar from the first slot in order to enable movement of the door from the open to the closed position.
In still another aspect, the invention provides a door panel and door stay assembly comprising a door panel attached to a stationary support for swinging movement between closed and open positions; a first door stay component attached to the stationary support, the first door stay component including a cam plate having a curved cam edge with a radius substantially matched to the swinging movement of the door panel between the closed and open positions, the cam plate having a first slot open at the curved cam edge at a location corresponding to the open position of the door panel; a second door stay component secured at a lower or upper edge of the door panel, the second door stay component having a lock bar arranged to move automatically into the first slot when the lock bar is aligned with the first slot and the door panel is in the open position.
The invention will now be described in connection with the drawings identified below.
The single drawing is a perspective view of a door stay comprising stationary and moveable components in accordance with an exemplary but non-limiting embodiment of the invention.
With reference to the single drawing figure, the door stay assembly 10 includes a stationary component 12 to be mounted to a door frame, wall or other stationary support, and a moveable component 14 adapted to be mounted on or at the bottom edge of the door (shown in phantom at D) mounted for pivoting movement about the pivot axis A. It will be appreciated, however, that both components as described herein may also be arranged at the top of the door if so desired.
The stationary component 12 includes a rigid angle bracket formed by flat metal rods 16, 18 arranged, in the exemplary embodiment, substantially perpendicular to each other, and that may be secured by, for example, welding, where they intersect each other. The angle bracket is reinforced by a substantially triangular-shaped gusset plate 20 which may be welded along the lower interior edges of the rods 16, 18.
A cam plate 22 is secured, for example, by welding, along the upper interior edges of the rods 16, 18, substantially parallel to the gusset plate 20. It should be understood that rods 16, 18 could also be formed as integral flanges of the cam plate 22. The cam plate 22 is formed with a curved cam edge 24 extending from a remote end of the angle rod or flange 16 to a corresponding remote end of the angle rod or flange 18, and interrupted by an elongated, substantially rectangular slot 26 extending parallel to the angle rod or flange 18 and in relatively close proximity thereto. Thus, the cam edge in the illustrated embodiment extends along an arc of substantially 90 degrees, and is substantially matched to the swinging movement of the door D. It will be appreciated that the cam plate 22 and rods or flanges 16, could also be formed to accommodate wider swing range for the door, e.g., between about 80-130 degrees or more.
The moveable component 14 includes a U-shaped channel component 28 formed by parallel side plates 30, 32 connected by a flat-base component 34, thus forming an upwardly-open channel closed at its remote end by an end wall 36. The channel component 28 could also be a one-piece extruded, welded, or otherwise formed U-shaped or closed member with an end wall 36. A lock bar 38 is sized to slide within the channel component 28 with a coil spring or other suitable biasing means 40 exerting a force on the lock bar 38 in a direction axially away from the channel component, i.e., toward the cam plate 22.
A slot 42 formed in the side plate 30 of the U-shaped channel component 28 allows a transverse pin 44 fixed at the back end of the lock bar 38 to slide within the slot 42. Thus, the transverse pin 44, in effect, provides a handle by which a user may pull the lock bar 38 rearwardly (to the left in
In use, as the door D to which the channel component 28 is secured moves from a closed to an opened position (in a clockwise direction as viewed in the drawing figure) the slanted end wall 46 of the lock bar 38 will move with the door, sliding along the fixed cam plate edge 24, with a substantial portion of the lock bar 28 located within the channel component 28, compressing the spring 40 to the left as viewed in the drawing. When the door D has swung approximately 90 degrees in the illustrated embodiment, the lock bar 38 will be driven into the slot 26 by the spring 40, thus locking the door in the open position.
It will be appreciated that no further unintended movement of the door in either the opening or closing direction is possible, thereby eliminating any possible unintended unlocking of the door stay under, for example, high wind conditions.
When it is desired to close the door, the transverse peg or pin 44 is grasped and pulled rearward (to the left), drawing the lock bar 38 out of slot 26. At this point, the door may return, automatically by a conventional spring bias, or may be swung to a closed position, with the end wall 46 again sliding along (and biased against) the curved cam edge 24 of the cam plate 22.
It will be understood that the configuration of the stationary component 12, and particularly the arrangement of the rods 16, 18 and the gusset plate 20 may vary with different applications. The configuration of the channel component 28, lock bar 38 and spring 40 may also vary, and the location of the slot 42 and pin 44 could be relocated to the other side of the channel component 28 for convenience. The choice of materials and specific dimensions of the components are also application dependent and well within the skill of the art.
while the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
