Closure fasteners – Bolts – Sliding
Reexamination Certificate
2001-05-25
2003-06-24
Knight, Anthony (Department: 3676)
Closure fasteners
Bolts
Sliding
C292S170000, C292S173000, C292S140000, C292S143000, C292S336300, C049S394000, C160S118000
Reexamination Certificate
active
06581985
ABSTRACT:
BACKGROUND OF THE INVENTION
a) Field of the Invention
The invention is directed to a latch closure for walls, doors and shutters which are articulated at frames, housings or the like by hinges, wherein the frame surfaces, housing surfaces, door surfaces or wall surfaces which are connected with one another by the hinges are essentially flush with one another toward the outside in the closed position, comprising a first closure housing which can be fastened to the frame or the like and which has a rear-engagement portion for receiving the latch of the latch closure in a locking manner and a second closure housing which can be fastened to the door or the like and in which the latch is arranged so as to be displaceable against spring force by means of a handle.
b) Description of the Related Art
Room door closures are usually latch closures but are installed inside the door leaf. Formerly, it was often common to attach such latch closures to the door leaf also.
Particularly in the latter case, the latch is accessible through the gap remaining when the door is closed and it is possible to push the latch back with a suitable tool such as a screwdriver and to open the door even when the actual actuating device that should draw back the latch is locked. This is a substantial disadvantage in the known latch closures and is particularly troublesome in connection with doors of switching cabinets whose interior must be protected against tampering or whose interior poses a danger to unauthorized persons.
OBJECT AND SUMMARY OF THE INVENTION
It is the primary object of the invention to improve the latch closure of the type mentioned above in such a way that the latch is better protected from attempts at tampering and in particular it is made more difficult to push the latch back with a screwdriver or similar tool.
In certain applications, for example, simply constructed housings which are to be closed by a shutter, a stop at the door leaf or at the shutter or housing is omitted, so that it is difficult under certain circumstances to bring the door into the position in which the closure locks neatly. Therefore, a further object consists in providing, in these cases, a stop for the door or shutter in the closed position which is not formed by the door or the housing itself, but by the closure.
This object is met in that the second closure housing in the latch closure of the type mentioned in the beginning forms a projection which contacts an end face formed by the first closure housing essentially parallel to the door plane when the door is closed.
By means of this step, the gap formed between the two closure housing parts of the closure is closed toward the outside in such a way that it is no longer possible to penetrate without difficulty between the two closure housing parts, for example, with a screwdriver, and to pry them apart and, in some cases, even push the latch out of its closed position.
Further, it is possible by means of this projection to realize a stop function which functions independent from the door leaf or door frame and forms a stop for the door in the closed position. The advantage of this stop—compared with stops that are formed by the door leaf or the door frame itself—is that it enables a more precise position of the stop with respect to the latch and accordingly also prevents the door from rattling when there is play between the other stops, for example, due to inexact dimensioning of the stops or warping of the door or frame.
Additional protection against tampering by prying apart the closure parts is achieved when a groove which extends parallel to the frame is formed in the end face and when a spring or strip which can be fitted into the groove projects from the projection.
For a good frictional engagement, it is advantageous when the rear-engaging surface formed by the first closure housing for receiving the latch lies below the end face and parallel to it according to a further development of the invention.
In case the outer surface of the door and frame are not exactly aligned relative to one another, it may be advantageous to provide a spacer plate which compensates for this difference in distance.
The latch closure according to the invention is particularly advantageous when the frame or the like and the outer contour of the door or the like are formed by profile pieces outfitted with undercut grooves. A further development of this embodiment form is characterized in that the two closure housings likewise have undercut grooves in their mounting surfaces; however, these undercut grooves preferably extend vertical to the profile axis and accordingly enable a favorable adjustability, e.g., even with profiles of different width. Other fastening possibilities, which may be adjustable as the case may be, are threaded bore holes arranged in the fastening surface in an offset manner in a grid (according to given profile widths) or fastening tabs at the sides of the closure housings which have a round opening or an elongated hole extending transverse to the profile axis, optionally with locking ribbing. The lever for opening the closure is preferably mounted so as to be swivelable about an axis extending parallel to the stop surface and at the height of the shoulder. This shortens the acting lever arm and accordingly increases the stability of the arrangement. The movement path of the handle can be limited by a protuberance which is formed, for example, by a cylinder lock. It is possible to lock into the closure in this way.
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Boswell Christopher
Knight Anthony
Reed Smith LLP
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