The present invention relates to a panic-safe lock comprising a device for adapting the lock to the opening direction of a door, for presetting the lock to open only from one side, and for temporarily allowing to open it from the opposite side.
Conventional panic-safe locks provided with a latch and a bolt that can be moved into their release position by actuating a handle are installed in emergency doors. With these locks, in case of emergency the door can be opened only from the inside outward.
However, the need arises to install these locks in emergency doors that open to the right or to the left and to temporarily open the door from the outside as well.
The technical aim of the present invention is to provide a device which, when installed in a panic-safe lock, renders it possible to open the door from one side and, only with an appropriate actuation, from the opposite side.
Within the scope of this aim, an object of the present invention is to provide a device which is constructively simple, highly reliable in operation and easy to modify according to the rightward or leftward opening characteristics of the door.
The invention provides a panic-safe lock comprising a device for adapting the lock to the opening direction of a door, for presetting the lock to open only from one side and for temporarily allowing to open it from the opposite side, with the features set forth in the characterizing part of claim 1.
Further particularities of the present invention will become apparent from the following description of a preferred embodiment thereof, illustrated only by way of non-limitative example in the accompanying drawings, wherein:
With reference to the above figures, the device comprises a bush 1 having a peripheral collar 2 on which two annular elements 3 and 4 are centered on opposite sides; said elements are substantially mirror images of each other and make mutual contact at the centerline plane P.
The annular elements 3 and 4, termed simply "rings" hereinafter for brevity, have on their outer faces respective raised portions 3a, 4a by means of which they are rotatably supportable in openings of the side walls of a lock case. Each one of the rings 3 and 4 has two teeth 5, 6 and 7, 8 that lie diagonally opposite with respect to the bush 1, a central seat 9, 10 and a threaded hole 11, 12. The central seats 9, 10 are coaxial to the bush 1 and have a square cross-section which is complementary to the cross-sections of the tangs of lock actuation handles.
The holes 11, 12 are located outside the seats 9, 10, and the raised portions 3a, 4a are conveniently expanded radially at said holes so as to engage in recesses of the lock case openings which rotatably support the rings 3, 4. The angular extension of these recesses determines the rotation angle of the rings 3, 4. The teeth 5, 7 have notches for the insertion of rods subjected to the action of springs (see figure 1) that react against shoulders of the case and bias the rings 3, 4 in abutment in a clearly set angular position. A seat 13 is formed between the rings 3, 4, which accommodates a lever, generally designated by the reference numeral 14 and shown in greater detail in figure 5.
The lever 14 comprises two rings 15, 16 which are internally provided with two respective openings 17, 18 aligneable with the holes 11, 12. The opening 18 is located in a wing 19 of the ring 16 that extends outward. The ring 16 forms a tooth-shaped arm 20, with a front 21, in a position that lies diametrically opposite the wing 19.
The rings 15, 16 can be alternately coupled to the ring 3 or to the ring 4 by means of a screw 22 inserted in the hole 11 or 12.
The length of the screw 22 is such that when it has been fully screwed into the hole 11 or 12 of an annular element 3 or 4, its end engages both openings 17, 18 of the rings 15, 16 but not the hole of the opposite annular element, which is thus free to rotate. Figure 3 shows that the screw 22 produces the rotational coupling between the element 3 and the rings 15, 16, whereas the element 4 is free.
The ring 15 of the lever 14 has an arm 23 extending radially opposite the tooth 20, and a tab 24 in which a pawl 26 is articulated by means of a pivot 25. A pin 27 arranged substantially radially to the bush 1 is guided in the pawl 26 and has a collar 28 on which a spring 29 acts, said spring being accommodated in a seat 30 formed in the pawl around the pin 27.
The spring 29 pushes the pin 27 against the edge of the ring 15, so that the pawl 26 is constantly biased in a position in which a tooth 31, formed therein, is out of the path of the teeth 6, 8 of the annular elements or rings 3, 4.
The described device is installed in a lock so that the lever 23 can act directly on the spring latch 32 and the tooth 20 can act on the bolt 33 by means of an interposed lever 34 which rests on the front 21 with one end and acts on the tang of the bolt with its opposite end. The tumbler of a key-operated cylinder 36 can also act, by means of an interposed lever 35, on the pawl 26.
Assuming that the device is to be installed so that the ring 3 is on the inner side of the door, the inner ring is connected to the lever 14 by means of the screw 22. In this manner the outer ring 4 is free. Therefore, by actuating in a clockwise direction the inner handle that engages the seat 9, the latch and the bolt will retract simultaneously. However, any rotation of the outer handle has no effect, since there is no rotational connection between the lever 14 and the ring 4. In this situation, in order to open the door from the outside, by means of the cylinder 36, the pawl 26 is moved adjacent to the rings 3, 4, causing the the tooth 31 to engage the teeth 6, 8, so that the rotation of the outer ring 4 can be transmitted to the levers 14, rotates said lever and actuates the latch so that it opens.
As can be seen, the invention perfectly achieves the intended aim and object.
Particularly, by shifting the screw 22 from one hole 11 to the other one 12 it is possible to modify the lock in order to make it usable in right-opening or left-opening doors.
Numerous modifications and variations, all within the purview of the invention as claimed, are possible in the practical embodiment of the invention. Particularly, the lever 14 can be formed monolithically.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.