GB2089420A - Mechanism for locking a keyhole shutter - Google Patents

Abstract

A keyhole 1' is obstructed by a sliding shutter plate 5 which may be raised or lowered, to obstruct or clear the key hole, by a knob 2, but which may be prevented from descending to its clear position by a combination lock 8, 10. <IMAGE>

Description

SPECIFICATION Mechanism for locking up a keyhole of a lock by a locking plate The invention relates to a mechanism for locking up a keyhole of a lock by a locking plate being slidable by turning a latch into a position on of unlocked keyhole after radial cuts made in pivotedly mounted catch discs of a locking device with number or signal combination are brought into covering each other and an extension of the locking plate is in mashing engagement with the cuts of the catch discs.

In a previously known solution disclosed in DE-PS No. 2 233 481, the locking device for the keyhole is arranged in a hollow made in the door.

However, the door gets at this place considerably weakened. Beside this, the plate locking up the keyhole is moved by the turning latch of the lock on the door. Thus, this locking device can only be used with locks having a turning latch.

Furthermore, the latch can not be operated in the locking position of the locking plate. It is inconvenient, too, that a lot of catch discs placed parallel with each other must be operated directly from outside. In addition, the locking combination is adjusted and fixed at the fabrication and it can practically not be changed outside the factory.

The first and main object of our invention is to eliminate the above mentioned inconveniences and greatly to improve the locking mechanism for keyholes. Further object of the invention is that it has to be suitable for all existing locks.

Furthermore, the number for signal combination has to be adjustable from outside the door by hand, but opening the number or signal combination lock by feeling or scanning must be prevented.

The improvement, i.e. the invention itself is in that the locking plate is slidably mounted into a preferably vertical groove guide made in the keyplate and is kinematically connected to a guiding piece of the turning latch with the help of a guide rod, and one of the catch discs is provided with a hub emerging outwardly from the keyplate, a disc having numbers or signals on its outer surFace and being associated to one of the catch discs is mounted in the hub, a second catch disc is fixed inside the keyplate on one end of a shaft which is pivotedly mounted into the hub of the first catch disc, on the other end of this shaft which is emerging from the hub, a second disc having numbers or signals is fixed, this second disc is associated with the second catch disc.

For preventing opening the keyhole lock by feeling or scanning, a toothing formed from preferably circular grooves can be provided according to the invention on the circumference of the catch discs, wherein the grooves have a stable length of cord and an alternatedly varying depth.

For easy adjusting the number or signal combination in another embodiment of this invention the catch discs can be kinematically coupled to the disc having numbers or signals associated with them by way of splined serration on toothing.

Other objects and details of the invention will be described hereinafter in connection with exemplified embodiments and with reference to the attached drawings.

In the drawings, Fig. 1 shows a side view of the mechanism in this invention, in locked position.

Fig. 1 a and 1 b show a cross section and the inside of the mechanism in Fig. 1.

Fig. 2 and 2b are views similar to that in Fig. 1 and 1 b, respectively, but in the unlocked position.

Fig. 3 is a view, partly cross section of a detail of the mechanism in Fig. 1, magnified.

Fig. 4 shows another detail, also magnified.

Fig. 4 and 5 show two other details, also magnified.

Fig. 6, 6a and 6b show some details of the catch discs and Fig. 7, 7a and 7b that of the discs having numbers or signals.

Fig. 8 and 9 show the embodiment of the invention with simple cylinder locks.

Fig. 10 and 10a, 11 and gila, 12 and 12a, respectively, are the kinematical schemes of various embodiments of the mechanism in this invention.

,In Fig. 1 and 1 a, a keyplate or escutcheon 1 made from cast aluminium is shown, wherein a vertical guide groove is provided. In this groove, a hardened locking plate 5 made from spring steel band is slidably arranged which covers and, thus, locks up a keyhole 1' in the keyplate in its locking position.

The locking plate 5 is connected to a coupling piece 2" provided on a hub 2' of a turning latch 2 in the inside of keyplate 1.

Hub 2' fulfils a double function. On the one hand, it connects the outer latch half to the lock by way of the latch rod, and on the other, locking plate 5 can be moved straight-lined upwards and downwards in the guide groove of keyplate 1 by a guide rod 3 as part of a crank gear. Therefor, hub 2' of turning latch 2 is fixed with a fishplate 4 and a circlip or snapspring 1 7.

Furthermore, fishplate 4 serves as a cover of a groove provided in keyplate 1. In this groove, a pressure ring 14 and a steel bullett 1 5 are arranged. By spring 14 and steel bullett 15, various positions of hub 2' of turning latch 2 are determined.

Locking plate 5 is fixed in its locking position shown in Fig. 1 b by catch discs 11 and 12. The lock can only be operated if catch discs 11 and 12 will be turned with the help of number discs 8 and 10 so as to make possible for a locking extension 7 to penetrate into the radial cuts made in catch discs 11 and 12. This is the situation, when the radial cuts are one under the other, i.e. they are brought into covering each other (Fig. 2a). Locking extension 7 is arranged on locking plate 5 and can be moved with it.

The constructions members of the mechanism arranged in the inside of keyplate 1 are backwardly covered by a cover 1 3. Furthermore, boreholes for mounting the keyplate 1 are provided on the backside of the housing of the mechanism, thus, keyplate 1 can not be removed from outside the door.

In Fig. 3, the construction parts of a lock with number or signal combination as used in this invention are shown in detail and partly in section.

This construction parts are very simple in fabrication and mounting and, at the same time, they provide a very simple possibility for quick change of the combination.

Adjusting the combination is possible by way of splined serrations formed on the constructional parts coupled to each other. These serrations are shown in detail, greatly magnified on Fig. 6, 6a, 6b and 7, 7a, 7b, respectively.

For adjusting the combination of numbers or signals, cover 13 of keyplate 1 must be removed and a circlip or snap ring 18 (Fig. 3) taken out from its groove in shaft butt 9. Thereafter, rear catch disc 12 can be pulled down from shaft butt 9.

Outer number disc 8 can now be removed together with shaft butt 9 from the borehole provided in hub 11' of the front catch disc 11.

After this, a circlip or snap ring 1 9 will be demounted and number disc 10 pulled down from hub 11'. Now it is possible to adjust an optional number or signal combination in the course of the mounting together.

The steps of mounting together the mechanism are as follow: To hub 11' of catch disc 11 remained in its place, number disc 10 will be pulled up and fixed with circlip 1 9.

Shaft butt 9 fixed to outer number disc 8 (Fig.

7a) will be pulled through the borehole in hub 1 1'.

Thereafter, a plastic spacer 20 foilows on the emerging part of shaft butt 9. The catch disc 12 can now be pulled up in an optional position on shaft butt 9. Finally, circlip 18 will be fastened on shaft butt 9, and by this, adjusting the number combination is finished.

Thereafter, only cover 13 has to be fixed and the complete locking mechanism to be mounted into the door.

The splined serrations on hub 11' of catch disc 11 and rear number disc 10 on one hand (Fig. 6) and on catch disc 12 and shaft butt 9 of outer number disc 8 (Fig. 7, 7a, 7b) on the other hand provide numerous possibilities for variation.

In the specification and in the figures described hereinabove, catch discs 11 and 12 were shown as simple discs with an outer profile made by plane or simple turning for the sake of the simplification. In this case, however, it would be possible to determine the opening position by feeling or scanning on a relatively simple way and, thus, the security of the locking mechanism would be greatly reduced. To prevent this occurrence, the outer circumference or profile of catch discs 11 and 12 have a special toothing or serration.

In Fig. 4 the outer profile of catch discs 11 and 12 is shown, whereon the toothing or serration is formed as grooves having a semicircular shape between the teeth. Fig. 5 shows the form of locking extension 7 greatly magnified.

The length of chord of the grooves of circular serration provided on catch discs 11 and 12 corresponds to the width of radial cuts for engaging the locking extension 7. The depth of the grooves of the circular serration, however, varies regularly one after the other, more precisely so that every second groove has the same depth, e.g.

a depth of 0.5 mm and 1.0 mm, respectively.

These values are of course given as a mere example. In this way, on every circumference of catch discs 11 and 12, 40 to 45 grooves can be formed, thus, for opening the mechanism by feeling or scanning, about two thousand failed attempts must be conducted.

For closing the lock outside the door the key is to be rotated in the cylinder lock provided in the conventional locks. Thereupon, the key will be pulled out from the keyhole 1' and the turning latch 2 will be rotated to the left till impact. In this position, the knurled grips of turning latch 2 are vertical and locking plate 5 covers, thus, locks up the keyhole 1' (Fig. 1, la).

The number discs 8 and 10 will be now rotated optionally for showing a combination other than the opening one. In this way, not only the key opening the conventional cylinder lock but the knowledge of the number combination is necessary, too, for opening the door.

For opening, number disc 10 will be adjusted first for being the desired number or signal under the marking on keyplate 1. The desired signal or number of number disc 8 will be rotated, too, for being unilinear with another marking. This other marking is made on number disc 10 and is necessary since number disc 8 is quite far from the first marking, thus, the easy handling will be promoted. In this way, the previously predetermined combination of numbers or signals are reproduced with number discs 8 and 10 for opening the mechanism. The turning latch can be rotated now with the help of the knurled grips till impact whereupon the keyhole 1' gets free, the mechanism is unlocked the key can be pulled into the cylinder lock and the door will be opened (Fig.

2, 2a).

After opening the lock and pulling out the key but before entering through the door, turning latch 2 is to be rotated to the left till impact and, thus, the keyhole 1' will be covered again. Furthermore, the number discs must be rotated either for removing them from the opening position and preventing the reading out of the opening number combination. In this way, one has to know the number combination as well as to have the key of the cylinder lock for opening the door again.

Applying the mechanism according to this invention in locks of furniture or boxes, cases or containers, its function is similar to what have been disclosed above, with the difference, however, that the opening or closing occurs only from outside.

The various embodiments of this invention can be realized on many ways.

Fig. 8 and 9 show a mechanism according to the invention for a door. In this case -- entrance door, the keyplate 1 is preferably to be mounted only on the outside of the door, on the inside a conventional keyplate or escutcheon is arranged (Fig. 9).

In Fig. 10 and 1 Oa, an embodiment adaptable in security locks (without latch) is shown.

In Fig. 11 and 1 a, a modification of the mechanism according to the invention for locks in furniture and containers is illustrated. Therein, parts referred to by a, b and c correspond in their function to that of the first embodiment in Fig. 1 referred to by 2, 5, 11 and 12, thus, further explanation is not necessary.

The embodiment shown in Fig. 12 and 1 2a differs from the one in Fig. 1 and 2 in that the locking plate b will be moved and locked by a cam plate a having a guide curvature. The rotation of cam plate a occurs with the help of a cylinder lock insert, the mechanism will be locked up here by a key lock not with number combination lock.

Fig. 12 shows the locking plate b in closed position. This closed position of locking plate b is secured by a locking member coupled to the cam plate a by holding a stub of the lower locking extension dby a borehole provided in locking member f.

The solution in this scheme will be opened as follows. To cam plate a, a turning cylinder of a cylinder lock is connected. By opening, the cylinder is rotated with the key, thus, the cam plate a rotates around a bearing g as well. At the beginning of its rotation, till 1 5 to 20 degrees, locking plate b stays in its place without motion.

During this, locking extension d leaves locking member f. After this, by further turning the key, the guide curve of cam plate a forces a guide motion upwards of locking extension d, further of locking plate b and upper locking extension c against the force of a spring-e. After turning the key with 130 to 1 50 degrees the mechanism gets in open position: the keyhole of the conventional lock in the door is uncovered and is open for penetration of the key. Thereafter, opening the door occurs on the conventional way.

This system can be called as "double key system".

It is clearly apparent from what have been said hereinabove that the mechanism in this invention is very simple, it can be used in all conventional locks and, at the same time, the security of the conventional locks is highly enlarged.

Claims (4)

1. Mechanism for locking up a keyhole of a lock by a locking plate being slidable by a turning latch into a position of unlocked keyhole after radial cuts of pivotedly mounted catch discs of a locking device with number or signal combination being brought into covering each other and an extension of said locking plate being in mashing engagement with said cuts of the catch discs, characterized in that said locking plate being slidably mounted into a preferably vertical guide groove of the keyplate and kinematically connected to a coupling piece of the turning latch with the help of a guide rod, and one of said catch discs having a hub emerging outwardly from the keyplate, a disc with numbers or signals associated to one of said catch discs being mounted on said hub and a second catch disc (12) being fixed inside the keyplate on one end of a shaft pivotedly mounted into the hub of said first catch disc, and a second disc with numbers or signals associated to said second catch disc being fixed to the other end of the shaft emerging from the hub.

2. Mechanism as claimed in Claim 1, wherein the circumference of said catch discs having a toothing formed from preferably circular grooves with stable length of cord but with alternately varying depth.

3. Mechanism as claimed in Claim 2, wherein each of said catch discs being kinematically coupled to one of said discs with numbers or signal by way of splined serration.

4. A mechanism for locking up a keyhole substantially as herein described with reference to and as shown in the accompanying drawings.