DE1060961B - Contact device operated by a key to prevent unauthorized use of a switch in electrical systems - Google Patents

Description

The invention relates to a key operated prevention contact device unauthorized use of a switch in electrical systems with a plurality of differently arranged and shaped reeds that are actuated by a key that is one of the reed assemblies has a corresponding number and arrangement of teeth.

The invention aims at a simple and cheap design of such contact devices, which in spite of its simplicity prevents unauthorized use of the switch with certainty.

Devices have already become known which use a device provided for electrical systems Prevent the switch mechanically or electrically. For example, with telephone stations, establish their connection by means of a pulse transmitter, known, the pulse transmitter by means of a Lock the lock. This lock is attached to the finger washer in the known devices, by rotating the impulse transmitter is put into operation. A disadvantage of such locking devices however, it is that it is readily possible without using the finger washer, for example by pressing the hook switch several times to send out dialing impulses. With others Locking devices, the circuit is interrupted by a contact point whose closure only is possible using a certain key. But in this case to complete the circuit Only one contact point is required, there is no great difficulty in finding a suitable duplicate key to produce, if not a particularly complicated and therefore expensive special lock finds.

Furthermore, contact devices are known which consist of spring sets connected in series consist of springs of different lengths, which are supported by a correspondingly shaped key bit movable isolating intermediate links are actuated. This contact device is through the intermediate links and the guides required for this are complicated and take up a correspondingly large amount of space. In another known embodiment, instead of spring sets of different lengths Correspondingly wired contacts arranged in the lock, between which on a key made of insulating material arranged and also interconnected in a certain way mating contacts a circuit for the system switch or an alarm circuit. Here is an actuation with wrong key excluded with considerable certainty or solves such an attempted operation off an alarm, but the key itself is

Key operated

Contact device for prevention

unauthorized use of a switch

in electrical systems

Applicant:
Siemens Sd Halske Aktiengesellschaft,

Berlin and Munich,
Munich 2, Witteisbacherplatz 2

Dipl.-Ing. Wilhelm Eissfeldt, Munich,
has been named as the inventor.

catchy and complicated and must. if necessary be connected to a special switching device via - a cord. ■ -.-

According to the invention, these disadvantages are eliminated by the fact that the contact tongues of the electrically insulating material existing teeth of the key are deflected directly. So that will achieved that no special contacts on the key or switching devices to be connected to the key become necessary and that the key be small and simple. By eliminating the intermediate links the space requirement of the lock is also small, and the lock consists of only a few individual parts.

In order to make the circuit for the system switch to be secured as independent as possible of interference from the lock contacts, you can enjoy. According to the invention, the contact tongues are electrically connected / connected in parallel and are located in a closed circuit bridging the switch. By using a closed circuit, it is possible to provide several contact points connected in parallel. This lock is only lifted if ^ MM. Contact tongues can be operated by the appropriate key. However, because of the large number of possible combinations of its teeth acting on several contact tongues, such a device is not easy to reproduce. The device according to the invention thus ensures a high level of security against unauthorized use.

.. ..... ν «.. ..- 909 560/333

The simplification of the lock structure can be achieved according to the invention in that each Contact tongues lying in a row protrude from a common contact plate. The operations in the manufacture and assembly of these contact tongues are thus reduced.

The direct actuation of the contact tongues by the key cams can be done according to the invention be used to create variations in a simple manner with otherwise the same lock structure, in which the spatial arrangement of the contact tongues can be varied by optionally shortening individual tongues.

An increase in security against actuation with a wrong key is achieved according to the invention Use of the shortened contact tongues achieved in that the shortened tongues as a stop for redundant teeth of the key are used.

According to the invention, further possible variations can be obtained in a simple manner by that the key protrudes laterally from its shaft, arranged in two rows of teeth owns. Depending on the interconnection of the contact tongues in the lock, the lock can work with Teeth of one or both rows are made suitable.

The production of such a key according to the invention is significantly simplified in that the Key is made in one piece from insulating material. The different keys can e.g. B. by a controllable injection mold can be produced in a wide variety of variants.

In the drawings, an embodiment of the device according to the invention is shown. It shows

1 shows a cross section through the contact device with the key inserted,

Fig. 2 is a side view of the device,

Fig. 3 is a view in the direction of arrow B in Fig. 2 and

FIG. 4 is a view in the direction of arrow A in FIG. 1.

On a lock body 1 made of plastic, two contact plates 2 and 3 are each fastened with the tabs 2a and 3a, respectively. Each contact sheet has a solder lug 2 b or 3 b and five contact tongues, a number of which are long, 2 c or 3 c, or short, 2 d or 3 d, respectively. The key 4 has teeth arranged laterally in two rows on its elongated shaft, it being possible for the number and the position of the teeth to be different in order to distinguish the individual keys from one another. When assembling the contact device, those tongues of the five contact tongues of the individual contact sheets that do not work together with a tooth of the key are shortened by means of pliers.

The operation of the contact device is the following: In the locked state, connect the long tongues 2 c and 3 c the two contact plates and thus close the closed circuit, which bridges in a known manner to the blocking switch. By retracting and turning the key 4, the long tongues 2c and 3c are lifted from one another by the teeth 4 & of the key, thus opening the bridging closed circuit. A nose 4 α of the key 4 runs in a groove Ια in the lock body 1 and thus ensures the correct insertion of the key and prevents it from turning prematurely. If a wrong key is inserted, which differs from the matching key, for example by a missing tooth, it cannot open the closed circuit because of the missing tooth

ίο a pair of spring tongues 2 c, 3 c not lifted from one another is, the closed circuit remains closed. Does the inserted key differ? from the matching tooth through a surplus tooth, this hits a shortened tongue and prevents it turning the key 4. In this case too, the closed circuit remains closed.

Claims (7)

Patent claims: 1. Contact device to be operated by key to prevent unauthorized use of a switch in electrical systems with a plurality of differently arranged and shaped contact tongues which are operated by a key which has a number and arrangement of teeth corresponding to the contact tongue arrangement, characterized in that the contact tongues (2 Cj 3 c) are directly deflected by the electrically insulating material teeth (4 &) of the key (4). 2. Contact device according to claim 1, characterized in that the contact tongues (2 c, 3 c) are connected electrically in parallel and are in a closed circuit bridging the switch. 3. Contact device according to claim 1, characterized in that the contact tongues (2 c, 2d or 3 c, 3d) lying in a row protrude from a common contact plate (2 or 3). 4. Contact device according to claim 1, characterized in that the spatial arrangement of the contact tongues (2 c, 3 c) can be varied by optionally shortening individual tongues (2o *, 3d) . 5. Contact device according to claim 4, characterized in that the shortened tongues (2d, 3d) serve as a stop for excess teeth of the key. 6. Contact device according to claim 1, characterized in that the key (4) laterally protruding from its elongated shaft, arranged in two rows of teeth (4 b) . 7. Contact device according to claim 1, characterized in that the key (4) in one piece is made of insulating material. Considered publications:
German Patent Nos. 369 782, 623 829;
"Handbook for drivers", Verlag S. Mittler and Sohn, Berlin 1939 (Fig. 130). 1 sheet of drawings © 909 560/333 6.59