DE658805C - Arrangement to increase the contact pressure of contact arms of automatic switches - Google Patents

Description

The invention relates to an arrangement for increasing the contact pressure of contact arms automatic switch, in particular of voters for telephone systems, in which an increased contact pressure as required, preferably after setting the movable one Contacts to the desired fixed contact, generated by magnetic pulling forces will.

The contact pressure with which a resilient, movable switch contact rests on the fixed mating contact, is essentially dependent on the degree of its preload, the greater the spring pressure, with which the arm rests, make the contact better. While on the one hand So the aim is to make the contact pressure as large as possible, but occurs on the other hand considerable friction and wear of such contacts when sweeping over the fixed contacts. It has therefore already been proposed for voters of telephone systems, the contact arms through which the Connections made to the fixed contacts connected to the speech wires be in constant contact with the associated to maintain steady contacts and only through when the desired contact is achieved Bringing a magnet or the like with the fixed contacts in contact.

Another well-known proposal for electrical switches is to control the movement to influence the adjusted contact part by a magnet so that the contact part always pulled abruptly shortly before the contact with the mating contact will.

In all known proposals of this type, the switching arms are only lifted brought its wearer into contact with the bank contacts; therefore there can only ever be one one-sided contact pressure on the bank contacts can be achieved, so that these suggestions for switches that are provided with double contact arms to achieve reliable contact are completely unsuitable. The contact pressure exerted on one side can also the forces acting in the direction of the axis when the arms are pressed against bruises cause. These disadvantages are avoided according to the invention by reducing the contact pressure between the movable and fixed contacts as required, preferably after setting the moving contacts on the desired contact, generated by magnetic tensile forces in that the magnetic lines of force of these tensile forces over the moving contacts themselves or run over magnetic parts that are in direct contact with them (counter surface) and the one on the permanent contacts of

*) The patent seeker stated as the inventor:

Artur Flad in Berlin.

Claims (3)

'■ · ■ Si! Increase the pressure exerted on two opposite sides by creating magnetic poles of different polarity. The invention is described in more detail using an exemplary embodiment illustrated in the drawing. ** \ It represents a switch axis therein. 2 are the two springs of a contact arm. 3 is a fixed contact and 5 is the magnetizing coil. When the coil is switched on, the flux of lines of force generated thereby runs from the coil 5 via the iron body 6, which carries the coil and is insulated from the axis 1, to the two. Springs of the contact - (5 arm 2, at the free ends of which magnetic poles of different polarity are thereby formed, under the influence of which the springs are pressed firmly against the bank contact 3, which consists, for example, of a brass lamella, so that the Springs generated pressure is amplified by a multiple according to the dimensioning of the coil and the applied current strength. The magnetizing coils can of course also be arranged at another point of the switch, and a magnetizing coil can be assigned to several contact arms together with a corresponding design of the switch takes place, for example, on switches for automatic establishment of telephone connections by a contact arm not used for speech purposes, preferably by the test arm, when the switch is shut down after the setting movement Means are effected. If non-magnetic material is used for the contact arms, e.g. a material with increased electrical conductivity, such as phosphor bronze, is used for the magnetizing current, isolated from the springs, the contact arms, arranged parts made of mechanical material.? ·. '■>? Patent claims: 1. Arrangement to increase the contact pressure of contact arms more automatically Switches whose increased contact pressure as required, preferably after setting the moving contacts to the desired fixed contact, through magnetic Tensile forces are generated, especially by voters in telephone systems, characterized in that the magnetic lines of force over these tensile forces the moving contacts themselves or through direct contact with them Standing magnetic parts (counter surface) run and onto the fixed contacts pressure exerted from two opposite sides by forming magnetic Reinforce poles of different polarity. 2. Arrangement according to claim 1, characterized in that the additional Magnetic tensile forces are generated by magnetizing coils (s) which are individually assigned to the movable contacts (2) and preferably mounted on the axis (1) of the movable contacts are to a flow of force over contact arms (2) and fixed contact (3) to create. 3. Arrangement according to claim 2, characterized in that the switching of the magnetizing coils (5) by a non-speaking one Contact (test arm of a self-connecting selector) takes place. 1 sheet of drawings