FI56760C - ELECTROMAGNETIC SOLUTIONS - Google Patents

Description

I-IT · .— 1 rl m, ADVERTISEMENT CE, c- / ac \ Patent meddelat • # / ΟΛ · (45) 'v ^ (51) Kv.lk.' / Lnt.CI. * E 04 B 11 / 00 S1ÖK 1/064 FINLAND — FINLAND (21) p »Mnttlhsikemu * —p * t« »tm * elcnin * 2671/71 (22) Hikeml * cloud— Aniöknlngtdag 2U.09.71 (23) Start date - Giltlghetsdag 2U.09.71 (41) ) Made public - Bllvlt offwitlig 2g 03 72

National Board of Patents and Registration (44) Date of issue and date of publication—

Patent- och registerstyrelsen 'Ansökan utlagd och utl.skrHten publicerad 30.11.79 (32) (33) (31) Requested privilege —Begärd priority 25.09.70

Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) P 20U730U.5 (71) Siemens Aktiengesellschaft, Berlin / Miinchen, DE; Wittelsbacherplatz 2, 8OOO Munchen 2, Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (72) Erich Muller, Munich, Horst Anton, Pöcking, Heinz Lonmicky, Baier-Brunn / Buchenhain, Federal Republic of Germany-Förbundsrepublik Ab (5U) Electromagnetic sound generator - Elektromagnetisk ljudalstrare

The invention relates to an electromagnetic sound generator, in particular to a telephone bell with a polarized operating system and a flat anchor movably arranged relative to the magnetic poles relative to the magnetic poles, the largest cross-sectional dimension of which extends perpendicular to the direction of movement of the anchor.

In such sound generators, the anchor rests in its rest position against the magnetic pole at one end in its rest position, and in particular at its other end, which extends freely from the bearing point close to the second magnetic pole.

Since such a bell, which in this case acts as a microphone, in the telephone sets is connected to the central cord, despite the handset being lowered into place, the currents generated by it can be taken from an arbitrary point on the central cord and made audible.

2 56760 Thus, unobtrusive listening to calls made close to the telephone is possible. This possibility must, of course, be eliminated and it then feels natural to start with the starting point of the microphone streams, the bell.

There are a whole host of suggestions for reducing the microphone power of polarized bells. Thus, it has been proposed to attenuate the developed magnetic alternating current with short-circuit rings fitted to the magnetic circuit so that the currents induced in the winding could no longer be listened to.

According to other proposals, the generation of a magnetic exchange flux is completely prevented by fixing the anchor to its rest position with springs or by conducting the magnetic flux asymmetrically with a corresponding design of the anchor cross-section.

The common feature of all these proposals is that, since spring forces must be overcome or short-circuit currents must be developed, they also adversely affect the detection sensitivity of the bell system.

The object of the invention is to prevent the generation of a magnetic alternating current which generates a microphone voltage, without attaching the free end of the anchor in particular to its rest position.

This object is thus achieved and it is characteristic of the invention that the anchor is provided with a stiffening element attached to the anchor or with a stiffening profile formed on the anchor in order to increase the bending stiffness of the anchor in its direction of movement. In this case, it is assumed that the anchor, as mentioned at the beginning, in its rest position rests on one end against the pole piece of the second magnetic yoke, and is held by the magnet. Due to its stiffening, the vibration sensitivity of the free anchor end is effectively prevented, without adversely affecting the start-up sensitivity of the operating system.

Since the stiffening immediately depends on the thickness of the material used, the anchor could be made of a thick material, i.e. increase its diameter in the direction of movement or bending compared to conventional 3,56760 structures. On the other hand will be described äänenkehit-converter-like mass of the armature be as small as possible, because in a certain extent depends on the system havahtumisherkkyys.

According to the invention, it is therefore proposed that the stiffening element is formed by at least one rib extending in the longitudinal direction of the anchor, the largest cross-sectional dimension of which is in the direction of movement of the anchor.

Such a stiffening element does not have to significantly increase the mass of the anchor, as it does not have to be a magnetically conductive material, or even a metal. Sufficient strength is the main thing in the choice of material, the mass being as small as possible. The desired combinations of properties can be found among the active ingredients which are therefore particularly suitable for this purpose.

The stiffening element may be glued, riveted, screwed or otherwise suitably attached to the anchor. All that matters is that it extends over the major part of the length of the anchor and even possibly comprises its pole faces, since even a short unstiffened end of the anchor resting on the magnetic yoke promotes the oscillation tendency of the free anchor end.

When connecting both parts, the points of the connection must also be distributed over the entire length of the anchor, so that the effect of the anchor stiffening support benefits the anchor along its entire length.

The stiffening element can also be formed of at least one rib with a maximum cross-sectional dimension in the direction of movement of the anchor.

In this case, it is also conceivable to form the anchor and the support in one piece. The cross section of the anchor tuned to the magnetic force can then be dimensioned to correspond to the structure of the unstiffened anchor.

Instead of a rib, the anchor may also be provided with at least one stiffening fold extending mainly over its entire length. This design makes it possible to manufacture the anchor in a simple manner by stamping and deep drawing and provides the same effect as previously mentioned.

4,56760

Just as good a stiffening effect is obtained by equipping the anchor with at least one of its longitudinal sides with an approximately rectangular edge, which should essentially extend over its entire length. Such an anchor can be simply manufactured as a punch-bending piece.

However, the anchor can be formed of a profile material with an L-shaped or U-shaped cross-section or of a rectangular tube profile, which further simplifies its manufacture.

In the area between the pole faces of the anchor, near its bearing points, the anchors in the U- or rectangular tube profile may contain a material that is not relevant to the rigidity of the anchor and may be removed at will to reduce mass or for structural reasons. This results not only in a reduction in the mass of the anchor but also in the possibility of adapting the anchor to the shape of the winding and shaping it so that it can be fitted tightly to the winding. Thus, the losses of magnetic scattering can be kept small.

In addition, with side walls edged in the anchor, part of the side walls in their central area, e.g. by pulling out in connection with the bending method, can remain in the level of the anchor. Such a part subsequently extends in the anchor plane outside the side wall and can advantageously be used to mechanically guide the anchor in the system.

The invention will now be described in more detail with reference to exemplary embodiments shown in the drawing. It presents:

Figure 1 is a side view, a simplified view, of a polarized operating system of an electromagnetic sound generator.

Figures 2-6 are stiffened cross-sectional shapes of an anchor according to the invention.

Figure 7 is a perspective view of an anchor according to the invention.

Figure 8 shows a second embodiment of an anchor according to the invention.

The operating system shown in Fig. 1 has a permanent magnet 1, the power flow of which is concentrated in two symmetrical current circuits. Both vuopiirit are each derived from the magnet yoke 2 over the other half and thus exported from one soittokellokäämin 3 käämikeskiön through vaihtovirtapuoleisesti closed and the pole piece 4 and is easily movable, e.g. through the tips of the anchor 5 with bearings 6 of the second half. On the back side of the anchor, a stiffening element 7 is detected, which 56760 extends over the entire length of the anchor. The hammer arm 8 is rigidly connected to the anchor, which with its hammer 9 strikes the sounding sound pieces (not shown).

The electronic operation of such an operating system is not discussed further here. It should only be mentioned that the anchor at both end points of the movement in each case rests on one of its arms, possibly via a magnetically non-conductive spacer 10 against the other pole shoe. In the rest position of the system, it is in each of these positions, called the resting states of the anchor, that it is held by a magnetic force.

The other end of the anchor, which then extends unsupported over the second hub shoe at least from its bearing point, can also, if it is not made rigid in accordance with the present invention, also vibrate from the acoustic vibrations. This would result in an undesired change in the width of the air gap 11 between the anchor and the pole piece and thus a change in the magnetic flux in this circuit.

Different possibilities are conceivable for the stiffened structure of the anchor. Figure 2 shows the cross-section of the anchor 6, with its reinforcing stiffening elements 12. This element can be a metal or a sufficiently rigid non-metallic material. In Fig. 3, the stiffening element 7 is shaped as a rib, the larger diameter b of which extends in the direction of movement 13 of the anchor. Such a rib can either be fixed to the anchor according to Fig. 2 or shaped in one piece therewith. Of course, it is possible to fit several such parallel ribs on the back of the anchor. According to Figure 4, the anchor 6 is provided with a stiffening fold 14, while according to Figure 5 it is provided with one of its longitudinal sides with a rectangular edge 15. Anchors with rectangular edge edges 15 along their longitudinal sides according to Figures 5 and 6 can also be made of a corresponding profile material. A special structure of the anchor, with edges 15 on each longitudinal side, although not of profile material, is shown in Figure 7. Part 16, in the central region of each side wall of the anchor, is not bent here along the other edge but left in the anchor plane 17. These parts protrude outside the anchor sides anchor

Claims (7)

6 56760 for mechanical control. The anchor 6 of the rectangular tube profile according to Fig. 8 has been machined free in its central part 17 so that it can thus be tightly mounted in the winding. The pole shoes 4 can in this case be made considerably shorter than in the structure according to Fig. 1. An electromagnetic sound generator, in particular a telephone bell, with a polarized operating system and a flat anchor (6) movably arranged relative to the magnetic poles (4) relative to the magnetic bearing point (5), having a maximum cross-sectional dimension extending perpendicular to the direction of anchor movement, the anchor (6) is provided with a stiffening element (7; 12) attached to the anchor or a stiffening profile (14j 15) formed in the anchor to increase the bending stiffness of the anchor in its direction of movement. Sound generator according to Claim 1, characterized in that the stiffening element is formed by at least one rib (7) extending in the longitudinal direction of the anchor, the largest cross-sectional dimension (b) of which is in the direction of movement (13) of the anchor. Sound generator according to Claim 1, characterized in that the stiffening profile is formed by at least one corrugation (14) extending in the longitudinal direction of the anchor. Sound generator according to claim 1, characterized in that the anchor (6) is provided along at least one of its longitudinal sides with an approximately rectangularly bent edge (15) which forms said stiffening profile. Sound generator according to Claim 4, characterized in that in the central region of the anchor (6) a part of the bent edge (15) of the anchor is left in the anchor plane (17). 1. Electromagnetic circuits, integrated circuits for telephones, with a polarizing drive system or a relative core-net polar (4) circuit and stationary circuit breaker (5)