GB2027996A

GB2027996A - Electro-magnetic relay

Info

Publication number: GB2027996A
Application number: GB7926258A
Authority: GB
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1978-07-28
Filing date: 1979-07-27
Publication date: 1980-02-27
Also published as: PL217381A1; FR2433826A1; GB2027996B; PL135267B1; IT7924712A0; FR2433826B1; IT1123483B; DE2833153A1; DE2833153C2

Abstract

The metal parts of a relay, such as the magnet yoke (11), terminals 22a of the switching contacts and coil connection members (24, 25) are secured to an insulating base plate (10) of the relay by means of fastening tabs (22b, 25b, 27, 28) whose narrow sides have ribs (29) (33) which project laterally across corresponding recesses (31) (34) incorporated in the base plate (10) for the purpose of receiving the tabs. The narrow sides of the tabs are sunk into the recesses and ribs 33 may be fused into slot side walls by ultrasonic treatment. <IMAGE>

Description

SPECIFICATION Electro-magnetic relay The invention relates to electromagnetic relays.

In a known relay, as described in French Patent Specification No. 2341 935, flat plug pins are inserted into corresponding slots in an insulating base plate and are clamped to the underside of the base plate by lateral incisions in the slots. This has the disadvantage that the relatively small clamping location becomes loose when flat plug sockets are slipped on to or removed from the plug pins. Since the regions of the flat plug tongues located above the base plate are frequently provided with switching contacts, a relay of this kind might fail completely or its function might be greatly impaired. Furthermore, when assembling a relay of this kind, the positions of the relay contacts have to be manually adjusted by an additional working operation after the connections have been clamped in the base plate,.

Furthermore, to avoid too weak a clamping location on the flat plug tongues, it is known to provide the flat plug tongues with angled portions at which the flat plug tongues are secured to the base plate by means of additional rivets. However, this solution also requires an additional working operation for the purpose of adjusting the contacts. Furthermore, it is expensive with respect to material and labour, and the riveted joint is subject to the risk of corrosion.

Furthermore, the spacing and leakage paths to voltage-carrying parts are reduced by additional metal rivets.

An object of the invention is to secure the metal parts of the relay to the base plate so as to be protected against corrosion as far as possible, and in a reliable and simple manner so as to be able to assemble the relay largely mechanically.

An electromagnetic relay in accordance with the invention comprises an insulating base plate which carries electrical connection members, a magnet yoke which is secured on the base plate, an iron core attached to the yoke, a winding on the core, and an armature having a switching contact which cooperates with at least one counter-contact secured to the base plate, at least some of these parts being fixed in corresponding recesses in the base plate by means of tabs or rectangular cross section, the narrow sides of the tabs being provided with contours which are sunk in a positive manner into the side walls of the recesses in the base plate.

This construction has the advantages that metal parts can be inserted and secured in the base plate in a single working operation, that the fastening can be subjected to high stresses, and that, with the excep tion of the connection contacts, all the metal parts are arranged on that side of the base plate which is protected against corrosion and spray water.

It is particularly advantageous for the contours on the narrow side of the fastening tabs to comprise ribs and depressions, each rib having an associated depression which is disposed in front of the rib in the direction in which the tab is sunk in.

The invention is further described, by way of example, with reference to the drawings, in which: Figure 1 is an elevation of a relay in accordance with the invention, with its housing cap of insulating material removed, and Figure 2 is a sectional view of the same relay with the housing cap of insulating material in place.

The small relay illustrated in Figures 1 and 2 for, for example, switching from the high beam to the dipped beam of a motor vehicle, has a base plate 10 which is injection-moulded from insulating material and to which is secured the end face of a magnet yoke 11 bent to an L-shaped configuration. The magnet yoke 11 carries a relay winding 12 which is wound onto a coil former 13. The coil former 12 is slipped onto an iron core 14, one end 14a of which iron core is riveted to the magnet yoke 11. A hinged armature 15 is arranged at the other end of the iron core 13 and is pivotally mounted in a recess 16 in the magnet yoke 11. A contact blade 17 is riveted to the hinged armature 15. Its angled end is secured to the magnet yoke by a welded joint 18 (Figure 2) to form a bias spring and its front end carries a switching contact 19.The switching contact 19 is disposed between two counter-contacts 20 and 21 each of which is fixed at the end of a metal strip 22 and 23 respectively in the base plate 10. The metal strips 22 and 23 are bent in a step-shaped manner and the bottom end of each metal strip is in the form of a flat plug tongue. The flat plug tongues extend through corresponding slots in the base plate 10, only the front flat plug tongue 22a being shown in Figure 2.

Two further flat plug tongues 24 and 25 are secured in the base plate 10 and serve for connection of the relay winding 12, and the top end 26 of a flat plug tongue (not visible) is welded to the magnet yoke 11.

Figure 1 shows the relay in its "on" position in which the switching contact abuts against the countercontact 21 acting as a normally-open contact. When the relay is in its "off" state, the hinged armature 15 is raised from the iron core 14 by means of the contact spring 17 and is pressed against the countercontact 20 acting as a normally-closed contact.

As is shown in Figure 2, for the purpose of securing the magnet yoke 11 to the base plate 10 of the relay, the long limb of the magnet yoke is provided with a fastening tab 27 and the short limb of the magnet yoke is provided with two fastening tabs 28 which are located adjacent to one another and only one of which is shown. The fastening tabs 27 and 28 have a rectangular cross section and their narrow sides are provided with contours in the form of ribs 29 and depressions 30 located therebetween.

The ribs 29 are sunk in a positive manner into the side walls of recesses in the base plate 10. The recesses are formed by three rectangular pockets 31 into each of which are sunk a respective one of the three fastening tabs 27 and 28 which are punched free on the magnet yoke 11. The contours punched free at the narrow sides of the fastening tabs 27 and 28 comprise a plurality of ribs 29 and depressions 30 arranged one above the other and their configuration is such that the width of the fastening tabs 27 and 28 decreases in a Christmas-tree-like manner in the sinking-in direction. The ribs 29 are in the form of barbs which dig into the side walls of the pockets 31 in a positive and frictional manner when the fastening tabs 27 and 28 are pressed into the pockets 31.

The material of the base plate 10 which is thereby displaced or scraped off is pressed into the recesses 30.

Each of the flat plug tongues 22a, 24 and 25 also has a tab portion 22b, 25b which is sunk into a respective slot 32 in the base plate 10 by means of lateral contours. In this instance, the contours on the narrow sides of the portion 22b, 25b each comprise a rib 33 having a depression 34 disposed in front of the rib 33 in the sinking-in direction. The portions 22b, 25b of the flat plug tongues 22a, 24 and 25 are wider in the region of the rib 33 than the slot 32 in the base plate. The ribs 33 are fused into the side walls of the slots 33 by ultrasonic treatment; the material 35 (indicated by broken lines in Figure 2) of the base plate 10 which is gripped by the ribs is displaced into the space formed by the depression 34.Furthermore, the portion 22b of the flat plug tongue 22a which is sunk into the base plate 10 is provided with impressed corrugations 39. Each corrugation 39 opens into a respective one of the depressions 34 and, if required, can receive the material of the base plate 10 displaced by the ribs 33.

By virtue of this solution, the various parts of the relay can be sunk mechanically into the pockets 31 or into the slots 32 in the base plate during assembly of the relay. Furthermore, the parts of the relay on the base plate 10 are protected against spray water by the sinking-in of the tab portions flat plug tongues 22a, 24 and 25 by ultrasonic treatment. Furthermore, they are encased externally by a housing cap 26 which is made from insulating material and whose edge has a continuous spigot 37 which is fused in a water tight manner in a continuous depression 38 at the edge of the base plate 10 by ultrasonic treatment.

Claims

1. An electro-magnetic relay comprising an insulating base plate which carries electrical connection members, a magnet yoke which is secured on the base plate, an iron core attached to the yoke, a winding on the core, and an armature having a switching contact which cooperates with at least one counter-contact secured to the base plate, at least some of these parts being fixed in corresponding recesses in the base plate by means of tabs of rectangular cross section, the narrow sides of the tabs being provided with contours which are sunk in a positive manner into the side walls of the recesses in the base plate.

2. A relay as claimed in claim 1, in which the contours on the narrow sides of the tabs comprise at least one rib and a depression which is disposed in front of the rib in the direction in which the latter is sunk in and into which is displaced the material of the base plate which is gripped by the rib during the sinking-in.

3. A relay as claimed in claim 2, in which the contours comprise a plurality of ribs and depressions arranged one above the other, the width of the tabs decreasing in a Christmas-tree-like manner in the sinking-in direction.

4. A relay as claimed in any of claims 1 to 3, in which contours are located on fastening tabs which are punched free on the magnet yoke and each of which is sunk into a respective rectangular pocket in the base plate.

5. A relay as claimed in any one claims 1 to 4, in which contours are punched out of a tab portion of a flat plug tongue which is sunk into a respective slot in the base plate.

6. A relay as claimed in any of claims 1 to 5, in which the contours on the tabs are in the form of barbs.

7. A relay as claimed in any preceding claim, in which the contours on the tabs are fused into the side walls of the recesses in the base plate by an ultrasonic process.

8. A relay as claimed in claims 2 and 7, in which corrugations are impressed into the tabs and each corrugation opens into the depression located in front of a respective rib.

9. A relay as claimed in any preceding claim, in which the said parts secured to the base plate are enclosed by an insulating housing cap whose edge has a continuous spigot which is fused in a watertight manner in a continuous depression at the edge of the base plate by an ultrasonic process.

10. An electromagnet relay constructed substantially as herein described with reference to and as illustrated in the drawings.