GB1576493A - Electromagentic relays - Google Patents

Description

(54) IMPROVEMENTS RELATING TO ELECTROMAGNETIC RELAYS (71) We, THE PLESSEY COMPANY LIM SITED, a British Company of 2/60 Vicarage Lane, Ilford, Essex do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following state ment - This invention relates to electromågnetic relays and relates more especially but n6t exclusively to electromagnetic relays of the low profile type.

In known constructions of electromagnetic relays the relay armature is commonly pivoted on a knife edge of a yoke member so that the normal position of the relay armature relative to a pole-piece of the relay core is fixed.

According to the present invention there is provided an electromagnetic relay comprising an energising coil with associated magnetic core and yoke structure, in which an apertured plate which extends through an aperture in an armature of the relay is slidably adjustable on the yoke structure to vary the position of the armature pivoting on a knife edge of the plate relative to a pole piece of the magnetic core structure.

By adjustment of the armature position the operating characteristics of the relay can be varied according to requirements and the usual residual stud which is normally provided on the armature to prevent retention of the armature after de-energisation of the relay winding may be dispensed with.

By way of example the present invention will now be described with reference to the drawings accompanying the Provisional Specification in which: Fig. 1 is a plan view of a low profile electromagnetic relay embodying an armature positioning adjuster according to the present invention; and Fig. 2 shows a further armature positioning adjuster according to the invention.

Referring to Fig. 1 of the drawings the relay illustrated comprises an energising winding 1 wound on to an insulating bobbin 2. The relay has a magnetic core 3 extending through the bobbin 2 and a generally Lshaped magnetic yoke member 4 is attached to one end of the core !. A generally Lshaped pivoted armature S co-opelråtes with pole-piece 6 of the cote 3. By m ans of screws 8 and 9 two c6nta-ct-spiing pilè-fip,s iO and 11 are -secured to the yoke structure 6f the relay these screws threading into threaded holes Sa and 9a in'the yoke member 4. The Contact spring pile--nps comprise fixed springs 12 and moving springs 13, the springs for the pile-up 10 being obscrued from view by a contacts-actuating structure 14 provided with shoulders, such as the shoulders 15, for actuating and/or supporting the moving contact springs. The contacts-actuating structure 14 also comprises a cylindrical part 17 which projects into a hole 1 7a in the yoke member 4 whilst an arcuate part 18 of the structure 14 normally rests against the armature 5 as shown.

The insulating contacts-actuating structure 14 is urged upwards in Fig. 1 by means of a biasing blade spring 25 which is secured at its ends by the screws 8 and 9 which clamp tongues 25a to a bridging plate 30 which is slotted to slidingly receive the bottom end of the structure 14.

The biasing spring force exerted on the structure 14 by the spring 25 may be adjusted by means of screw adjustment arrangement including screw 23 and block 20 slidably located in slot 19 of structure 14.

In operation of the relay described, the energisation of the winding 1 causes the armtaure 5 to be attracted towards the polepiece 6 and in so doing the armature urges the actuating structure 14 downwards against the action of the spring 25 in order to effect operation of the relay contacts.

In accordance with the present invention the yoke structure includes an apertured plate 4a which has elongated holes 8b and 9b where the clamping screws 8 and 9 pass through the plate and an elongated hole 17b through which the cylindrical part 17 of the actuating structure 14 passes. It will be seen that the armature 5 passes through a slot 5a in the plate 4a and pivots about the edge 5b of slot 5a. The elongation of the holes 8b and 9b and 1 7b enables the plate 4a to be slid longitudinally relative to the yoke member 4 when the screws 8 and 9 are slackened off so that the pivot - -for the- armature 5 can be varied according to requirements. It may be arranged for example that the armature 5 cannot make contact with the pole-piece 6 when the relay is energised. In this way the need for a residual stud on the armature is avoided.

Fig. 2 of the drawings shows a modified form of yoke plate. As regards this yoke plate the right hand end is turned up to provide an upstanding armature support section 32 of generally E-shape with the side limbs being bent out of the plane of the centre but as shown so as to make pressure engage ment- with the armature 5 which will be pivoted bun the edges 33 and 34. The armature 5 is formed with opening 35 to facilitate the insertion of the section 32 therethrough as well as screw 9 whilst slots 36 and 37 provide for the passage of the screw 8 and the cylindrical part 17 of the contacts actuating structure 14.

WHAT WE CLAIM IS: 1. - An electromagnetic relay comprising an energising coil with associated magnetic core and yoke structure, in which an apertured plate which extends through an aperture in an armature of the relay is slidably adjustable on the yoke structure to vary the position of the armature pivoting on a knife edge of said plate relative to a pole piece of the magnetic core structure.

2. An electromagnetic relay substantially as hereinbefore described with reference to the drawings accompanying the Provisional Specification.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (2)

**WARNING** start of CLMS field may overlap end of DESC **. longitudinally relative to the yoke member 4 when the screws 8 and 9 are slackened off so that the pivot - -for the- armature 5 can be varied according to requirements. It may be arranged for example that the armature 5 cannot make contact with the pole-piece 6 when the relay is energised. In this way the need for a residual stud on the armature is avoided. Fig. 2 of the drawings shows a modified form of yoke plate. As regards this yoke plate the right hand end is turned up to provide an upstanding armature support section 32 of generally E-shape with the side limbs being bent out of the plane of the centre but as shown so as to make pressure engage ment- with the armature 5 which will be pivoted bun the edges 33 and 34. The armature 5 is formed with opening 35 to facilitate the insertion of the section 32 therethrough as well as screw 9 whilst slots 36 and 37 provide for the passage of the screw 8 and the cylindrical part 17 of the contacts actuating structure 14. WHAT WE CLAIM IS:

1. - An electromagnetic relay comprising an energising coil with associated magnetic core and yoke structure, in which an apertured plate which extends through an aperture in an armature of the relay is slidably adjustable on the yoke structure to vary the position of the armature pivoting on a knife edge of said plate relative to a pole piece of the magnetic core structure.

2. An electromagnetic relay substantially as hereinbefore described with reference to the drawings accompanying the Provisional Specification.