US3839690A

US3839690A - Insulating means for an electromagnetic relay

Info

Publication number: US3839690A
Application number: US00413649A
Authority: US
Inventors: U Kobler; H Schroder
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1972-11-29
Filing date: 1973-11-07
Publication date: 1974-10-01
Anticipated expiration: 1991-10-01
Also published as: CH565447A5; BE807982A; IT1001958B; DE2258479A1; FR2208174B1; FR2208174A1; DE2258479B2; GB1441940A

Abstract

Insulating device for the coil of a relay and particularly a miniaturized relay, in the form of an insulating receptacle for the relay coil. The receptacle receives the coil and extends about the coil on three sides. The insulating receptacle may be molded or drawn from a plastic insulating material and besides insulating the coil from the contact springs of the relay, serves to insulate the coil and contacts from the legs of the yoke, which may be parallel to the coil.

Description

United States Patent 1 Kobler et al.

INSULATING MEANS FOR AN ELECTROMAGNETIC RELAY Inventors: Ulrich Kobler; Harry Schroder,

both of Munich, Germany Assignee: Siemens Aktiengesellschaft, Berlin &

Munich, Germany Filed: Nov. 7, 1973 Appl. No.: 413,649

Foreign Application Priority Data Nov. 29, 1972 Germany 2258479 US. Cl 335/278, 336/198 Int. Cl. H01f 7/00 Field of Search 335/278, 279, 282;

References Cited UNITED STATES PATENTS 12/1966 Brown 335/278 X Oct. 1, 1974 3,701,066 10/1972 Bosch et al. 335/279 X 3,750,073 7/1973 Okano 336/208 X 3,775,718 ll/1973 Kanawa.....

3,778,719 l2/1973 Kanawa 335/278 Primary Examiner-G. Harris Attorney, Agent, or Firm-Hill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson [5 7 ABSTRACT Insulating device for the coil of a relay and particularly a miniaturized relay, in the form of an insulating receptacle for the relay coil. The receptacle receives the coil and extends about the coil on three sides. The insulating receptacle may be molded or drawn from a plastic insulating material and besides insulating the coil from the contactsprings of the relay, serves to insulate the coil and contacts from the legs of the yoke, which may be parallel to the coil.

10 Claims, 8 Drawing Figures PATENIEUBBH 1514 I SHEET 1 [If 3 PATENIE unH m4 sum 20; 3

PATENIEDUETI m4 3.839.690 SHEET 3m a" INSULATING MEANS FOR AN ELECTROMAGNETIC RELAY FIELD OF THE INVENTION Insulating device for the coils of miniaturized relays.

BACKGROUND, SUMMARY AND ADVANTAGES OF INVENTION An important problem in relay design and particularly miniaturized flat relays, is to provide adequate insulation for all of the conductive parts of the relay, which may have different potentials, and including the coil winding, the contacts of the relay and the yoke, which in most cases, is grounded.

This problem is especially present in miniaturized flat relays where the contact springs are arranged close to the coil winding and where, in addition, one of several yoke legs of the yoke may run parallel to the coil. Where such a relay is used for the switching of heavier currents than normal, special insulating measures are necessary in order to guarantee a perfect and safe functioning of the relay.

A known relay of this type is shown and described in the Siemens Magazine of 1968, on pages 259-261. In such relays, it has been common practice to wind an insulation band around the coil winding and, in addition, to provide an insulating plate between the coil and the spring contact set. Further, the coil connections and the yoke have required insulation which was attained by the insertion of individual insulating parts. With such relays, the wrapping of the coil with insulation had to be carried out by hand with great care in order to assure adequite insulation of the parts of the relay and a clean contact at the coil flanges. This was a timeconsuming operation, greatly increasing the cost the the relay and many times resulted in an improperly functioning relay.

The advantages of the present invention, among others, are that it creates an insulating arrangement of the relay providing adequate insulation for the parts of the relay, and easily assembled and produced.

This is attained by the provision of an insulating receptacle receiving a coil and insulating the coil from the contact-making parts and surrounding the coil, except for the top thereof.

In accordance with the principles of the present invention, the insulating receptacle replaces the former wound insulation and various additional insulating parts which cannot be produced by automated equipment, and requires a minimum of assembly line work and further makes it possible for the assembly of the relay to be mechanized.

This further avoids winding of the coil with insulating material by providing an insulating receptacle in its final form prior to assembly.

In a preferred embodiment of the invention illustrated, the insulating receptacle is particularly adapted to a flat relay having an E-shaped core yoke. The high side walls of the insulating receptacle are located between the coil winding and the outer legs of the core yoke and the receptacle partially extends about the coil flanges to increase the creep distances to the longest amount possible.

A further advantage of the insulating receptacle is that the receptacle may be provided with end walls grooved to receive the coil flanges.

A further advantageous development of the invention is that the insulating receptacle may be provided with prolongations forming end pockets protecting the coil connections.

Where the insulating receptacle is used with a relay having an E-shaped magnetic system, the receptacle covers the yoke and the resting of the foil on the yoke can be prevented by insulating projections at one end of the receptacle to prevent the flow of creep current between the coil connections and the yoke and to provide an air distance around the receptacle wall providing efficient insulating conditions.

Other objects, features and advantages of the invention will be readily apparent from the following description of preferred embodiments thereof, taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a forming of insulating receptacle constructed in accordance with the principles of the present invention.

FIG. 2 illustrates a partial fragmentary longitudinal sectional view taken through a relay utilizing the insulating receptacle of the invention showing the relay coil and insulating receptacle in longitudinal section, with parts removed.

FIG. 3 is a partial fragmentary top plan view illustrating the insulating receptacle and relay coil as viewed from the top thereof.

FIG. 4 is a perspective view showing a modified form of insulating receptacle which may be used to carry out the principles of the present invention.

FIG. 5 is a perspective view of a miniaturized electromagnetic relay showing the coil insulated by the insulating receptacle of FIG. 4.

FIG. 6 is a view in side elevation of the miniaturized relay shown in FIG. 5 with certain parts broken away and certain other parts shown in section.

FIG. 7 is a partial fragmentary perspective view illustrating the assembly of an E-shaped yoke to the insulating receptacle of FIG. 4; and

FIG. 8 is a perspective view further illustrating the assembly of the yoke to the receptacle and armature of the relay.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION In the embodiment of the invention illustrated in FIGS. 1, 2 and 3, we have shown in FIG. 1 an insulating receptacle 1 constructed in accordance with the principles of the present invention having parallel side walls 1a and lb projecting upwardly from opposite sides of a base 1e of the receptacle. The side walls 1a and lb are of greater height than the coil winding and are connected together by end walls having similar openings therein to form ribs 10 and 1d extending upwardly of the base 1e and inwardly of said side walls. As shown in FIGS. 2 and 3, a relay coil 2 including a winding 3 wound in a recessed portion 2e of a body 2d for the relay is shown as mounted in the receptacle 1. The body 2d is formed from a suitable plastic insulating material and has outwardly opening

recesses

2c and 2f opening to the bottom and sides thereof accommodating the body and winding 3 to be received in the receptacle l with the

end ribs

1 c and 1d extending in said

recesses

20 and 2f to provide insulation for the coil and create a good insulation density. The body 2d is also shown as having a central passageway 4 extending along the axis of the coil within which may be mounted an iron core (not shown). The body 2d is provided with an armature stop 2a extending from one end thereof and an extension 2b supporting a yoke (not shown).

A base 5 for the relay has a pair of contact springs 6 and 6a having contacts 6c and 6d engageable with each other and insulated from the coil winding by the insulating receptacle 1. The contact springs 6 and 6a are shown as being leaf springs secured to the base 5 and their ends opposite the contacts 6c and 6d.

The coil 2 and body 2d, as shown in FIGS. 2 and 3, are thus recessed in the

ribs

1c and 1d of the receptacle 1 extending within the grooves and 2f of the body 2d, which extend along the bottom and sides of the coil at least to the top surface thereof. The side walls are thus relatively high and project upwardly from the base 12 a distance greater than the diameter of the wound coil to adequately insulate the coil and provide sufficient creep distance for the coil winding 3.

In FIGS. 4 through 8, we have shown a more sophisticated development of the insulating receptacle from that shown in FIGS. 1, 2 and 3. These figures show an insulating receptacle l1 constructed on principles similar to the insulating receptacle 1, in which the side walls of the receptacle extend upwardly from the bottom of the receptacle a greater distance than the diameter of the coil.

The receptacle has

opposite end walls

13 and 16 cut away to receive the body 15 of the relay and wound coil 12 and provide sufficient creep and air distance between the yoke 17 of the relay and the potential conducting contact spring (not shown).

The armature and yoke are made from metal, such as iron. The armature completes the flux path of the yoke. The yoke 17 is of a conventional E-shaped form including a transverse bar 22, parallel legs 17a and a center leg 27 extending from the transverse bar 22 through the central passageway (not shown) of the coil 12 and forming a core for the coil. The yoke or core passageway is formed in the coil body 15 about which the coil 12 is wound between flanges 12a in a manner similar to that shown in FIG. 2. The leaf spring 38 are secured to the legs 170 at one of their ends on studs 29 and extend along said legs and are clamped to the legs of the armature 34 by claw-like ends 35 of said springs. The springs 38 may be attached to the studs 29, to extend along the legs 17a of the yoke by riveting or any other suitable manner, after the yoke has been assembled to the receptacle 11.

The ends of the body 15 are in contact with soldering lugs 18 conducting current to the coil. The lugs 18 are protected by pockets 19 formed by widened extensions of the side walls of the receptacle and extending to the height of the side walls of the receptacle 11. The pockets 19 have a bottom wall 1% extending across the opening 16 and protect the soldering lugs 18 from the yoke 17 and surround the soldering lugs 18 along the bottom ends and sides thereof and extend above said lugs.

The outer ends of the vertical walls of the pockets l9 terminate into thickened tapering inwardly extending end portions 20 extending toward each other along the bottom wall 19a at the outer end thereof, to completely protect the soldering lugs 18 and provide the required air distance between the soldering points of the soldering lugs 18 and any exposed yoke part.

Moreover, in order to prevent contacting of the receptacle with the yoke 17 in the area of a cross-bar 22 of the yoke 17, the receptacle is provided with one or more projections 21 depending from the bottom all 19a and engaging the end of the yoke to avoid unfavorable short creep distances between the soldering lugs and the cross-bar 22 of the yoke.

The cross-bar 22 of the yoke is further insulated from coil energizing plugs 23 by an insulating extension of the bottom wall 19a in the form of a foil 24, formed as a part of the bottom wall to normally depend from said bottom wall, but to hinge upwardly to accommodate insertion of the yoke along the receptacle. This further protects the connecting plugs 23 from the yoke 17, particularly along the transverse bar 22 thereof. The foil 24 extends entirely across the receptacle to assure adequate protection of the cross-bar 22 of the yoke 17. v

The insulating

receptacles

1 and 11 may be made from a suitable plastic insulating material, deep-drawn to the final shape, with the necessary indentations, bulges, projections and rib produced by corresponding form shaping. One form of material is a polycarbonate known to the trade under the German Trademark of the firm Bayer Leverkusen as Makrofol." Other forms of plastic insulating materials may also be used.

- In order to produce the

recesses

25 and 26 in the

end walls

13 and 16 of the receptacle, after deep-drawing of the receptacle, the

opposite walls

13 and 16 are shown-in FIG. 6 as extending generally parallel, but slightly inclined relative to the vertical at an angle of from 1 to 10, shown in FIG. 6 as being an angle a and substantially 10. This angle corresponds to the inclination of the drawing form and is to provide the proper draft. A cutting tool (not shown) may then operate perpendicular to this angle to cut out the opening 26 and at the same time take out the vertical piece from the wall 13 and cut the opening 25.

Prior to the assembly of the yoke 17 to be finished insulating receptacle 11, the coil 12 is wound about the body 15 between

end flanges

12a and 12b of the body as shown in FIG. 5. The coil and body are then positioned in the correct position relative to the receptacle 11. The E-shaped yoke may then be inserted with the core 27 of the yoke extending through the central passageway extending along the body 15 along the axis of the coil in the direction of the arrow 28 (FIG. 7). In order to do this, the foil or extension 24 may be hinged upwardly as indicated by dashed lines in FIG. 6. The extension 24 bulges upwardly in the regions of the lugs 29, as indicated by reference numeral 30. To facilitate insertion of the yoke, the extension 24 has a leading edge 31 which may be turned outwardly at its free end about a radius 32 to prevent the catching of the edge 33 of the cross-bar 22 with said extension. After the insertion of the yoke with the legs 17a extending along opposite sides of the insulating receptacle, the extension 24 may be hinged downwardly to cover the crossbar 22 of the yoke and insulate the front side of said cross-bar from the electrical parts of the relay.

In FIG. 8 the coil 12 and yoke 17 are shown as completely assembled to the receptacle 11 with the armature 34 resiliently attached thereto by the leaf spring 38 free from the side walls of the receptacle, giving it complete freedom to properly perform its function and insulating the armature and yoke with respect to the coil and its energizing connections, to assure safe functioning of the relay.

It may be seen from the foregoing that the insulating receptacle of the present invention, as shown in all of the figures of the drawings, provides an integral preformed insulating device assuring safe and adequate insulation for the coil and simplifying the insulation of the coil and assembly of the relay, making it possible to assemble the relay without first winding the coil with an insulating covering.

It should further be understood that while the receptacle in FIGS. 4 through 8 is more sophisticated than that shown in FIGS. 1 through 3, the insulating principles of both receptacles are the same and the receptacles of both figures serve as a pre-formed effective insulating means for the coil of a miniaturized relay and substantially simplify the assembly thereof, and thus reduce the-cost of the relay.

We claim as our invention:

1. In a pre-formed insulating means for the coil of an electromagnetic relay including the coil,

an iron yoke forming a core for the coil,

contact-making parts arranged in proximity to the coil,

and a body forming a mounting for the coil, the improvement comprising an insulating receptacle receiving the coil and its body and having a base and parallel side walls extending along the bottom and each side of the coil and end walls having aligned openings therein and recessed within the coil body.

2. The insulating means of claim 1,

wherein the yoke is an iron E-shaped yoke having a transverse bar, a center leg forming the core for the coil and parallel legs extending from said transverse bar along opposite sides of the coil, and

wherein the receptacle extends between the coil and outer parallel legs of the yoke and insulates said legs from the coil.

3. The insulating means of claim 1,

wherein the coil is wound about an insulating body including parallel flanges, between which the coil is wound,

and

wherein the body forms a stop for the yoke and further insulates the yoke from the coil.

4. The insulating means of claim 3, wherein the receptacle has pockets at one end thereof extending laterally of opposite side walls of the receptacle, and forming insulating pockets for the energizing connections to the coil.

5. The insulating means of claim 4, wherein the pockets have a bottom wall extending across the receptacle and over the transverse bar of the yoke to form an insulating means therefor.

6. The insulating means of claim 5,

wherein the bottom for the pocket has an insulating extension extending outwardly of the bottom, hinged downwardly upon assembly of the yoke and core to the coil, and

wherein the side walls of the receptacle extend between the coil and outer legs of the yoke and the hinged extension hinges upwardly to accommodate insertion of the yoke to the receptacle and downwardly upon insertion of the yoke to insulate the cross-bar of the yoke from the coil and electrical energizing connections for the coil.

7. The insulating means of claim 5, wherein the bottom wall connecting the pockets together has a lug depending therefrom for engaging the cross-bar upon insertion of the yoke, to space said bottom wall above the cross-bar as the yoke is inserted in position.

8. The insulating means of claim 6, wherein the hinged extension has an arcuate outer edge forming an entering edge for the cross-bar and yoke and preventing interference between said hinged extension and yoke as the yoke is inserted along the sides and center of the coil.

9. The insulating means of claim 6, wherein the outer legs of the yoke each have a stud projecting upwardly therefrom forming a connecting means for the armature of the relay and the hinged extension has outwardly extending roof-shaped bulges in alignment with the lugs on the yoke legs, to prevent interference between the hinged extension and studs on the yoke legs upon assembly of the yoke to the coil and insulating receptacle.

10. The insulating receptacle of claim 8, wherein the insulating receptacle is a deep-drawn plastic part made from a plastic insulating material and opposite end walls of the receptacle extend parallel to each other and are inclined relative to the vertical at an angle a.

Claims

1. In a pre-formed insulating means for the coil of an electromagnetic relay including the coil, an iron yoke forming a core for the coil, contact-making parts arranged in proximity to the coil, and a body forming a mounting for the coil, the improvemEnt comprising an insulating receptacle receiving the coil and its body and having a base and parallel side walls extending along the bottom and each side of the coil and end walls having aligned openings therein and recessed within the coil body.

2. The insulating means of claim 1, wherein the yoke is an iron E-shaped yoke having a transverse bar, a center leg forming the core for the coil and parallel legs extending from said transverse bar along opposite sides of the coil, and wherein the receptacle extends between the coil and outer parallel legs of the yoke and insulates said legs from the coil.

3. The insulating means of claim 1, wherein the coil is wound about an insulating body including parallel flanges, between which the coil is wound, and wherein the body forms a stop for the yoke and further insulates the yoke from the coil.

6. The insulating means of claim 5, wherein the bottom for the pocket has an insulating extension extending outwardly of the bottom, hinged downwardly upon assembly of the yoke and core to the coil, and wherein the side walls of the receptacle extend between the coil and outer legs of the yoke and the hinged extension hinges upwardly to accommodate insertion of the yoke to the receptacle and downwardly upon insertion of the yoke to insulate the cross-bar of the yoke from the coil and electrical energizing connections for the coil.