US3825865A

US3825865A - Electromagnetic relay

Info

Publication number: US3825865A
Application number: US00359613A
Authority: US
Inventors: R Prouty; R Graf
Original assignee: Essex International Inc
Current assignee: Emerson Electric Co
Priority date: 1973-05-11
Filing date: 1973-05-11
Publication date: 1974-07-23
Anticipated expiration: 1991-07-23
Also published as: CA992591A

Abstract

An electromagnetic relay having an electromagnetic coil, frame and a pivotable armature. The frame is a generally C-shaped magnetizable member. One end of the frame is enlarged to increase air gap area while an armature is pivoted on the other end of the frame. A contact assembly connected directly to the armature provides for normally closed as well as normally open contacts and includes a post connected to the armature as well as contact carrying arms which slide on the post.

Description

United States Patent [191 Prouty et al.

3,825,865 [451 July 23, 1974 ZOO/I66 BF 200/16 A 335/281 3,436,497 4/1969 Mading.................... 3,436,697 4/1969 Snyder..... 3,723,925 3/1973 Primary Examiner-Harold Broome- Fort Wayne, lnd.

Attorney, Agent, or Firm-Robert D. Sommer [22] Filed:

May 1 1, 1973 [57] g ABSTRACT An electromagnetic relay having an electromagnetic coil, frame and a pivotable armature. The frame is a 21 Appl. No.: 359,613

5" 335/128 200/166 generally C-shaped magnetizable member. One end of [58] Field 126 the frame is enlarged to increase air gap area while an BF armature is pivoted on the other end of theframe. A

contact assembly connected directly to the armature provides for normally closed as well as normally open [56] References Cited ,3

UNITED STATES PATENTS contacts and includes a post connected to the armature as well as contact carrying arms which slide on 1 the post.

Cooper........ 1/1965 Hayward...... 8/1965 .lelley............................

. 1 ELECTROMAGNETIC RELAY This application relates to modifications andimprovements on relaysof the type disclosed in US. Pat. No. 3,733,568 entitled Push Button Relay and assigned to the same assignee as the present application.

6 Electromagnetic relays such as the one disclosed in the aforementioned patent application have typically included a push button assembly which physically moves an armaturecloserto a frame portion to enable it to pickup. Usually, the push button assembly did nothing after-the armature had picked up. Thus, it was I necessary to manually start relays of this general type by depressing the push button. This was true because the magnetic circuit did not provide a strong enough magnetic attraction for the-armature.

For certain. reasons it is desirable to have a relay of this general 'type which will automatically pick up the instant the coil is energized."I-hus the present invention provides ithe modifications and improvements, necessary to make an,.electromagnetic relay of this type whichiwill automatically pick up without the use of any pushbuttons.

' Generallyspeaking, the present invention. provides a 7 frame with an enlarged end portion to increase the air gap area betweenthe frame'and the armature allowing the armature to pick up the instant the coil is energized without anymanual assistance. v

The'invention also provides a means for positioning ajpairof movablecontacts so that they "are parallel to apair of fixed contacts. This is desirable to prevent arcing and also to increase the life of, the contacts,

. In the course of the description of the preferred embodimentof the invention, reference will be made to the drawings in which: FIG. 1 is anexplode'd view of a preferred embodi mentof an electromagnetic relay-constructed in accordance with the principles; of the invention;

FIG. 2 isa partially exploded cross sectional view of therelay shown' in FIG. 1; a'nd FIG. 3 is a crossjsectional view taken along line 3- -3 -o'fFlG; 2. Referring'first to FlGS. 1 and2, a preferred embodiment of an electromagnetic relay' constructed in accordance withthe principles of the invention is shown. The

- means, for example, by peening their ends at in a rivet fashion to suitable conductive terminalssuch as tab.

terminals

21 and 22 respectively.

A second pair of

contacts

23 and 24 are mounted on Z-shaped

contact supporting brackets

25 and 26 respectively. The

brackets

25 and 26 are fixedly mounted upon the upper face 14 of the base member by a pair of

rivets

27 and 28 which extend

throughholes

29 and 30 in the base member and a second pair of tab termirials 30 and 3l. The end of

rivets

27 and 28 are peened ets and tab terminals in place. The

contact supporting brackets

25 and 26 further include tabs 32 and '33respectively which extend into slots 34 and 35 to prevent the brackets from rotating.

Brackets

25 and 26 each have a

contact mounting leg

36 and 37 respectively which extend substantially parallel to the base member.

. Howeven'legs 36 and 37 are not exactly parallel to the over such thatthey hold the contact supporting brackbase member and are bent at a slight angle for reasons described later. i l An electromagnetic coil 40, comprising a plurality .of conductive turns 41 upon a bobbin 42, is also'mounted on the upper face 14 of the base by way of an angular member 44 which is of generally Z-shaped configuretion, and whichincludes an elongate leg portion 45 which extends axially into the core of the coil 40, a shorter leg portion 46 which extends vertically upward from the base member 10, and a foot portion 47. The coil 40 may be connected to

wires

107 and 108 respectively. The foot portion 47 is used to mount the coil 40 on the base and is attached to the upper face 14 of the base by way of suitable mounting,v means, such as threaded aperture 48 in the foot and a bolt 49"which extends through a hole 50 from the, underside 18 of the base and which is threaded into the aperture '48. It should be understood that member 44rnay be .of L- shaped'configuration and separate means" may be used to mount the coil 40 on the base. I 7

An L-shaped elongate member 54"also includes a longer leg.55fwhich extends axially through the core of the coil inoverlying relationship toleg '45 as shown in FIG. 2. The combination of

members

44 and 54 form a, generally C-shaped magnetizable member. The coil 40-is firmly attached to the oppositely axially extending

legs

44 and 55 preferably by way of a curved resilient shim piece 56 and the shorter leg 58 of L-shaped member 54 has an enlarged end portion 59 and extends downward in exterior relationship to the other end of the coil 24 as shown in FIG. 2 to firmly secure the coil against axial movement between

legs

46 and 58; The enlarged'endportion 59 provides increased area'in the airgap to be described later and maybe formedfor example by'a coining operation; The longerleg 55 of Z:

. shaped'member 54 is longer than the length of the coil 40 so as to define an extended spring mounting portion 60 which extends from the coil, as shown in FIG. 2. This extended portion 60 is suitably notched at 62'so as to receive the end 63 of a spring 64.

Members

44 and 54 are preferably formed of a suitable magnetizable material such as steel and may be formed by stamping intothe shapes shown in FIGS. a and 2.

A pair of laterally extending tabs 66 are formed on the shorter leg portion 46 of member 44 so as to provide a pivotal mounting upon which an elongate, generally rectangular, arrnature 68 is pivotally mounted as shown in FIG. 2. The armature 68 is also formed of a suitable magnetizable material, such as steel, and includes a lateral slot 70 through which the leg 46 of member 44 extends. The distance between the ends of tab 66 is greater than the width of slot 70 such that when the armature is positioned upon the member 44 and its tabs 66, the armature is mounted for pivotal movement relative to the member 44.

When assembled, one end 72 of the armature extends for a substantial distance beneath the coil 40 and between the coil and the upper face .14. of the base. This end 72 of the armature is preferably slotted at 73as shown in FIG 1 and a non-magnetizable shading ring on piece 74, preferably formed of copper, is positioned in the slot surrounding the center leg of the armature directlyunder the coil. This shading ring 74 substantially reduces the'likelihood of objectionable hum in the relay when the coil is energized.

A generally C-shaped slot 75 is also formed in the armature 68 between slot 70 and the other end 76 of the armature. This slot 75 is also notched at 77 so as to receive the other end 65 of the spring 64 and thus spring 64 exerts a force on the armature such that the annature tends to pivot clockwise as shown in FIG. 2 and assumethe position shown in solid, Extending from end 76 of the armature68 is a generally rectangular shaped armature. However, it may be bent slightly downward.

A small upraised portion 80 is located on the upper side of the armature extension near the end 76 of the armature as viewed in FIG. 1.

A contact assembly includes a post or vertical aligning member 81 which is'generally circular in cross sectiona'nd which has an end 82, a contact carrying portion 83 and a shoulder 84. The post is adapted to slideably fit through an aperture 85 in upper contact carrying arm 86, a compression spring 87, an aperture 88 in lower contact carrying arm 89, hole 79 in the armature extension, and a hole 90 in a guide member 91. After the contact assembly is assembled, the end 82 of the post 81 is peened over to hold the assembly together as shown at 93 in FIG. 2.

Upper contact carrying arm 86 is made of an electrically conductive material, such as a springy resilient copper, and has contacts 94and 95 mounted thereon. An insulating sleeve 96 surrounds the central portion of upper contactcarrying arm. Aperture 85 is large enough sov that the upper contact carrying arm will slide on portion 83 of .the post 81. Lower contact carrying assembly will move in a downward direction as viewed in FIG. 2. Shoulder 84 on post 81 will pull contacts 94 s and 95 out of engagement with upper fixed contacts 23 arm 89 is similar to upperxcontact carrying arm and has 7

contacts

97 and 98 mounted thereon. However, contact carrying arm 89 does not have a surrounding insulating sleeve.

Guide 91 is generallyL-shaped as viewed in FIG. 2

from the side, and has fingers 100 and 101 extending therefrom. Fingers l 0and 101 are located far enough apart so thatiarmature-extension 78 can fit between them and hole 79 can line up with hole 90. The fingers 100 and 101 of guide 91 extend at right angles to the plane of the armature and act to prevent contact carryson, leg 36 of bracket and leg'37 of bracket 26 are bent upward slightly from the horizontal as shown in FIG. 250 that

contacts

94 and 23 are parallel and

contacts

95 and 24 are parallel.

When the coil is energized and the armature picks 6 up, the armature will assume the position shown in the s do'tted'lines in FIG. 2. As the armature 60 picks up, it

will pivot on tabs 66 of frame piece and the contact and 24. Spring 87 will maintain contact carrying arm 89 in engagement with raised portion on armature extension 78 and the front part of armature extension 78.

Eventually contacts

97 and 98 will contact lower fixed contacts 11 and 12. These four contacts will be substantially parallel when they make because portion 83 of post 81 will slide through aperture 88 in contact carrying arm 89 and spring 87 will maintain

contacts

97 and 98 in engagement with contacts 11 and 12.

The insulating sleeve 96 on the upper contact bar furnishes isolation between circuits so that arcing from one side of the contacts will not produce current through-spring 87 when the oposite side makes. If this should happen the spring 87 can anneal and the contacts might fail.

Of course, numerous modifications may be made without departing from the true spirit of the invention which is defined in the claims.

What is claimed is:

1. An improved contact assembly for an electromagnetic relay having a base member, an electromagnet and a pivotable flat armature movable between an attracted position generally parallel to said base member and an unattracted position angular to said base member,,which comprises:

an elongated post, one end of said post being rigidly fixed to said armature, the other end of said post having a shoulder therearound, said post being fixed to said armature at substantially right angles to the plane defined by said armature;

a first pair of electrical contacts disposed on opposite sides of said armature and fixed to, and substantially parallel, to, said base;

a first electrically conductive, elongated, flat contact carrying arm having an electrical contact mounted at each end and adapted to bridge said first pair of electrical contacts, said post passing through an aperture in the central portion of said first contact arm so that said first contact carrying arm is slideable on said post;

a second electrically conductive, elongated, flat contact carrying arm having an electrical contact mounted at each end, said post passing through an aperture in the central portion of said second contact carrying arm so that said second contact carrying arm is slideable on said post;

a slightly upraised portion on said armature disposed adjacent said post and facing said first contact carrying arm;

a compression spring mounted concentrically with said post between said first and second contact carrying arms, said compression spring urging one side of said first contact carrying arm against said slightly upraised portion on said armature to cause the contacts mounted on said first contact carrying arm to be substantially parallel to said first pair of fixed contacts when said armature moves to its second energized position, and said spring urging said second contact carrying arm against the shoulder on said post;

a second pair of electrical contacts fixed to said base, said second pair of electrical contacts being adapted to be bridged by, and substantially parallel to, the contacts mounted on said second contact carrying arm when said armature moves to its first deenergized position;

guide means secured to said armature for preventing rotation of said first and second contact carrying arms on said post; and s an electrically insulating sleeve surrounding one of said contact carrying arms to electrically insulate said first and second contact carrying arms.

2. An electromagnetic relay, comprising:

a base member;

an electromagnetic coil having a plurality of conductive turns wound upon a coil bobbin, the axis of said coil extending parallel to said base member;

meansifor mounting said coil bobbin on said base member;

a first L-shaped magnetizable member, the first leg of said L-shaped member extending axially through said electromagnetic coil, the second leg of said L- shaped member extending toward said base memher;

a second L-shaped magnetizable member, the first leg of said second L-shaped member extending axially through said electromagnetic coil in overlying relationship with the first leg of said first L-shaped magnetizable member to form a C-shaped magnetizable member, the second leg of said second L- shaped member extending toward said base member;

a flat elongate magnetizable armature pivotally connected to the second leg of said first L-shaped member, said armature having a first portion disposed for pivotal movement between said electromagnetic coil and said base member, and a second portion extending away from said electromagnetic coil, said second portion having an upraised portion thereon, said armature moving from a first deenergized position to a second energized position upon energization of said electromagnetic coil;

spring means for biasing said armature to said first position;

an elongated post, one end of saidpost being rigidly fixed to said armature, the other end of said post having a shoulder therearound, said post being fixed to said armature at substantially right angles to the plane defined by said armature;

a first pair of electrical contacts disposed on opposite sides of said armature and fixed to, and substantially parallel to, said base;

a first electrically conductive, elongated, flat contact carrying arm having an electrical contact mounted at each end and adapted to bridge said first pair of electrical contacts, said post passing through an aperture in the central portion of said first contact carrying arm so that said first contact carrying arm is slideable on said post;

a second electrically conductive, elongated, flat contact carrying arm having an electrical contact mounted at each end, said post passing through an aperture in the central portion of said contact carrying arm so that said second contact carrying arm is slideable on said post;

a second pair of electrical contacts fixed to said base, said second pair of electrical contacts being adapted to be bridged by, and substantially parallel to, the contacts mounted on said second contact carrying arm when said armature moves to its first deenergized postion;

guide means secured to said armature for preventing rotation on said first and second contact carrying arms on said post; and

an electrically insulating sleeve surrounding one of said contact carrying arms to electrically insulate said first and second contact carrying arms.

Claims

1. An improved contact assembly for an electromagnetic relay having a base member, an electromagnet and a pivotable flat armature movable between an attracted position generally parallel to said base member and an unattracted position angular to said base member, which comprises: an elongated post, one end of said post being rigidly fixed to said armature, the other end of said post having a shoulder therearound, said post being fixed to said armature at substantially right angles to the plane defined by said armature; a first pair of electrical contacts disposed on opposite sides of said armature and fixed to, and substantially parallel, to, said base; a first electrically conductive, elongated, flat contact carrying arm having an electrical contact mounted at each end and adapted to bridge said first pair of electrical contacts, said post passing through an aperture in the central portion of said first contact arm so that said first contact carrying arm is slideable on said post; a second electrically conductive, elongated, flat contact carrying arm having an electrical contact mounted at each end, said post passing through an aperture in the central portion of said second contact carrying arm so that said second contact carrying arm is slideable on said post; a slightly upraised portion on said armature disposed adjacent said post and facing said first contact carrying arm; a compression spring mounted concentrically with said post between said first and second contact carrying arms, said compression spring urging one side of said first contact carrying arm against said slightly upraised portion on said armature to cause the contacts mounted on said first contact carrying arm to be substantially parallel to said first pair of fixed contacts when said armature moves to its second energized position, and said spring urging said second contact carrying arm against the shoulder on said post; a second pair of electrical contacts fixed to said base, said second pair of electrical contacts being adapted to be bridged by, and substantially parallel to, the contacts mounted on said second contact carrying arm when said armature moves to its first deenergized position; guide means secured to said armature for preventing rotation of said first and second contact carrying arms on said post; and an electrically insulating sleeve surrounding one of said contact carrying arms to electrically insulate said first and second contact carrying arms.

2. An electromagnetic relay, comprising: a base member; an electromagnetic coil having a plurality of conductive turns wound upon a coil bobbin, the axis of said coil extending parallel to said base member; means for mounting said coil bobbin on said base member; a first L-shaped magnetizable member, the first leg of said L-shaped member extending axially through said electromagnetic coil, the second leg of said L-shaped member extending toward said base member; a second L-shaped magnetizable member, the first leg of said second L-shaped member extending axially through said electromagnetic coil in overlying relationship with the first leg of said first L-shaped magnetizable member to form a C-shaped magnetizable member, the second leg of said second L-shaped member extending toward said base member; a flat elongate magnetizable armature pivotally connected to the second leg of said first L-shaped member, said armature having a first portion disposed for pivotal movement between said electromagnetic coIl and said base member, and a second portion extending away from said electromagnetic coil, said second portion having an upraised portion thereon, said armature moving from a first deenergized position to a second energized position upon energization of said electromagnetic coil; spring means for biasing said armature to said first position; an elongated post, one end of said post being rigidly fixed to said armature, the other end of said post having a shoulder therearound, said post being fixed to said armature at substantially right angles to the plane defined by said armature; a first pair of electrical contacts disposed on opposite sides of said armature and fixed to, and substantially parallel to, said base; a first electrically conductive, elongated, flat contact carrying arm having an electrical contact mounted at each end and adapted to bridge said first pair of electrical contacts, said post passing through an aperture in the central portion of said first contact carrying arm so that said first contact carrying arm is slideable on said post; a second electrically conductive, elongated, flat contact carrying arm having an electrical contact mounted at each end, said post passing through an aperture in the central portion of said contact carrying arm so that said second contact carrying arm is slideable on said post; a compression spring mounted concentrically with said post between said first and second contact carrying arms, said compression spring urging one side of said first contact carrying arm against said slightly upraised portion on said armature to cause the contacts mounted on said first contact carrying arm to be substantially parallel to said first pair of fixed contacts when said armature moves to its second energized position, and said spring urging said second contact carrying arm against the shoulder on said post; a second pair of electrical contacts fixed to said base, said second pair of electrical contacts being adapted to be bridged by, and substantially parallel to, the contacts mounted on said second contact carrying arm when said armature moves to its first deenergized postion; guide means secured to said armature for preventing rotation on said first and second contact carrying arms on said post; and an electrically insulating sleeve surrounding one of said contact carrying arms to electrically insulate said first and second contact carrying arms.