US3391359A

US3391359A - Stationary contact structure and magnet support for an electromagnetic contactor

Info

Publication number: US3391359A
Application number: US556414A
Authority: US
Inventors: Don J Arneberg; Jordan F Puetz
Original assignee: Square D Co
Current assignee: Schneider Electric USA Inc
Priority date: 1966-06-09
Filing date: 1966-06-09
Publication date: 1968-07-02
Anticipated expiration: 1985-07-02
Also published as: GB1142593A

Description

y 1963 D. J. ARNEBERG ET AL 3,391,359

STATIONARY CONTACT STRUCTURE AND MAGNET SUPPORT FOR AN ELECTROMAGNETIC CONTACTOR Filed June 9, 1966 2 Sheets-Sheet 2.

51 awn/me.

United States Patent 3,391,359 STATIONARY CONTACT STRUCTURE AND MAG- NET SUPPORT FOR AN ELECTROMAGNETIC CONTACTOR Don .I. Arneberg and .Iordan F. Puetz, Milwaukee, Wis., assiguors to Square ll) Company, Park Ridge, Ill., a corporation of Michigan Filed June 9, 1966, Ser. No. 556,414 9 Claims. (Cl. 335115) ABSTRACT OF THE DISCLOSURE A preferred stationary contact structure and magnet support for an electromagnetic contactor embodying the present invention comprises a molded body which has a cavity with a front opening and a top opening, each opening providing an entrance from the outside of the body into the cavity. A stationary contact is inserted end foremost through the front opening and when so inserted is prevented from removal through the top opening by shoulders formed in the walls of the cavity. An element, which preferably is in the form of a terminal connector, is inserted through the top opening and then detachably connected to the stationary contact. When so connected, the connector is held against removal through the top opening by the contact and, in turn, engages shoulders in the cavity so as to prevent removal of the stationary contact through the front opening. An electromagnetic contactor is provided in the body and has a movable contact cooperable with the stationary contact. The body is arranged so that the electromagnetic structure can be readily installed and secured in the body with the core of the magnet cushioned so as to relieve the shocks imposed on it by the armature.

This invention relates to electromagnetic contactors, and particularly to electromagnetic contactors in which the various operating parts can be readily assembled and disassembled, and of which the parts themselves are well adapted to quantity production.

An object is to provide an electromagnetic contactor in which a molded body comprising a cover and a base are configured so as to cooperate with various operating parts of the contactor for holding them in proper assembled relation to each other with a minimum of extraneous fastening devices.

A more specific object is to provide an electromagnetic contactor having stationary contacts of types which can be installed readily in the cover of the body as desired by the user, and having an interlock which may readily be installed in the base of the body when desired.

Another specific object is to provide a bracket and bolt arrangement which performs the dual function of holding the cover and base in operating relation to each other and the core of the electromagnetic assembly in proper relation in the base and to cushion impact forces incident to energization of the electromagnet.

Various other objects and advantages will become apparent from the following illustrative example wherein reference is made to the drawings, in which FIG. 1 is a front elevation of an electromagnetic contactor embodying the principles of the present invention;

FIG. 2 is a vertical, sectional view of the electromagnetic contactor taken on line 22 of FIG. 1, part thereof being shown in elevation for clearness in illustration;

FIG. 3 is a vertical section at right angles to the view of FIG. 2 and is taken on the line 33 in FIG. 2, part thereof being shown in elevation for clearness in illustration;

"Ice

FIG. 4 is a top plan view of the contactor illustrated in FIG. 1;

FIG. 5 is a right end elevation of the contactor illustrated in FIG. 1;

FIG. 6 is a fragmentary horizontal view of the base of the body with the cover and contact carrier removed, and is taken on the line 6-6 in FIG. 5;

FIG. 7 is an enlarged vertical sectional view of the form of stationary contact assemblage illustrated in FIG. 1, and is taken on the line 77 in FIG. 1.

FIG. 8 is a perspective view of an interlock used in connection with the present invention, as viewed generally from the forward or outer face thereof;

FIG. 9 is a perspective View, similar to FIG. 8, of the interlock viewed from the opposite face thereof;

FIG. 10 is a perspective view of a type of bracket used for holding the core of the electromagnetic means of the present invention in operating position in the base of the body;

FIG. 11 is an enlarged fragmentary perspective view of a portion of the electromagnetic contactor with a modified form of stationary contact installed;

FIG. 12 is a bottom plan view, partly in section of a portion of the structure illustrated in FIG. 11, showing the interlocking relation between the stationary contact and the cover of the electromagnetic contactor; and

FIG. 13 is a vertical sectional view through the contactor of FIGS. 11 and 12, and is taken on the line 13-13 thereof.

For purposes of illustration and convenience in description, the electromagnetic contactor is described herein as disposed in an upright position wherein its movable car rier operates in a vertical path, the other parts of the contactor being described in relation to this position. Accordingly, the terms vertical, horizontal, and the like, are not absolute but are merely to define more readily the relative positions of the operating parts.

Referring to the drawings, the contactor, indicated generally at 1, comprises a base 2 and a cover 3 secured to gether by suitable bolts 4. The base is molded in one piece and is provided with an open top main cavity 5 and a pair of open top auxiliary cavities 6 which are disposed alongside diagonally oposite portions of the main cavity 5 and are in communication therewith.

Mounted within the cavity 5 and extending upwardly through the open top thereof, is a movable contact carrier 8 carrying a plurality of movable contacts 9 each of which is held in position relative to the carrier by an associated spring 10. The carrier 8 has two lateral depending end portions 12 which are guided by suitable upright guideways in the main cavity 5 and interval therewith. At their lower ends the portions 12 support an armature 13. A suitable snap-fastening bracket 15 is provided for securing the armature detachably in fixed position on the lower end of the carrier portions 12. This bracket comprises a strip of metal having upwardly extending arms 15a, each with a flange 15b at its upper end detachably engaging a suitable notch in the associated one of the portions 12 of the carrier. The bracket its provided with fingers 15c which engage the front and rear of the armature and, with the arms 15a, constraining the armature in fixed relation to the carrier 12.

The base 2, cover 3, and carrier 8 each is molded in one piece of suitable rigid electrical insulating material.

Also mounted within the cavity 5 is an electromagnetic coil 17 which is preferably encased in a molded body 18 which rests on bosses 19 in the cavity 5 of the base 2. The shoulders 19 constrain the coil from movement downwardly in the cavity 5 beyond a predetermined position.

Mounted within the cavity is an iron core 20 having a dependent central pole 20a and two dependent outer shaded poles 20b. The central pole 26a extends through coil 17, and it and the poles b terminate normally in spaced relation above the armature 13. The poles 20]) are shaded, as illustrated.

In order to cushion the impact forces incident to energization of the magnet, a bracket 21, which is best illustrated in FIG. 10, is provided. For cooperation with the bracket, the base 2 is provided at two diagonally opposite corners with exterior downwardly facing shoulders 22 and the cover is provided with an aligned upwardly facing shoulder 23. The cover and base have aligned passages extending through the

shoulders

22 and 23 for accommodating the screw 4.

The bracket 21 has an upper laterally directed resilient portion 25 which extends between the upper end of the base 2 and lower end of the cover 3 and which may engage, but preferably lies in slightly spaced overhanging relation to, an upwardly facing surface portion of the core 20. The bracket is provided with a lower laterally directed portion 26 which, when the upper lateral finger or portion 25 is in its operating position, is juxtaposed against the shoulder 22. Thus the portion 25 is engaged by the core 20, as the core jumps upwardly when struck by the armature 13 upon energization of the magnet, and cushions the shocks that would otherwise result from the impact forces. Two such brackets are provided, one at diagonally opposite corners of the contactor.

For economy in manufacture and assembly the lower lateral portions 26 of the brackets 21 may be internally threaded for threaded engagement with the lower end of the screws 4.

The bracket 21 is preferably fitted so that its upright intermediate portion lies in a suitable groove 27 formed in the base 1, as best illustrated in FIG. 9, so as to present exteriorly of the contactor a surface flush with the side wall of the base.

The cover 3 has internal cavities 30 in which the upper end portion of the carrier 8 projects. Suitable return springs 31 are disposed between the upper end wall of the cavities 30 and the upper end of the carrier and yieldably urge the carrier downwardly to its fully lowered position illustrated in FIG. 3.

The cover is provided with forwardly and rearwardly extending upright outer side walls 32, intermediate barrier walls 32a parallel to the walls 32, and a central wall 33. These walls form, with other portions of the cover, a plurality of cavities 34, one between each two adjacent forwardly and rearwardly extending walls at each side of the central wall 33. Each of the cavities 34 is open at the front and closed at the rear. It is to be understood that front is used for clarity in illustration to define the end of a cavity 34 which is opposite from the central wall 33, even though cavities at one side of the wall 33 open in a direction forwardly of the cover as a whole and those at the opposite side of the wall 33 open rearwardly of the base as a whole. Each of the cavities 34 has an upwardly facing shoulder 35 at its forward end and is closed at the rear by the central wall 33. The side walls of each cavity are provided with bosses 36, respectively, which extend horizontally forwardly and rearwardly of the cavity. Each of the bosses 36 has an upwardly facing shoulder 37 and a downwardly facing shoulder 38, and a flat upright face facing transversely of the cavity 34. At the front of each cavity 34 parallel upright shoulders 39 are provided on, and are integral with, the side walls, respectively. Each shoulder 39 is somewhat curvilinear and convex inwardly of the cavity at its upper portion 39a. A stationary contact 40 is mounted within each of the cavities. Each contact 46 is in the form of a strip of metal bent so that in side elevation it has a lower contact portion 41, an upper connecting portion 42, a depending forward portion 43, and a rear neck portion 44. The portion 42 may be provided at its opposite lateral edges with tines 4211 which are adapted to pass the shoulders 39 and cut slightly thereinto during in sertion of the contact into the cavity. The neck portion 44 is of less width laterally, of the contact 40 or cavity 34 in which it is disposed.

This width of the neck 44 is such that it can pass readily face forwardly, between the upright faces of the bosses 36 of a cavity 34 as the contact is inserted into an associated cavity 34 neck foremost through the open front end of the cavity. The contact is of such overall width that it can pass between the upright shoulders 39 during such insertion. Thus, the contact may be inserted through the forward open end of its associated cavity parallel to its operating position. When so inserted, the neck 44, as explained, has passed between the upright faces of the bosses 36. The bosses 36 are of such height that they fit between the underside of the upper portion 42 and the upper side of the lower portion 41 of the contact 40. Thus, when the contact is disposed fully within its cavity 34 so that the rear face of the neck 44 is in engagement with the wall 33, the bosses 36 are disposed between the upper and

lower portions

41 and 42 and constrain the contact 40 from movement upwardly out of its associated cavity 34. In this position also, the dependent portion 43 is preferably forwardly of the shoulders 39 and may rest at its lower end on the shoulders 35, preferably flush with the forward edge of the shoulders 39. Thus the contact 40 is constrained from movement out of its cavity 34 in all directions except forwardly.

The contact is held in place forwardly and rearwardly by suitable means engaging the cover 3. In the form illustrated in FIG. 1, the means for constraining the contact 40 from movement forwardly out of its cavity 34 comprises a terminal connector 46. The terminal connector is preferably in the form of a strip of metal bent into O-shape in front elevation as viewed from the left in FIG. 7, and provided with an upper threaded bore 47 and an aligned lower bore 48.

The terminal connector 46 is receivable through the open top of an associated cavity 34 and is adapted to fit snugly, with operating clearance, behind the rear of the shoulder 39a and to be secured to the top of the contact 40 when in this position. For this purpose, it is secured in fixed position to top portion 42 of the contact 40 by suitable screws 49 which extends through the lower bore 48 and is in threaded engagement with the contact 40. Thus connected by engagement with the shoulders 39, it constrains the contact 40 from movement forwardly out of its associated cavity 34. A suitable connecting screw 50 in the upper bore 47 of the terminal connector 46 is adapted to be screwed downwardly to secure a wire or other terminal between the upper end of the bolt 4? and the screw 50.

The installation of the stationary contacts in the cover is one depending upon the type of stationary contacts employed. The type of contacts heretofore described are merely slid into the cavities 34 through the front ends thereof and in engagement with the shoulders of the bosses 36, in the position illustrated in FIGS. 1 through 4. While in this position, the terminal connectors 46 are inserted and secured by the screws 49 to the stationary contacts 40, thus securing the stationary contacts from movement back out of the front end of their respective cavities. This installation is made before installation of the cover on the base.

It is apparent from the foregoing description that the electromagnetic switch may be readily assembled. For this purpose, all that is necessary is to snap the desired movable contacts for the desired current rating into the carrier 8, assemble the core 20 and coil 17 and connect them to the carrier 8 by first disposing the armature 13 in the bracket 15, and then snap fastening the bracket onto the dependent portions 12 of the carrier 8.

Next, the carrier with the electromagnetic means described are lowered int-o the main open top cavity 5 of the base 2, and when in place therein the cover 3 is installed. The portions 25 of the brackets 21 are slid into place between the cover 3 and base 2 so as to overlie the stop of the core in spaced relation and limit its movement in a direction toward the cover 3. The lower portions 26 of the brackets 21 are moved concurrently beneath the shoulders 22, respectively. Thereupon, the cover 3, with its installed contacts, is applied and the screws 4 are installed for securing the cover to the base 2. The interlock switch, if desired, later to be described, is installed prior to the assemblage of the cover and the base, merely by pushing the interlock switch into position in the auxiliary cavity 6 in the base. It is held in place by the installed cover.

Referring next to FIGS. 11 through 13, the modified form of stationary contact 51 is provided. This contact is best illustrated in FIGS. 11 and 12 and is essentially the same in general shape as the contact heretofore described. It comprises a strip of metal having a top portion 52, a bottom portion 53, a front portion 54, and a rear or neck portion which, as in the case of the contact 40, is of less width than the other portions so that the contact 51 can be slid into place neck foremost through the front of a cavity, such as the cavity heretofore described. As illustratedin FIG. 11, a portion of one of the forwardly and readwardly extending walls of the cover is indicated at 56 and a portion of an intermediate or central wall is indicated at 57, these corresponding to the

cover walls

32 and 33 heretofore described.

The two walls between which the contact 51 is slid have bosses, such as indicated at 58 in FIG. 13, which have adjacent faces faced so that the neck 55 can pass therebetween as the contact is inserted into the cavity. The upper and lower edges of the bosses 58 can engage the upper and lower margins of the contact to prevent its removal upwardly out of the cavity, all as in the case of the contact 40 shown in FIG. 2. Suitable shear nibs 59 may be provided on the bosses to assure an effective fit of the contacts for frictionally holding them in position and for compensating for manufacturing tolerance deviations. Also, to assure a tight fit, the portion 53 of the contact 51 may be slightly overformed so that it slopes upwardly forwardly. Then, when the contact is slid into place, the upper and lower portions thereof have a clamping engagement with the upper and lower edges of the bosses 58, respectively. If desired, the upper portion 52 may be provided with tines 60 at opposite lateral edges, these tines being adapted to pass upright shoulders 62 on the side walls 56 and cut slightly thereinto during insertion of the contact into its cavity. The lower portion 53 of the contactor is provided at its outer forward end with a notch 64 which defines at that end a pair of connecting ears 65 spaced apart laterally of the contact. These ears are connected to the portion 53 by neck portions 66 of small cross section, formed by the notch 64 and lateral notches 67. The neck portions are such that suitable screwdriver or other tool can be inserted between the ears 65 and twisted to spread the ears apart so that their forward ends engage behind the shoulders 56a on the walls 56 and thus constrain the contact from movement forwardly out of its cavity. By means of the ears 65 and shoulders 56a, the shoulders 62, and cooperation of the upper portion 52 and lower portion 53 with the bosses 58, the contactor is fixedly secured in place.

If desired, terminal connections may be provided by suitable screws entering threaded openings 68 in the forward portion 54 of the contacts, respectively.

Again, if desired, the terminal connectors 69 may be secured to the contacts 51 by means of bolts or screws 70. In this type of contactor it is desirable that the stationary contacts 51 be installed in the cover before installing the cover on the base, inasmuch as the bottom wall portions 53 thereof should be readily accessible by a tool through the bottom of the cover for spreading the ears 65 apart.

Referring next to FIGS. 1, 8 and 9, an interlock switch which may be inserted through the open top of the auxiliary cavity 6 is illustrated.

The interlock switch shown is a normally open switch.

It comprises a body 71 formed of two molded

parts

71a and 71b of insulating material which may be placed into edgewise matching relation. Within the body 71 is a stationary contact 72 and a movable contact 73, the movable contact being mounted on a suitable spring finger 74 having a cam surface 75. The finger 74, when unrestrained, holds the contact 73 out of contact with the contact 72. Also mounted in suitable upright slideways 76 in the body 71 is a slide 77 on which is a cam 78. In the form illustrated, the cam 78 is adapted to engage the cam surface of the finger 74 for closing the

contacts

72 and 73 when the slide 77 is moved upwardly. The slide is yieldably retained in its lowered position by a return spring '79. A finger 80 on the slide 71 extends through an opening in the side of the cavity 6. A complementary finger 81 is provided on the carrier 8. These fingers cooperate and provide means for moving the slide upwardly against the force of the spring 79 when the carrier 8 is moved upwardly, thus causing closure of the

contacts

72 and 73.

A pad 82 of sponge rubber is secured to the bottom of the body 71 for resiliently urging the interlock switch upwardly into engagement with the cover, thus compensating for manufacturing tolerance deviations.

If a normally closed interlock switch is desired, the cam surface 78 is modified and positioned to engage the cam 75 and hold the

contacts

72 and 73 closed when the slide 77 is in its lowered position and to release the

contacts

72 and 73 for opening when the slide is in its raised position.

Two such interlocks may be provided in a single contactor. If so, they are arranged at diagonally opposite corners of the base 2 wherein corresponding auxiliary cavities 6 are provided, respectively.

Having thus described our invention, we claim:

1. An electromagnetic contactor comprising a body;

a movable contact carrier mounted therein;

a movable contact carried by the carrier;

said body having a pair of upright insulating walls in spaced face to face relation to each other and defining a contact accommodating cavity having a top opening and a front opening;

said openings providing entrances, respectively, from the outside of the body into the cavity;

a stationary contact in the cavity, and adapted to be received in the cavity end foremost through one of said openings and to be removable from the cavity through said one of said openings;

sets of shoulders on the body within the cavity;

the shoulders of one set engaging the contact when the contact is in the cavity and constraining the contact from withdrawal through the other of said openings; and

means received through the other of said openings and connected to the contact and engaging the shoulders of the other set and constraining the contact from withdrawal through said one of said openings, and being constrained by the contact from withdrawal through said other opening.

2. The structure according to claim 1 wherein said shoulders of the other set have portions facing away from said one opening; and

the means connected to the contact are a terminal connector :detachably connected to the contact and disposed at, and engaging, said portions facing away from said one opening.

3. The structure according to claim 1 wherein the means interconnecting the contact and said shoulders of said other set comprise a pair of ears on the contact at opposite lateral edges thereof, respectively, and normally spaced apart edgewise from each other at their outermost limits transversely of the contact a distance affording their entrance into the cavity through one of the openings past said shoulders of the other set upon insertion of the contact end foremost through said one of the openings, and said ears being spread apart permanently edgewise in situ into interconnecting relation to said shoulders of the other set, when the contact is in said cavity.

4. The structure according to claim 1 wherein said body includes a base and a cover;

the base has an upwardly open main cavity and an upwardly open auxiliary cavity disposed alongside the main cavity and in communication therewith through lateral walls of the cavities;

the carrier is in the main cavity;

guide means are provided in the main cavity and guide the carrier for upward and downward movement therein;

an interlock switch means is detachably accommodated in the auxiliary cavity and includes a stationary contact, a movable contact, and a slide for controlling the making and breaking of contact the interlock contacts;

means drivingly interconnect the carrier and slide;

the cover is detachably secured to the base; and

the stationary contact and cooperating shoulders are in the cover.

5. The structure according to claim 1 further including an electromagnetic coil, a core for the coil, and an armature, said body includes a base and a detachable cover, said base has a cavity wherein the movable carrier, coil, core, and armature are contained;

means in the base cavity constraining the core from movement in a direction away from the cover;

said base has an upright screw passage therein;

said cover has an upright screw passage aligned with the screw passage of the base;

said base has a downwardly facing shoulder spaced downwardly from the cover and through which the screw passage of the base opens at its lower end;

a bracket having a main body portion and spaced upper and lower lateral portions, one of said portions engaging the underside of said downwardly facing shoulder and the other of said portions extending between the base and cover and being operable to limit movement of the core toward the cover;

a bolt received through the passages and connected to said one lateral portion of the bracket and thereby holding the cover, bracket, and body together, and limiting said movement of the core toward the cover by the bracket.

6. The structure according to claim 5 wherein said one lateral portion is juxtaposed against said downwardly facing shoulder and has an internally threaded passage aligned with the screw passage and in threaded engagement with the bolt.

7. The structure according to claim 5 wherein the core is supported in the body for movement in a direction toward the core by impact forces imposed on the core by the armature when the coil is energized, said other of said portions is spaced slightly from the core in a direction toward the cover, and said other of said portions is resilient and engageable by the core when the core is so moved partway toward the cover and is operative when so engaged to yieldably Oppose said movement and thereby cushion shocks caused by the impact forces.

8. An electromagnetic contactor comprising- -a body including a base and a cover;

said base having an upwardly open main cavity;

a movable contactor;

a movable contact carried thereby;

an electromagnetic coil;

a core for said coil;

an armature connected to the carrier and cooperable with the core;

said coil, core, and armature being disposed in said main cavity;

means in the main cavity guiding the armature for movement toward and away from the cover;

said cover having a pair of upright insulating Walls in spaced face to face relation to each other and defining a contactor accommodating cavity having a top opening and a front opening;

a stationary contact in the cover cavity;

sets of shoulders in the cover cavity, the shoulders of one set engaging the contact and constraining the contact from withdrawal through one of said openings;

means connected to the contact and engaging the shoulders of the other set and constraining the contact from withdrawal through the other of said openmgs;

said cover and base having aligned bolt openings therein;

means including a bolt extending through said aligned openings and detachably connecting the cover to the base; and

said last mentioned means including a member secured in place on the base by said bolt and having a portion engaging the core and constraining the core from movement in a direction toward the cover.

9. An electromagnetic contactor comprising an electromagnetic coil, a core for the coil, and an armature, said body including a base and a detachable cover, said base having a cavity wherein the movable carrier, coil, core, and armature are contained;

means in the cavity constraining the core from movement in a direction away from the cover;

said base having a pair of upright screw passages therein;

said cover having upright screw passages aligned with the screw passages of the base, respectively;

said base having a pair of shoulders facing in a direction toward the end of the base opposite from the cover and through which the screw passages of the base open, respectively, at their lower ends;

a pair of brackets each having a main body portion and lateral portions, one of said portions of each bracket engaging an associated one of said shoulders and the other of said portions of each bracket extending between the base and cover and engaging the core so as to limit movement of the core toward the cover;

bolts received through each pair, respectively, of aligned ones of said passages and connected to said first mentioned lateral portion of the brackets, respectively, and thereby holding the cover, brackets, and body together, and limiting said movement of the core toward the cover by the brackets.

References Cited UNITED STATES PATENTS 2,394,090 2/1946 McFarland 335-196 2,539,628 1/ 1951 Kingdon 200-166 2,811,617 10/1957 Townsend 200-166 2,945,098 7/1960 Ludwig 200-166 3,099,730 7/1963 Tateishi 335-133 3,194,920 7/1965 Scheib 335-133 3,324,431 6/1967 Cataldo et al. 335-197 2,361,808 10/1944 Ayers 335-277 3,060,355 10/1962 Kruzic 335-277 3,088,058 4/1963 J'zikel 335-277 BERNARD A. GILHEANY, Primary Examiner. H. BROOME, Assistant Examiner.