US2071149A

US2071149A - Electric switch

Info

Publication number: US2071149A
Application number: US30790A
Authority: US
Inventors: Gustav O Wilms; Petersen Hans
Original assignee: Allen Bradley Co LLC
Current assignee: Allen Bradley Co LLC
Priority date: 1935-07-11
Filing date: 1935-07-11
Publication date: 1937-02-16
Anticipated expiration: 1954-02-16

Description

Feb. 16, 1937. e. '0. WlLMS ET AL 2,071,149

ELECTRIC swrrcn Filed July 11, 1935 4 Sheets-Sheet 1 2 f/vsumr/oN 23 i ma Patented Feb. 16, 19 1 UNITED STATES.

,PATENT OFFICE f ELECTRIC swrron Wisconsin Application July 11, 1935, Serial No. 30,790

31 Claims.

This invention relates to improvements in electric switches and refers more particularly to electromagnetically actuated control switches of the type shown in Patent No. 1,981,534, issued to Gustav O. Wilms, et a1., November 20th, 1934.

As in the patent above noted, the switch of this invention is of the solenoid type wherein the movable contacts have a straight line motion to and from engagement with their respective stationary contacts,

It is a general object of this invention to improve the construction of switches of this character and to increase their are rupturing capacity through the provision of novel arc enclosing chambers which completely enclose the contacts.

Another object of this invention is to provide an arc enclosing chamber so constructed that while it completely encloses the contacts, they are readily accessible for inspection.

Another object of this invention is to provide an arc enclosing chamber having a readily removable section on which the stationary con,- tacts are mounted. I

In this connection, it is a further object of this invention to provide a combined arc enclosing chamber and terminal head so designed that the component parts are all readily removable from the front of the switch.

Another object of this invention is to provide practical means for actuating the movable con.- tacts from without the arc enclosing chambers in such a manner that while the necessary opening through which said means enters the chamber, communicates the chamber interior with the atmosphere and enables substantially a rapid venting of accumulated gases from within the chamber, the completeness of the enclosure is not destroyed to the point of interfering with the effective confinement of the are within the chamber.

tially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereinclisclosed invention may be made as come within the scope of the claims,

The accompanying drawings illustrate one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

Figure 1 15a front view of a switch embodying this invention, parts thereof being broken away and in section;

Figure 2 is a longitudinal section view through Figure 1 on the plane of the line 22;

Figure 3 is a perspective view of the cover section of the arc enclosing chamber;

Figure 4 is a perspective view of the top wall of the arc enclosing chamber with the stationary contacts mounted thereon;

Figure 5 is a perspective view of the rear section or base of the arc enclosing chamber;

Figure 6 is a perspective view of the movable contactor unit with one of the contact arms and its associated mechanism removed; v

Figure "Us a perspective view of the removed contact arm and its associated mechanism;

Figure 8 is a top view of the switch showing particularly the arc enclosing chamber properly assembled;

Figure 9 is a fragmentary top view of the arc enclosing chamber showing how improper as sembly thereof is precluded;

Figure 10 is a perspective view of the lower portion of the solenoid and the overload reset memgenerally by the numeral 6, and the electromagnetic actuating means or solenoid l are mounted.

The switch mechanism comprises a plurality of pairs of stationary contacts 8 adapted to be electrically bridged by movable contact units 9' actuated in a straight line motion by the electromagnetic actuator r solenoid 1.

The electromagnetic actuator or solenoid I in its general aspects is substantially like that shown in the aforementioned patent to Wilm et a1. It incorporates a laminated field piece l9 rigidly mounted on the panel 6 by means of a bracket iii. The field piece in is substantially 7 ledges i2 and prevent endwise motion of the coil.

The pole pieces ofjthe magnet are provided by downwardly extending projections ii on the bottom of the ledges l2. Shading coils I! are mounted on these projections as is customary.

The armature II is of inverted T-shape with the stem thereof slidable in the guideways l4 and its head projecting to opposite sides for co- 'action with the pole pieces i6. Like the'field piece ID, the armature is also of laminated construction and. a'central lamination i8, which is composed of non-magnetic metal, slidably projects through an opening l9 in the top of the field piece. The opening i9 is provided by cut-v ting away some of the central laminations .of the field piece. v I

Attached to a-tongue formed by the lamination l8 by means of a screw 2i is a contact'carrier 20. This carrier 29 comprises a cross bar of molded insulatingmaterial with a metal'insert '22 providing a reinforcingflb therefor.. .The

front of the molded'crossbar is recessed at its lower portion as at 23 to expose the. adjacent central portion of the metal reinforcing rib 22 so that the end of the tongue i3 is engageable directly therewith. V

Three upstanding equispaced bosses 24 project from the top of the carrier 29 and have metal posts 25 embedded therein with their upper end portions exposed. The exposed upper end portions of the posts are substantially T-"shaped to provide sidewise extending hooks or projections 26 on their upper ends which liein a plane parallel to the major axis of the carrier bar. Seated on each boss 24 is a spring retaining cup 21 in which the lower end portion of an expansile spring 23 is nested. The spring 23 encircles the post 25 and also the boss 24 and its upper end bears against a washer 29 slotted as at 39 to permit its disposition over the T-shaped post 25.

Teiescoped over this entire assembled structure is an outer cup-shaped member 3i, the

upper closed end of which has a raised bead 32 pressed transversely therein and in which a cross! shaped opening 33.is formed. The cross-shaped opening 33 has a long and short leg with the long -leg transverse or at right angles to the axis of thepost 23 therethrough so that by properly disposing the cup member 3| with respect to the post 23, it is possible to engage the same therewith. After engagement to -a point at which the opening 33 aligns with the narrow lower portion 23' of the post, the cup membermay be'turned-f ninetynegrees to align theshort leg of its crossshaped opening 33 with thepost', 'the short le receiving the wider portion of the post between the extensions 26 and the narrow part 25. The cup member is thus held against turning and yieldingly urged against the extensions or arms 26 a This disposes the cup member M in a position of rotation at which the axis ot'its head 32 is parallel with the major axis of the carrier bar and holds the spring 28 in a state of compression. Mounted on each post 25 outwardly of the cup member 3| is one of the movable contact units 9. These units are all alike and comprise a contact bar 34 which is in the form of a relatively heavy strip of metal, preferably copper, with contacts 31 of a silver-cadmium alloy electro- I welded to its end portions. The central portion 35 of the bar is humped up to seat on the bead 32 of the cup member 3! and a cross-shaped opening '36 similar to the opening 33 permits the application of the bar to the post;:25. Upon being properly assembled, the bar'is confinedbetween the head 32 and the extensions 26 of the post 26.

The manner of mounting the contact bar permits the same torock about a transversejaxis toenable its contacts to properly engage the stain that it is totally enclosed andprovides a complete enclosure for the contacts. It consists. of three separable interengaging sections, abase or near section 49, the top wall 33, and a cover or front-section 4|. 1

The ,base or rear section 40 comprises a rear wall 42, side walls 43, and a bottom wall 44, the rear wall 42 projecting down beneath the bottom wall 44 and having forwardly extending flanges 46 at'its opposite side edge portions which form substantially continuations of the side walls 43.

The rear wall 42 has two spaced square openings 46 to snugly receive mounting posts 41 riveted or otherwise fixed to the metal panel 5. The base section is held on the posts 41 in flat engagement with the panel by a screw 43 passed through the downwardly projectingpart of the rear wall and threaded into the panel 5.

The rear and

side walls

42 and 43, respective-- ly,. of the base section have connecting grooves 49 and 49', respectively, formed in their inner races to snugly receive the adjacent edge portions of the upper section of the arc enclosing chamber comprising the top wall 33. The top wall 33 is thus slidably engageabie with the baseor rear section from the front of. the switch.

This top wall 33 has two downwardly pro-- jecting webs 30 which provide partition walls to divide the interior of the arc enclosing or arcsuppressing' chamber into .three separated com--. partments. Obviously, each pair of stationary contacts 3 is disposed in .one of the compartments thus formed and likewise. the cooperating movable contacts move in these separated compartments for coaction with the stationary con- The stationarycontacts, like movable con- :5 v

2,071,149 tacts,are formed of a silver cadmium alloy and are electro-welded onto the heads of copper bolts 5|, the stems of which project through and above the top wall to also mount terminals 52. The top wall 38thus not only provides one wall of the arc hood, but also serves as a terminal head to which the stationary contacts and their terminals are secured, and it is to be noted that the terminals for the contacts are offset with respect to each other so that all of them are readily accessible from the front of the switch to "facilitate the attachment of conductor wires thereto.

The upper surface of the top wall 38 is .pro vided with upstanding ribs 53 which divide the top thereof into shallow compartments so as to isolate the respective terminals from each other. The central or longitudinal rib 53 has its ends offset as shown in Figures 8 and 9 and has its extremities overlying the adjacent edges of the side walls 43. When the top wall is properly as sembled with the base or rear section of the arc enclosing chamber, the engagement between the ends of the ribs 53' and the front edges of the side walls 43 permits the top wall to move all the way back, but if the top wall is angaged in the grooves 49' in reversed position, i. e., with its front edge rearward, the engagement of the extremities of the rib 53 with the front edges of the side walls 43 will preclude complete and proper engagement of the top wall with the base or rearsection, and as will be hereinafter described, will preclude the application of the cover or front section, thus clearly indicating that the flanges 55 which engage in complementary grooves 56 inthe rear wall of the rear or base section and similar grooves orrecesses 51 in the front wall 58 of the cover or front section 4|; and the lower edgesof the two webs or partitions 50 have sliding engagement with grooves 58 in the bottom wall 44 Pof the rear or base section and grooves 60 in the bottom .wall 6| of the coveror front section.

Consequently, the partitionwalls which "divide' the arc enclosing chamber into separated compartments have a tongue and groove interengagement with both the rear or base section and the front or cover section so as to provide an effective seal betweenthe respective compartments. This interengaging tongue and groove joint-between the engaging portions of the different sections provides overlapping surfaces suflicient to form a tortuous leakage path long enough to cool an are or hot gases escaping from .one compartment into the other so that the poswith the bottom wall 44 of the rear or base section to complete the bottom'for the arc enclosing chamber. The side walls 62 of the cover section coact with the side walls 43 of the base section to complete the side walls of the arc enclosing chamber and like the rear or base section, the inner faces of the front and side walls have continuous and connecting grooves 03 and 83 to slidably receive the adjacent edge portions of the top wall 38. To accommodatethe extremities of the longitudinal rib I3 on the top wall, the side walls 62 have recesses 84 above and communicating with the grooves-63', these recesses being of a size to just receive the extremh ties of the longitudinal rib 53' when the top wall is properly assembled but to prevent complete application of the cover when the top wall is improperly mounted.

There is also an interengaging overlapping joint between the abutting edges of the side walls of the front and rear sections, as shown.

Holes 63 in the front wall 58 receive the threaded outer ends of the posts 41 so that by means of nuts 66 threaded on the posts, the three sections comprising the arc enclosing chamber are held assembled. Obviously, it is only necessary to remove the nuts 66 to permit withdrawal of the cover section when it is desired to expose the contacts for inspection and if a new set of stationary contacts is necessary, the entire top wall may be replaced so that the substitution of contacts is an extremely simple matter.

The bottom wall of the arc enclosing chamber. which is formed jointly by the bottom walls 44 and SI of the base and 'cover sections, respectively; has three holes 61 formed half in the base section and half in the cover section, as illustrated, These holes lead to the separated arc suppressing compartments and are of a size to slidably receive the cup members 3| with just sumcient clearance for free sliding action. In

other words, the cup members 3| substantially close the holes 61 so that while the movable contacts are actuatable from without the arc suppressing chamber, the completeness of the en- .closure aiforded thereby is not destroyed to the point of interfering with the confinement of the arc, but it is to be observed that the clearance between the cup members and the walls of the holes is sufficient to facilitate or enable rapid venting of accumulated gases from within the chamber At this point it may be noted that the cup members 3| in conjunction with the cup members 31 a guards againstthe possibility'of having their coils catch on the edges of the holes 81. Besides these- -functions, the spring enclosures afforded by the telescoped cups 2! and 3| serve to close the holes 61 as noted and coact with the heads of the posts to prevent. rocking of the contact bars on their lcngitudinal'axes.

In operation, when the electromagnet is energized, the armature is drawn up in a straight line to impart a straight line motion to the contactcarrier which lifts all of the movable conthus simultaneously disengaging all of the may-- able contacts from their respective stationary contacts and breaking each line at two places.

The arc which tends to form upon opening of the switch is suppressed and quickly and effectually extinguished. While -it is not positively known just what produces the exceptional arc extinction obtained with this switch, tests indicate that it must be the combined efiect of a tions away from each other and against opposite walls of the chamber by reason of the relative positions of the stationary contacts and bridging bar and the conductors leading to the contacts,

plus the deionizing effect which the silver cadmium alloy of the contacts has upon the closely confined arcs, and the fact that the clearance between the spring-enclosures and the holes 61 through which the spring assemblies enter the chamber compartments facilitates the escape or enables venting of the accumulated gases from the interior of the chamber without delay after extinction of the arc so that the chamber is cleared of any deleterious and objectionable gases to make it ready for a closely following cycle, possibly explains how this desirable arc quenching or suppressing efiect is obtained.

Stated briefly, it is thought to be the close confinement of thearc to produce a suppressing pressure, cooling of the are by contact with closely adjacent wall surfaces, the deionizing effect of the metal of which the contacts are composed and the rapid venting of the accumulated gases after extinction of the are which brings the desired results.

The cooling effect mentioned is augmented by shallow cavities 10 in the walls which the arcs impinge.

A hold-in switch to maintain the solenoid energized is provided by means of two spaced stationary l2 and 13 mounted on

terminal members

14 and 15, respectively, fixed to the downward projection of the rear wall and one ofthe flanges 45 projecting therefrom on the base section of. the arc hood. Cooperating with these stationary contacts 12 and 13 are auxiliary movable contacts l6 and '11, respectively, both carried by a contact bar 18 which serves toelectrically bridge the contacts .12 and 13 when the movable contact structure is in its circuit closing position. The contact bar 18 is slidably mounted on a post I! fixed to an insulated arm secured to a web ll formed as-an integral part of the molded contact carrier 20, and an expansive spring 82 coiled about the post .18 provides contactpressure for the hold-in switch.

As will be readily apparent from the drawings, the stationary contacts 12 and I3 may be mounted at either side of the switch and likewise; the cooperating movable contacts may be mounted at either end of the carrier bar 20.

Overload relays, indicated generally by the numeral 85, are mounted one at each side of the electromagnet assembly. The detail of these units forms no part of this invention and is therefore not shown or described. For a descriptionof their specific construction, reference may be had to Patent No. 1,992,595, issued to Gustav O. Wilms February 26, 1935.

These overload relays are of the resiste-therm type and when tripped may be reset by depressing a button 86 which is accessible from the outside of the cabinet in which the switch is mounted.

The resetting mechanism includes, besides the button 86, a sliding-structure 81 slidable in a stationary guideway 88. The inner spaced ends 89 of the sliding structure are engageable'with the reset arms 90 of the relays so that upon depressicn of the button, the resetting of the relays is eflected.

Heretofore, in switches of this type, it was possible to defeat the overloadprotection by holdingin the reset button, but with the present invention.this is impossible because of the fact that as long as the reset button is held down closure of the contactor unit to switch closing position is prevented. To this end, the sliding structure 81 has two wings 9| which move into the path of the pole pieces of the armature upon depression of the reset button, as shown in Figure 10. Consequently, as long as the button is held down, lifting of the armature by the solenoid to close the switch is prevented. Hence, it is impossible with this construction to defeat the protective feature of the overload relays.

From the foregoing description taken in connection with the accompanying drawings, it will be readily apparent to those skilled in the art, that this invention provides a substantial improve ment in the construction and design of plunger type electric switches and that by reason of the novel are enclosing cham'ben, flash-over between the poles of the switch is eiiectually prevented and as a consequence, instantaneous rupturing of the arc is practically insured and the interrupting capacity of the switch is materially increased.

It will also be apparent thatthe inherent design of the switch of this invention makes the I same self-insulating so that it may be mounted on any non-insulating support. This very highly desirable feature 'is the direct result of the particular construction of the arc suppressing chamber in that all live parts of the switch are either carried directly by or enclosed within this chamber which being formed of a food insulating material provides all the insulation for the switch and thus entirely obviates theneed for slate or other insuiating panels.

The means whereby closure of the switch is prevented during the resetting of the overload protective relay and the novel structural relationship of the switch parts and their mounting as defined herein, form the subject matter of divisional applications, Serial Nos. 119,554 and 119,555, respectively, both filed January 8th, 1937.

What we claim as our invention is:

1. In an electric switch, a plurality of sets of stationary and movable contacts, an enclosure comprising three separable fitting sections, integral webs on one of the sections to form partitions dividing the interior of the enclosure into separated compartments each of which contains a set of stationary and movable contacts, and

interfitting connections between the edges of said verse axis and to restrain rocking movement of said part comprising a contact spring yieldingly urging the movable contact towards the stationary contact and a spring enclosure telescoped over the contact spring and freely slidable' through the opening so as to substantially close the opening without interfering with the action of the spring.

3. In' an electric switch, a pair of spaced stationary contacts, a contact bar for electrically bridging the same, a cup member having a transverse bead pressed into its end wall, and means for maintaining the contact bar and cup member "assembled so that the bead provides a fulcrum upon which said contact bar may rock, said last named means including a spring seated in said cup member.

4. In an electric switch, spaced contacts, a contact member for electrically bridging the same, a T-shaped post having an interengaging separable connection with the contact member limiting outward endwise' motion of said member on the post and permitting inward endw'ise motion thereof, a spring foryieldingly urging the contact member outwardly on the post, and a cup member telescoped over the post and the spring with its end wall interposed between the spring and the contact member, the meeting portions of said members being shaped to provide a fulcrum about which the contact member may rock.

5. In an electric switch, a pair of spaced contacts, a contact bar for electrically bridging the same,a mounting post for the contact bar, a detachable connection between the contact bar and ,the mounting post preventing disassembly of said parts in the normal position of the contact bar, a compression spring mounted on said post for yieldingly urging the contact bar outwardly on the post and thereby providing contact pressure for the contacts, and a complete enclosure for the spring comprising telescoped cup members,

the ends of the spring bearing against the end walls of the cup members so that said cup members are yieldingly held apart by the spring and the end wall of the cup member adjacent the contact bar being interposed between the spring and the contact bar.

6. In an electric switch, a pair of spaced mov- ,able contacts, a contact bar carrying the contacts and electrically bridging the same, and an actuator for the contacts including a movable member of insulating material, a mounting post projecting from said member of insulating material, a detachable connection between the mounting post and the contact bar preventing disassembling of the parts as long as the bar is in its normal position and enabling detachment of the contact bar from the post upon revolving the bar about the axis of the post to a predetermined position, an

expansile spring encircling the post and adapted to yieldingly urge the contact bar outwardly on the post, and an enclosure for the spring comprising two telescoped cup members, one cup member having its end wall disposed between the insulating member from which the post projects and the adjacent end of the spring and the other cup member having its end wall interposed between the contact bar and the adjacent end of the'spring.

'7. In an electric switch, a pair of spaced sta-v the bar on its longitudinal axis.

, 8. In an electric switch, a pair of spaced stationary contacts, a contact member for electrically bridging the same, a post on which the contact member is slidably mounted, a spring encircling nection with the contact bar permitting limited sliding-of the contact bar on the post, a cup member telescoped over the post and resting on a shoulder at the base thereof, a second cup member positioned over the post and having a telescoped engagement with the first named cup member, the end wall of the second named cup member being formed with a transverse bead having a sliding but non-rotatable connection with the post which holds said beadtransverse to the contact bar so that the bead forms a fulcrum on which the contact bar may rock, and a spring encircling the post and having its ends bearing against the end walls of the cup members to yieldingly urge the same apart and provid contact pressure for the contact.

10. In an electric switch, the combination ofa chamber having a hole in itsbottom wall, stationary contacts within the chamber, a contact bar for electrically bridging the stationary contacts, a carrier for the movable contact bar outside the chamber, a mounting post on said carrier and projecting through said hole to have a connection with the contact bar inside the chamber, a spring coiled about the post and pressing against the contact bar to yieldingly urge the same toward the stationary contacts, and telescoped cup members encircling the spring to completelyenclose the same with the ends of the spring bearing against the end walls of the cup members, and one of the cup members having a free sliding relationship to the walls of the hole so as to substantially close the same.

11. In an electric switch, two spaced stationary contacts, a contact bar for electrically bridging the same, a mounting post on which the contact bar is slidably mounted, a spring encircling the post and pressing against the bar to yieldingly urge the same outwardly on the post, and corrimon means to enclose the spring without eifectivelyginterferlng with the action of the spring and to hold the contact bar against rocking on its longitud nal axis. I

12. In an electric switch including cooperating stationary and movable contacts, a'chamber enclosing the contacts and having an opening into the interior thereof, a stationary contact secured to one wall of said chamber, a member movable through said opening and having a retention head at the extremity thereof, a movable contact carried slidably upon said member, a spring surrounding said member and tim said movable contact against the retention head of said member, and a sleeve surrounding said spring and movable with said member and conformed to the shape of said opening so that said sleeve may slide therethrough while substantially closing th same.

same outwardly on the post, and a cup-like enclosure for the spring fitted over the spring with its end wall interposed between the bar and the adjacent end of the spring and so fitted to the spring and the bar as to enable rocking movement of the bar about a transverse axis while restrainingi rocking movement of the bar on a longitudinal axis.

14. In an electric switch, spaced stationary contacts, a movable contact adapted to bridge the stationary. contacts, an actuator for the movable contact comprising a carrier of insulating material, means for moving the carrier toward and from the stationary contacts, an upstanding post rigidly mounted on the carrier and having a retention head on its upper extremity, the movable contact being slidably mounted on said post and constrained againstoutward movement thereon by said retention head, a coil spring encircling the post and bearing against the carrier and the movable contact so as to yieldingly urge the movable contact outwardly on the post, and a cylinder-like enclosure for the spring, said enclosure having at least one end wall slidably receiving the post and confined between the adjacent end of the spring and the part against which it bears so as to be held in place by the spring.

15. In an electric switch for industrial control service, a contact enclosing chamber composed of three separate sections, one of said sections providing a solid top wall and the other two sections conjointlyproviding rear, front, bottom and side walls for the enclosure, an interfltting connection between the first named section and at least one of said other two sections embodying overlapping surfaces so that the first named section is supported therefrom when the other of said two sections is removed to afford access to the interior of the enclosure and at the same time said first.named section is readily detachable from its supporting section, a stationary contact on the undersurface of the top wall, an exposed,

outside terminal above the top wall and electrically connected with the stationary contact, the bottom having an opening opposite the stationary contact, a movable contact engageable with the stationary contact, and a carrier and actuator assembly mounting the movable contact and having a part slidable through said opening in the bottom wall to effect engagement and disengagement of the contacts from outside the chamber.

16. In an electric switch for industrial control service having cooperating stationary and movable contacts, a carrier assembly mounting the movable contact and operable to carry the same 'into and out of engagement with the stationary contact, an enclosure for the contacts comprising three separate sections, one of said sections being a top section and forming a solid top wall for-the enclosure and 'mounting the stationary contacts, the other two sections being compleseparable connection between the top section and the rear section so that the top section is readily detachably supported by the rear section to enable the front section to be removed without disturbing said top and rear sections, andsecuring means for holding said complementary sections together.

17. In an electric switch for industrial control service having cooperating stationary and mov-v able contacts. a carrier mounting the movable contact and operable to carry the same into and out of engagement with the stationary contact,

an enclosure for the contacts comprising three fitting sections, one being a rear section, one

a front section, and the other a top section.

means on the rear section for mounting the same on a supporting member, a connection between the top section and the rear section whereby the top section restricted to a sliding motion in assembly is readily detachably supported from the rear section and detachable therefrom with a forward sliding motion, and means for removably holding the front section in fitting relationship with the rear section and with part thereof obstructing forward sliding motion of the top section so that by securement of the front section in-fitting relationship to the rear section, all of said sections are held assembled and upon removal of the front section complete disassembly of the sections is permitted.

18. In an electric switch-having cooperating stationary and movable contacts, a supporting member, a housing of insulating material for enclosing the contacts and mounting the-stationary contacts on the supporting member, said housing comprising three fitting sections, one being a rear section, one a front section, and the other a top section, the top section having the stationary contacts mounted thereon, a connection between the top section and the rear section restricted to a sliding motion in assembly whereby the top section is readily detachably supported from the rear section and detachable therefrom with a forward sliding motion, and means rigidly fixed against lateral motion with respect to the supporting member for removably holding the front section in fitting relationship to the rear section with a part of the front section obstructing forward sliding motion of the top 'section and for holding the assembled sections fixed against shifting on the supporting member.

19. In an electric switch including cooperating stationary and movable contacts, a; chamber enclosing the contacts and having an opening into the interior thereof, a stationary contact secured to one wall of said chamber, a carrier, a movable contact carried by said carrier, resilient means between said carrier and said movable contact, and a shield surrounding said resilient means and movable in said opening for substantially closing the same. v

20. In an electric switch including a plurality of sets oi cooperating stationary and movable contacts, a plurality of chambers enclosing said sets of contacts and having openings into the interior thereof, a set of stationary contacts secured to one wall of each of said chambers, a carrier, a plurality of movable contact sets carried by said carrier, resilient means between said carrier and each of said movable contact sets, and shields surrounding said resilient means and movable in said openings for substantially closing the same.

21. In an electric switch for industrial control Service, two spaced stationary contacts, a bar toward and from the contacts to electrically bridge the same, conductors leading to the contacts from a direction opposite to the approach of the bar, an arc-enclosing chamber enclosing said contacts and bar, said chamber having but a single opening leading thereto, a carrier assembly for moving the bar to and fromthe contacts and having a part movable through said opening and substantially closing the same, the internal dimensions of the enclosure being such that its walls lie closely adjacent to the contacts and bar, and the clearance between said part which moves through the opening and the walls of the opening being sufiicient to facilitate the escape of accumulated gases from within the chamber but close enough to confine the arc within the chamber.

22. In an electric switch for industrial control service, two spaced stationary contacts, a bar movable with substantially a translating motion toward and from the contacts to electrically bridge the same, conductors leading to the contacts from a direction opposite to the approach 01' the bar, an arc-enclosing chamber enclosing said contacts and bar, said chamber having but a single opening leading thereto, a carrier assembly for moving the bar to and from the contacts said opposite walls to produce a quenching effect upon the arcs, and the clearance between said part which moves through the opening and the walls of theopening being sufllcient to facilitate the escape of accumulated gases from within the chamber but close enough to confine the are within the chamber.

'23. In an electric switch for industrial con-- trol service, an arc enclosing chamber having a top wall and having but'a single opening leading into the chamber, two spaced stationary contacts mounted from the under surface of .the top wall, terminals disposed above the top wall and electrically connected with said contacts, the portions of the terminal connections adjacent to the contacts approaching the same in a downwardly direction, a bar movable upwardly with a translating motion toward the contacts to elec trically bridge the same, a carrier assembly for moving the bar to and from the contacts and having a part movable through said opening and substantially closing the same, said enclosure being of such internal dimensions that its walls lie closely adjacent to the contacts and bar, and the clearance between said part which moves through the opening and the walls of the opening being sufficient to facilitate the escape of accumulated gases from within the chamber but close enough to confine the are within the chamber.

24. In an electric switch for industrial control service, an arc enclosing chamber having a top wall and having but a single opening leading into the chamber, two spaced stationary'contacts mounted from the under surface of the top wall, terminals disposed above the top wall and electrically connected with said contacts, the portions of the terminal connections. adjacent to the contacts approaching the same in a down-' wardly direction, a bar movable upwardly with a translating motion toward the contacts to electrically bridge the same, a carrier assembly for moving the bar to and from the contacts and having a part movable through said opening and substantially closing the same, said relative positions of the bar, contacts and conductors being such as to cause arcs drawn between the contacts and bar to move outwardly away from each otherin a definite direction towards opposite walls of the chamber, and theinternal dimensions of the enclosure being such that its walls lie closely adjacent to the contacts and bar, whereby the'outwardly projected arcs impinge said opposite walls to produce a quenching effect upon the arcs, and the clearance between said part which moves through the opening and the walls of the openingbeing suflicient to facilitate the escape of accumulated gases from within the chamber but close enough to confine the arc within the chamber.

25. In an electric switch for industrial control service, an arc suppressing chamber of restricted volume and closed on all sides exceptfor, an entrance opening in its bottom, a stationary contact mounted inside the chamber, a movable contact cooperable therewith, and a carrier assembly mounting. themovable contact and'operable to move the same with a translating motion toward and from the stationary contact, said actuator having, a carrier part and another part providing a resilient and the sole mounting of the movable contact from the carrier part and supporting the movable contact in such a manner as to allow the same to adjust itself to the stationary contact, one of \said parts being movable in the entrance opening and conformed thereto so as to. substantially close the same wherebyopening of the switch under load is accompanied by a compression of gases within the chamber to effect are suppression.

26. In an electric switch for industrial control service, two spaced stationary contacts, a movable bar for electrically bridging the same, an arc enclosing chamber enclosing said contacts and bar, said chamber having but a single opening leading thereto, a carrier assembly for moving the bar to and from the stationary contacts with a translating motion, said carrier assembly having a carrier part and another part providing a resilient, andthe sole, mounting of the movable contact from the carrier part and supporting the movable contact. in such a manner as to allow the same to adjust itself to the stationary contacts, one of said parts being movable in the entrance opening and conformed thereto so as to substantially close the same, the internal dimensions of the enclosure being such that it has a restricted volume with its walls lying closely adjacent to the contacts andbar, and the clearance between said part which moves through the opening and the walls of the opening being suflicient to facilitate the escape of accumulated gases from within the chamber but close enough to the movable contactand operable to move the same with atr'anslating motion into and out of engagement with the stationary contact, a boxlike housing providing a chamber enclosing the contacts, said housing comprising front and rear sections, which together provide the front, rear,

bottom and side walls 01' the housing, and a top section so fitted to at least the ,rear section that when properly assembled therewith said top and rear sections are held against all relative motion except an assembling and disassembling motion substantially parallel with the plane oi! the top wall, and means for readily detachably holding the sections against separation.

28. In an electric switch for industrial control service, a chamber closed on all sides except for an entrance opening leading thereto, a stationary contact mounted inside the chamber from one wall thereof, a movable contact cooperable therewith, and a carrier assembly mounting the movable contact and having a part extending through the entrance opening to carry the movable contact with a translating motion to and" from engagement with the stationary contact, said chamber being of sectional construction,

means on one of the sections for attaching the rier for the movable contactmember, and means for-mounting the contact member from the carrier including a ,coiledfsprlng, a two-part enclosure for said spring, each part having an open end, one of said parts having its closed end bear ing against the carrier and receiving the thrust- ,of the spring, the other of saidparts having its open'en'd receiving the opposite end of the spring and biased by the spring against the contact member, said two parts being positioned with reent r 2,071,149.v

I on the arc.

spect to each other by mutually engaging sur-' faces, and means to limit outward travel of the contact member from the carrier.

80. In an electric switch, a chamber closed on all sides except for an entrance opening, two spaced stationary contacts inside the chamber, a movable contact member to-electrically bridge the stationary contacts, a carrier for the movable contact member disposed exteriorly or the chamher, and means for mounting the movable contact member from the carrier, said means entering the chamber through the entrance open ing and substantially closing the same and including a coil spring, a two-part. enclosure for the spring, each part having an open end; one of said parts having'tits closed .end bearing against the carrier and receiving the thrust of the spring, and the other of said parts having. its open end receiving the opposite end of the spring and biased by the spring against the contact member, said two parts being positioned with respect to each other by mutually engaging suri'aces, and means to limit movement of the con- -tact member away from the carrier.

31. In an electric switch for industrial control service, a stationary contact, a movable contact engageable therewith, an arc enclosing chamber enclosing'said contacts and having but a single opening leading into the chamber, a carrier assembly having a part movable through said opening to substantially close the same, the internal dimensions of the enclosure and the clearance between said part which moves through the opening and the opening walls being such that an are drawn between the contacts is clowly confined, and the meeting faces of thecontacts being composed substantially of a silver cadmium alloy so as to GUSTAV 0. WILMS. HANS PETERSEN.

/ CERTIFIQATE or cosascrron.

February 16, 1,937.

cus'rAvo. WI-LlviS, ET. AL.

have a deionizing effect It is. hereby certified that error appears in the printed specification 1 erthe :above' numbered patentfrequiring correction .as follows: Page 5, I se no column, 15.119939, claim-l0, strike out the word "movable"; sebondi column, lines l9 and ,20, claim 17, strike out the words "restricted we sliding motion in assembmy" and insert thewame after "section" second occurrence, line 18;, same claim; and that the said Letters Patent ohm-11 be read with these corrections therein that the same may conform to the record of the case in the Patent; Office.

Signed and sealed this 30th day of. March, A. D. 1937."

can I Henry ivan Aredale Acting Commissioner of Patents.

Disclaimer 2,071,149.Gustav 0. Wilms, Milwaukee, and Hans Petersen, Wauwatosa, Wis. ELECTRIC SWITCH. Patent dated Feb. 16, 1937. Disclaimer filed Dec. 13,

1948, by the assignee, Allen-Bradley Company. Hereby enters this disclaimer to 01 2 and claims 19 to 26, inclusive, in said specification.

[Ofiicial Gazette January 11, 1949.]

Disclaimer 2,071,149.Gustav O. Wilms, Milwaukee, and Hans Petersen, Wauwatosa, Wis. ELECTRIC SWITCH. Patent dated'Feb. 16, 1937. Disclaimer filed Dec. 13, 1948, by the assignee, Allen-Bradley Company. Hereby enters this disclaimer to elajni 2 and claims 19 to 26, inclusive, in said specification.

[Oflicial Gazette January 11, 1.949.]