US1995896A - Magnetic switch - Google Patents

Description

March 26, 1935. J, pENGlLLY p -r AL 1,995,896

MAGNETIC swITcH Filed April 24. 1929 5 Sheets-Sheet 1 H TTG/QA/E Y.

oct. 1o, 1933.

vE. H. MERRTT ET AL METHOD AND APPARATUS FOR APPLYING FLUID MATERIALS TO IOVING SURFA'CES Filed lay 8, 1931 4 Sheets-Sheet 2 r-UC INVENTORS A TTORNEYS March 26, 1935. J. H. PENGILLY ET AL MAGNETIC SWITCH 5 Sheets-Sheet 3 Filed April 24. 1929 .9 n/perf P Jna Lawrcnca G. Naccb/e J. H. PENGILLY Er AL 1,995,896

March 26, 1935.

MAGNETIC SWITCH Filed April 24, 1929 5 Sheets-Sheet 4 F, t (9' E0 7 /5/ /42 /3 /350/$71 g Ef Z Wj/{f/Z/ g .u @a 'WMM gllllll 9, M5

*Il M A Tron/vir Mmh 26, 1935.

J. H. PENGILLY Er AL 1,995,896

MAGNETIC SWITCH Filed April 24, 1929 5 Sheets-Sheet 5 Patented Mar. 26, 1935 ,Y

UNITED STATES PATENT OFFICE MAGNETIC SWITCH Joseph H. Penlllly, Rupert P. Snoke, and hwrence G. Maechtlen. Los Angeles, Calif., assignora to Square D Company, Inc., a corporation of Delaware Application April 24, 1929, Serial No. 357,672

6 Claims. (Cl. 200-5) Our invention relates to electrical switches, and net extends into the wiring space. Such a conmore particularly to those switches which are opstruction permits a deiinite saving in space and erated by a magnetic means which is controlled allows the pivot point about which the contactor by a control switch. Such control switches are bar moves to be so positioned that this contacter 5 usually situated some distance from the magnetic bar, and the amature associated therewith, may 5 switch itself, thus requiring vunnecessary wiring be moved gravitationally without the use of any and a separate container therefor. linkage.

It is an object of our invention to provide a mag- Still a further object of the invention is to pronetic switch controlled by `o, control switch situvide a contactor bar with a plurality of shields l ated in the same enclosing structure as the magformed integrally therewith, each adjacent pair 10 netic switch, this control switch being operable of shields defining a channel in which a contact from the exterior of the enclosing structure withmay be moved. out danger of manual contact with any of the Still other objects lie inthe particular structure working parts of the switch. of the contactor mounting. In the mounting of i A further object of the invention is to provide our invention, the contactors are easily and quickl5 a magnetic switch and a control switch therefor, ly removable for inspection or replacement, and both mounted on the same panel, and to provide are resiliently retained against corresponding an opening in the enclosing structure through contacts by a spring. In our construction this which an arm capable of operating the control spring is not obliged to carryany electrical curswitch may extend when the enclosing structure rent, thus preventing any annealing thereof due 20 is closed. Such an arrangement permits easy to the heat generated therein by the passage of access to the terminals and working parts of the electrical current therethrough. switch when the switch is dead and when the Another object of the invention is to provide enclosing structure is open, and eliminates any contacts which are pivoted to the contacting bar flexible leads connecting the control switch conand which have a very desirable wiping action 25 tacts with the main switch contact. during the closing and opening of the switch.

A further object of the invention is to provide Still a further object of the invention is to proa magnetic switch controlled by a single control vide a switc having easily removable arc shields member, which if moved in one direction, causes for prevent g any arcing between the contacts the switch to close, and if moved in another diconnected to contactors of different potential. 30 rection opens the switch. Another object of the invention lies in the novel Still a further object of the invention is to pivot support for the armature which carries the provide a relay which may be reset by a movement contactors and a contactor bar. of such a control member. Still another, and very important, object of the A further object of this invention is to provide invention is to provide a switch which may be 35 a contactar bar carrying one or more contacts utilized for a number of dlilerent purposes inand moved under the iniluence of an electrocluding both the magnetic and manual control magnet during the closing of the switch, this conof electrical appliances. tactor bar being so mounted as to utilize gravi- Further objects and advantages of this inventational forces during the opening of the switch. tion will be made evident in the following descrip- 4o A further object of the invention is to provide tion. 'Ihis is especially true with regard to the an enclosing structure for a switch in which a particular construction of the switch which we wiring space is provided in the rear of the switch have found to be not only a very efllcient one, but panel so that all conduits may communicate with also one permitting manufacturing economies not this space. Such a construction allows wires to heretofore attained. 45 be brought in from any side of the enclosing struc- Referring to the drawings, in which we have ture through suitable knock-outs provided thereshown a preferred embodiment of our invention in, and allows all of the external wires to lie in for illustration,- this wiring space, thus preventing these wires Fig. l is a perspective view of our switch unit from passing in front ot the operating mechwith one ofthe arc shields removed. 5o anism or being otherwise in danger of entangle- Fig. 2 is a front view of the switch with the ment therewith. cover of the enclosing structure closed.

A further object of the invention is to mount Fig. 3 is a front view of the switch with the enan electromagnet solenoid in an opening of the closing structure open. switch panel. preferablv so that the electromag- Fig. 4 is a detailed sectional view of the main 55 switch elements of our invention, and is taken as indicated by line 4-4 of Fig. 3.

Fig. 5 is another detail of this construction taken on the line 5-5 of Fig. 3.

Fig. 6 is a view of the key of our invention.

Fig. 7 is a vertical sectional view taken on the line 7-7 of Fig. 3.

Figs. 8, 9, and 10 are sectional views of the con- `trol switch of our invention in three different Fig. 14 illustrates the wiring diagram of our.

switch. 4

Fig. 15 is a view similar to Figs. 8, 9, and 10 and illustrates an attachment' which may be utilized to adapt the switch of our invention for use with any pilot control, such as iioat switches, pressure governors, thermostats, etc.

Fig. 16 is a wiring diagram of the form of our switch shown in Fig. 15.

Referring particularly to Figs. 2, 3, and 7, the

switch of our invention is enclosed in an enclosing structure 15 formed of a box 16 and a cover 17 suitably hinged together as indicated at 18. The box 16 and cover 17 are preferably formed of metal, and are drawn to shape by well-known methods. I

Mounted inside the enclosing structure 15, and supported by brackets 18 suitably secured, to the box 16 and comprising a switch-supporting means, is a switch unit 20 of our invention. This switch unit is best illustrated in Fig. 1 and the details `thereof are illustrated in the subsequent figures. This unit comprises a panel 21 which is clamped to the brackets 19 by a pair of screws 22 and by a screw 23, The former screws t into slots 25, while the latter bolt ts in a button-hole socket 26 so that the whole switch unit may be quickly and easily removed from the supporting structure by loosening the screws 22 and 23 and raising this unit a small distance so that the heads i of the bolts will not interfere with the direct withdrawal of the switch unit from the enclosing structure. The panel 21 is preferably formed of molded insulating material, the type of material we prefer to utilize being that known in the art as bakelte.

The switch unit 20 provides a mounting for four groups of switch elements. The main group of these elements is designated generally by the numeral 27'which is utilized as the main contact for supplying current to the electrical apparatus controlled by the switch. The operation of the main switch elements 27 is governed by a magnetic means 28 controlled by a set of control switch elements l indicated generauy by the' numeral 29.

We also provide interlock or auxiliary switch elements 30 which are utilized for maintaining the energization of the magnetic means 28 during the time that the switch is closed, as will be hereinafter explained. So also, the switch unit 20 provides relay switch elements 3l which are adapted to trip the switch upon the occurrence of certain predetermined adverse conditions.

Referring particularly to Figs. 1, 3, 4, 5, and 7 we have'illustrated the main switch elements 27 as comprising three contacts 33, 34, and 35, each of which is secured tothe panel 21 by screws 36 threaded into sleeves 36a retained by the panel;

and three contactors 37, 38, and 39 which are adapted to move into engagement with the contacts 33, 34, and when the magnetic means 28 is energized in a manner to be hereinafter described. Inasmuch as the details of construction of each contact and contactor are identical only one pair of these elements and their associated structures will be described.

Thus, referring to these figures, we provide an arc shield 40 for each pair of main switch elements, this shield being preferably formed of a molded material having a high dielectric strength such, for instance, as that material known in the art as bakelite. apron which surrounds its pair of main switch elements on three sides, this apron being open at the rear end, and providing side walls 41 extending nrearward into contact with the panel 21. Each arc shield is held in place by a springclip 43 retained by a screw 36 thereadjacent, in a. manner best shown in Fig. 5. This clip is formed of a piece of spring metal bent into a U-shape illustrated in Fig. 5, the arms of the U being normally spaced a distance greater than the distance between the walls 41 of the arc shield, so that when the arc shield is forced over the clip, these arms press outward against the side walls 41, thus acting to hold the arc shield in place.

The position of the arc shield on the panel 21 is determined by ribs 44 which are molded into the panel 21 and shaped as best illustratedin Fig. 3, these ribs being spaced apart a suflicient distance so that the side walls 41 of the arc shield fit therebetween. These arc shields `prevent arcs from forming between adjacent contacts or contactors, and the ease of removal of` these arc shields is an important part of this invention inasmuch as it permits easy installation of -the switch. The removal of the are shield permits direct access to screws 45 threaded into the contacts 33 to 35 and serve as a convenient means for making 'the electrical connections to these contacts.

All of the contactors 37,38, and 39 are mount; ed on a. contactor bar 46 formed of insulating material, these contactors being retained in channels 47 formed between adjacent barriers 48 which are formed integrally with the contactor bar 46. Each contactor comprises a metallic bar, the lower end of which is pivoted to the contactor b ar 46 by means of a pin 48a cast in place in the contactor-bar 46, this pin extending into an opening 49 formed in the adjacent contactor. As best shown in Figs. 4 and 7, the pin 48a is mounted in a projection 50 of the contactor bar 46, this projection having an arcuate front surface 51 on which-the contactor pivots, the pin 48a acting to retain the contactor in place. The upper end of .each contactor provides a bent portion 52 which comes into engagement with the contact thereadjacent.

A resilient engagement between each contactor and its respective contact is maintained by a spring 53, which is compressed between a head 54 of a key 55, and the contactor. The shape of the key is best shown in Fig. 6 and provides a lug 56 from which lingers '57 project. 'I'hekey 55 is punched from a relatively thin sheet of metal, and the lug 56 passes through an opening 58 of the contactor and also through an opening 59 of the contactor bar.

elongated in a vertical plane to permit the passage of the lingers 57, but are too narrow in a Each arc shield provides an The openings 58 and'59 are pivotally connecting horizontal plane to permit this passage. Thus. by inserting the key through this opening and turning the key through 90, the ngers 57 engage notches formed at the rear end of the openings 59.

If the spring 53 is at this time in place, the

key will be iirmly locked, and can only be removed by forcing the head of the key toward the contactor, turning the key through 90, and withdrawing the key and its associated spring.

This contactor mounting is extremely simple in construction, and yet rugged enough to stand up under extremely severe conditions of operation. The pivotal connection between the contactors and the contacter bar is an important part of this invention, inasmuch as it insures line or surface contact between each contactar and its adjacent contact. Certain previous switches not using such a universal pivotal connection allow point contact to take place rather than line contact. Furthermore, while various methods of the contactor to the contactor bar are possible and fall within the scope of this invention, nevertheless, we have found the particular one shown to be extremely simple and effective.-

v'Ihe contactor bar 46 is directly vconnected to an armature 63 which is formed of a plurality of laminations 64 bounded on either side by an armature side plate 65. These armature side plates have lugs 66 at the upper ends thereof;

these lugs being bent sidewise and forming an attaching means for connecting the contacter bar to the armature. The lower ends of the armature side plates extend rearward and terminate in toes 67, these rearward extending portions having circular openings 68 formed therethrough.

The axes of the openings 68 formed in both of the side plates 65 are in alignment and are adapted to form a pivotal connection between the armature 63 and a core 69, this connection being completed by any suitable pivot means such as a pivot pin 70 which passes through the openings 68.

The core 69 is formed of U-shaped core laminations 71 bounded by core side plates extend below the U-shaped core and provide elongated openings 74 through which the pivot pin 70 passes, these openings being elongated in a horizontal plane. To provide an adjusting means permitting small adjustments of the contacter bar 46 and the armature 63 in an upright plane, we prefer to form the pivot pin 70 slightly smaller in diameter than the distance across the elongated openings 74. Similar openings 75 are formed a distance to the rear of the openings 74 and are adapted to receive screws 76 which are slidable therein, each of these screws being threaded into one end of a link 77, the other end of the link having a circular opening through which the pivot pin 70 passes. This structure provides an adjustable pivot means for pivoting the armature to the core, and is an important feature of this invention inasmuch as it permits the armature to be so adjusted with relation to the core as to eliminate the humming invariably present if the armature is not in surface contact with the upper leg of the U-sha'ped core. This upper leg is indicated by the numeral 78 and has a contacting surface 79 engaged by the armature.

The elongated openings 74 permit a relatively large forward and rearward adjustment of the lower end of the armature. and the independent attachment of the links 77 to the side plates 72 side plates 72. These permits one end of the pin 70 to be moved more than the other if desired, thus pivoting the armature on an upright axis. Thus, this pivot means provides a universal adjustment of the armature to insure surface contact between the armature 63 and the contacting surface 79. When once properly adjusted the screws 76 may be tightened, thus clamping the link to the core side plate thereadjacent.

The extreme retracted position of the armature 63 is determined when the toes 67 of the armature side plates respectively contact an extrusion 72a formed on each core side plate 72.

The magnetic means 28 includes an electromagnet forming a holding coil 80 which is positioned around the leg 78 of the core 69 and is adapted to attract the armature 63 when energized. This holding coil is retained in place by a U-shaped retainer 8l which fits over the core and extends therealong through the holding coil 80. 'I'he forward ends of this retainer are bent sideward, as indicated by the numeral 82, to retain the holding coil in position relative to `the core.

As will be noted from Figs. 3 and 7 in particular, the magnetic means is mounted in an opening of the panel 2l, the core 69 extending rearward into a wiring space 86 defined between a base 87 of the box 16 and the panel 21. Fig. 7 shows this relationship most clearly. this figure also illustrating knock-outs 88 which are formed in the walls of the box 16, preferably on all sides, so that when the cores thereof are knocked out, the remaining openings communicate directly with the wiring space 86.

Thus, conduits may be secured in place in any of the desired knock-out openings, as indicated by the dotted lines 89 of Fig. 7, and it is not necessary that the line wires and load wires extend from opposite sides of the switch as has been the case in previous structures. 'lhe provision of the wiring space86 eliminates any wires in front of the switch unit and permits the switch unit to be completely. wired even before positioning the switch unit in the enclosing structure if desired. Similarly, the switch unit may be removed from the enclosing structure without disturbing any of the wiring, the wiring space 86 acting as a storage space for a loop of wire in the event that a removal of more than a few inches is desired without disturbing e wiring of the unit.

Any particular m unting means may be utilized for mounting the magnetic means 28 in the opening 85, but we prefer to utilize a bracket 90 which is secured to the panel 2l by screws 90a and extends rearward and across the opening 85, this bracket being secured to lips 91 formed on the core side plates 72 and bent sidewise in the form of ears. If necessary washers may be placed around the screws 90a and between the panel and the bracket 90 to adjust the armature in a manner to insure that all of the contactors 37, 38, and 39 will simultaneously engage the contacts 33, 34, and 35.

The control switch elements 29 are positioned on a plate 95 formed of insulating material arid having apair of legs 96 contacting the panel 21 and retainedr thereagainst by screws 97. Positioned centi-ally on this plate is a metallic bracket 98 held thereagainst by screws 99 and 100 which pass through the plate and are threadedly received by the bracket.

A metallic plate 101 is similarly held in contact with that portion of the plate 95 to the left of the bracket 98 by means of screws 102 and 103. So also, a metallic plate 104 is retained in a similar manner by screws 105 and 106. A primary switch member 110 is slidably journalled in an opening 111 formed through the plate between the screws 100 and 105 and through a boss 112 extending rearward sfron this plate. This switch member passes loosely through a disc 113, or other current-carrying member, which is adapted to short-circuit the forward ends of the screws and 105 when the primary switch member is depressed. As will be apparent fromFigs. 8 to 10, this disc is resiliently retained between compression springs 114 and 115, the spring 114 being between the disc and a head of the primary switch member, while the spring 115 is between the disc and the lower end of an opening 116 formed concentric with the opening 111.

The screws 100 and 105 cooperate with the vdisc 113 in providing primary control switch elements which allow current to pass therethrough when a control member 120 is moved to the right. This control member is pivoted on a pin 121 retained in the bracket 98 and provides tabs 122 and 123 extending respectively to the right and to the left of the pin 121, the tab 122 being adapted to engage the head of the primary switch member 110 and move the primary control switch elements into engagement.

A portion of the control member 120 extends through an opening 124 of the cover 17 of the enclosing structure, this portion being termed an arm 125 and having at its outer end corrugations 126 to permit manual operation thereof. The opening 124 is formed in the rear Wall of a cavity 12611 of the cover 17, this cavity being preferably formed by a stamping operation. As will be noted from Fig. 7, the forward end of the arm 125 extends substantially in the same plane as the cover 17, and thus does not extend substantially beyond the walls of the cavity l26a. This prevents any accidental contact with the control member, inasmuch as no part of this member extends forward of the enclosing structure.

Adapted to be moved by the tab 123 when the control member is moved leftward, and slidably journaled -in an opening 127 between the screws 99 and 102, is a secondary switch member 128 having a shoulder 129 formed at the junction of the body of this switch member and a reduced diameter portion 130.

A disc 131, or other current-carrying member, loosely surrounds the reduced diameter portion 130, and is adapted to short-circuit the screws 99 and 102 when the secondary switch member 128 is not being depressed by the control member 120.A This engagement is made possible by a spring 132 compressed between the disc 131 and a cotter pin 133 extending through the reduced diameter portion 130. Another spring 134 is compressed between the plate 95 and a head formed on the secondary switch member The springs 114 and 115 are so designed that they hold the disc 113 in a position shown in Fig. 8 under normal conditions, and the springs- 132 and 134`are so designed that they hold the disc in contact with the screws 99 and 102 under such conditions. Similarly, these springs are designed to return the control member to a central position after manual engagement therewith'has ceased.

, The details of the relay switch elements 31 are best illustrated in Figs. 1, 3, 7, and 8 to l0.

Referring to these gures, we provide relay contact springs 135 and 136 extending in channels formed in the face of the panel 21, these channels meeting in the form of a V, as best shown in Fig. 3, the relay contact springs 135 and 136 being retained therein by screws 137. The adjacent ends of these contact springs overlap and provide contacts which normally tend to separate, but which are held in engagement by a latch pivoted in a bracket 141 retained in a channel of the panel 21. This latch member is pivoted on a pin 142 and is moved by a spring 143 in such a direction that a tooth 144 thereof normally retains the contact spring 135 in engagement with the contact spring 136.

The forward end of the latch 140 provides a tongue 147 and shoulders 148. A bracket 149 is mounted on the panel 21 and provides supports 150 and 151 to which bimetallic thermostatic elements 152 and 153 are secured. These thermostatic elements extend toward each other and are adapted, when heated, to bend in a manner to engage the shoulders 148. This engagement rotates the latch 140 counter-clockwise, as seen in Fig. 7, thus moving the tooth 144 from contact with the relay spring 135 and allowing the relay contacts to open. The thermostatic elements 152 and 153 are respectively heated by heating elements or resistors 155 and 156 mounted in front of the panel 21 in the immediate vicinity of their respective thermostatic elements.

e relay contact spring 135 is mounted in the path of movement of the secondary switch meme ber 128 so that when this member is moved into a position shown in Fig. 10, the end of the reduced diameter portion 130 comes into contact with the relay contact spring 135 and moves this spring into engagement withthe relay contact spring 136. If at this time the temperature of the thermostatic elements 152 and 153 has been suiciently decreased, the latch 140 may be actuated by the spring 143 to retain the relay contacts closed until such a time as the temperature of the thermostatic elements is suicient to disengage the relay contacts. It should thus be clear that the control member 120 acts to reset the relay contacts, as well as to actuate the primary and secondary switch members 110 and 128.

The interlock or auxiliary switch elements comprise a spring contact retained in place under the contact 35 by the screw 36 which retains this contact in place. This spring contact extends downward and in front of a bolt 161, a head 162 of which is adapted to be engaged by the spring contact 160 when the main switch elements are closed. This is accomplished by means of a leg 165 extending rearward from the contactor bar 46 and formed integrally therewith, this leg engaging the spring contact and moving it into engagement with the bolt 161 after the main switch contacts have been closed.

The wiring diagram of our invention is indicated in Fig. 14. Referring tothis figure, the conductors of a three-phase supply line are connected to the contacts 33, 34, and 35. One conductor of this supply line is connected to a conductor 16511 which extends to one terminal of the holding coil 80, the other terminal of this coil being connected by a conductor 166 to the relay spring contact 136. The other relay spring contact 135 is connected by a conductor 167 to the screw 102, the screw 99 being connected through the bracket 98 with the screw 100. This latter screw is connected to a conductor 168 which ex- 'rends to the bou; 161 of the interlock switch. The

ments, as indicated 'lock switch elements are screw 105 is connected to another o! the conductors of the supply line by a conductor 169 so that ii the control arm 120 is moved to the right in a manner to close the primary control switch elein Fig. 9, the holding coil, the relay contacts, and the primary and secondary control switch elements will be in series with each other across one phase of the supply line.

'I'his energizes the solenoid 80 and closes the main switch elements, and also closes the interlock elements, thus sending current through these interlock switch elements as well as through the primary control switch elements. When manual engagement with the control member 120 has ceased, this control member will assume its neutral position shown in Fig. 8, thus allowing the current necessary for energizing the holding coil to pass through the relay contacts, the secondary switch elements, and the interlock switch elements. This is made possible because the interconnected in parallel with the primary control switch elements.

When the main switch elements are closed, current is supplied therethrough to the load. The current passing through two o! the phases is put through the resistors 155 and 156, these resistors being respectively connected to contactors 39 and 37 by flexible conductors 170 and 171. The other side of these resistors are connected directly to the load 172 indicated in Fig. 14. A flexible conductor 173 is connected to the contactar 38 and to a conductor bar 174 embedded in the panel 21, this conductor bar being connected to a terminal `175 which is directly connected to the load.

Should an over-load occur in any phase, one or the other of the resistors will be heated thereby, and should this over-load be excessive, the heat will trip the relay contacts, thus de-energizlng the holding coil and allowing the armature and its associatedcontactar bar to move forward by the action of gravity. To reset the relay, it is only necessary to move the control member 120 to the left and into the position shown in Fig. 10, as previously explained.

Similarly, to de-energize the load 172 it is only necessary to momentarily move the control member 120 to the left, which opens the secondary control switch contacts, and de-energize the holding coil.

In certain instances it is desirable to connect the switch ot our invention to other types ot circuit than that illustrated in Fig. 14. Thus, the switch of our invention is adapted for use with any type of pilot control such as a float-operated switch, pressure governors, or a thermostatic control. When used in any of these capacities, it is often desirable to control the load either automatically or manually. This may readily be accomplished with the switch of our invention by placing a spring clip 180 under the olt 106 as indicated in Fig. 15, this spring clip having a channel 181 adapted to receive the free end of the control member when the arm 125 is moved to the right to retain the control member in a position shown in Fig. 9 until such a time as the switch is returned either tc neutral position or to the position shown in Fig. 10. A similar spring clip 182 is adapted to be secured under the bolt 103 and to retain the control member in this position. With this form of the invention the interlock switch elements are not used, and a thermostatic switch or oat or pressure-operated switch, or other pilot switch, such as indicated by the numeral 185 of Fig. 16 is connected between the screws 100 and 105 so as to be in parallel -low voltage, etc.

Thus, with the control element in neutral position, and the switch oi the high pressure cut, or similar device closed, the holding coil 80 is energized whenever the contacts oi the thermostatic,

'or other control switch, close,fand is de-energlzed whenever these contactsv open, thus providing automatic control governed by the control switch 185. Ii', however, manual control is to be resumed, the control energizing the load until such a time as the contacts of the high-presure cut-out or similar device open, which would, of course, de-energize the holding coil 80.

It should be understood that we are not limited to the particular form of the elements shown although the particular combination of elements illustrated has proved very e'ective. Various modifications may be made without departing from the spirit of the invention and we desire our invention to be limited only by the appended claims taken in conjunction with this disclosure and interpreted in their broadest scope.

We claim as our invention:

1. In a switch device of the character described, the combination of: a supporting structure; primary switch means supported by said supporting structure; secondary switch said supporting structure; means supported by said supporting, structure; a control member movably mounted on said supporting structure to separately operate said primary and secondary switch means and to operate said reset relay switch simultaneously with one of said primary or'secondary switch means, and resilient means urging said control member into position in which it operates none oi' said switch means.

2. In a switch construction, the combination of an enclosing structure; switch means mounted in said enclosing structure; a swingable control lever ior controlling the operation of said switch means having a position in which said switch means is opened and another in which said switch means is closed; and a cover i'or said enclosing structure, having a depression with an opening therein through which said control lever extends so as to be operable from the exterior of said enclosing structure and cover while not protruding beyond the face of said cover, said control lever having a portion which fillsl said opening at all positions of said control lever.

3. In a switch construction, the combination of: an enclosing structure; switch means mounted in said enclosing structure; a swingable control lever for controlling the operation of said switch means having a position in which said switch means is opened and another in which said switch means is closed; and a cover for said enclosing structure, having an elongated opening through which said control leverextends so as to be op- 6 erable from the exterior of said enclosing structure and cover, said control lever having a segment-shaped portion which fills said opening at all positions of said control lever.

4. In combination: a plate; primary and secondary switch members movable relative to said plate; primary and secondary switch elements respectively actuated by a movement of said primary and secondary switch members; a control member mounted in pivoting relationship with said plate in a manner to engage said primary switch member when moved in a primary direction and to engage said secondary switch member when moved in a secondary direction; and

resilient means urging said primary switch mem' ber for actuating said primary switch element to circuit closing position and urging said secondary switch member for actuating said secondary switch element to circuit opening position, saidV resilient means urging said control member into neutral position.

5. In combination: a plate; primary and secondary switch members movable relative to said plate; primary and secondary switch elements respectively actuated by a movement of said primary and secondary switch members; a control member mounted in pivoting relationship with said plate in a manner to engage said primary switch member when moved in al primary direction and to engage said secondary switch member when moved in a secondary direction; resilient means urging said primary switch member for actuating said primary switch elementv to circuit closing position and urging said secondary switch member for actuating said secondary switch element to circuit opening position, said resilient means urging said control member into neutral position; and other resilient means between each of said switch members and its companion switch element for resiliently resisting further movement of said switch member after its companion switch element is in circuit closing position.

6. In combination: a plate; primary and secondary switch members movable relative to said plate; 'primary and secondary switch elements movable into circuit closing and circuit opening positions in response to movement of said switch members; a control member mounted in pivoting relationship with said plate in a manner to actuate said primarysswitch member when moved in a primary direction and to actuate said secondary switch member when moved in a secondary direction; and resilient means associated with each o! said switch elements for permitting further movement of either of said switch members and further movement of said control member in a direction to actuate said either of said switch members to circuit closing position after said switch element associated with said either of said switch members is in circuit closing position.

JOSEPH H. PENGILLY. RUPERT P. SNOKE. LAWRENCE G. MAECHTLEN

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