US3188406A

US3188406A - Multiple plunger electrical switch for sequential contact operation and dynamic braking

Info

Publication number: US3188406A
Application number: US80862A
Authority: US
Inventors: Scribner Arthur Clayton
Original assignee: Ward Leonard Electric Co
Current assignee: Ward Leonard Electric Co
Priority date: 1961-01-05
Filing date: 1961-01-05
Publication date: 1965-06-08
Anticipated expiration: 1982-06-08

Description

3,188,406 CONTACT June 8, 1965 I A. c. SCRIBNER MULTIPLE PLUNGER ELECTRICAL SWITCH FOR SEQUENTIAL OPERATION AND DYNAMIC BRAKING 4 Sheets-Sheet 1 Filed Jan. 5. 1961 INVENTOR. Aqrflw (Znyro V 6017/5054 BY W XM Q ArTOqr/EY June 8, 1965 A. c. SCRIBNER 3,188,406 MULTIPLE PLUNGER ELECTRICAL SWITCH FOR SEQUENTIAL CONTACT QPERATION AND DYNAMIC BRAKING Filed Jan. 5. 1951 4 Sheets-Sheet 2 Ti ='.11= m m 40 INVENTOR.

3,188,406 CONTACT m 1955 A. c. SCRIBNER MULTIPLE PLUNGER ELECTRICAL SWITCH FOR SEQUENTIAL OPERATION AND DYNAMIC BRAKING 4 Sheets-Sheet 5 Filed Jan. 5. 1961 INVEN TOR.

f Mayra/v Se /a #5 June 8, 1965 A.'C. SCRIBNER 3,188,406

MULTIPLE PLUNGER ELECTRICAL swmcn FOR SEQUENTIAL CONTACT OPERATION AND DYNAMIC BRAKING Filed Jan. 5. 1961 4 Sheets-Sheet 4 Arrwwr United States Patent 3 133,406 MULTIPLE PLUNGER ELECTRICAL SWITCH FER SEQUENTIAL CONTACT OPERATIQN AND DYNAMIC BRAKING Arthur Clayton Scribner, Rowayton, Conn, assignor to Ward Leonard Electric Co., Mount Vernon, N.Y., a corporation of New York Filed Jan. 5, 1961, Ser. No. 80,862 11 Claims. (Cl. zoo-17 This invention relates to plunger operated electrical switches and particularly to switches having a plurality of sets of contacts making and breaking in a given relation.

In electrical apparatus it is often desirable to connect the elements of the apparatus in different relationships to provide for dilierent electrical conditions. For example, in starting, running and stopping an electrical motor the windings are preferably connected in a different manner for each condition. On starting the motor the starting winding and a starting capacitor are connected between the inputterminals and in parallel with the main winding. Under running conditions the starting winding is disconnected and the main winding is connected between the input terminals. In stopping the motor the main winding is disconnected from the input, and the starting winding' and the capacitor are connected in series across the main winding to create a dynamic braking.

An object of this invention is to provide an electric switch with a plurality of sets of contacts that may be operated in a given relationship in response to mechanical actuation.

Another object of the invention is to provide a multicontact switch that comprises a minimum number of parts that are easily assembled.

Another object of the invention is to provide a multi contact electric switch that on starting connects the starter winding across the main winding, connects the main winding to the input terminals, disconnects the starting winding and then on stopping disconnects the main winding from the input and connects the starting winding across the main winding to apply dynamic braking.

Other and further objects and advantages will be apparent from the following description taken in connection with the drawings in which:

FIG. 1 is an exploded perspective view of the major components of the switch;

FIG. 2 is a top view of the assembled switch;

FIG. 3 is an open side view of the switch with one of the housing sections omitted;

FIG. 4 is a cross-sectional view of the assembled switch taken along lines 44 of FIG. 3.

FIG. 5 is a sectional view of the upper contact portion of the switch taken along line 55 of FIG. 3;

FIG. 6 is a schematic view of the functional portions of the switch and the circuit connections to the motor;

FIG. 7 is a perspective view of the center terminal;

FIG. 8 is a perspective view of the main terminal;

FIG. 9 is a perspective view of the armature;

FIG. 10 is a perspective view of the stop lever; and

FIGS. 11a-e are diagrammatic representation of the relationship of the fixed contacts and movable contacts.

Referring to the drawings, there are illustrated in FIGS. 1-5 the major components of the switch. The housing or casing is formed in two

identical housing sections

21, 22 and forms the major supporting and guiding means for the stationary and moving elements of the switch. The two

housing sections

21, 22 are held together as an integral unitary housing 20 by means of overlapping contacting

edges

100, 101 of the sections and the bolts 27 and nuts 28. The armature is held by the sections in fixed relation thereto and in a position for engagement by the main contact carrier 23 on the starting and running of a motor. The terminals 132-137 are also held in fixed relation to the housing with the fixed contacts 32-37 within the housing for engagement by the moving

contact bars

33, 39, 4G and the terminal clamps 132a137a exterior to the housing for securing the leads to the terminals.

The housing supports and guides the movement of the main contact carrier 23, the trip or disconnect actuator 24 along with the stop lever 25. In cooperation with the housing section 21 the main contact carrier supports and guides the starting and braking contact plunger 26 along the line of movement of the carrier. The movement of the main contacts is limited in the disengaged position by the stop 29 and in the engaging position by the armature 3G. The magnet means 31 on the carrier 23 holds the carrier in the engaging position by engaging the armature 3d until the magnetic linkage is disrupted by the trip actuator 24 and stop lever 25. The contact carrier 23 is pressed upwardly against the stop means 29 by resilient means such as

helical spring

41, 42, and the starting and braking contact plunger is also urged upwardly by resilient means, such as the helical spring 43 positioned between the lower portion of the contact carrier 23 and the plunger. Stop means 47 on the plunger limits the upward movement of the starting contact plunger in relation to the main contact carrier. The

contact bars

38, 39, 49 are, on the other hand, resiliently urged downward by resilient means such as the

helical springs

44, 45, 56.

Referring more particularly to FIG. 6, the connections of the switch to the motor 50 and the operation of the switch will be explained. The motor 55) is an alternating current motor having a main winding 51 and a starting winding 52. A starting condenser 53 is connected in series with the starting winding 52. Alternating

current input terminals

54, 55 are connected to the motor windings through the contacts of the switch. The

terminals

54 and 55 are connected to main

fixed contacts

32 and 37 and the main winding is connected between the main

fixed contacts

33 and 36 so that on bridging of

contacts

32, 33 by the contact bar 38 and

contacts

36, 37 by contact bar 49 current will be supplied to the main winding. The starting winding and condenser are connected across main winding to start the motor by the contact bar 39 bridging the

fixed contacts

34, 35. The auxiliary contacts 34, 34a are connected to one end of the main winding and the

auxiliary contacts

35 and 35a are connected to the other end through the series connected starting winding and condenser. These fixed contacts form upper and lower auxiliary contact means. On the initiation of a starting procedure the contact carrier 23 and the starting contact plunger 26 are in the raised position as indicated in FIGS. 6 and 11a. As the starting contact plunger is depressed the contact bar 39 is disconnected from contacts 34a, 35a and the lower end of the starting contact plunger 26 engages the contact carrier 23 to move the main contact bars 33 and 4e simultaneously with contact bar 39 which is in advance of bars 38 and 49. The bar 39 connects the starting winding 52 and condenser 53 across the main winding 51 (FIG. 11b) prior to the connection of main winding 51 to the input terminals by

bars

38, 40. On the completed downward movement the

bars

38 and 40 complete the circuit (FIG. 11c) and the main contact carrier 23 is locked in the load current supply position by the magnetic means 31 and the armature 30. When the motor has accelerated to a speed at which the main winding 51 is able to carry the load without aid from the starting winding 52, the pressure on the starting contact carrier is removed. The resilient means or spring 43 forces snae see the plunger 26 upward to disconnect the bar 39 from the

contacts

34, 35 and thereby disconnecting the starting winding from input terminals. The stop means 47 limits the upward 'movementto prevent engagement of the contacts 34a, 35a by the bar 39. The contact bar 39 is in a :neutral position (FIG. 11d). The motor is stopped by depressing the trip plunger 24 which pivots the stop lever 25 to separate the magnetic means 31 and armature 3.0. The

springs

41, 42 force the contact carrier 23 and starting contact plunger 26 upward to the initial position With'the bar 39ZCO11I16CtiI1g'the starting winding 52 and condenser 53 across the main winding 51 to apply dynamic braking and-thus quickly stop the motor.

The

housing sections

21 and 22 are made of plastic material and are formed by the same mold. The sections have

side walls

60,61; top Walls '62, 63; bottom-

walls

64, 65; and end walls :66, 67 and 68, 69 respectively. 'On

the exterior of the housing sections are terminal blocks 71 and 71 respectively formed as a single piece with a respective housing. The terminal blocks include

corner bosses

72, 73 and 74, 75 for fastening the switch to an appropriate structural member. The bosses have

slots

76,77, 78 and 79 respectivelyfor receiving bolts or other suitable fastening means. Theblock 76 has terminal recesses 80, 81 and 83 and block 71 has

terminal recesses

84, 85 and 36. The

side walls

60, 61 having openings 90 91,92 and 93, )4, 95'respectively for passing contact armstof terminalsintotheinterior of the housing.

The

main'terminals

132, 133, 136, 137 are illustrated inFIG. 8 and each comprises acontact supporting mem- --ber158, an L-shaped member 138 and a fastening member 1149. The contact supporting members 158 extend through openings at 93, 92, 95 respectively within the housing'and support the

main contacts

32, 33, 36, 37 of a respective terminal. The-L-shaped supporting members 138 have apportion 138a recessed in the grooves 90a, 92a, 93a, 95ain the side walls 61 61 and a portion '138bpositionedin the bottom of the

recesses

30, 84, 83, 86. Plates "139, 140 fitinthe side walls-60, 61 to close the openings 911-95 and cover the terminalportions138a. Theplates hold theterminals in position by thebolts 27 and nuts 28. Grooves 141, 141a are providedto recess the

plates

139, 1 1th in the outside surface of the housing.

The terminal clamps-148 are mounted on the fastening members149 extending from the L-shaped member 133 andare located in the

recesses

80, 84, 83, 86.

The'terminals 134,135 are similar to the main terminals with L-shaped members 1432, fastening members 173 and contactsupporting member-171 withextension member 172. The member 142 has a portion 142a recessed-in grooves 91a, 94a and covered and retained by plates 139, 14-0 and aportion 1142b recessedin the bottom of the openings 81,85. The

terminals

134, 135 have a second contact 34a, 35a extending upwardly from the

contacts

34, 35 and spaced-therefromwith the contact buttonsfacing one another for engagement by the bar 39. The fasteningmembers .173 extend from the -L-shapedmember142 and clamps 174 are mounted on the fastening members-for securing leads .to the terminals.

7 --wall. Alongtheside edges of the'portions 138b, 142b are ears 1.45 which fit into slots146 formed by the raised portions 147' on the sidewalls of .the 'recesses. Thus .the contacts are held firmly in place. 'The tabs 143 have a slight upward offset so that the distance between the contact supporting members and the tabs is slightly less than. the corresponding .distance between the openings 90-95 and the respective openings'144, This in combination with the ears holds the terminals snugly in place and prevents the upward displacement of the contacts. The terminals snugly fit in the openings 90 to 95, recesses 96a to 95a and recesses 80 to 86 to prevent sidewise movement 'of the contacts. The

end cover plates

139, 140 retain the terminals in place.

Inside the

housing sections

21, 22 are

partitions

97, 98 and 99, 100 extending from the insidesurfaces of the

side walls

60, 61

and'top walls

62, 63. The partitions extend to be substantially'even with the edges 101 and 161a so that on assembly of the sections the partitions of the opposing section engage to form a contact chamber housing the contact carrier 23. The partitions are spaced from the adjacent side walls to form

passages

102, 103 at each side of the housing for the trip or endplunger24. Also projecting from and molded as a part ofthe side walls are

guide bosses

104, 105 and 10.6, .107 spaced to guide the plunger 26. i

The main contactcarrier 23'is a singlemoldedpiece and has a flat platform 110, a generally U-shaped member 111 on one side thereof. The U-shaped member has

side portions

112, 113 and a topcross member 114 having a U-shaped section forming a slot in the center of the contact carrier.

The starting and stopping contact carryingplunger '26 has an elongated shaft having a rectangular cross section and two longitudinally extending slots 115, 1-16 spaced by contact. barin the slot.

a web 117. The slot-115 carriesthe contact bar 39 and helical spring 45. The spring urgesthebarto'ward the web. The spring 45 is'of. the helicaltype and is seated around the boss which preferably hasa rectangular shape. Thebossforms a means for preventing sidewise movement of the end of the. spring and forlocating the spring in the slot. The contact bar 39 is a thin metal piece having a generally rectangular shape extending on opposite sides of the plunger 26 andhaving generally rectangular notches 11am the side edgesto retainthe Inthe center ofthe baris an eyelet 11? punched in the contact bar toprovide an attachingmeansfor the end .of the spring 45 to the contact bar for retaining the spring inplace in theslot. '-The contact bar has two, pairs of contact buttons,1 2tla, [7, 121a, b, with one. pair on the opposite side of the bar from the other pair to provide twoseparate contacting positions. The spring 45 normally holds the contact bar against the bottom surface of the slot. The side walls or surfaces of the slot and the notches on the contact bar provide means .for guiding the bar on relative movement between the plunger and the movable contact .bar.

The spring .43 is positioned'between the end of the starting contact plunger 26 and the member ofpthe, contact carrier to impart a movement between the plunger 26 and carrier 23. The spring is seatedon the boss122 on the plunger and boss122a on the carrier 23 to center .the spring andprevent sidewise orlateral movement of the spring. The contact plungerld has extensions 123 on each side of the spring. of equalilength' to limit the movement of the contact plunger"26 towardthe member of the contact carrier'23. Stop means'injthe form 'of fianges47 are provided to. limit the relativernovement of the plunger 26 andcarrier' 2 3 in the opposite direction. Thus the plunger'26 is movable relative to contact carrier 23; in the plane of movement of'the carrier -23with a resilient means urging the plungeri26' inthe opposite direction to the resilient means engaging the1contactbar 39.

The contact carrier,23 also carriespthe contact" bars 38,40. However, these bars have a single movement in relation to the -fixed contacts as distinguishedfrom-the compound movement of the' bar 39 in relation to the fixed contacts. The contact bars are mounted in-

slots

125, 126 formed by the partitions and the" U-shapedmember. The slots are positioned-at opposite sides of plunger 26. The plunger 26'is thus positioned between the con- -tact bars 38 and t0. The contact bars inlanditt, are

53 similar to contact bar 39 and in this embodiment the bars are of the same length. The notches 127 in the longitudinal edges fit in the slots and provide a guide on cooperation with the surfaces of the carrier.

The

springs

44, 45 are positioned within the

slots

125, 126 respectively to urge the contact bars 38, 41} in the same direction as contact bar 39. The springs are seated around the

rectangular bosses

128, 129 at one end and interlocked with the contact bars by the end of the springs fitting into

eyelets

139, 131 stamped in the bars.

The plunger 26 is slideably mounted in the housing 25.

' The ribs or

partitions

98, 99 and 97, 190 are formed with guide grooves 159, 151. The

side walls

112, 113 of the carrier engage the groove to limit the movement to a linear action. The carrier has projecting flanges 152 on each side to engage the respective stop edges 29, 29a of the partitions to limit the disconnect movement of the carrier 23. The contact engaging movement is limited by the magnetic means 31 engaging the armature 3i Helical springs 41, 42 resiliently urge the

contacts

38, 39 and 31D out of contact with the fixed contacts 32417. The armature 30 is in fixed relation with the housing 2! and has projections 153 for seating the springs 4-1, 42 and the carrier 23 has rectangular bosses 154 for seating and holding the springs against sidewise movement.

The magnetic means 31 is mounted on the platform 110 of the carrier 23 and comprises a yoke member 155 and a rectangular wafer-shaped magnet 15 5. The yoke member 155 and the armature 30 are made of high permeability material and the magnet is a relatively thin section of permanent magnet material that can be readily magnetized through its thickness with north and south poles on opposite sides.

The platform 110 of the carrier 23 extends on each side of the U-shaped member to form a larger rectangular surface 157. On each side of this surface extending normally from the member are thin retaining

members

160, 161, 162 with hooked shaped

edges

163, 164, 165 for holding the yoke 155 and magnet 156 on the carrier to form a strong interlocking of the magnetic means 31 and the carrier 23. The carrier 23 is molded plastic material and the thin retaining members 160-162 are resilient in relation to the member to permit the yielding of the thin members so that the yoke and magnet may be snapped into place. The retaining edges have sloped

surfaces

166, 167, 168 and the magnet means on being pressed against these surfaces causes the thin retaining members to separate and the magnetic means seat against the surface of the platform 110 and are held in place by the retaining edges. The retaining members 160, ll are separated by a space 16?. The retaining member 162 on the opposite side is located opposite the space 169 so that the carrier can be molded without using complex die mechanisms to form the hookshaped edges. The opposite ends of the retaining met

bers

160, 161 have small webs 170 to retain the magnet in place.

The yoke 155 has turned edges 155:! which bear against the ribs 110a on the surface of the platform 119 to prevent endwise movement of the magnet means. Thus the magnet means is securely and fixedly fastened to the carrier 23. The retaining edges clamping the magnet means hold it from dislodgement by any force applied in a direction away from the carrier.

In the operation of the switch the magnet engages the armature forming a looking or latching means to hold the carrier 23 in the contact engaging position. The armature 30 comprises a single piece of magnetizable material and is held in a fixed position in the housing 20 by fitting in the notches 180 of the ribs 181. Two ribs 181 are molded as part of each housing section and the notches are formed with a flat surface 182 and an opposing V-shaped surface 183. The armature has four arms 134-187 positioned in 'the notches and spaced from the V-shaped surface 183 and bearing against the flat surface. The arms 184437 extend from the body portion 188 having openings 1%,

195. The magnet contacts the main portion of the armature and spans the openings on each side. The armature has tabs 19% extending toward and engaging the bottom wall of the housing on the edge away from the trip plunger 24. The tabs 1% firmly hold the

arms

184, 185 against the flat surfaces. At the other end the stop lever 25 fits between the arms 1th), 187 and the V-shaped surface 183 to firmly hold the arms 1%, 187 against the flat surfaces 182. The projections 153 are positioned at opposite ends of the armature for supporting the helical springs.

An unlocking means is provided to separate the armature and magnetic means. The stop lever 25 is actuated by the trip plunger 24 and pivots or rocks on the V-shaped surface 183. The lever is slightly bent to permit the rocking action. The notches 191 fit around the ribs 181 to retain or hold the stop lever 25 in place. Two fingers or projection means 192, 193 of unequal length extend toward the armature and on pivoting of the lever fit into the

openings

194, 195 to engage the magnet and separate the magnet from the fixed armature. The

fingers

192, 193 are of different lengths. The finger 193 engages the magnet first and the force of the plunger raises the magnet disrupting the strong attractive force. The finger 192 then engages the magnet on the continued application of force to the plunger to raise the other side of the magnet thus separating the magnet and the armature. The plunger continues to separate the magnet and armature until the force of attraction between the magnet and the armature is less than the combined separating force of the

springs

41 and 42. This spring force continues to return the main contact carrier 23 to the disconnect position and presses the flanges 152 against the stops 29, 29a formed by the edges of the partitions.

After the magnet is spaced from the armature the contact bars 38 and it) disengage from the

contacts

32, 33 and 35, 3'7 disconnecting the main motor winding from the input. The main contact carrier moves the contact bar 39 from the neutral position to engage the fixed contacts 34a, 35a. The spring 43 holds the flanges 47 against the carrier so the starting contact plunger 26 remains in fixed relation to the main contact carrier 23. After the main contacts are disconnected, the contact bar 39 closes the dynamic braking circuit by engaging the contacts 34a, 35a. This connects the main winding 50, starting winding 51 and condenser 53 in series promptly stopping the motor.

The stop lever 25 and trip plunger 24 are unbiased and the fingers are held in the recessed position by the magnetic means. The plunger 24 is slideably mounted in the passage between the partition and the end wall and extends outside of the casing through the opening 200. The plunger is provided with a slot 261 for passing the bolt 27 holding the housing section together.

The actuator 2 1 has a knob or head 2%2 on the exterior end. Pressure on the knob forces the plunger into the housing and the stop lever fitting in the groove 203 is pivoted about the fulcrum formed by the wedge shaped surface moving the fingers through the openings in contact with the magnet. The stop knob 202 is rectangular in shape and the surface engaged by the finger is ribbed. The start knob 2% is circular and has a convex upper surface. Thus the knobs may be distinguished by touching the upper surface or the shape of the knob.

The slot 2% is formed by removing the web pieces 2G4, 285. In order to utilize a single mold to manufacture the housing sections, the slot 200 is formed at each end of the housing with the thin web sections. The web section 264 on one section and the web section 205 on the other section are removed and the two sections fitted together. The web sections 264, 2115 at the other end are intact covering the opening. Thus a single piece may be formed from a single mold to form both halves of the housing.

One of the features of the switch is the ease of assem- -bly. The z'fixed terminals 132%37 are slid into the re- -cesses 89,-8.6 inserting the contacts 32%?7 throughthe openings 9fi.95 and fitting the tabs 1% in the openings 1A4- .and.-.the cars 1145 in the slots 146. The armature 3% and stoplever 25 are fittedinthe notches 180 in the ribs 181 ofone ofthe housing sections. The helical springs .areihooked into

theeyelets

130, 131, the open ends of the springsare seated on the .bosses 1:28, 129 andthe contact .bars 38, lllare fitted in

theopenings

125, 126

by tilting the bar, insertingit in the opening and then V :thegrooves -lt5fi, 151 in the-

partitions

97, 98. The helical springs 41, 4 2 are fitted in place on the projection 153.0fthe armature and the bosses 154 of the carrier. The starting contact-carrier is preassembled by placing the contact bar 39 and spring ,45 in the opening .115 in the same manner ascontactbars 38 and 40 are fitted .in carrier "23 and then by fitting the carrier into the notch in the. cross member 114 and the opening 22E? in the top .wall of the housingsection. The spring 4-3 is placed in .the opening 116 and seated on the bosses 12 2 and 1212a.

.The trip or stop plunger 2d is moved into place fitting the end of the stop lever in the groove 2% and the plunger in the slot 200 and either the

passage

102 or 103.

The other housing section ispositioned to mate with thepartly assembled housing section completely enclosing the Working parts with onlythe ends of the two .plungers and the'terminals extending through the house ing Walls. :The. cover plates-139 and 149 are fitted in the grooves 141,142 and the bolts 2'7 inserted and securely I held in placeby thenuts 28.

To start the motor the knob 206 is presseddown whichforces the starting contact carrier 23 down disconnecting the. contact bar 39 from the upper fixed con- .tacts 34a, 35a. and the starting Winding 52 and theco ndenser 53 from .across .the main winding. The downwardmovement continues andthe platform 110 is engaged pressing the contact carrier 23 down with the startvingcontact plunger 26. The contact bar 3,9 engages the

contacts

34 and 35 before the contact bars engage the contacts 32,-:33 and 36, 37 respectively (FIG. 11b). Thus the startingwindingSZ and condenserSS are reconnected :across the main winding before the main Winding is connected to the

input terminals

54, 155. The continued .downward'movement compresses the helical spring .43

and the contacts .38 and 4-6 are then moved into engagement withthe'fixed contacts (FIG. llc). Thus the switchinherently assures by this sequential action that 1 the capacitor 53 will be connected in series with the start- .ing winding; 52 and the series combination across the run or main winding filbefore any of the circuit elements .are connected. to the electrical supply.

With allthe contactsbridged .a circuit for themain current is provided through the fixed contact32, contact vbar 38, fixed contact'33, main Winding .51, fixed contact 3.6,\contact barAtLfixed contact 37 to the input terminal 55. Another current path is provided from 54 through the contact 32, contact bar 38, contact 33, contact'34, contact bar 39, contact .35, capacitor 53, start WindingxSZ, contact36, contact bar :40, contact 37 .to the terminal '-:55. .With these two circuits completed the motor-50 develops torqueand the. motor increases to the :desired speed.

The contact carrier 23 is moved further down to press .1116 magnet-2156 against the armature'ilfi to magnetically .couple the two elementsand hold the contact carrier in the'engaged position. The attractive pull ofv the lines of I ;force coupling the yoke, ,magnet andarmature. is greater than the combined force of the helical springs. The contact'bars 38 and at) are .heldin a firm electrical contact with the fixed contacts to transmit large amounts of current. The attractive force is sutficient to pull the carrier down when the airgap is reducedto a small space.

When the motor v5t) has accelerated to a speed at which the main or run winding is ableto carry the load without aid from the start winding .52, the pressure or force on the knob 206 may be removed. The starting contact carrier 23 will then move upwardly due to the compression of spring .43 and the flanges 47 engage the cross bar 114 and are firmly'held there under the force of spring 43. This upward movement disengagesthe contact bar 39 from the fixed contacts 34, (FIG. 11 61). The main carrier 23 is retained in the depressed condition by the magnet means .3 1 and armature 30 andthe contact bars 38 and remain in engagement with the fixed contacts. This is the normalrunningcondition.

"T he depressed positionof the contact carrier 23 prevents the contact bar 39 from engaging the contacts "34a, 35a andholds thebar in a neutralposition (FIG. lid). The winding 52 and capacitor'53 are disconnected.

In order to stop the ,motorthe stop actuator 24 is pressed down and the stop lever 25 pivotcd to separate the magnet 15s and the armature 30 so that the combined forces of the helical springs 4-1, d2 will lift the contact carrier and disconnect the contact-bars 3.8 .and ltl. The upward movement of the carrier carries the start contact carrying plunger 26 into engagement with'the fixed, contacts 34a, 35a (FIG. 110). The contact bar is forced against theweb 117 and the spring .43 is compressed pulling the flanges away from the carrier 23. Thebridging of the contacts 34a, 35a applies dynamicbrakingto the motor by connecting the winding 52 andcondnser 53 across the main winding with themain winding disconnected from theinputterminals From the foregoing description it is .seenthat the switch is small, compact andself-contained. ,Theparts are easily and inexpensively. made .-with ,a sequence of actionwhich starts and stops a motor with. only two manual operations. A minimum of fastening parts-are required and the operating and housing parts may. be easily molded. 7

With this simplicity of structure the switch, will accomplish the functions, of connecting the start, winding of a motor and its associated capacitor in parallelwith the run or main winding, of connecting.boththe start and run windings to the electrical power. supply, of disconnecting the start winding and capacitorfrom thepower. supply afterthe motor has accelerated to speed, of disconnecting the run winding from the powerv supply ,andof connectingthe start and runwindingsandcapacitorin series to apply-dynamic braking. i

Itis, of course, understood that the switch may be used with other electrical devices than, motors or motors having the particular arrangement of windings and capacitors. Also, various modifications may be made inthe shape of the magnet and the armaturdand the magnetic means and the armature may be interchanged.

The invention is set forth in the accompanying claims.

I claim:

1. In an electric switch; a casing fixedly a supporting main contacts and reciprocally supporting a main contact carrieractuatable inand .out of engagement with the main contacts and .having a first resilient means biasing the carrier into a non-engagingposition, .upper and lower auxiliary contactmeans spaced in direction of movement of the maincontact carrier, a, startingand stopping contact plunger reciprocally ,mounted. in said main contact carrierand having a contact bar resiliently .urged in the direction of the engaging position of themain contact carrier and the main contacts and second resilient means between said main contact carrier and plunger urging a separation of the contact bar and lowerauxiliary contact means in direction of .disengagementof the .main

- the upper auxiliary contact means.

2. In an electrical switch; fixed main contacts, a main contact carrier reciprocally mounted to move along a line of movement in and out of engaging position with said main contacts, resilient means engaging said carrier for urging said carrier out of engaging position, a first and second pair of fixed auxiliary contacts spaced along the line of movement of said contact carrier, a contact plunger reciprocally mounted on said main contact carrier to move in the direction of said contact carrier to engage the first pair of auxiliary contacts on movement in main contact engagement and to engage the second pair of auxiliary contacts on movement from the main contact engagement, resilient means mounted between said plunger and carrier for urging said plunger out of engaging position with said first pair and said main carrier, said plunger being normally spaced from said main carrier along the line of movement to provide an initial leading advance into auxiliary contact engaging position of said plunger over main contact position of said carrier, and said plunger resilient means returning said plunger to a position out of contact with either of said pairs of said auxiliary contacts on maintained engagement of the main contact carrier and on disengagement of said contact carrier from the engaging position said main resilient means forcing said plunger in cooperation with said plunger resilient means into engagement with the second pair of auxiliary contacts.

3. For starting and stopping an electric motor having a main winding and a starter winding with one end connected to the main winding, an electric switch comprising a two-section housing having means for reciprocally guiding contact carrying members and having two sets of main fixed contacts engageable by separate bridging contact bars, a set of starting fixed contacts and a set of stopping fixed contacts, said latter two sets being electrically one piece and spaced from one another in the direction of movement of the contact carrying members, a main contact carrier reciprocally mounted in said housing sections and having two contact bars for engaging a respective set of fixed main contacts with resilient means for urging the contacts against said fixed main contacts in the direction of movement of said contact carrier, a starting and stopping contact carrying plunger reciprocally mounted in said main contact carrier and said housing sections and resilient means between said plunger and said main carrier to urge said plunger from said main contact carrier in a direction opposite to the contact engaging of said main carrier, said plunger having a starting and stopping contact bar movable between said two sets of starting and stopping fixed contacts and resiliently urged toward said starting fixed contacts in the direction of engaging movement of said main contact carrier, said resilient means between said carrier and said plunger normally spacing said carrier and plunger so that on depression of said plunger said plunger contact bar engages said starting fixed contacts in advance of said main contact bars and on release of pressure said plunger contact bar disengaging to a neutral position between said starting and stopping contacts while said main contact bars remain in engagement and on disengagement of said main contact bars said plunger contact bar engages said upper set of stopping fixed contacts to apply dynamic braking.

4. An electric switch comprising two substantially identical housing sections positioned face to face with each section formed of a single molded piece having a side wall, end walls and a top wall, said housing sections having partitions extending from a respective side wall and top wall and spaced from said end walls to form in said housing sections a contact chamber between said partitions and bound by said top wall and said side wall and guide passages between said partitions and an adjacent end wall, guide bosses spaced laterally and extending from said side wall intermediate said partitions and spaced downwardly from said top wall, openings in said side walls and main fixed contacts and upper and lower fixed auxiliary contacts extending through said walls into said chamber, a main contact carrier positioned between said partitions in said chamber and reciprocally guided by the partitions and engaging the main fixed contacts in the downward engaging position, a starting and stopping contact carrying plunger reciprocally mounted on said main carrier and between said guide bosses to reciprocate said plunger independent of said main carrier, said upper and lower auxiliary contacts being spaced in direction of movement of said plunger, latch means below said main carrier for holding said main carrier in contact engaging position, and trip means including an actuator reciprocally mounted in one of said passages and resilient means between said latch means and the main carrier to urge said main carrier into disengaging position and resilient means between said main contact carrier and said plunger to urge said plunger out of engagement with said lower auxiliary contacts and space said plunger in a' neutral position between said upper and lower auxiliary contacts out of contact therewith when said main contact carrier is in engaging relation and on disengagement forcing said plunger in cooperation with said main contact carrier resilient means to raise the plunger into engagement with the upper auxiliary contacts.

5. An electric switch as set forth in claim 4 wherein said main carrier has means for engaging one of said partitions to limit the upward disengaging movement.

6. An electric switch as set forth in claim 3 wherein locking means are provided for holding said main contacts in engagement, said locking means comprising a magnetic means mounted on the bottom of the carrier and an armature fixedly mounted in said housing below said carrier and engaged by said magnetic means to hold said carrier in the engaging position.

7. An electric switch as set forth in claim 6 wherein actuating means are provided comprising a pivoted lever below said armature and having projection means for extending above said armature for engaging said magnetic means, a plunger reciprocally mounted in said housing and connected to said lever to pivot said projection means against said magnetic means to separate the magnetic means from said armature when said magnetic means is in contact therewith.

8. A locking electric switch comprising a casing hav ing an enclosed chamber, first and second sets of fixed contacts extending through said casing into said chamber, a contact carrier reciprocally mounted in said chamber, current carrying contacts resiliently mounted in said carrier for engaging the first set of said fixed contacts, means for locking said carrier in the engaging position, a plunger reciprocally mounted in said chamber, second current carrying contacts resiliently mounted on said plunger for engaging and said second set of said fixed contacts, said plunger in an engaging and disengaging relation with said carrier to move in the engaging relation the contacts on said carrier into engaging position with said first set of fixed contacts, said contact of said plunger positioned in relation to said second set of fixed contacts to engage said second set in advance of said carrier contacts engaging said first set and in the disengaging relation said plunger contact disengaging from said second set and moving to a position out of engagement with any contacts while said carrier contacts are in engagement with said first set of fixed contacts and trip means for disengaging said carrier from said locking means.

Claims

2. IN A ELECTRICAL SWITCH; FIXED MAIN CONTACTS, A MAIN CONTACT CARRIER RECIPROCALLY MOUNTED TO MOVE ALONG A LINE OF MOVEMENT IN AND OUT OF ENGAGING POSITION WITH SAID MAIN CONTACTS, RESILIENT MEANS ENGAGING SAID CARRIER FOR URGING SAID CARRIER OUT OF ENGAGING POSITION, A FIRST AND SECOND PAIR OF FIXED AUXILIARY CONTACCTS SPACED ALONG THE LINE OF MOVEMENT OF SAID CONTACT CARRIER, A CONTACT PLUNGER RECIPROCALLY MOUNTED ON SAID MAIN CONTACT CARRIER TO MOVE IN THE DIRECTION OF SAIF CONTACT CARRIER TO ENGAGE THE FIRST PAIR OF AUXILIARY CONTACTS ON MOVEMENT IN MAIN CONTACT ENGAGEMENT AND TO ENGAGE THE SECOND PAIR OF AUXILIARY CONTACTS ON MOVEMENT FROM THE MAIN CONTACT ENGAGEMENT, RESILIENT MEANS MOUNTED BETWEEN SAID PLUNGER AND CARRIER FOR URGING SAID PLUNGER OUT OF ENGAGING POSITION WITH SAID FIRST PAIR AND SAID MAIN CARRIER, SAID PLUNGER BEING NORMALLY SPACED FROM SAID MAIN CARRIER ALONG THE LINE OF MOVEMENT TO PROVIDE AN INITIAL LEADING ADVANCE INTO AUXILIARY CONTACT ENGAGING POSITION OF SAID PLUNGER OVER MAIN CONTACT ENGAGING POSITION RIER, AND SAID PLUNGER RESILIENT MEANS RETURNING SAID PLUNGER TO A POSITION OUT OF CONTACT ON MAINTAINED ENGAGEPAIRS OF SAID AUXILIARY CONTACTS ON MAINTAINING ENGAGEMENT OF SAID AUXIARY CONTACT CARRIER AND ON DISENGAGEMENT OF SAID CONTACT CARRIER FROM THE ENGAGING POSITION SAID MAIN RESILIENT MEANS FORCING SAID PLUNGER IN COOPERATION WITH SAID PLUNGER RESILIENT MEANS INTO ENGAGEMENT WITH THE SECOND PAIR OF AUXILIARY CONTACTS.