US1477871A - Motor-starting switch - Google Patents

Description

Dec.

1,477,871 B. E. GETCHELL MOTGR STARTING SWITCH Filed June 27. L922 2 Sheets-Sheet 1 Fig; 1

INVENTOR 13, 1923* 12 1 B, E. GETCHELL MOTOR STARTING SWITCH 2 Sheets--Sheet 2 Filed June 27 1922 INVENTOR Patented Dec. 18 1923.

UNITED STATES PATENT OFFICE. v

BENJAMIN E. GETCHELL, 0F PLAINVILLE, CONNECTICUT. ASSIGNOR TO THE TRUE- BULL ELECTRIC MANUFACTURING COMPANY, OF ILAI'NVILLE, CONNECTICUT, A

CORPORATION OF CONNECTICUT.

MOTOR-STARTING SWITCH.

T 0 all whom it may concern:

Be it known that I, BENJAMIN E. Gnrcm ELL, a citizen of the United States of America, residing at Plainville, Connecticut, have invented a new and useful Motor-Starting Switch of which the following is s specification.

This invention relates to switches which may be opened and closed by hand, but is more particularly directed to switches for controlling motor circuits, and which release automatically upon undue variations in the load, thereby protecting the motors.

An important object of the invention is to provide a. simple, rugged switch mechanismv arranged to be closed by hand, and to be opened either by hand or automatically in response to certain changes in the load or line voltage.

A further object is to provide such a. switch having powerful means constantly urging the inovuble contacts to open circuit position while but a small amount of energy is required to hold the contacts in closed position when the load is normal.

A further object of the invention is to wear to give a quick break of the switchcontacts.

Other objects of the invention will be come n iipurent as the description progresses.

ln carrying out the invention there are provided :1 contact operating member. means such as a spring to actuate said member to open the switch. a. toggle joint or member having one part connected to the operating nicnrbcr. and an elcctrmnugnet connected'in the load circuit having an armature connected to the other part oi the toggle to hold the two parts in locking alignment to main tain the switch closed when the magnet is normally energized.

One embodiment of the invention is i1lnstinted in the accompanying drawings in which:

Fig. 1 is a perspective view with certain parts broken away of a switch and its operating means.

Fig. 2 is a central longitudinal section of the switch with the contacts closed, and

Fig. 3 is a similar section talnen on :2. slightly different plane showing the contacts open.

. A casing 4 of any desired type houses the entire switch which is supported on an insu lating base secured the casing as by the screws 5. The circuit closing members may comprise any desired number of blades or movable contacts 7, each pivoted on a post 8 for engagement with a stationary contact such as spring clip 9, three sets of contacts being shown in the drawings. An insulating cross-bar 10 is connected 'as by angle pieces 11 to the blades 7. An operating handle 12 is journalled at one end 13 in one side of the casing 4. A crank shaped contact operating-member 14 has one end secured for rotation with the. end 13 of the handle, while its other end is journalled in the opposite wall of the casing. Operating member 146 may be connected to her 10 by any suitable linkage. but when an automatic quick break of the switch contacts is desired, crank l -l passes through a number of links 15 carried by bar 10. lVhen this construction is eIn-- ployed, a tension spring 16 provided near each link to connect the her and crank. A spring 17 stretched bet ween operating crank 14 and a tired point such as the bottom well of easing 4i constantly urges the crank and thus the movable contacts 7 into open circuit position, and normally holds the crank ngninst it stop 18 secured to the left hand WIll of the casing, with the switch parts in 'the position shown in F ig. 3.

- To hold the switch in closed position while the load current is normal, a magnet and toggle joint are provided. The magnet com prises angle plates 19 secured to base 5 in spaced relation as by screws 20. Riveted between plates 19 is it U-shnped core 2i for instance of laminated iron. about the upper leg of which is coiled the winding 22 of the magnet. Plates 19 extend downwardly and ted iron sheets 26 arranged to fit. snugly ageinst the ends of core 2]. when the armature is attrected. f t-copper separator 27 may be cincriedat the upper end of the armature to prevent its sticking to the core when l nersg'iaed, in which case the lower leg of the core is longer hy the thickness of the aerator 27 than the upper leg, as best seen 4 3. lln any case the slots 25 permit in suttlcient play of pin 24 to allow the armature to adapt itself to the core. and secure an strong magnetic attraction with a small current ll lO W in the winding 22. Frame have cars 28 which bear. against 21 to limit opening movement of the The armature acts as one part of a toggle joint, the other part consisting of a longitudinaily slotted bar 29 journalled at its upper end near the mid-point of crank' 14: while tslower portion slides between margins 30 ct plates 23 which are inwardly bent to hide it seen in 1. A roller 31 is mounted on a pin 32 carried between the lower ends of margins 30 ot armature plates This roller carries the thrust exerted on bar 29 by the spring 17 so long as the switch is cosed and bar 29 is in locking alignment with the armature. pin 33 passes through the slot in bar 29 and 'illliTOllfId the upper ends of armature plates tel to hold the bar in alignment with the armature when the latter is attracted. and serves to retract the armature when the magdeenergizes and the lower end of bu r 25? slit es free of roller 31. Since spring 11' eaerts no lilting" force on bar 29, tl1e lower of the bar is preferably given a slight evel, best seen in Fig. 3, so tha't the aownward pressure of the bar on roller 32 (is to lift the bar free of the ro'ler and met the armature. Such bevel is hower not essential to operation of the toggle oint, since the thrust of bar 29 produces 1, couple which acts on pins 32. and 2st tendup; to retract the armature, and thus to lift ar 29 by means of pin 83 and the pressure the upper-ends o'lf sheets 26 on the bar. in n switch of the type described which adapted to he used for example with a e phase power line or a three wire two so line, the line wires are connected to clips 9 b7 the usual terminals Motor termi als 34 are secured to '19 5 near the bottom of the casing, the two-outer terminals having sprinfi clips 35 till iilireet to its post 8 as by the insuial while the middle terminal 34: is

inn? shown. @uter posts 8 have spring ps lit in alignment with clips 35, while between each of these pairs are clips 3? indepen ently secured to the insulatine; base Hagnet winding connected between clips 37. A relay 36, it? norma-Ily serves to interconnect the clips, but is arranged upon the continuance of an over oad condition for u predetermincd time interval (which is short enough to prevent damuge to the motor) to disconnect clips 37 from the line circuits.

llhus upon closure of the switch by operation of the handle 12, the contact oi the switch '2' with jaw post 9 completes the circult through winding 22 in shunt with the motor to energize the magnet and thus drew the bar 2:9 am} armature 23 into alignment and lock the toggle joint members against the action of spring l7. and the switch remains closed. Should an underuoltagre condition arise, the current in winding 22 would become too weak to hold the armature attracted, and spring 17 would open the switch. Similarly if an overload condition arises, relays 38 will interrupt the circuit of windin 22 before the motor has become 38 held by each set of clips 31., V

overheate and the switch will be opened.

Whether the switch is opened by hand ,or by the spring 17 upon deenergiaation ot the magnet, the operating crank 14- moves as far as the outer end of limits 15 without dis turbine: the blades 7 (as shown in broken lines in Fig. 2) and thus puts springs UH- der considerable tension. When upon fun th er movement of the cranlr the blades are withdrawn from clips 9., the springs 16 suddenly contract to cause a very quick break between the contacts by snapping cross bar 1.0 towards the crank until the latter abuts the inner end of the links in the position shown in Fig. 3. The blades at the instant of opening therefore have a velocity towards the cranlr'caused by springs 16, while the crank has velocity towards its stop 18 caused by spring; 17, a resu'ltot which the blades leave their spring c ips 9 at a speed equal to the sum of the two velocities mentioned, and thereby minimize arcing and consequent wear. i i

To still further decrease arcing 'hetween the contacts, and to positively prevent any are'to' the walls oi the casing, there may be provided are snuliers 39 of insulating" com position. Each snuiler i-ltl comprises" two plates 40 united by across strip all. and pivoted to a clip 9 as at 42. The Sl'lllllGI'S are actuated by rods 43 pivoted to blades 7 at 44 and to the out side of plates l-O as at it will thus be apparent that when the switch isclosed', snufi'ing piece ll will have one'edgc close to blade 7, and as the blade moves out ltlll lltl ias

of engage ment with its clip 9, piece 41' will y be interposed between blade and clip to ll' the arc, while plates 40 at all times prevent arcing between clips 9 and the casing 4.

While one embodiment of the invention as applied to a particular motor starting switch has been described in detail, it is to be un' derstood that the invention is capable of man other embodiments as may be required in ifierent applications, and that certain parts may be changed or dispensed with entirely without departing from the spirit of the invention as defined by the appended claims.

I claim:

1. In a switch, a fixed contact, a movable contact, a crank to actuate the movable contact, a magnet comprising an armature havihg a stop, a bar journalled on the crank and having an end portion abutting the mature stop when the contacts are closed,

and means for forcingsaid end portion out of abutment with the stop to permit opening of the contacts.

2 In a switch, a fixed contact, a movable contact, means including a bar to control the movable contact, two guide plates for the bar, a stop between the guide plates, a pin and slot connection between the bar and guide plates, a support on which the guide plates are pivoted, a spring f rcing the bar against the stop when t e contacts are closed, an armature carried by the guide plates, the pressure of the bar on the stop tending to retract the armature to permit the bar to slide oil the stopto open the contacts, a magnet to attract the armature to prevent such sliding of the bar.

3, In a switch, two relatively movable contacts, a member to operate the contacts, a spring to open the contacts, a magnet having an armature, a stop carried by the armature and a bar slidably connected to the armature and secured to the contact operating member, said bar being arranged upon closing of the contacts to be moved into alignment with the stop to prevent opening of the, contacts and said pin and Slot connection maintaining said alignment while the magnet is energized.

4. In a switch, a fixed and a movable contact, an operating member for the movable contact, a relatively weak spring interconnecting said member and contact, and a relatively s1 roug spring opposing the action of the weak spring and urging the operating member to open the contacts said strong spring being adapted to initiate opening movement of the operating member to stretch the weak spring before the contacts open whereby the movable contact is disengaged from the fixed contact by the simultaneous contraction of both springs, a bar connected to the operating member, an in mature arranged when attracted to hold the bar in position to prevent contact opening movement of the operating member, and an clectromagnet to attract the armature.

5. In a switch a fixed and a movable contact, an opera! ng member "for the movable contact, a spring to ac uate the operating member to open the contacts, a longitudinally slotted bar journalled on the operating member, two guide plates conncctcd by a pin passing through the bar slot, an armature carried by said plates, a roller stop between said plates adapted to be engaged by said bar to prevent contact opening movement of said contacts when said armature is attracted, and a ma net to attract said armature.

6. in an electric switch, a contact blade, an operating crank. having a lost motion connection therewith, a spring connecting said crank with said blade, another spring more powerful than the first teiyding to 0perate said crank, a jointed memacr connected to said crvnk adapted to oppose the action of said operating spring: and hold said crank and switch blade in the closed circuit position, under certain circumstances, and an electromagnet for holding one part of said hingedmcmber, the other part of said hinged member having a slidingengagement with the first mentioned )art when the electro-magnet is dcenergized 7 In a switch, a movable contact, an operating member connected thereto, an electro-magnet, a pivoted armature therefor, an abutment carried by said armature, a bar connected to said operating member and having a hinged and sliding engagement with said armature and adapted to engage said abutment, and an operating spring holding said operating member under tension, said bar and armature holding the switch contact, in the closed circuitoosition when said magnet is energized, sai spring serving to disengage said bar from said abutment when themagnet is deenergized.

8. In an electric switch, an operating member, an electro-magnct, a pivoted armature for said magnet, an abutment carried by said armature, a bar connected to said opcirating member. and having a sliding engagement with said armature and adapted o engage silhd abutment when in a closed circuit position, the moment arm of said abutment being materially shorter than the moment arm of said armature with respect to said magnet.

9. In a switch, fixed contacts, movable contacts, an operating member to actuate the movable contacts, a magnet including an armature having a stop, a bar connected with the operating member and having an abrupt end adapted to abut against the ar- AW! on] inoture stop when the switch is in closed position end spring for constantly urging" the switch to open position, the said magnet being Mapted to retain the armature stop in abutment with the abrupt end of said her when the switch is in closed position.

vl0. lln a switch, fixed contacts, movable contacts, on operuting member to actuate the movable contacts, 2i magnet including an armature having stop, a hair connected to the opers ting member and having a sub-- stentielly square end portion adapted to abut ogeinst the armature stop when the switch is in closed position Blind e spring for constantly urging the switch to open osition, the said magnet losing adapted to 101d the armature stop and the square end of the said her in abutting relation against the power of the spring when the switch is in closed position. v

11. in u switch, fixed contacts, inovohle contacts, :1 crank member to sctuote the movable contacts, a magnet, e pivoted erumture for seid magnet having a stop, 2, bar connected to said crank member and having a sliding engagement with said armature, said having an abrupt end portion adopted to abut against the armature stop when the switch is in closed position end a spring for constently urging the switch to open position, the said magnet constituting zi'ineens for retaining the abrupt end of said -l)fti in abutment with the said stop against the power of the spring when the switch is in closed position. i

12. in a switch, lined contacts, movable 'contocts, an operating zneiiiher to actuate the movable contacts, ainagnet including an armature having a stop, a bar journelled on the operating member and hovin opernhle engagement with the armature, the said her having one of its ends adapted for on gzurement with the armature etc when the switch is in closed position on a. spring meens tor constantly urging the switch .to open position, the said magnet beingadeptcd to hold the said her in abutment with the said step egiiinst the power of ,the springwhcn the switch is closed.

13, lfn a switch, fixed contacts, movable contacts, on operating crank tor actuating ,the movable contacts. it inugznet including an erinuturc hovii it stop, it her journzilled on the operating crurk and having one of its ends adapted to shut against the armature stop when the switch is in closed position, :1 spring constantly urging the crank to open the switch, the said magnet beingndupted to retain the he: and armature stop in abutment against the tension of the spring when the switchiis closed sti l the angular relation of said her with said armature. stop being such that the shutting engagement will be broken and the switch Willloe thrown open by the spring upon s. reduction. in vol"- position and a spring for throwing the ,ably connecting said armature frame and .contacts, a movable member, it stop ego and the abutting engagement men broken and the switch opened by the inn. ual operation of the crunlt.

1 in o. switch, fixed contents, contacts, on operating Cflfili for o. the movable contscts, s. magnet in h armature having rotatable silo ersbly connecting the said c'rani. i' said armature, said linlt having; one ends adapted for abutment against mature stop when the switch in closed] 1 o c-vshlc switch to open position, the said inegne constituting, a means for holding the clout 3 went end of said link in engagement with said rotatable stop against the switch-ope 1- ing force of the spring when the switch s in closed position.

if). in a switch including pertinent lined and movable contacts, on operating crank 33 for actuating themovirhle contacts, 11 meg not including on ai'n'isture end a pivoted urmoture -trance supporting said armature and e rotatable stop, a link 'inemher ope so said operating crank and having one of its ends adapted to be drawn into locking ubut ment with the said stop by the magnet hen the switch is in closed position means constantly urging the switch to open posi- 95 tion and uuuuml means For disruptingthe 4 locking engagement of the link and stop to open the switch.

1". ln nswitch including; pertinent l and movable contacts, a crank for operepin the movable contacts, a movable P supporting a stop, a link opcmhl coon ing said crank and said member 2 one of its ends adapted to shut ago said stop when the switch is in c sition, magnetic means for holdi, link and said step in locking alumna the circuit is on, 1' spring for d said locking engagement of the stop when the circuit is de-cner" for constantly urging the switch to on position and nmnuul means {o disrupt the locking engagement of said lint: 2 stop to open the switch.

17. In a switch, lined contacts. movable contacts, a crank for actuating the movable sun ported by said member, o linlc opeifliol cohnecting said crank with said member and having one oi its ends adapted to shut against the said stop when the switch is in closed position with the normal circuit on, mhgnctic means for holding Sit-id link and stop in abutting solution when the nor-incl circuit is on and for releasing said abut-ting relation when the circuit is tlc-energizech spring" means for constantly urging the switch to oft" position and manual inserts for disrupting the abutting reletion oii the linlr and stop to open the switch,

ice

1 engagement with semi armature and Um! tgyengage said stop, a spring acting said .iink and a magnet acting upon Mair? armature to mid 119 parts in closed *3 "nosiuion. a S'WiiCl, a magnet, an armature pimied 3'6 end to swing toward away from the magnet, :2, stop carried by mid armature adjacent its pivot, a link 1121* ing a sliding enga eznenii with the apposite and 91: said armature and adapted to abut against said stop in the closed circuit positiufi and means for actuating said link.

BENJAMIN E "GETCHELL.

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