US2463020A - Starting switch - Google Patents

Description

March 1, 1949. E. COE, JR., ETAL 2,463,020

STARTING SWITCH Filed April 16, 1948 v 2 Sheets-Sheet l INVENTORS A Chan/e6 T. F'r'eeling 0* y Everett L. COQJ.

March 1, 1949. E. L. coE, JR, ET AL STARTING SWITCH 2 Sheets-Sheet 2 Filed April 16, 1948 Patented Mar. 1, 1949 UNITED STATES. PAT ENT OFFICE STARTING SWITCH EverettL'. Coe, J r.', and Charles T. Freeling, Portland, Oreg;, a-ssignors to Iron Fireman Manuitacturing 00., Portland, 0reg.-, atcorporation of Oregon Application April 16, 1948, Serial No. 21.367

(Cl. ZOO-80) 1 lfi cla-ims. 1.

The-present invention. relates to switches. and,

while-not necessarily limited-thereto, theswitches are particularly suitable for use in dynamo.- electric machinesain combination :with centrifugal perating devices for controlling thecircuitcf starting windings in singlephase desired'to control the circuits thereof in accorde ance with the speed of rotation of the machine or device.

It is a principal-objector the presen-tinvention to provide. an improved switchstructurewhich-:is simple in design, ofrlowzrcost manufacture, and reliablein. operation.

Aifurther object of the invention is to'provide a new andrimproved switch structuresparticularly suitable f or .use with centrifugal op'eratingdevices. and which consists. of: relatively few parts of. rugged design. and'xwhich is. compactly; arranged: so as to require a minimum. of space .suclras within. a machine housing.

In accordance with the illustratedzembodiment,

the switchstructure:comprisese-a base. plate; of

insulating material. having. a pair. of: elongated. leaf springrmembers secured. :at one end thereto. and:with the.free ends thereof biased toward;

the base plate'by theinherent.resiliency of the leaf spring material. Theireeends of the spring members. over-lap" each other. and; are. provided, with electricatcontactson their facing surfaces. The upper springmember is;v provided withe...

stop. portionior. limiting: the :movement" of the free end thereof'towardlthe base plate: and normally: to hold the contacts-in an. opencercuit position. An operatingmemberiis PIOVidE-dfhBN- ing a. lever portion at one endwhich is securedv to the free end ofbne-o-f F'the spring:.members, and outstanding shoulder; portions. intermediate its ends forming; a fulcrum. for: the operating lever upon the base: plate. Theopposite'outer end portion of :the' cperatingimember; is provided with a yoke for cooperative'engagementiby the out with greater particularity in the'appended.

claims; forming a part ofithis speciiicaticn'- In the drawingsFig; Lisa side elevationalviewe of a dynamo-electric. machineepartially broken induction motors, or other electrical devices in which it isaway to illustrate a switch structure embodying the invention in accordancewith one form thereof; Fig. 2'is a fragmentary side elevational view illustrating the switch structure in a dififerent position from that shown in Fig. 1; Fig; 3 is-an enlarged plan view of the switch structure and taken along the line 3'3- of Fig. 2; Fig; 4- is a plan view showing the reverse side of the switch structure of Fig. 3; Fig; 5- is a vertical cross-sec tionalview taken along the line 5-5 of Fig; 3;

Fig. 6'is a horizontal cross-sectional view, furtherenlarged, taken along the line 66 of Fig; 3; Fig. '7 is a plan view illustrating one of the spring members incorporated in the switch structure.

In the-drawings; the improved switch structure isillustrated'in its application to a centrifugal switch combination for connecting and disconnecting the starting winding of a capacitor orsplit phase motor. However, it is to beunderstood that the switch construction may be employed wherever'it is desired to open or close a circuit in-response to-movement of a suitable operating mechanism.

Referring more particularly to Figs. 1 andZ, a dynamo-electric machine is shown having a stationary member Iii anda-rotatable-member l'l mounted on a shaft i2 which issupported in suitable bearings 13 in the opposite end bells I4. The

dynamo-electric machine illustrated is a single phase induction motor and the excitation is'provided by a single phase main field exciting winding I5 and a starting field exciting winding l6;

which windings are arranged in slots provided therefor in the core I! of the stationary memberand are adaptedto induce electrical currents'in asquirrel cage winding I8 arranged in slots in the rotatable member I i.

In this type .of induction motor, it is desirable that the starting field exciting windingshould be energized during the period when the motor starts tooperate, or under such operating conditions thatthe speed of: the motor is reduced'below av predetermined value and that this fieldexciting winding be de-energized when the speed of the motor exceeds a predetermined value. to accomplish this, a control switch is provided having electrical contacts connected to the energizing'circuitof the starting field exciting winding IS; The control switch is mounted upon a.

mounting plate 28 suitably secured to the adjacent end bell M of the motor. The switch structure includes an operating member defining. a

yoke 22 at one end straddling the shaft l2 andwhich is adapted to be cooperatively engaged by the axially movable collar 25 slidably.mounted1 In order.

upon the shaft l2. The collar 25 is operatively connected to the inner ends of operating arms of the fiyweight units 2'! pivotally mounted upon the support member 28. The flyweight units 2? include weighted portions which, under centrifugal force, shift outwardly to cause axial movement of the collar 25 toward the support member 28 to the position shown in Fig. 2. In the condition of rest of the centrifugal operating mechanism, the collar 25 is biased away from the support member 28 by means of the springs 3! arranged around the operating arms of the flyweight units and into engagement with the ends of the yoke member 22 holding the switch in the closed circuit position. As shown in Fig. 2, when the collar 25 is moved inwardly toward the support 28 upon outward movement of the fiyweights 21, the collar 25 disengages the yoke 22 of the switch structure permitting the contacts thereof to move to the open circuit position. It is to be understood that the centrifugal operating mechanism for the switch structure may be of any suitable type, and the embodiment illustrated in Figs. 1 and 2 forms no part of the present invention and is separately described and claimed in the copending application Ser. No, 21,482 filed concurrently herewith.

Referring now to Figs. 3 to 6, inclusive, the details of the switch structure will now be described. The base plate 2!] may be made of any suitable insulating material and is provided with a plurality of holes 35 along its opposite outer edge portions for fastening the same within the end bell of the motor. A first U-shaped spring member is mounted upon the upper surface of the base plate 20, the spring member comprising a closed end portion 31 and relatively widely separated and diverging leg portions 38. The outer ends of the leg portions 33 are suitably stationarily fastened to the upper surface of the base plate 29 such as by means of eyelet rivets 38. A second relatively Wide and elongated spring member 4! is mounted upon the base plate 20 and secured stationarily thereto at one end at a pair of spaced apart points by means of eyelet rivets 42. Attention is directed to the fact that the rivets 42 are in transverse alignment with the rivets 39 securing the first spring member to the base plate. The free end of the spring member 4! extends beneath the closed end portion 37 of the first spring member, and cooperating electrical contacts 43 and 44 are suitably secured upon the facing surfaces of the overlapping portions of the two spring members. The two leaf spring members may be stamped from any suitable material such as bronze and are both biased toward the base plate 20 by their inherent resiliency. Means are provided for limiting the movement of the closed free end portion 31 of the upper spring member toward the base plate, and, as shown, the outer end portion of the spring member is provided with a tab 46 which is bent at right angles with respect to the portion 31 toward the base plate beyond the end of the lower member 4|. The tab 46 normally supports the contact 44 in a spaced, or open circuit, relation with respect to the contact 43. For reduction of noise, a pad 41 of suitable sound absorptive material, such as felt, is secured to the upper surface of the base plate 20 beneath the free end portions of the two spring members and against which the end portions of the two spring members will engage upon movement thereof to the open circuit position.

The outer ends of the bifurcated portions of yoke 22 are provided with inwardly extending wear pads 50 which are adapted to be engaged by the sliding collar 25 of the centrifugal operating mechanism. The opposite end of the yoke operating member is provided with a lever portion 52 which extends through the cooperating elongated opening 53 provided in the spring member ll, the end of the lever portion 52 being suitably secured to the lower side of the upper end of the spring member M. For convenience, the stud projecting from the rear side of the contact 43 extends through aligned cooperating openings in the end portion of the spring mernber 4! as well as the end of the lever 42 thereby accomplishing the dual purpose of mounting the contact 43 in place as well as securing the lever 52 to the spring member M.

The operating member 22 is fulcrumed intermediate its ends for pivotal rocking movement relative to the base plate 20. Opposite edge portions of the operating member are bent downwardly at right angles as shown more clearly in the sectional views of Figs. 4 and 5 defining a pair of shoulders til adapted to bear against the upper surface of the stationary portion of the spring member 4? between the eyelet rivets 42 and headed prong portions 6! adapted to extend through cooperating slots 62 in the base member. Referring to Fig. 7, it will be explained that the lower end of the spring member 4! is provided with a pair of notches 63 having a width substantially equal to the minimum width of the prong portions ii I and in the assembly of the switch structure the prong portions 62 are first inserted into the slots 63 before the end of the lever portion 52 is secured to the outer end of the spring member 4i by means of the contact stud as previously described. The enlarged heads of the prongs 6| are then inserted through the enlarged lower ends 64 of the slots 62 in the base plate and then moved upwardly into the narrow portions of the slots 62 before the eyelet 42 are inserted through the cooperating openings in the base plate for securing the spring member 4! thereto. Upon fastening of the spring member ll to the base plate, the heads of the prongs Bi are retained against withdrawal from the slots 62 within the base plate and the operating member is thus efiectively secured in position yet free to rock about the pivotal fulcrums defined by the shoulder portions 66. Durable, wear resistant bearing surfaces for the fulcrum shoulders Kill are provided by the portions of the spring member 4! adjacent the sides of the slots 63.

Electrical connections may be made to the switch contact bearing spring members by soldering the ends of conductors in the eyelet rivets 39 and 42 which form suitable terminals.

The operation of the switch structure will be obvious from the description given. Due to the resiliency of the spring members 33 and M, the switch contacts are normally biased to the open circuit position shown in Fig. 2. The switch is operated to the closed circuit position by engagement of the operating element of the centrifugal device with the ends of the yoke 22. Upon exertion of pressure against the end of the yoke, the operating member 22 is caused to pivot about the fulcrum shoulders 60 whereupon contact 43 upon the free end of the contact spring 41 is carried into contacting engagement with contact 44 upon the upper spring 38. Depending upon the extent of axial movement of the collar 25 of the centrifugal operating device, the outer ends of the two spring members and their contacts are carried away from the base asshown in Fig. 1. Due to the: bias: of the upper spring; member 38 toward the base;.firnr engagement between the contacts is desired that it be understood that the specificdetails shown aremerely illustrative and that-the invention may be carried outwith considerable variation without departing from the true spirit and scope of the invention.

We claim:

1. Ina switch mech-anism' of the kindd'escribed'. a base of insulating material, a first U--shaped spring m mber having a closed end portion and a. pair of relatively widely separated leg portions, means stationarily securing the" outer ends of said leg portions to: said base. an elongated relatively wide second spring member, means stationarily securing one end of said second spring member to said base at a pair of widely spaced apart points in transverse alignment with the secured end portions of said first'spring member, thenfree end of said second spring member underlying the closed end portion ofsaid first spring member, the free ends ofbcthof said spring members being biased toward said base by the resiliency thereof, a pair of cooperating contacts secured to thefacing surfaces of the overlapping portions of said two spring members, stop means for limiting the movement of said closed end of said first spring member t'oward saicl base whereby the contact on said first spring member is normally sup ported in an open circuit condition with respect to the contact on said second spring member, a longitudinal operating member including a lever portion secured to the free endof said second. spring, said operating member including means defining a fulcrum for said lever engaging the surface of said second spring member between the spaced apart fastening points for said second spring member.

2. I-n a switch'mechanism of the kind described, a base plate of insulating material, a first U- shaped leaf spring having closed end and leg portions, the outer ends of said leg portions being fixedly secured to said base plate whereby the closed end of saidspring is resiliently biased toward said base plate, meanson the closed end of said first spring extending toward said base plate for limiting movement of said closed end toward said base plate to a predetermined limit position, a second elongated leaf spring, one end of said second spring being secured to said baseplate between the legs of said first: springv andatpoints in alignment with the secured. ends of said first spring; the free end of said second spring extending: beneath. the closed. end of said first spring, cooperating facing contacts securedito the ends. of. said first andsaid second spring, an operating member including: a yoke at one end. and an operating. lever at the opposite end, said operating member including a pair of angularly extending shoulder forming portions on the opposite sides thereof, said shoulderportions forming a fulcrum with the upper surface of said base plate in transverse alignment with fastening points of said springs, a longitudinal centrally disposed, opening til in said second spring member, the outer end. ofsaid operating arm extending through saidopening and secured to the lower surface of said second spring member opposite the contact mounted thereon, and a sound deadening means secured to said base plate beneath the movable ends of said first and said second spring members.

3.. In a switch mechanism of the kind described, a base plate of insulating material, a first leaf spring member having a substantially U-shape and including longitudinal leg portions and a closed end portion, means fastening the outer ends of said leg portions to said base plate, said: first leaf spring member being biased by its ownresiliency toward said base plate, the outer edge of said closed end portion including a portion extending at right angles therefrom toward said base plate and spacing said closed end a predetermined distance from said base plate, a second elongated, relatively wide leaf spring member, a pair of spaced apart means securing one end of said second spring member to said base plate in transverse alignment with said fastening means for. said first spring member, the free end of'said second spring member being biased by the resiliency thereof toward said base plate, the free end. of said second spring member extending between the closed end of said first spring member and said base plate, a pair of cooperating contacts mounted on the facing surfaces of the end portions of said first and second spring members, said contacts being normally biased to the open circuit position, an operating member pivotally mounted on said base plate, said operating member including a yoke forming portion at one end and a lever forming portion at the opposite end, a pair of spaced apart portions extending from the opposite edges of said operating member toward said base plate having a pair of shoulders defining fulcrums engaging the upper surface of said base plate and about which said operating member may be rocked and also including a, pair of prongs extending through cooperating openings in said base plate, the outer ends of said prongs being offset to preclude Withdrawal of said prongs through said openings, an elongated opening in said second spring member, the lever forming portion of said operating member extending through said last mentioned opening and beneath the uppermost end of said second spring member, and means securing the free end of said lever to the free end of said second spring member, and a pad of sound absorptive material secured to the upper surface of said base plate beneath the free ends of said first and said second spring members.

4. In a switch mechanism of the kind described, a base plate of insulating material, a U-shaped spring member having the outer ends of its legs fixedly secured to said base plate, a portion of said spring at the closed end thereof being bent inwardly toward said base plate and spacing the closed end of said spring from said base plate; a first contact secured to the closed end of said spring on the side thereof facing said base plate,

a second. elongated spring secured one end thereof to said base plate between the legs of said first spring, a contact secured to the upper surface of said second spring on the side thereof facing said first spring, an operating lever has ing a yoke formed on one end thereof and fulcrumed on said base plate between the outer ends of said first spring, the opposite end of said lever being secured to said second spring for effecting. movement of the contact on said second spring into engagement with said contact on said first spring.

5. In a switch mechanism of the kind described, a base plate of insulating material, a first U- shaped leaf spring member, means fastening the ends of the legs of said spring member to said base plate, a second leaf spring member, means fastening one end of said second leaf spring member to said base plate in transverse alignment with the fastening means for said first spring member, both of said spring members being biased toward said base member by the inherent resiliency thereof, means spacing the closed end of said first spring member from said base plate, the free end of said second spring member being disposed in spaced relation beneath the closed end of said first spring member, cooperating contacts mounted on the facing surfaces of said two spring members, and lever operating means for said second spring member.

6. In a switch mechanism of the kind described, a base, a first U-shaped spring including a closed end portion and a pair of relatively widely separated legs, means stationarily securing the outer ends of said legs to said base, a relatively wide elongated second spring, means stationarily securing one end of said second spring at a pair of spaced apart points to said base between and spaced from the outer ends of the legs of said first spring, the free ends of both of said springs being biased toward said base by the resiliency thereof, the free end of said second spring underlying the close end portion of said first spring, a pair of cooperating contacts mounted on the fac ing surfaces of the overlapping portions of said two spring members, means for limiting movement of the closed end portion of said first spring member toward said base whereby said contacts are normally supported in an open circuit condition and lever means connected to the free end of said second spring for effecting movement thereof into closed circuit condition.

7. In a switch mechanism of the kind described, a base, a U-shaped spring member including a closed end portion and a pair of divergin leg'portions, means stationarily securing the outer ends of said leg portions to said base, a second elongated relatively wide spring member, means stationarily securing one end of said second spring member to said base at spaced apart points in alignment with the secured ends of said first spring member, the closed end portion of said first spring member overlapping the free end of said second spring member, the legs of said first spring member straddling and spaced from said second spring member, cooperating contacts mounted on the facing surfaces of the overlapping portions of said two spring members, an outer portion of the closed end of said first spring member extending angularly toward said base for restraining movement of the closed end of said first spring toward said base and for supporting the contact on said first spring out of engagement with the contact on said second spring.

, 8. In a switch mechanism of the kind described, a base plate of insulating material, a first U-shaped leaf spring member, means securing the outer ends of the legs of said memberv to the said base plate, an elongated second spring mem ber, means securing one end of said second spring member to said base plate in transverse alignment with the securing means for said first spring member, the free end of said second spring member extending in spaced relation beneath the closed end of said first spring member, both of said spring members being biased toward said base plate by the resiliency thereof, cooperating contacts mounted on the facing surfaces of said two spring members, and an operating lever operatively connected to said second spring member and pivotally mounted on said base plate.

9. In a switch mechanism of the kind described, a base, a pair of substantially fiat leaf springs, means stationarily securing one end of each of said springs to said base, the end of the first of said springs overlapping the free end of the second of said springs, cooperating contacts mounted on the facing surfaces of the overlap ping portions of said two springs, both of said' springs being biased toward said base by the resiliency thereof, said first spring including a portion extending toward said base and defining a stop for limiting movement of the contact thereon toward said base whereby said contacts are normally spaced apart, an elongated operating member having an angularly extending portion intermediate the ends thereof, said portion defining a fulcrum shoulder and a prong, an opening through the stationary end of said second spring and said base therebeneath, said prong extendin through said opening and said shoulder engaging with the upper surface of said stationary portion of said second spring, and means securing the free end of said operating member to the free end portion of said second spring for precluding withdrawal of said prong through said opening.

16. In a switch mechanism of the kind described, a base, a pair of leaf springs, means stationarily securing one end of each of said leaf springs to said base, said springs being biased toward said base by the resiliency thereof, the free end portion of the first of said springs overlapping the free end portion of the second of said springs, a pair of cooperating contacts mounted on the facing surfaces of said overlapping portions of said springs, the outermost portion of the free end of said first spring extending angularly toward said base beyond the end of said second spring and defining a stop for limiting movement of said first spring toward said base, and a cushion element secured to said base and adapted to be engaged by the free ends of both of said springs.

11. In a switch mechanism of the kind described, a base, a pair of elongated leaf springs, means securing one end of each of said leaf springs to said base, the free ends of said leaf springs being biased toward said base by the resiliency thereof, the free end of the first of said springs overlapping the free end of the second of said springs, means defining a stop for limiting movement of the free end of the first of said springs toward said base, cooperating contacts mounted on the facing surfaces of the overlapping portions of said springs, an elongated opening in the second of said springs, an operating lever having one end portion extending longitudinally throughsaid opening and secured to the lower side of the free end of said second spring, and means defining a fulcrum for said free end of the first of said springs overlapping the free end of the second of said springs, means defining a stop for limiting movement of the free end of the first of said springs toward said base and said second spring, cooperating contacts mounted on the facing surfaces of the overlapping portions of said springs, an operating lever having one end portion extending longitudinally of said second spring and secured to the lower side of the free end of said second spring, and means on said operating lever defining a pivotal fulcrum for said lever intermediate the opposite ends thereof against the upper surface of said base adjacent the fixed ends of said springs.

13. In a switch mechanism of the kind described, a base, a pair of elongated leaf springs, means securing one end of each of said leaf springs to said base adjacent one end thereof, the free ends of said leaf springs extending toward the opposite end of said base and being biased toward said base by the resiliency thereof, the free end of the first of said springs overlapping the free end of the second of said springs, means defining a stop for limiting movement of the free end of the first of said springs toward said base, cooperating contacts mounted on the facing surfaces of the overlapping portions of said springs, an operating lever having one end portion secured to the free end of said second spring, and means defining a fulcrum for said lever intermediate the opposite ends thereof and adjacent the fixed end of said second spring.

14. In a switch mechanism of the kind described, a base plate, a first leaf spring member, means fastening one end of said first spring member to said base plate, a second leaf spring member, means stationarily fastening one end of said second spring member to said base plate adjacent the stationary end of said first spring member, the free ends of said two spring members being biased toward said base plate, means limiting the movement of the free end of said first spring member in the direction toward said plate to a predetermined spaced apart distance from said base plate, the free end of said second spring member being disposed normally in spaced relation beneath the free end of said first spring member, cooperating fixed contacts mounted on the facing surfaces of said two spring members,

an operating member having a yoke portion at one end and a lever portion at the opposite end, means connecting said lever portion to the free end of said second spring member, means extending outwardly from one side of said member defining a pivotal fulcrum for said member, said fulcrum bearing against the upper surface of the stationary end portion of said second spring member.

15. In a switch mechanism of the kind described, a base plate, a pair of leaf spring members, means fixing one end of each of said spring members to said base plate, the free ends of said two spring members being biased toward said base plate, the free end of the first spring member being normally disposed in spaced relation above the free end of the second spring member, coopcrating contacts fixedly mounted on the facing surfaces of said two spring members, an operating member having a lever portion at one end fiixedly connected to the free end of said second spring member, and means extending outwardly from one side of said member intermediate its ends defining a pivotal fulcrum for said operating member, said fulcrum bearing against the upper surface of the stationary end portion of said second spring member.

16. In a switch mechanism of the kind described, a base plate, a pair of leaf spring members defining a pair of electrical conductors, terminal means securing one end of each of said spring members to said base plate, the free ends of said two spring members being biased toward said base plate, and the free end of a first spring member being normally disposed in spaced relation from the free end of the second spring member, cooperating fixed contacts mounted on the facing surfaces of said two spring members, an operating member having a lever portion at one end fixedly connected to the free end of one of said spring members, and means defining a pivotal fulcrum for said operating member upon said base plate, said operating member being retained in position upon said base plate by said connection with said one spring member.

EVERETT L. COE, JR. CHARLES T. FREELING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 0 Number Name Date 2,305,093 Lefiar et a1 Dec. 15, 1942 2,305,441 Pepper Dec. 15, 1942 Certificate of Correction Patent No. 2,463,020. March 1, 1949 EVERETT L. COE, JR., ET AL.

It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 1, line 34, for cercuit read circuit; column 3, line 63, after the Word lower insert spring; column 4, line 13, for lever 42 read lever 52; line 41, after eyelet insert rivets; column 7, line 33, claim 6, for close read closed; column 10, line 30, claim 16, for plate, and the read plate, the;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 21st day of June, A. D. 1949.

THOMAS F. MURPHY,

Assistant Commissioner 0 f Patents.

Certificate of Correction Patent No. 2,463,020. March 1, 1949, EVERETT L. COE, JR., ET AL. It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 1, line 34, for cercuit read circuit; column 3, line 63, after the word lower insert spring; column 4, line 13, for lever 42 read lever 52; line 41, after eyelet insert rivets; column 7, line 33, claim 6, for close read closed; column 10, line 30, claim 16, for plate, and the read plate, the;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 21st day of June, A. D. 1949.

THOMAS F. MURPHY,

Assistant Gammz'ssioner of Patents.

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