US1799975A

US1799975A - Centrifugal transfer switch

Info

Publication number: US1799975A
Application number: US361870A
Authority: US
Inventors: Harry D Else
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1929-05-10
Filing date: 1929-05-10
Publication date: 1931-04-07
Anticipated expiration: 1948-04-07

Description

Aptil,7, 1931. H. D. ELSE 1,799,975

CENTRIFUGAL TRANSFER SWITCH Filed May 10, 1929 26 3 2 INVENTOR 4 1 Harry A E/se,

In-rulafion I8 23 38 2/ 23 ll ATTORNEY Patented Apr. 7, 1931 UNITED STATES PATENT OFFICE HARRY D. ELSE, OF SPRINGFIELD, MASSACHUSEITS, ASSIGNOB '10 WESTINGHOUSE ELECTBJO & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA outrun-near. rmsrnn. swrroir.

Application filed Kay 10, 1929. Serla1 No. 881,870.

My invention relates to induction motors and particularly to centrifugally-actuable switches therefor.

An object of my invention is to provide a.

relatively simple, inexpensive and easily manufactured and installed centrifugallyactuable switch to be operatively associated with an induction motor of the split-phase or capacitor type.

Another object of m invention is to provide a relatively simp e, centrifugally-actuable switch embodying a minimum number of parts, the engagement and disengagement of the cooperating contact members being effected with a snap action.

In practicing my invention, I provide a substantially fixed base plate having a lurality of laterally bent slotted guide portions thereon, a two-part carriage movable in said slotted guide portions,

members operatively connecting the parts of the .carriage of the base plate, a spring connecting the two parts 0 the carriage, and fixed contact members on the base plate, and a movable contact arm or switch member on one of the parts of the carriage.

In the single sheet of drawings,

Figure 1 1s a view, in front elevation of a switch assembly embodying my inventlon,

' shown in one of its limiting operative positions,

Fig. 2 is a view, in front elevation, of

the same device shown in the other of its limiting positions, I

Fig. 31s a view, in front elevation, of one detail of the switch,

Fig. 4 is a view, in end elevation, of the switch assembly embodying my invention, Fig. 5 is an exploded view, taken in end elevation, of a switch embodying my invention and a centrifugally-actuable weight assembly for actuating the switch,

Fi 6 is a view, in front elevation, of the centrlfugally-actuable weight-member assembly, and

Fig. 7 is a schematic diagram of connections of an induction motor with which the device embodying my invention may be operatively associated.

A centrifugally-actuable switch embodies a pair of toggle-joint a base plate 11 which is ofsubstantially rectangular shape in outline andhas an opening 12 in its central portionin order that it may be located around the shaft of an induction motor. A plurality of laterally extending guide portions 13 and1'4" are provided, gfalch of these guide portions; having. a slot 16 erem.

While no ,specificstructure shown for supporting the base plate-1 1, it is tobe understood that it will be supportedbyor from the stator structure of the-motorin which it is mounted and with whichit'is operatively associated. Oneor more openings 17 may be provided in the body portion of the base I plate 11 in order that it maybe secured in proper operative position.

A plate 18 of electric-insulating material is mounted on one part and one face of the base plate 11 between thev guide portions 14, and has mounted thereon aplurality of fixed

contact members

19, 21 and 22-. The

contact members

19 and 21 may be of substantially L-shape, one leg portion thereof being secured against the plate 18 while the other portion thereof extends laterally therefrom. The contact member 22 may be of substantially U-shape, as v is shown more particularly in Fig. 4 of the drawings, and may be secured against plate 18 by any suitable or desired means, here shown as by a plurality of rivets 23. Similar securing means may also be employed for securing the

contact members

19 and 21 in position.

A two-part carriage, movable relatively to the base plate 11, in a plane parallel'thereto and spaced therefrom, includes apart 24 and a second part 26, whichmay be made of punched and formedsheet-meta-l plate.

The part 24 is, in general, of L-shape and includes outer or

side portions

27 and 28 which are adapted to be located and moved in the slots 16 of the guide portions 13. Upstanding or laterally

ent lugs

29 and 31 are made integral with the part 24 and are of substantially arcuate shape, for a purpose to be hereinafter set forth.

The second part 26 of the carriage, is also of L-shape, in general, although the one leg portion thereof is relatively short. The part A pair of toggle joints, each including relatively stiff and

inflexible bar members

32 and 33, is provided, the members 32 respectively extending between the

end portions

27 and 28 of the part 24 and a pair of later ally-

bent lug portions

34 and 36 which are integral with the base plate 11. Recesses are contact members "41 mounted provided in the

members

24 and 26 and'in the

lugs

34 and 36 in order that the toggle-

jomt members

32 and 33 may interfit therewith. A. spring 37 extends between the left-hand ends of the parts 24" and 26 and is, therefore, effective to yieldingly pullthe two

parts

24 and 26 of the carriage'toward each other, against the pairs of toggle

joint members

32 and 33. 1 v

A switch arm 38 is loosely mounted on the part 26 and comprises a resilient bar or strip of metal having contact members 39 secured thereto at the outer end thereof and a' pair of thereon at the inner end thereofi The-member 38 is provided with an opening 42, intermediate its ends, in' orderth'at a vpair of relatively thin strips 43 and 44, of insulating material, may

extend therethrough and be secured against the opposite faces of thepart 26 of the car-' riage. The members 43 and 44 are severally provided with recessesin opposite edges, substantially midway of the lengths thereof, and aresuitably'secured against the member 26 by rivets 46. The articular outline of the opening 42 is provi edin order that the parts 43, 44and 26 may be assembled in the relative positions shown in the drawings-to extend through the member 38.

Means for insuring positive operation of the part 26 of the carriage by the part 24 thereof, comprises a recess 47 in the part 26 and a lug 48 on that arm of the part 24 which extends toward the part 26, and the action thereof will be hereinafter described in detail.

Any desired type of centrifugally actuable weight membermay be provided, one form of suchstructurebeing shown in Figs. 5 and 6 of the drawings. I have there shown a motor shaft 51 on which is mounted a disc 52 having a plurality of Ys rings 53 extending parallel to its face an therefore, at substantially right angles to the axis of the shaft 51. ,A' plurality of weight members 54,

here shown as three 1n number, are provided and are so mounted relatively to the disc 52 and arms 56 extending therefrom, and relatively to the springs 53, as to be moved rae dially outward when a predetermined speed of the rotor shaft 51 is exceeded. Conversely, the weight members 54 will move radially inward when the speed falls below said prede termined value. While I have illustrated and described a specific embodiment of a centrifugally actuable structure, I do not desire to 'allel toitself. No movement of. t

be limited thereto, this structure being shown for purposes of illustration only. It is to be understood, however, that the weight members 54 or their equivalents, will move he tween'the

lugs

29 and 31 of the part 24 of the carriage and operatively engage either the lug.-31 or the lug '29, in accordance with whether the speed is increasing or decreasing. Referring more particularly to Fig. 7, I have'there illustrated a stator structure 61, having mountedthereon-a main winding 62 and an. auxiliary winding 63, the centrifually-a'ctuable switch being shown schematlcally at 64. In this particular illustration, it isobvious that the auxiliar winding 63 is to be open-circuited after t e motor has been brought to a predetermined speed by the combined action of the two windings, in a manner well known in the art.

However, as will be presently herein set forth, the switch embodying my invention motors inwhich the capacitance operatively associated'with the motor is connected, by means of a transfer switch,{to a higher voltage at starting than during the normal runmay be used also in connection with capacitor I v mug of the motor. However, the 'swi'tch' the starting switch of the motor is closed, it t is obvious that the rotor will be caused to turn and that, at a predetermined speed of rotation thereof, the weight members 54 will move radially outwardly and engage the lug 31. The positionv of the carria e, up to this time, will be that shown "in" ig. 1. of the drawings, and, upon the aforesaid engagement of the weight members and the lug3l, the part 24 willmove toward the right, as viewed in the drawings,'the movement of this part being directly in accordance with the outward direction,

movement, in a radially of the welght members 54." The'spreading apart of the

parts

24 and 26 of the carria e, required by the relatively stiff and unyie d;. 1

mg toggle-joint members. .32 and 33, will be permitted by,reason of the spring 37, and the part 24 will, therefore, move'in a plane pare part 26 of the carriage will result until the axis of "the spring 37 is substantially parallel to the toggle-joint members 33. As soon as the axis of the spring37 has moved so far as to be sl ghtly beyond such parallelism, the part 26 will be moved with a snap action, the general action, therefore, being. that of the usual overcenter spring and.toggle-oint combination.

' The switch arm 38 will, t erefore, be moved ingto disengage, one of the contact members 39 from the fixed contact member 19 and one tions, this means including the lug 48 'on one ber 39 of the switch arm 38 with a snap action.-

I provide, also, means for insuring positive movement of the part 26 upon movement of the part 24 to either of its limiting posileg of the part 24, located in the recess 47 of the part 26. The relative dimensions of the lug 48 and the recess 47 are such that if, for any reason, the hereinbefore described action of the spring 37 and the toggle

joint members

32 and 33 should not effect movement of the part 26, the lug 48 will strike the wall of the recess 47 and effect movement of the part 26 by direct and positive impact.

The device embodying-my invention thus provides a relatively simple, compact centrifugally-actuable switch structure, the movable part of which embodies two resilientlyconnected parts, one of which is movable directly in accordancewith the radially outward movement of a weight member and the other part of the carriage being movable with a snap action to thereby disestablish or estab lish a circuit, with a minimum amount of arcing between the cooperating contactmembers Since -various modifications may be made in the device embodying my invention without departing from the spirit and scope thereof, I desire that only such limitations shall be placed thereon as are imposed by the prior art or are set forth in the appended claims.

I claim as my invention:

1. A transfer switch including a base plate, guides thereon, a two-part carriage movable in said guides, a pivotal connection between the two parts of said carriage at each end thereof, a resilient connecting means between the two parts of the carriage at one end there of, lugs on one of said parts adapted to be engaged by a centrifugally-actuable meansto move one part relatively to the base and a contact arm on the other part of said carriage.

2. A transfer switch including a base plate,

' guides thereon, a two-part carriage movable in said guides, means on one of said parts adapted to be engaged by a centrifugallv actuable weight to move said part, a resilient connecting means between the two parts of the carriage to cause movement of the second part of the carriage, with a snap action, in response to movementof the first part of said carriage through apredetermined distance and a switch arm loosely mounted on the second part of the carriage.

3. -Atransfer switch including a base plate, guides thereon, a two-part carriage spaced parts of the carriage ,to

guides, two spaced sets of toggle-joint mem-J bers connecting the two parts of the carria, e and the base plate, .a spring connecting the two parts of the carriageand effective to hold the carriage and the toggle-joint members in proper operative positions relatively to each other, laterally-projecting lugs on one of said centrifugally actuable weight to move said engaged by part and a switch member mounted on said second part of the carriage. r g

4. A transfer switch including a base plate having laterally-projecting slotted. guide portions, a two-part carriageslidable in said guide portions, laterally-extending lugs on one of the parts of said carriage to be ens gaged by a centrifugally-actuable weight member to move the part in direct accordance with the radial movement of a weight member, means operatively connecting the two parts of the carriage and the base plate COmpllSlH parts of t e carriage and a pair of togglejoint members extending between the parts of. the carriage and the base plate for causing movement of the second part of the carriage to be eiiected with a snap action upon a predetermined amount of movement of the first part of the carriage and a switch arm on the second part of the carriage. I

' 5. Atransfer switch including a base plate having laterally-projecting slotted guide portions, a two-part carriage slidable in said guide portions, laterally-extending lugs on one of the parts of said carriage adapted to be engaged by a centrifugally-actuable a spring extending between the h weight member to move the part in direct accordance with the radial movement of a welght member, means operably connecting the two parts of the carriage and thebase plate comprising a: spring extending between the parts of the carriage and a pair of toggle-joint members extending between the parts of the carriage and the base plate for causing movement of the second part of the carriage to,be efiected with a snap action upon a redetermined amount of movement of the rst part of the carriage, means-including an interfitting lug and recess on the two parts of the carriage for positively effecting movement of the second part upon predetermined movement of the first art and a switch arm on the second part of the carriage.

6. A transfer switch including a base plate having laterally-bent slotted guides thereon, a two-part carriage movable in said guides, means embodying a pair of toggle-joint members between the carriage arts and the base plate and a spring operatively connec ing the'parts of the carriage for ensuring Ill movement of one of said parts of the carriage in advance of the second part and movement of the second part with a snap action, means comprising an interfitting'lug and recess on the two parts of the carriage for positively effecting movement of the second part of the carriage in response to movement of the first part 0 the carnage, and a swltch arm on the second partofthe carria e. i

In testimony whereof,- ave hereunto subscribed my name this 4th do, of Me 1929. HARR D. E SE. v