US983063A - Motor-controlling switch. - Google Patents

Description

S. H. KEEPER. MOTOR CONTROLLING SWITCH. n'rmummn rum) nov. 8, mos.

Paifified Ja.11.31, 1911.

2 SHEETS-SHBBT l.

S. H. KEEPER;

MOTOR CONTROLLING SWITCH. firms-M101; FILED nov, 8, 1909.

Patented Jan. 31, 1911.

a Emma-511E121 2.

UNITED STATES PATENT OFFICE.

SAMUEL H. KEEFER, F PLAINFIELD, NEW JERSEY, ASSIGNOR 'I'O NILES-BEMENT-POND COMPANY, OF JERSEY CITY, NEW JERSEY, CORPORATION OF NEW JERSEY.

iioron-con'rnontrne swrron.

Be it known that I, SAMUEL H; Kama,

. a citizen of the United States, residing in Plainfield; New Jersey, have invented certain Improvements. in Motor-Goxitrolling ,Switches, of which the following is a specification.-

My invention relates to that class of switches particularly desi ed to control the starting and reversal 'of e ectric motors; one object of the present invention being to proyide' a switch of said clam which, while bemg capable of effectually performing the work for which it is designed, shall be simple and substantial in construction and possess but relatively few parts.

, I further-desire to provide an improved 'electro magnetic motor-controlling switch which shall be capable of not only governing the starting of a motor but also of determining its direction of rotation; the arrangement and construction of the parts being such that said switch may be itself controlled from a distance by means of a pilot.

switch.

The invention also contemplates the pro vision of such a switch with means whereby,

' after the motor has been driven'in' one direction, it'shall be impossible to supply current to turn it in the opposite direction, even though the pilot switch be 'suitably.1nanipulated, until the counter E. M. F. of said mo.-

for has fallen toa predetermined point.

Another object'of the invention is to provide an electro magnetic vmotor-controlling switch which sha-ll possess but two solenoid windings, and shall, in addition to being ca:

'pable of reversing the motor, be also capa-' ble of causing its gradual starting by a series a of steps.

These objects and other advantageous ends 1 Secure as hereinafter set forth, reference being had to'the accompany ngdrawings, in

which v Figure 1, 15 a diagrammatic as of the switch constituting m invention; 2, is a similar view of a s ightly modifie form of the switch; andl'Fig. 3, is a side elevation," diagrammatic, illustrating ie sw tc ter ins initiates? liigs', 1 represents the armature or a having --a shunt ,field lflpeciflcation of hetterslatent;

-Mounted above ,Zthe spring contact l' ieli Patented Jan. 31, 1911.

2, and two bodies of field resistance 3' and 4. Current is supplied from mains a and b and its flow to the solenoids is governed by a pilot switch 5 which has three fixed -,contacts 6, 7 and 8, and a movable contact 9, capable of, connecting either of the contacts '6 or 8 with the contact 7.

The main motor switch consists of two solenolds 10 and 11 provided with longitudinally movable cores 12 and 13, of which the first has atits lower end a spring contact 14 capable vof engaging, when in its lower positionf a fixed contact 15. When in its upper position, this contact 14 is capable of engaginga' second fixed contact 16, and theupper end of the core 12 carries a second spring contact 17 which in its lowerp'osition is capable of engaging a fixed contact 18.

piypted "or othe igwise movable contact a a fixed contact 20. by the upward movement 19'; free iirdnght into engagement with of said spring contact; there'being a'body of insulating material, carried .in the pres-- :ent instance by the contact arm-19, placed to prevent electrical co ection. betweenit and the spring contact- 7. .Siinilarly, 'thecor'e 13 of the solen'oidll has at its lower end a spring contact arm 21 and at its upper enda second spring contact arm'22. Of these,

the first is'ca able of engaging a fixed con tact 23 when 111" its lower position and a second fixed ,contact 24 when in its upper posi- 4 tion, while the spring contact 22 can engage a fixed contact 25 when in its lower position and when moved upwardly is. designed ,=to

move a 'contactarm 26 into engagement with a fixed contact 27-; there being as before, a

bodyof insulating materialjinterposed be tween this spring contact 22 and the arm 26. A blow out magnet 28 is somountedthat it is capable of producing a magnetic flux in the immediate vicinity of all of the above qmentioned contacts so ante break any -'ar c which may be formed;-;and. in the device shown' in Fig. 1, there is suitably mounted in the ,upperend ofitsfcore a rod29 having anarmature 30,. whic h,;as l ong as the flux in a the .core"'of said magnet is greater than" a predetermined} amount, prevents 1 the upward movement o'f'eitherof the cores 1-2 or 13 under the actionof'their windings; this i being accomplished through the medium ofreleased from the core of the magnet:

a ores bar 31 pivotally COI'llttltilCd to the rod 29 am to bars 32 and 1:55 respectively (-o|lnected L the two cores [2 and 1 5.

bod ot armature resistance Ill is vided tor the motor and the various parts are so coln'iccted that when current is sup-- plied to the mains o and /i. it at once flows through the shunt field winding and through the two bodies of lield resistance 25 and I in parallel, so that the. motor field irntr gized. atetl that, for example. its contact. 5) connects the contacts 6 and 7, current flows from the main a thrtnrgh said contacts, through the winding of. the solenoid it) and back to the main 7). its a result the core 12 of this solenoid is raised and separates the contacts H- and 13, thereby open-circuiting the tietd resistance 4 and slightly \vcakei'iim; the shunt field of the motor. lmn'tediately thereafter the, contact ll engages the contact 11', so thatcurrent [lows from the main n through the contae 2t, 16 and 1-]; to the. core l") thence to the motor armature ,1. the. winding of the blow magnet 25, core 13, contacts 22 and E23 and part of the armature resistance ll. to the main 1'). The motor then starts and attains a c rtain definite speed, which is turther increased by reason ot the spring contact 17 moving the contact arm into engagement with the contact to cause the short cireuitineof the resistz'inee 34. It now the pilot switch be moved to its olt' position, the solenoid 10 is det nergizcd; its core 12 drops so as to bring its contact l-t into engagement with the contact 15. and the contact 14 into engagement with the contact 18. The motor armature is thus short circuited onitself through the armature resistance 31 and since the motor field is still energized, the motor at once acts as a generator, the current flowing from the armature to the core 12, through contacts 1 and 18, all of the resistance ll, contacts 25 and 22, core 1?), blow magnet 28 and back to the armature. 'lhis currentnaturally produces a magnetic flux in the core of the blow out magnet and attracts to it the armature 30, so that. even though the pilot switch be moved to connect the contacts T and St the energization of the winding t the. solenoid 11 is not sul'licient to raise the cure tilt which is held in its lower position against such action by means of the cross har 2.31 and the rod 33. until this current generated in the motor has fallen to a predetermined extent suflicient to permit of the armature t] being Thereafter the solenoid ll is tree to raise itscore 13, and in this case the field resistance 3 is open eireuited, while. the resistance 4 is left in series with the shunt lield windi ng. As before, the upward movement of the spring contacts 21 and successively completes the main motor circuit, cuts out,

ll now the pilotv switch is so oper' 5 the armature re istance. Ill. and when thrpilot switch i.--1 moved to its oil position causes short eircuitine' oi the armature, so that a braking action is exerted on the arma ture which is Slit-(willy brought to rest.

In the ease illustrated in Fig. 2 the. vari us electric connectionsof the solenoids and of the main eontat actuated by them are substantially the same as previously noted, except that a switch. (it the construction shown in Fig. .l, and covered in detail in nr'v' application for patent on a system of motor control, tiled (Ii even date herewith, Serial. No. 'l is emploved for the mrpoi=ge of preventing the. energization of the. solenoid windings until the counter I). .\l. ot the armature has 'lallen lo a uedetermined low point. ll'itli this idea in vi w there is; pirotaltr connected to the lower ends 0']? the two cores 1'! and plate or bar oi insulating n'niterial, ha ving a central upwardly extending portion l designed to be capable ot moving between an arn'lature 37 of magnetic man-rial aml the core -lt) ot the blow magi'iet so ttrto maintain a contact 38. connected to said plunger, in engagement with a second contact 4-] in spite of the attraction of the blow out magnet As long as the plate or bar 33 is in its lower position shown in Fig. the armature :1-7 may be drawn toward the core :10 when the blow Qtltl is energized o as to break the connettion between t :e contac s 33 and 4-1. When, however. said plate is raised by the upward nmvement of either of the cores 1) or 13 o't'the two solenoids. the contacts 18 and 4-1 are prewnted from setmt'atin under the action of the magnetic flux at. the blow magnet. is a consequence, it while the .n'iotor ari'nature is short.- cireuited owing to the movement of the pilot switch to its oil position and current is eenerated by the motor owing to its contitnled l'tiVOllllQlOlL the pilot switch he moved from its {lit position to such a position as would cause closing of the reversing switch and the supply of current to the motor. the windings of neither of the solenoids 1t and 11 can he energized, sin e as long as current above. a predetermined anrount is flowing throiigh the armature circuit the armature 57 is drawn toward the core of the blow magnet and the contacts 38 and =11 which are connected in circuit with the solenoid windings, are separated. it" is not until this generated urrent has fallen to a predetermined low point that said armature is released. and then under the action of the spring arm 39 on -\'lll"i\ the. contact 138 is mounted. the two contacts i and -11 are caused to engage each other so that current may flow through-th m and through the pilot'switeh to one of the solenoids 10 or 11.- Under normal operating conditions these two contacts 1% and it are. not separated even though the blow out iii-agnet40 be energized, since when either of the cores of the solenoid'is in its raised position, the part 36 of the plate 35-is introduced be.-

tween the core of said magnet and the armature 37, thus holding the two contacts 38 and all in engagement.

From the above, it will be notedthat by the use of two solenoids whose energization may be controlled from a distanceby a pilot switch, 'I am enabled to graduallystart a mptor in a plurality of steps and to control the direction of rotation of its armature; at the same time providing means whereby current is prevented from being supplied to the motor after the ilot switch has been moved to its 01f p0sit1on, until the speed of the armature has fallen to such a, point as will permit of the introduction of current without danger of injury. Moreover, the arrangement is such that I am enabled to employ two independent bodies of field resistance of which one is in circuit when the motor 'is' turned in one direction and the other is circuit when it is turned in an opposite direction.

In order that the operation of the solenoids may not be too quick, I may connect to their movable elements a retarding devicein the present case a dash pot 43 of the oil film type. This has its piston 954 connected through a slotted link 45 with the middle of the plate 35, so that hile eitherof the cores 12 or 13 is retarded to a definite extent when moved upwardly under the action of its winding, it may be free to quickly return to its extreme lower position by reason of the slotted connection between the link and the plate 35 as soon as current is cut of? from said winding.

V I claim l. A motor controlling switch consisting of a solenoid; two contacts carried bythe ea e movable member of said solenoid; two fixed contacts 'placed'ito be respectively engaged by said solenoid/contacts when the solenoid is deenergized and two other fixed contacts placed to be successively engaged by the sole-.

noid contacts after the solenoid has been energized.

2 A. motor controlling switch consisting of a solenoid; two contacts carried by the opposite ends of the movable member of said solenoid; a pair of fixed contacts respectively placed to be engaged by said solenoid contacts when the solenoid is deinergiaed; a third fixed contact placed to be enby one of the solenoid contact-sailor the solenoid has been energized; and a pair of contacts of which one" is placed. to be movable into engagement with the other by the second solenoid contact.

A motor controlling switch consisting of a; solenoid having a movable core; two

1 ,v contacts yieldinglymounted on said core; two contacts placed. to be engaged by said of a supporting structure; a solenoid hav' ing a movable core; two contacts yieldingly mounted on said core; and three contacts on --the supporting structure of which two are placed to .be successively engaged by said corecarried contacts when the solenoid is energized; one of said three contacts being free to move into engagement with another contact under the action of one of the core contacts. 1

5. A motor controlling switch consisting of'a solenoid having a movable core; two spring contacts carried by said core; a fixed contact placed to be engaged by one of said spring cont-acts; and a pair of contacts, of which one is movable toward and from the other, placed to be closed by the second spring contact. j

6. A motor controlling switch consisting of a solenoid having a movable core; two

' spring contacts; a pair of contacts, of which one is movable toward and from the other, placed to be closed by the second spring contact; with two additional contacts placed to be respectively engaged'by the spring contacts when the solenoid is denergized.

7. A system including an electro magnetic reversing switch having two solenoids; a motor; a pilot switch in circuit with the solenoids of the reversing switch; a magnet in circuit with the motor; and mechanism controlled by the magnet to positively hold the movable members of either solenoid from operation until the current flowing in the magnet falls below a predetermined point after the motor has been short circnited by said reversing switch.

'8. A motor controlling switch consisting of a solenoid winding having a movable core; a pilot switch therefor; contacts con-; trolled by the solenoid core; a blow out magnet-for said contacts; and a mechanical device actuated by said magnet for forcibly opposing movement of the core under predetermined conditions.

9. A system including a motor; an electromagnetic reversing switch'thereior; a blow magnet for said reversing switch, in circuit with the motor; a pilot switch for the reversing switch; and a mechanical device controlled bythe blow magnet for pre venting operation of the reversing switch under predetermined conditions.

IOVA system including a motor; a pair of solenoids having contacts connected to serve Y as a reversing switch for the motor; a pilot switch connected to the windings of the s0-

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