US1288275A - Electrical control system for hydraulic transmission. - Google Patents

Description

I A. SUNDH. ELECTRICAL CONTROL SYSTEM FOR HYDRAULIC TRANSMISSION.

APPLICATION FILED MAR. I4. I914.

1,288,275. Patented Dec.17,191 8.

WITNESSES: INI/E/VTOR wmfigz w WSWJK nu: Mumus mans co, Pnomumu. v/Asnmcnm. n. c.

' UNITED STATES PATENT QFFIGE.

AUGUST SUNDII, OE HASTINGS-UPON-HUDSON; NEW'YORK; ASSIGNOR' TO' OTIS ELEVATOR COMPANY. A CDRPORATION OFNEW JERSEY.

ELEGTBIGALCONTROL SYSTEM FOR- HYDRHULIG TRANSMISSION;

Specification of Letters Patent.

Patented Dec; 1'7, 1'91'8.

Applicatimrfiled-'lilarch 14, 1914i Serial No. 824.780:

To add whom, itnnay, concern-r do it known that 1, AUGUST: SUNDH, a citizen of the United States,.residing at= Hastings-upon-Hudson, inthe county; ofi WVestchester and State of New York have in vented a. new and useful Improvement in Electrical Control; Systems for: Hydraulic ilransmission, of which the following is a specification.

My invention I'BlfllI-ESillO' illl electrical control system,v and has for" its' obj ectnthe provision of: simple and; efiicient meansfon con- 1 rolling-a power unit comprising the following ele1nents,.a fiuidimot'or, pumping-{mechanisnr for supplying: fluid; under pressure to the fiuidmotonandza prime'moven such. as an electric motor: for driving-thepumpingi mechanism;

to the hydraulic transmission: mechanism; will be brlef, SIIICGxthflSSDld" mechanism. 1s--- fully. shown andidescribed in detiill'flnd'lly co-pending: application, Serial No. 764 994, filedFMay 2, 19.135

The fluid. pressure motor F- comprises a,. plurality; of double acting: cylinders; whose.

pistons 1 are connected to a common" crank: pin 2. A driven member 3 compnsesm-cablesheave- 3,. which l is :lieyed': to the crank shaft and is adapted toreceive:theihoistingicables,

of'an elevator or:otlienhoistgelthough ifidee sired the sheave 3 may bee-replaced bys-mbe'lt; pulley, gear: or other devicewhereby power may betransmitted' fronr the :cranlti shaft) to :1 ny desired? power consuming device;

The. puiiipi P" isadaptedi to 1 deliver fluidunder pressure to the fluid: motor F. The stroke oi the pumpplungers 5' iscontrolled by means of atiltinghead 6; ca-m'iedmponashafh 7 in anti-friction bearings 8. The right hand end of the tilting head is providedon its inner circumference-With a ball race 4t; which is secured in piliicoby means of :1 ring 9 andkroacting ballra-cc 9". carricd b ring- 13, which is concentric withthe shaft 7, but is'adapteditobe shifted-in zines-centric position with respect to the shaftTby-uneans ofa slidingkey or wedgelO. The-latteris arranged to slide longitudinally in atslot .in the shaftv bye ineansof a lever 11,. which is bifurcated at its lowerrendand basemin of oppositely disposed pins w-hiclienter ci rcumferential groovein thepa-rt l2, which-is integraliwitlnthe key or wedge-10. By this arrangement thezeccentricityof thering: 13:3 can bevaried fromv zero to. maximum in either direction by; sliding the wedge lengthwise of the shaft by'mcans-of' the-lever l1. The length of the stroke 50f tl1e--plun gel-s wil l obviously depend; uponathe amount of tilt or inclination given to the tilting; head by means of the wedgmnnd sincethis factor may. be varied: at will, theoutput of.- the pump may be controlled, within predetermined limits, or if desired, the'pmnp-ma-y be arrangedto reverse the direction of flow of fluid-f by movingthe- Wedgein a. right hand direction past center;

A rotary valve 14'. isoperated from: the pump shaft and is adaptedto have wsliding movementx thereon; This valve directs. the fluid between thepump: and fluid motor.

Means for imparting-11 sliding movement of;

the-valve l tupon the shaft 7, comprisesa grooved collar. 15, provided on eitherlateral THCWAYIHI ballzthnust bearingsawhich are se cured to or carried=upon thervalve. A1 piv.-. oted? lever 16 has-a PID'OJLliZ which ridesin thegroove on said collar; the arrangement being such that the valve may be-shifted longitudinally oh the shaft means'ofi the lever 16: The latter is provided v with pin l7'at its'other enchwhioli pin is=adaptedi to ride/in: a cam slot 18 'formedin: theczun. 19. The lever 11' by. which the wedge is shifted; is also provided 'withraipiinw; which ridesinacamr slot 21v in thecamiQQ; The cams l9 andiZQare secured; to. a shaft 23, to

which is keyed: a worm wheel 245;.Wl1l0ll is actuated through aworm 25 by -mea-ns of pilot motor Gr; The pilot motor'isprovided with reversethfieldlwindings 26 111161 27; by means of which the directioniot" rotation of thepilot motor and consequently. theworm 25-is reversed: Electromagnetic switches 28 and 29control.the circuits-of the field Wind ing's 2G andiFZ'r', respectively. A bar 30rca-rry- Eng contact strips -31 and 32, is movable either to the left or right with the lever 11, said bar being connected to the lever by a link 33. Stationary contacts 34, 34 and 34" normall engaging the contact strip 31, 0011-, trol a circuit for the winding 28, and stationary contacts 35, 35 and 35", normally engaging the contact strip 32, control a circuit for the winding 29'. A member 36 is formed integrally with or may be otherwise connected to the bar 30, said member having cam surfaces 37, 37 adapted to actuate a switch 38, and cam surfaces 39, 39 adapted to actuate a switch 40, as hereinafter more fully described.

An electric motor M is directly connected to the shaft 7. This motor is of the direct current compound wound type, which is particularly adapted for hoisting purposes, in that it combines the powerful starting torque at low speed of the series wound motor with the substantially constant speed characteristics of the shunt wound motor. The series, shunt and extra field windings are designated A,'B and C, respectively. Theswitch 3S whenclosed by one or the other of the cams 37 or 37, establishes a short circuit around the series field winding.

' The switch 40 is normally closed, and when opened by one or the other of the cams 39, 39' opens the circuit of the extra-field winding. It is to be noted that the arrangement of the two sets of cams 37, 37' and 39, 39, are such that the switch 40 is-opened before the switch 38 is closed thus the extra fieldwinding is cut out before the series field winding is short circuited.

A sectional resistance H in series with the armature of the motor M, is controlled by a plurality of electro- magnetic switches 41, 42, 43 and 44. These switches are provided with windings 41', 42, 43 and 44, whose cores are adjusted in-a well known. manner to effect the operation of said switches in successive order as above enu- Inerated. The energization of said windings to effect said operation is dependent on the counter-electro-m'otive force of the rotating armature, since they are connected across or in shunt to the motor armature and a portion of the starting resistance H.

The electric motor M is adapted to drive the shaft 7 in one directioir only, and the operation of the driven member 3 in' reverse. direction is effected by means of the pump, which by moving the wedge 10 in a right or left ltand direction past center reverses the direction of flow of fluid.

A winding 45., of the electromagnetic main line switch J is controlled by a switch 46, which is controlled by a relay magnet 47. The'relay magnet is provided with a dash pot 48 by means of which a time period is obtained when the relay magnet is dcnergized, whereby the main line switch will be maintained closed and the motor M kept running, during the stopping period of the fluid motor F, which time in amount we will say for example, is equal to the average time required in elevator practice to discharge and take on passengers.

A manually operable switch D controls the relay magnet 47, and also the pilot motor G. The switch D comprises a pivoted lever 48 carrying contact strips 49 and 50. When the lever is moved to the right the contact 49 is adapted to engage contacts 51, 52 and 53, and when moved to the left engages contacts 51, 52 and 53. A segment 54 supplies current to the contact 50 which spans contact segments 54 and 55 or 54 and 55 when the lever 48 is moved to the right or left, respectively.

The-operation is as follows: By moving the contact segments 49 and-50 to the right to engage contacts 51 and 55, respectively, circuits are completed for the windings 47 and 29'. The circuit for the winding 47 is as follows: from the-lmain to conductor 56 to segment 54 and contact strip 50 to seg ment 55, conductor 57, winding 47, conduct'or 58-to line. The circuit for the winding 29' is as follows: contact 49, contact 51, conductor 59,-contact 35 and contact strip 32 to conductor 60, winding 29, to conductors 61 and 62 to line. The Winding 47 now being energized will close the switch 46, thereby closing a circuit for the winding 45, the latter thereby closing the main line switch J, which closes a circuit for the mo tor armature, the series, shunt and extra fields, under which condition the motor will now start running at slow speed, the current taken by the armature being limited by the resistance H. The motor circuitmay be traced as follows, from main through switch J to wire 67, resistance .H, wires 68, 69, series field winding to wire 70, through motor armature to wire 71, and thence through switch J to the line. The winding 29 being energized will close the switch 29, thereby closing a circuit for the field winding 27 and armature of the pilot motor G, said circuit being as follows: from main to conductor 56, junction 56 to conductor 63,. through the armature of pilot motor to conductor 64, field'winding 27 to conductor 65, through switch 29, and conductor. 62 to line. The pilot motor, through the worm and gear connection will now rotate the cams 19 and 22 a predetermined amount, and in a clockwise direction, we will say for example, looking toward the left on the drawing, thereby moving the valve 14 to the left, and the wedge 10 now being moved to the left off center will tilt the head from a concentric to an eccentric position, whereupon the same will operate and effect the reciprocation of all the pump plungers in their respective cylinders. The pump will now deliver but a small quantity of liuid to the fluid motor, thereby starting the same at slow speed but with a powerful torque.

It will be notedthat the: pilot motor will efi'ect a movement of thewedgelO to change the eccentricity of the head, onlya predeten mined amount, or in other words,- until the lever 11 has moved'the strip-32. carriedloythe bar to the right in this instance, out of engagement; with the contact whereupon the circuit for the armature of'the'pilot' motor and field 2i' just t-raced' will be'opened and the pilot motor will come-to rest. Now it will be seen that as-the lever-48 is-moved farther toward the right so that the contact d9 engages the contacts 52-and 53; respectively, that a predetermined increase: in'the eccentricity of the head is effected; thereby: increasiug'the output of thepump, and resulting' in air-increase in' the a'ocelemtion of the-fluid motor'to its-maximum spced, that is when the contact 49 engages the contact 53: Theelect-ric motor will* accelerate in proportion tov the load thereom. sinceas the speed of the motor armature increases thewindings 451'", 42, etc.-, willbe energize-d," thus effecting thesuccessiveoperation of the switches 41, 42, etc., in a wellknown ma no'er, to short-circuit the sections of starting resistanceI-Ii As: the'memher' 36' is moved to thee-right and at a-timewhenthespeed ot" the fluid motor is almost at its maximunu the cam face 39 011 the member 36 aotuates the switch 1 10 thusopen cirouiting 'the' extra Held-'wiudingG, and a further movement of said arm effects the closing-of 'the righthand contactof switch 38, thereby short. circuiting the series field winding: The motor now accelerates-'-to-full speed with all the resistance H; the extra and series field? windings cut out, andbeing'excited the shunt fielda-lone runs at substantially constant speed;

It Willbc noted that when-the bar 30 -'is'in its full right hand position the-contactstrip isout of engagement with the contact 35", and the eontact strip-31 willhein-engagement with astationary contact 66'a-nd also contacts 35'and 35"; Now as the lever 48 is returned to its central position, wind ing 28 is energized, thus closing a. circuit for the field 26 and armature of the pilot motor by means of the switch :28 which will effect the operation of the pilot motor in a: reverse'dire ction to thatjust described; thus effecting the rotation of the cams 19 an'd to gradually decreasethe eccentricity of the head until the same is-concentric with the shaft 7; at which time the contact strip 31 will have been moved out of engagement with the contacts 35', 35 and 66' and will attain its normal position. as shown. valve 14 is likewise gradually moved toits central or closed position to cut off the fluid supply to the fluid motor, and the fluid is The thus locked in said motor and acts as a hraket'or the-same. The movement of: the bar 30 toward its central position reinserts the series and extra fields,. thus'the motor speed will: decrease, and the resistance II will be automatically inserted again, and tlI6 m0tO11 will run ataslow speed for a periodof time determined bythe dashpot relay which keeps the main line switch J closed and' consequently the motor' circuit, fol-r a period of. time after the lever 48' is moved: to its central position, or in other wordseafteri the contact strip 50 disengages the segment/551 Thus it will. be seen. that electric motor M" will? not stop eachtime llllflfllllilLIIlO'tOlf stops if the time consumed ton-'suchestopds not excessive, ormore than the average:

By. moving the'lerer' l8 toward the left, the/fluid motor F is operated in itreverse direction tothati herein described. In this operation. the field winding 26 is energ'zed by meansnof the .switchQS; thus efiecting the operation) of said pilot motor toell'ect the rotation of the cams 19 and 221m an anticlock-wise direction instead of a: clockwise dircctiolras was the'case when the lever 48 was moved totheright at starting; This rotation of the cam 22:willdnove the wedge- 10't'o the right oif center; and thus efie'ctnaireverse action of the pump, tothat heretofore described the cam 19 acting the same regardless 'ofits' direction of rotation. The mode of= operation of the fluid motor and electric motor; will otherwise be the same as heretofore just described andtthcrefore need not be further explained;

fllt is to beparticularly noted that the pilot motor has-freedom to-rotate the cam 19 in either-direction a short distance when the-lever 11 is'in" central'position as shown. without the cam slot; 21 being" effectiveowingtothestraight portion thereof; Such an arrangement; is made necessary onl ac count of the difl'iculty met with'by the pilot motor in 1 not stopping 'directly, as it returns the lever 11 to itscentral position;

Various changes in the details and arrangement of parts might obviously be uni-dc by those slilledin the art; without depart-- ingfromthe" spirit and scope of the invention. I wish thereforenot' to be limited: to the'precise details and arrangement herein shown.

What I claim is:

1. Thecombination with a fluid pressure motor, pumping V mechanism adapted" to supply said motor with fluid under pressure, a non reversin'g electric motor for drivingthe pumping mechanism, a pilot motor, means actuated thereby for varying the output of the pump, means for controlling the pilot motor'to efi'ct the starting, stopping; and variation in the speed of the fluid motor in either direction independently of the electric motor, a manually controlled electromagnetic switch for controlling the startin and stopping of the electric motor, an means for automatically regulating the acceleration of the electric motor in proportion to the load thereon.

2. The combination with a fluid pressure motor, pumping mechanism for supplying fluid under pressure to said motor, a nonreversing electric motor for driving the pumping mechanism, a pilot motor, means actuated thereby for directing fluid from the pump to the fluid motor and for simultaneously varying the output of the pump independently of the electric motor, a manually operable switch, means controlled thereby for controlling the pilot motor to eflect the starting, stopping and variation in speed of the fluid motor in either direction, an electromagnetic switch controlled by said switch for connecting and disconnecting the electric motor with a source of current supply, and means .for automatically accelerating the.electric motor in proportion to the load thereon.

3. The combination with a fluid pressure motor, pumping mechanism adapted to supply said motor with fluid under pressure, an

electric motor. for driving the pumping mechanism, said motor having a series, shunt, and extra field windings, a manually operable switch, an electromagnetic switch controlled thereby for connecting and disconnecting the electric motor with a source of current supply, means controlled by said switch forcontrolling the starting, stopping and speed of the fluid motor, a starting. resistance in series with the armature of said electric motor, electro-responsive mechanism for automatically cutting out said resistance as the speed of the motor increases,-- and means operable when the fluid motor reaches a predetermined speed, to automatically short circuit the extra and series field windings substantially as described.

4. A driving and driven member, power transmission mechanism interposed between said members, means for controlling the starting, stopping and the accleration of the power transmission mechanism at will, and means for controlling the starting and stopping of the driving member, said means be-.

ing arranged automatically to maintain the operation of the driving member for a predetermined period of time, relative to the stoppingtiperiod of the power transmission mechanism.

5. Tlie combination with fluid power being arranged automatically to maintain a supply of current to said motor for a predetermined period of time after the stopping of the power transmission mechanism.

6. The combination with fluid power transmission mechanism, a manually operable switch, means controlled thereby for starting and stopping the fluid Power transmission mechanism, an electro-magnetic switch for connecting and disconnecting the motor with a source of current supply, and means for controlling the operation of said switch to maintain a supply of current to the motor armature for a predetermined period of time when the power transmission mechanism is stopped by moving the manually operable switch to its normal or central position.

7. The combination with a driving and driven member, power transmission mechanism interposed between said members, means to start the driving member and transmitting mechanism simultaneously, and means to stop the transmitting mechanism and to efiect the stopping of the driving member in a predetermined period of time after the stopping of the transmitting mechanism.

- 8. The combination with a driving member and driven member, variable speed power transmission mechanism interposed between said members, means for starting and stopping the driving member and power transmission mechanism, and a timing device to automatically eflect the stopping of the driving member in a predetermined period of time after the stopping of the transmission mechanism.

9. The combination with variable speed power transmission mechanism, manually operative means for controlling the starting, stoppin and acceleration of said mechanism,a %riving member for the power transmission mechanism, manually operative means for starting said member, said manually operative means for both the power transmission mechanism and the driving member being adapted to eflect the stopping of the transmission mechanism and the driving member, and a timing device for-automatically maintaining the driving member in operation for a predetermined period of time after the stopping of the transmission mechanism.

10. The combination with a fluid pressure motor, pumping mechanism adapted to supply said motor with fluid under pressure, an electric motor for driving the same, a pilot motor, and means actuated thereby for varying the output of the pump, said means being arranged so that the pilot motor may have a certain amount of play at starting.

11. The combination with a fluid pressure motor, pumping mechanism adapted to supply said motor with fluid under pressure, a

non-reversing electric motor for driving the same, a reversible pilot motor, means actuated thereby for varying the output of the pump, said means being arranged so that the pilot motor may have a certain amount of play in either direction at starting.

12. The combination with a fluid pressure motor, Jumping mechanism adapted to supply said motor with fluid under pressure, an electric motor for driving the pumpin mechanism, a pilot motor, means actuated thereby for directing fluid from the pump to the fluid motor and for simultaneously varying the output of the pump independently of the electric motor, a switch controlled by said means for automatically controlling the pilot motor to effect a step by step variation in the output of the pump, and a manually operative switch for controlling supply circuits to the first named switch;

13. The combination with a fluid pressure motor, pumping mechanism adapted to supply said motor with fluid under pressure, an electric motor for driving the pumping mechanism, said motor having a series, shunt and extra field windings, a center shitting device associated with the pump, a pilot motor for actuating the same, a manually operable switch, an electromagnetic switch controlled thereby for connecting and disconnecting the electric motor with a source of current supply, means controlled by said switch for controlling the pilot motor to effect the starting, stopping and variation in speed of the fluid motor, a starting resistance in series with the armature of said electric motor, electro-responsive mechanism for automatically cutting out said resistance as the motor speed increases, and means de endent on the movement of the center shi ting device for automatically cutting out the extra and series field windings when the pump stroke is almost at its maximum.

14. A driving and driven member, power transmission mechanism interposed between copies of this patent may be obtained for five cents each, by addressing Washington, D. 0.

said members, means for controlling the operation of the power transmission mecha nism at will in either direction and the driving member in one direction, an electric motor, and means dependent upon the counterelectro-motive force of the motor for automatically regulating the speed of the driving men'rbcr in proportion to the speed of the driven member.

15. The combination with a fluid pressure motor, a pumping mechanism adapted to supply said motor with fluid under pressure, a non-reversing electric motor for driving the pumping mechanism, manually controlled electro-responsive means for starting, stopping and accelerating the fluid motor in either direction mechanically, independently of the electric motor, manually controlled means for controlling the starting and stopping of the electric motor, and means for automatically regulating the speed of the electric motor in proportion to the load and speed of the fluid motor.

16. The combination with a fluid pressure motor, pumping mechanism adapted to sup ply said motor with fluid under pressure, a non-reversing electric motor for driving the pumping mechanism, electro-responsive means for starting, stopping and accelerating the fluid motor in either direction mechanically, independently of the electric motor, an electromagnetic switch for connecting and disconnecting the electric motor with a source of current supply, a manually operable switch for controlling the said elcctro-responsivc means and said electro-magnet-ic switch, and means for automatically accelerating the electric motor in proportion to the load on the motor.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

AUGUST SUNDH.

Witnesses:

WALTER G. STRANG, JAMES G. BETHELL.

the Commissioner of Patents,

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