US1421244A - Control system - Google Patents

Description

H. n. JAMES. CONTROL SYSTEM.

RENEwED MAR. 23,1922.

APPLlcATloN FILED Nov. 4, 191s. V. 1,244, Patlltd Jun@ 27, 1922.

2 SHEETS-SHEET l.

' INVENTOR I Henry D. .Ja/moi ATTRNEY H. D. JAMES.

CONTROL SYSTEM. APPLICATION FILED NOV. 4| 1918. RENEWED MAR. 23. 1922.

2 SHEETS-SHEET 2.

WITNESSES: INVENTOR /Qj: l 2 l, Hen/y D James` UNITED sTATssPATENT OFFICE.

HENRY D. JAMES, OF EDGEVIOOD PARK, PENNSYLVANIA., ASSIGNOR TO WESTING- HOUSE ILLEGTRIC LMAliTUFACTURING COMPANY, A CORPORATION OF I]i1l\l'.l\TSYLH VANIA.

CONTROL mensili..

Specification of Letters Patent. Ptnfgd June, 27, 1922,

Application filed Novembcrll, 1918, Serial No. 269,949. Renewed March 23, 1922.k Serial No. 546,183.

To all whom 'it may concern.'-

Be it known that l, HENRY D. ,li-mins, a citizen oif the" United States, and a resident ot Edgewood Park, in the county of Allegheny and State of Pennsylvania, have invented a vnew and usetul Improvement in Control Systems, of which the following is a specification. Y

My invention relates to reversing systems for electric circuits, especially electric motors, andis particularly adapted toruse in connection with motor-control systems ot the character set forth inmy co-pending apl plicat-ion, Serial No. 236,937, filed May 27, 1918, control'systems, patented September 27, 1921, No. 1,392,056.

The reversing systems forming the subject-matter ot' the present application are modifications of those found in my co-pending application, Serial No. 249,344, tiled August 10, 1918, patented September 2i', 1921, No. 1,392,057, in which the acceleration oit the motor is controlled by an energizing coil in parallel circuit with the acceleratingr resistor through its iniiuenceover-a relay, preferably ot the type illustrated in a copending application of De Camp, Serial No.

241,259, tiled J une 21, 1918, and assigned tof the lVestiiighouse Electric hiianutacturing Co. The relay is maintained closed by a holding circuit.

The object ot my invention is to provide an improved reversing system Vot this character'.

According to my present invention, I so :fri-range the 'control circuits oi the motor that it is impossible to start or reverse it, until the main armature ot the above-mentioned. De Camp relay has iirst been actuated to release the relay armature. Such a system vis `more particularly illustrated at Fig. 8 oit' my above-mentioned application, Serial No. 249,344. In the present system, the circuit ot the coil, mentioned 'above as being in parallel relation to the accelerating resistor, is closed only when the reversing contactors are in their inoperative positions, by switches mechanically connected to them. According to one torni ot my invention, the main armature ot the De Camp relay is initially actuated by this energizing` coil and, according to another iorm of my invention, this armature is actuated by the above-mentioned holding coil.

In the accompanying drawings, Figs. 1,

2 and 3 are respectively. ay side and an end elevation, and a plan view oiia relay ot the tvpe illustrated in the aforementioned application ot De Camp.` Fig. 4 is a diagrammatic view ot' circuits and apparatus illus trat-ing one form of my invention, and Fig. 5 is a similar diagrammatic view illustrating` another form of my invention.

As my inventionk is of particular value in a system employing the above-reterred-to De Camp relay, illustrated in Figs. 1 to 3,

it will conduce to clearness todesc'ribe this relay first.

An insulating panel 29 carries two brackets 30 and 31 supporting coils 22 and 23 -which, when energized by current flowing through them, produce magnetic fields for attracting an armature 32 and any desired number of additional armatures 33, 34 and A compression spring 3G is adjustablv mounted upon a non-magnetizable rod 87, slidably mounted in arms 3S and 3.9, which are rigidly connected to, or constitute integral parts ot,V the bracket 31'. The arm 88 servesalso as a pole piece for the armature 32, and the arm 39 as a pole piece for the armatures 33, 84 and 3.5. A. bar 40 is rigidly connected to the rod 37 and normally engages the armatures 33, 34 and. l The spring 36 thus normally maintains the armatures 33, 34 and 35 in their open positions, with the members 41, which are carried by vthese armatures, in contact with the pole piece' 39. The members 41 are preferably ot non-magnetizable material to prevent treezing.

VThe armature '32 is provided with ears or lugs 42, which are pivotally mounted `upon the bracket 30, and is normally mains .tained in contact with one end oi. the rod 3T by a weak spring 425. The bracket 3() supports a non-magnetizable, U-shaped member 44 between the arms ot which are pivotally mounted the armatures 33, 34 and 35, which carry, respectively, the movable contact members 45, 46 and 47 ot relays 25, 26 and 27. The corresponding stationary contact members 48, 49 and 5() are mounted upon the insulating panel 29.

Springs 51 are attached to longitudinally r adjustable members 52 and to the other ends of the members 41. The pole piece 39 is provided with longitudinally adjustable members 53 to regulate air gaps 70 between these members and the corresponding armai no tures. By means et this adjustment, or by means of the members 52, which control the tension ot the springs 51, the action et the magnetic flux produced by the coils 22 and 23 may be so regulated that the armatures 33, 3d and 85 will be operated in proper sequence.

The armature 32 is provided with an extension 54, preferably ot insul ating material, which carries a switch member 55 for cooperating with stationary switch members 57 mounted upon the insulating panel 29. As shown in Fig. 1, the switch members and 57 are open when the armature 32 .occupies its normal or open position.

The operation may be briefly described as follows. Upon current iiowing through the coil 22, a magnetic Vfield is produced which causes the armature 32 to be attracted toward the pole piece 38. The 'torce or the spring 36 is thereupon overcome, and the bar 4:0 is moved out of engagement with the armatures 33, 34; and 35, the stop members .t1 of which are, nevertheless, maintained in engagement with the pole piece $39 until. the flux of the magnetic lield successively becomes sutliciently low to permit the springs 51 to successively actuate the movable contact members Ll5, 4t@ and i7, thereby to close the relays 25, 26 and 27. In the event that the magnetic lield becomes too weak to hold the armature 32 in its elevated' position, the spring 3G, becoming released, will separate the movable from the stationary contact members. Actuation oit the armature 32, oi" course, eiiects correspending actuation ot' the switch member I shall now describe the invention illustrated in Fig. 4l. A motor, the armature of which is shown at l and the shunt ieldmagnet winding at 2, is connected. between line conductors and 41, with a regulating resistor 6 normally in series with the armature l. Although l have here shown, tor purposes of illustration, a shunt-wound motor, it will be understood. that my invention is equally applicable to ay se 'ies or compound-wound motor. A plui ity of reversing contactors 59, 60, 58 and 6l, mechanically interlocled in pairs, control the direction of rotation ot the motor. A master controller or switch 7 controls the actuation of the reversing contactors through the medium oit energizing coils (i2 and G3. The movable contact members ot contactors G6 and 67 are, respectively, mechanically interlocked with the movable contact nicmbers oit the reversing contactors tor a purpose below described. The movable member of the master controller 7 is designed to bridge cont-act members 9a, 9]), 1G, 17, 18a. and 18h, in a certain order, when operated as hereinafter specified. One or more contactors 10, 11 and 12 (three are illustrated) control the shunting of successive portions 1,3, letand 15 ot the regulating resistor.' l5, through the medium ot energizing coils l5), and 2l. rlhe coil 22 is connected across the terminals olf the resistor (l, at 79 and 8l), in series with a resistor 86. The energizing o't the coil 22 causes the successive closi' g of the relays 25, 26 and 27, as above dcscribed, in accordance with the strength ot the current passing through thc coil 22. rl`he coil 19 is connected. in a circuit leading irom the line conductor 3, by a conductor 28, through the contact .member 1G or the member 17, according` Ato the position ot the controller 7, the coil 1i), the relay 25, the point SO and a line ccmtactor 5, to the line conductor fl. The coils 20 and 21 are similarly connected to the relays 26 and 27 in parallel to the coil 19 and the relay 25. rlhe circuit ol the coil 2213 is closed at the same time as that oit the coil. 2l by the relay 27. The line contactor 5 is adapted to be actuated by a coil e, which is controlled by Contact members 97 and ieb, according to the iliomvard or reverse position ot the controller 7. initially energizing the coil by connecting it in circuit with the contact members (Stand G7', and a resistor 2d, as described below.

The operation is as Vfollows lVhen the controller 7 is actuated to the lett, a circuit is established lrom the line conductor 23, by the conductor 2G, through the contact members 9L' and the coil 8, to the line conductor l. The contactor 5 is thereupon closed.

A second circuit entends from the Contact members 9?), through the contactors G7 and G6, the resistor 24, the coil 22, the point SO anfl the contacter 5, to the line conductor -l-. The coil is thus energized by line roltage lto cause the actuation oll the armature L to the pole piece $58, in opposition to the Ytorce ot the spring 3G, thereby to release the armaturcs 33, Sill and b5, and to close the contact members and 57 Fin'. l) A circuit is thereupon established trom the line comlucH vtor 3, by the conductor 2S, through contY members tlc, thc actuating coil (SIE, thc contact members and 57, the point Sli and tlle contacter 5, to the li'uc,` comluctor la .lllncrgi";ltion ol the coil "I3 thereupon. causes the closing olf the reversing contactors 5S) and (il), whereupon. the motor circuit may be traced 'from the line conductor 3, through the reversing contacter 59, the armature l., the contactor GO, the resistor.' G, and the line contactor 5 to the line conductor .l. The closing o'l the contactors 5l) and C() causes the opening o'lf the contacter' 6i" and the conse quent opening` cllr the circuit el the coil 2. A new circuit 'tor this coil is, however, immediately established, in parallel relation to the resistor G, as above described, between the points 79 and 80. This circuit includes the resistor 8G. The armature 32 is thus maintained in actuated position to maintain l providll 'tor ii. i Ac the bar out of engagement with the armatures 33, 34 and 35 ofthe relays 25, 26 and 27 Ii the current is above a previously-selected sate value, the flux oi the magnetic iield created by the coil 22 will overcome the forces ci the springs 51, and the armatures 33, 34 and-35 will remain `with the stops 4-1 in 4engagement with the pole piece 39 (Fig. 1). As the motor accelerates and the current begins to die down, the magnetic flux set up by the coil 22 becomes weakened. After a time, when Ythe flux has decreased to a predetermined value, the spring 51, attached to the armature 33, Will overcome the force exerted by the flux of this eld, so that the relay 25, controlled by the armature 33, will be closed. The time when this operation Will occur Will depend uponA the size of the air gap 70 and the tension of the-spring 51. The armatures 34 and 35, however, Will remain open. The closing of the relay 25 establishes the above-described circuit of the coil 19. The contactor 10 is thereupon closed to shortcircuit the section 13 of the resistor 6. The motor then further accelerates, and, by decreasing the voltage across the terminals of the coil 22, the magnetic-field in the lneighborhood of this coil is further weakened, which permits the closing of the second relay 26, controlled by the armature 3 A cirw cuit is then completed from the line conductor 3, by the conductor 28, through the contact members 16, the coil v20, the relay 26, the point 8() andthe contactor 5, to the line `conductor il. The coil 20, `thus becoming energized, causes the `closing of the contactor 11 and the consequent shunting oit the second portion 14- o'f the resistor 6. After the motor has accelerated further,

the magnetic field surrounding the coil 22 is again weakened and the relay 27 is closed, creating a circuit extending from the Contact members 16, which, as above described, kare connected to the line conductor 3, through the coil 21, the relay 27 the point 30 and the contacter 5, to the line conductor 4, thereby causing the closing oi' the contacter 12 and the shunting oia the third portion 15 of the resistor 6. The Whole resistor 6 is then entirely shunted from the armature circuit and the armature 1 is connected directly across the line.

The shuntin g of the resistor 6 de-energiZes the kcoil 22 which would release the armature 32 and cause the relays 25, 26 and 27 to be reopened, thus resulting in. d e-energization ot the coils 19, 20 and 21 and the consequent reinsertion of the resistor 6 into the armature circuit, except for the coil 23, which becomes energized at the same time with the coil 21., upon the closing of the armature 35 of the relay 27. The circuit of this coil is from the line conductor 3, by the contactor 28, through the contact members :16, the coil 23, the relay 27, the point S0 coil 63 (or, if operation in the reverse direction be desired, thc coil The contact members and 5-7, moreover, cannot be closed until the armature 32 has been actuated by the coil 22, which, inturn, cannot be energized until the reversing contactors have opened, and the contactors 66 and 67, mechanically connected thereto have been closed. It is thus impossible to start or to reverse the motor until after the reversing contactors all occupy their inoperative positions. It, then, the controller 7 be moved suddenly 'from one operative position to the other to effect reversal of the motor, it will be impossible to effect the operation of the motor in the reverse direction, with the relays 25, 26 and 27, and, consequently, the contactors 10, 11 and 12, closed, and, therefore, with the resistor 6 entirely shortcircuited. Thedanger oit suddenly throwing the motor across the line Without any resistance in circuit With the armature is thus avoided.

y,The system ot Fig. 5 is similar to that ot Fig. 4L, with the exception that the initial actuation of the armature 32 is effected by the coil 23, instead oi by the coil 22. The essential difference is that the coil 22 is permanently connected, at 79 and 30, in parallel circuit with the resistor 6 and is not, as in the system ot' Fig. 1, at any time con.- nected directly across the line. The coil 23 is initially connected in a circuit extending from the line conductor 3, by the conductor 28, `the contact member 9a or the member 13a, as the case may be, the `coil 23, the contactors 67 and 66, the point 30 and the contactor 5 to the line conductor Ll. Upon the closing oi this circuit, the armature 32 `is actuated to force the bar 40 out of engagement with the armatures 33, 341 and 35 `(Fig. 1). Zhen the contacter 67 or the contacter 66 is opened by the coil 63 or by the coil 62 to close the reversing` contactors for forward or reverse operation of the motor, the circuit o' the coil is broken, but `the circuit o the coil 22 is energized, upon the closing ot the motor circuit, to maintain the armature 32 in actuated position. When the resistor 6 is entirely short-circuited by the closing ot the relays 25, 26 and 27, the coil 22 becomes cle-.energized but the coil becornes again energized simultaneously with the closing of the relay 27.

The circuits may be traced as follows: upon actuating the controller 7, for example, to the right, a circuit is completed which extends from the line conductor 3, by the conductor 28, the contact members 18a` and the actuating coil 8 to the line conductor 4. The contactor 5 is thereupon closed. rlhe above described circuit of the coil 23 is also closed at 18a, the coil 23 becoming,` thereby energized to actuate the armature 32. The switches 55 and 57 are also thereupon closed, whereupon a circuit may be traced trom the line conductor 3, by the conductor 28, through the contact members 187), the actu atcoil G2, the contact members 55 and 57, the point 80, and the contacter 5, to the line conductor 4. The armature circuit may then be traced from the line conductor 3, by a conductor 28o, through the contactor 61, the armature 1, the contacter 58, the point 70, the resistor 6 and the cont-actor 5, to the line conductor 4. The circuit of the coil 23 is broken at 66 and the circuit ot the coil 22 is energized in shunt to the resistor (5 at the points 79 and 80. lVhen the relay 25 closes, in accordance with the circuit conditions, as described in connection with Fig. 4, a circuit tor the actuating coil 19 oi the contacter 10 is established from the line conductor 3, by the conductor 28, the contact members 185, the coil 19, the relay 25, the point and the contacter 5, to the line conductor 4. The contactors 11 and 12 are similarly closed upon the closing ot the relays 2G and 27, the closing ot `the latter relay serving also to close a new circuit for the coil 23, which extends 'trom vthe line conductor 3, by the conductor 28, through the contact members 18a, the coil 23, a resistor 24a, the relay 27, the point 8O and the contactor 5, to the line conductor 4. Upon the de-energization of the coil 22, therefore, when the resistor 6 becomes entirely shortcircuited, the coil 23 becomes energized to maintain the relays closed, and the resistor 6, therefore short-circuited.

It will be noted that, in the system of Fig. 5, before the motor can be reversed, by actuation ot the controller 7 from one operative position to the other, the circuit of the coil 23 will be broken to cause the release ot the armature 32 (Fig. 1). Assuming the motor to be running as above described, the circuit ot the coil 23 will be broken at the contact members 18a. The relays 25, 26 and 27 will thereupon open to break the circuits ot the actuating` coils 19, 2O and 21 of the contactors 10, 11 and 12, thereby to cause the resistor G to be reinserted into the armature circuit before the reversal of the motor. lllhen the controller 7 bridges the contact members 9a, a new circuit will be created for the coil 23, preliminary to the reversal of the motor, and the operation will then proceed as be'lore described, but with the reversing' contactors 59 and 60, instead ot those indicated at 58 and 61, closed; but beitore the motor can loe started in the reverse direction, the resistor G will be in circuit with the armature. The same safeguards lays ot ordinary kinds, as discussed in my i above-mentioned applications, Serial Nos. 236,937 and 249,344. Or I may modify the De Camp relay, doing,` away with the contact members 55 and 57 and having their function performed by an additional relay like those numbered at 25, 26 and 27. Other changes will be obvious. l desire, theretore, that my claims be broadly construed, except in so iiar as limitations may be ei;- pressly set forth therein.

I claim as my invention:

1.-. The combination with an electric mi tor, a resistor in circuit therewith, a switch for closing the circuit et said motor, and a coil :tor actuating said switch, of a. relay mechanism tor controlling said resistor and the circuit ot said. coil, said relay mechanism comprising` an actuating, coil, and a switch ineclianically connected to said first-named switch igor controlling the circuit olil said relay coil.

2. The combination with an electric mo tor having a resistor, a pair ot reversing` switches for said motor, and a coil 'for controlling said resistor, ot switches mechanically connected to said reversing;` switches tor closing the circuit oi: said coil betere the starting of said motor.

3. The combination with an electric 1no tor having a. resistor, a pair of reversing switches -for said motor, a coil in parallel circuit with said resistor for controlling the short-circuiting of said resistor, and a coil Ator maintaining said resistor short-circuited, ot switches mechanically connected to said reversing` switches for closing the circuit et one of said coils before the starting oit said motor.

4. The combination with an electric uiotor havinfr a resistor, a pair of reaersing;Y

switches tor said motor, each ha ving` an artuating coil, and a switch `'tor short-circuiting said resistor, ot a switch for closing` the circuits ot said coils, and coil for closing said closing switch and Ytor controlling said resistor switches.

5. The combination with an electric `motor having a resistor, a source ot energy :for said motor, a pair of reversing switches tor said motor, and a coil, ot switches nieclmnically connected to said reversing switches for connecting' said coil to said source to start said motor, and means for thereupon connecting said coil in parallel circuit with said resistor to short-circuit said resistor.

tor having a resistor, and a pair of reversing switches for said motor, of a coil for controlling said resistor and said switches, and a pair of switches mechanically connected to said reversing switches for preventing the energization of said coil except When said reversing switches occupy inoperative positions.

In testimony whereof, I have hereunto subscribed my name this 30th day of Oct.,

HENRY D. JAMES.

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