US972625A - Motor-controlling apparatus. - Google Patents

Description

S. H. KEEPER.

MOTOR CONTROLLING APPARATUS. APPLICATION FILED JULY 23, 1909.

Patented Oct. 11, 1910.

2 SHEETSSHEET 1.

s. H. KEEPER. MOTOR CONTROLLING APPARATUS. APPLICATION FILED JULY 23, 1909. I 972,625 Patented Oct. 11, 1910.

2 SHEETS-SHEET 2.

SAMUEL H. KEEPER, OF PLAINFIELD, NEW JERSEY.

MOTOR-CONTROLLING APPARATUS.

Specification of Letters Patent.

Patented (hot. if, 1910.

Application filed July 23, 1909. Serial No. 509,223.

To all whom it may concern.-

Be it known that I, SAMUEL H. KEEFER, a citizen of the United States, residing in Plainfield, New Jersey, have invented certain Improvements in Motor- Controlling Apparatus, of which the following is a specification.

One object of my invention is to provide a combined starting and reversing switch for controlling the operation of an electric motor, which shall possess but relatively few parts, be of simple and substantial construction, and of such an arrangement and form as to require a minimum of attention and repairs; itbeing further desired that the motor starting element of the apparatus shall be dependent upon the counter-electro-motive force of the motor for its operation, and at the same time be to some extent under the control of a blowout or other magnet, in order to prevent cutting out of the motor starting resistance until predetermined conditions exist.

I also desire to provide a motor reversing switch which shall be provided with relatively eflicient arc-blowout means and shall have certain of its parts definitely placed in regard to a motor starting switch with a view to controlling the action thereof under certain conditions.

I further desire to provide a system of motor controlling apparatus which shall include in addition to starting and reversing apparatus, a relatively uncomplicated and.

substantial device for varying the series and shunt fields of the motor.

These objects and other advantageous ends I secure as hereinafter set forth, reference being had to the accompanying drawings, in which Figure 1, is a front elevation of a panel or other supporting structure upon which is mounted the controlling apparatus forming part of my invention, said apparatus being shown in vertical section; Fig. 2, is a diagrammatic representation of the connections between a compound motor and the various devices constituting my invention; and Fig. 3, is a perspective view of one of the contact rings forming part .of the motor starting switch.

In the above drawings, A represents a slab or plate of some non-conducting material such as slate or marble, on which is mounted the iron casing or frame .7) of a solenoid B of which the winding Z) is mounted within said casing and is provided with a core Z1 When the winding is deenergized, the greater part of this core hangs below the solenoid as clearly shown in Fig. 1, so that an iron disk 6 carried on its lower end extends within the magnetic field of a blow out magnet hereafter described. The lower end of the core 5 has a shoulder or head 6, between which and the bottom of the casing b are mounted a number of contact elements, in the present instance five. The lowermost of these elements consists of an insulating disk b resting on the shoulder Z2 and carrying a copper or other suitable metal ring b of such a diameter that its inner edge is some distance awayfrom the core 6 Immediately against the under side of the bottom of the casing Z) and concentric with the core 6 is a second insulating ring 6 having fastened to its under face another metal ring Z) similar to the first ring Z), and like it, spaced away from the core. Between these two metal rings b are slidably mounted three double contact elements, each of which consists of an insulating ring I) having fastened to each face a metallic ring 6 A spring I) surrounding the core, extends between each pair of fiber rings If and the diameters of these springs are such that they cannot contact with any of the rings 5 With this arrangement of parts, it will be seen that there are three double and two single contact members, and, as shown in Fig. 3, each of the metal rings has a slot formed in its edge in which is fastened the end of one or more extremely flexible copper or other metal ribbons, 6 and the various ribbons from the different rings Z) are, as indicated in Fig. 2, connected at different points to abody of resistance material G. The parts are so proportioned that as the core 79 is drawn upwardly by the energization of the winding Z), the lowermost pair of rings Z) are caused to contact with each other, thereby short circuiting the body of resistance connected between them. As the energization of the winding increases, other pairs of said rings are successively brou ht into engagement with each other, until finally, when the core has reached its highest position, all of the rings are in contact and the entire mass of resistance G is short circuited.

Mounted on the top of the casing b but insulated therefrom is a pair of contacts f and f, respectively connected to one of the main motor supply mains a: and one end of the body of field resistance as.

Slidably mounted in a plug 7" carr 1ed by the top of the casing b is a rod f wh ch extends within the center of the winding Z) so as to be engaged and moved vertically by the core b after this has been moved upwardly into the winding for a certain dis-, tance. Said rod f carries at its upper end a disk 7 of insulating material having metal rings f and f attached to its opposite faces. When in its lowermost position, as shown in Fig. 1, the ring f rests upon and electrically connects the two terminals f and f, and when said rod has been raised to its uppermost position, the ring f is caused to engage and electrically connect a second pair of terminals 7" and f mounted on the slab A. 1 preferably provide a head f for the rod f" and mount the. rings f, f and f between this and a shoulder f on'said rod, placing a spring between the lower faces of the insulating disk and said shoulder so that there is a yielding connection between said various rings and the rod.

The reversing mechanism of the motor consists of a pair of solenoids O and C,

. each having an iron casing c and 0 in which are windings 0 and 0 respectively. The winding 0 has a core 0* which carries at its lower end a spring mounted contact 0 capable of engaging a metallic ring d. Similarly, the winding 0 has a core a which also carries a spring contact 0", likewise capable of engaging said ring 03. The core 0 has mounted in its upper end a rod 6 carrying a spring contact 0 While the core 0 likewise has a rod e which in turn carries a second spring contact 0 Both of these contacts are mounted to engage a metallic ring 11?, when they are in their lowermost positions corresponding to the denergized condition of the solenoid; the contacts 0 and 0 being designed to engage the ring at when the cores 0 and 0 have been drawn into the solenoids. In order to prevent the possibility of the cores sticking in their upper positions and to facilitate their downward movement, light springs e may be placed on the rods 6 and e between the upper ends of the two cores and metallic ugs e removably screwed into the top of the two casings c and c.

Between the two solenoids C and C a blow magnet D is mounted, and this has a core d on whose ends are bushings of insulating material serving to carry the rings 0? and d within the field of said magnet and with plates or other suitably shaped pieces of insulating material 6 serving to properly space said rings from the metal of the two casings 0 and c. These plates 6? of insulating material are also designed to form invarious contacts 0 c 0 and c all engage the rings d and d within them. The casing c of the solenoid C carries at its top a pair of terminals 6 and e placed to be engaged by a metal ring 6 carried by an insulating ring 6 on the rod 6, and similarly there is on the casing c a pair of contacts 6 and e electrically connected by a metal ring 6 carried by an insulating ring e on the rod 6.

Referring to Fig. 2, the motor M to be controlled is illustrated as of the compound round type, having an armature m, a shunt field winding m, and a series field winding m In addition to the armature resistanceG above referred to, there are two banks of field resistance w and 00 and a pilot or controlling switch P. The core 0 is electrically connected to one end of the winding of the magnet D, and the other end of this winding is connected to one terminal of the armature m. The supply main 1 is connected through the terminal f to one end of the series fieldwinding 112?, whose second end is connected through the terminal f with the ring d. The second armature terminal is connected through the starting resistance G to the core 0 The two current supply mains 1 and 2 are connected to the above described apparatus through a double pole switch X; there being a connection directly from the main 2 to the ring (I. The winding 1) of the solenoid B is connected to the two terminals of the armature m, certain contacts of the pilot switch being interposed in this circuit as shown in Fig. 2. Said switch is provided with an operating handle 39 which carries at its lower end a contact p capable of simultaneously engaging and electrically connecting a contact 32 either with a contact p or with a contact Said vcontacts p and p are connecte together and to one of the armature terminals, while the contact p is connected throughthe winding 6 to the other armature terminal. The other end of the handle p of the pilot switch carries a contact piece 39 capable of electrically connecting a contact p with either of the contacts p or 9 Said contact 17 is connected both to one of the supply mains 2 and also with one end of the shunt field winding m, while the contact 8 is connected through the reverse solenoid winding 0 to the main 1; the contact p being connected through the reverse solenoid winding 0 with the same main.

With the above described arrangement of parts, the closure of the main switch X and the moving of the handle of the pilot switch so that its contact p connects the contacts p and p supplies current to the winding 0 the said pilot switch being so designed that its closures Within the magnetic field of the second contact p cannot connect the con winding D, for it willbe noted that the i tacts p and 29* until after the above noted 1 0 contact is made. Under these conditions the energization of the solenoid C causes the core 0 to be drawn upwardly and brings the contact 0 into electrical connection with the ring d. Current therefore flows from the main 1 to the series field m thence through the ring d to the contact a, the core c thence through all of the resistance G, the motor armature m the blow magnet D, core a contact c 1ing (Z and back to the second supply main 2. Current also flows from the supply main 1 to the terminal through one of the rings carried by the rod 7, contact f, shunt field winding m, and to the supply main 2. The motor will consequently start and as the counter-electro-motive force of its armature rises, an increasing amount of current will fiow through the winding 1) of the solenoid B, which will therefore more strongly attract its core and gradually cut out successive bodies of the resistance G as the various rings 12 engage with each other. Just as the last section of said resistance is cut out, the core Z) of the solenoid will strike the rod f and raise the rings carried thereby so as to break the circuit between the contacts and f, As a result, the shunt field winding, instead of receiving the current direct from the supply mains, now receives it through the bank of resistance at" the flow being from the main 1 through the series field, the ring (1, contact a, contact 6, resistance a through the winding m, and so to the supply main 2. The field of the motor is therefore weakened by a predetermined amount and the speed of the armature is increased. The continued upward movement of the core I) finally brings the ring 7 into engagement with the two terminals f and f and thus short circuits the series field winding m, still further weakening the field of the motor and causing its armature to turn at its maximum speed. If the pilot switch P is now moved to its o'li' position, the solenoid C is at once denergized and its core would drop into the position shown in Fig. 1, thereby bringing the contacts a into engagement with the ring (Z, and the ring 6 into engagement with thetwo contacts 0* and 0 At the same time the circuit of the winding 6 is likewise broken, so that the core 6 also drops to its lowest position, thereby cutting into the motor circuit all of the resistance G. Said motor will now act as a generator for the reason that its armature is short circuited on itself and its shunt field circuit is closed. \Vhat is known as a dynamic current then fiows from one terminal of the armature through the resistance G, core 0', contact 0. ring d, contact 0 core 0*, winding D, and thence to the other armature terminal, thus exerting on the motor a braking force which quickly brings its armature to rest. If instead of being brought to its off position, the pilot switch is rapidly moved from its full on position, corresponding to a certain direction of rotation of the motor, to its similar full on position corresponding to an opposite rotation of said motor, it is obvious that while the dynamic current was flowing as above noted, the winding D would be energized, as would also the winding 0 By reason of the fact that the head is within the magnetic field of the winding D, the core b is prevented from rising until said dynamic current has fallen to a predetermined low point. Similarly the core a is not raised by its winding 0 since said winding is so arranged relatively to the winding D as to be largely neutralized thereby when the current generated by the motor flows in this latter winding. The flux set up by the winding D when this is supplied by the so called dynamic current generated by the motor neutralizes the flux of that solenoid winding which would otherwise act to close the switch and permit current to flow to the motor in opposition to that generated by it. With the arrangement of parts shown, the solenoid cores 0 or 0 cannot be raised unless the current generated by the motor flows in the same direction as that which would be supplied by the mains, or unless said current has fallen to a predetermined and relatively small amount. The same is equally true of the winding 0 so that even though the pilot switch be rapidly moved from one set of contacts to the other, no injurious operation of the apparatus is possible, as above pointed out.

Owing to the peculiar placing of the contacts c 0 and c with their cooperating rings d and d, any injury from burning or arcing is avoided by reason of the field produced by the winding D.

I claim l 1. A motor controlling apparatus consisting of a solenoid having a core, a series of contacts carried by said core and normally out of engagement with each other while capable of engaging when the solenoid is energized, a body of resistance, and means for connecting said contacts to different points of said resistance.

2. A motor controlling apparatus consisting of a movable core, electro-magnetic means for actuating said core, a serles of contacts carried by the core and capable of being successively brought into engagement with each other when the core is moved, a body of resistance, and means for connecting various points of said resistance to said contacts.

3. A motor controlling device consisting of a core, a number of pairs of contacts carried by said core and normally out of engagement with each other, electromagnetic means for actuating the core to successively bring the contacts of each pair into engagement with each other, a body of resistance,

and means for connecting said contacts thereto.

4. The combination of a core, a series of i rings thereon, springs yieldingly separating said rings, a body of resistance, flexible conductors connecting said rings with said resistance, and electro-magnetic means for moving the core to cause certain of said rings to successively engage each other.

5. A motor controlling device consisting of a supporting structure, a plurality of contacts mounted thereon, a body of resistance, conductors connecting said resistance to said contacts, springs interposed between successive contacts, and means for moving the contacts to cause certain of them to successively engage each other.

6. The combination of a solenoid, a core therefor, a series of insulating rings carried by said core, springs normally separating said rings, metallic rings mounted on the faces of said insulatin rings, a body of resistance, and means for connecting said metallic rings thereto.

7. A motor controlling device including a reversing switch consisting of two solenoids I having cores, a blow magnet common to said solenolds, with switch contact members having their contact surfaces within the field of said blow magnet.

8. A motor controlling apparatus consisting of an electro-magnetic reversing switch,

a blow magnet therefor, and a motor starting switch including a member extending into the field of said blow magnet.

9. A motor reversing switch consisting of a pair of solenoids, cores therefor, switch contacts governed by said cores, and a blow magnet for said contacts placed to control the action of said solenoids.

10. A motor reversing switch consisting of two solenoids having cores, two switch contact members actuated by said cores,

. fixed contacts placed to cooperate with said contact members, and a blow magnet common to all of said contacts.

11. The combination-of aasolenoid having a core, two contact members carried by the core, a blow magnet, with two fixed contacts mounted adjacent to said blow magnet and placed to cooperate with the contact members of said core.

12. A motor reversing switch consisting of two solenoids each having a core, a contact member carried by each end of each core, a blow magnet, with fixed contacts mounted adjacent to each end of said magnet and placed to cooperate with certain of the contact members of said solenoid cores.-

13. A motor reversing switch consisting of a blow magnet having a metal ring at each end in circuit with a motor, two solenoids each having a core, with a spring contact connected to each end of each core, the contacts on the adjacent ends of said cores being capable of engaging the same blow magnet ring.

14. A motor controlling apparatus consisting of two solenoids, cores therefor, maincontact members actuated by said cores, fixed contacts for said contact members, a blow magnet common to said main contact members, with auxiliary contact members carried by each core, and fixed contacts cooperating therewith.

15. A system includin a motor, a reversing switch therefor inc uding two elect'ro magnets, contacts in circuit with the motor and controlled by said electro-magnets, a pilot switch in circuit with the windings of said magnets, and a blow magnet for the contacts, said blow magnet constituting means controlling the movable elements of the electro-magnets to prevent operation thereof under pre-determlned conditions.

16. A system including a motor, a reversing switch therefor including two solenoids, contacts governed thereby, a blow magnet in circuit with said motor and common to all of said contacts, with a controlling switch having contacts in circuit with the windings of the solenoids.

17. A system including a compound wound motor, a starting switch therefor consisting of a solenoid having a core, a body of resistance, a normally closed switch in series with the shunt field winding and in arallel with the resistance, a second switch in parallel with the series field, and a member controlled by the solenoid for opening the shunt field switch and closing the series field switch.

18. A system including a motor, a reversing switch therefor consistin of two soleno1ds, a blow magnet mounte adjacent said solenoids and in circuit with the motor, contacts controlled by the solenoids and placed within the field of the blow magnet, a starting switch for the motor consisting of a solenoid havin a portion of its movable element extending within the field of the blow magnet, and a body of resistance conof said latter means being placed to be op-' erated by the movable element of thestarting means after the starting resistance has been cut out of circuit.

20. A system including a motor having a reversing switch consisting of two solenoids, a field switch, an automatic starting switch capable of operating said field switch, contacts controlled by the solenoids of the reversing switch, and banks of resistance in circuit with certain contacts of each of said reversing switch solenoids.

21. A switch consisting of a blow magnet having a metallic contact member mounted 10 to be within its field, two solenoids each having a core and a contact carried by each core and ca able of engaging the contact member of t e blow magnet.

In testimony whereof, I have signed my name to this specification, in the presence of 5 two subscribing witnesses.

i SAMUEL H. KEEFER. Witnesses:

GEo. B. WEAN, C. W. BEITER.

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