US1289788A - Motor-starter. - Google Patents

Description

B. B..JACKSON.

MOTOR STARTER.

APPLICATION FILED MAY 9. 1916.

1,289,788. Patented Dec. 31, 1918.

3 SHEETS-SHEET l.

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By M W J AfioRNEy B, BIJACKSON.

MOTOR STARTER.

APPLICATION FILED MAY 9,1916.

Patented Dec. 31, 1918.

1,289,788. 3 SHEETS+SHEET 2.

N 1Q h sh VII/III 7 IA- Be jamin JQC/{jon/ INVENTOR' M W a ATTORNEY B. B. JACKSON.

MOTOR STARTER.

APPLICATION FILED MAY 9. 1916 3 SHEETSSHEET 3.

Q N Ln OQLQKQ s 5 CO I I) W W I W 1 E \I I I a E 03 jg jq fr; JZC j 0 l, INVENTOR.

BY @W A TTORNEY Patented Dec. 31, 1918.-

JUNIIEn STATES PATENT. orrio BENJAMIN BJJACKSON, OF CHICAGO, ILLINOIS.

MOTOR-STARTER.

Y '0 alt whom it may concern; I 1

Be it known that IQBENJAMINB. 4JACK- son, citizen of the United States, residing at Chicago, in the county of ,Cook and State of Illinois, have invented certain new and useful; Improvements in Motor-Starters; and I do hereby declare the following to be a full,

clear, and'exact description of the invention,

such as will enable othersskilled in the art to which it appertains to make and use the same.

My invention relates to starters for such prime movers as require auxiliary means for bringing them to the speed at which they become self-propelling, its general object being to provide a starter in which the energy will be stored by the prime mover itself and which will require no attention whatever after it is once adjusted in opera.- tive condition. More particularly, my invention aims to provide an attachment for a non-self-starting prime mover such as an internal combustion engine or a single phase alternating current motor of the induction type) having energy storage means arranged to: produce a rotary torque in an element which may also be oppositely rotated by the prime mover for replenishing the stored energy; to provide simple and automatically controlled means for connecting the said torque-actuated elements for its said starting purpose when the prime mover is at rest, for automatically releasing. element when'the prime mover is to be started, for disconnecting and stopping said element when the stored energy been used for imparting rotation to the rotor of the prime mover, for thereafter oppositely connecting said element to the prime moverand thereby replenishing the stored energy, for disconnecting said element when the desired amount of energy has been stored, and for returning said element to its starting position when the prime mover is being stopped. Further objectsare to provide simple neans. for overcoming any imperfect meshing of the teeth of the said torque-actuated element with those of the gears associated therewith, to utilize both the torque stored in the said element and the torque of other rotatable parts for controlling the position of the said element, to provide simple means for a djusting' the forces required for moving the said element from one to another of its said positions (that is to say, its motor-accelerating, recharging, motor-running and motor Specification of Letters Patent. Put-3 111311 Dec, 31-, 1918 Application 'fileaivra 9, 1916." Serial No, 96,329. i y

stopped or'neutral positions), and to provide simple means for utilizin centrifugal action as one of the forces for eflecting a transfer said element from its motor-runnin to its neutral position. A further object o my invention is to provide simple means whereby the starting attachment may readily be useel for starting the prime mover in either direction.

More particularly, my invention aims to provide mechanical means for augmenting the starting torque. of an electric motor and for checking the flow of current to such a motor while the latter is being accelerated,

thereby enabling an inductionmotor to be I started with a relatively small current; to

provide electromagnetic means in circuit with the motor for releasing the mechanical means when the motor is to be started, to utilize theresistance of'the said electromagnetic means for checking the flow of current to the motor while the latter is being accelerated; also to provide means for cutting this resistance out of the motor circuit when the starting has been eifected,, and means for automatically re-inserting this resistance when the motor comes to rest,

Further objects will appear from the following speecification and from the accompanying drawings which show myinvention as embodied in a starter for an electric mo- ,tor. In the drawings,

Figure 1 is a fragmentary side elevation of an electric motor equipped with one embodi-.

ment of the starter of my invention.

Fig. 2 is a fragmentary end view of the same.

Fig. 3 is an enlarged section through two of the clutching members associated with the actuating pinion.

Fig; 4: is an enlarged longitudinal section through the pinion and parts adjacent thereto.

Fig. 5 is a fragmentaryelevation of the ratchet on the shaft of the pinion.

Fig. 6 is a diagrammatic view of portions of the mechanism showing their positions while the energy storing spring is being nd- Fig. 7 is a similar view showing the parts during the acceleration of the motor by the starter. I

Fig. 8 is a vertical section through Fig. 1 along the line 8-8.

' Fig. 9 is a central vertical section through and affords bearings for a secondar Fig. 10 is a partially diagrammatic perspective view of the starter mechanism (with the spring and certain other parts removed) taken when the motor is slowing ing current motor, 1 mount upon a suitable portion of the motor, such as the oil reservoir of the motor 24 in Fig. 1, a forked frame presenting upper and lower arms 10 and 41 extending parallel to the shaft of the motor. The upper of these arms carries a depending electromagnet 1 and a bracket 36 extending below this magnet between the said arms. 1 Interposed between the bracket 36 and the lower arm 411 is a frame 29 which is rotatable on pivot-s 28, the rotation being effected by means of a handle 27 fast upon the frame 29 and normally interlocked with 'a latch 34 on the arm d1. I a Pivoted upon the frame 29 by means of horizontal pivots 20 is a rocker arm 121-hav ing two projecting arms 33 and 'i'xwhich both overhang the shaft of the motor. The free end of the lower arm 33 is connected by a tension spring 16 to a rack on'the frame 29, which rack permits of adjusting the spring by moving the adjacent end of the spring from one notch to another. The upper arm 7 has a main portion concentric with the pivots 20 and is equipped near its free end with successive stops, A, B and C arranged in steps and adapted to engage a pin 3 carried by the armature 2 of the elec tromagnet, which armature is pivoted to the forked frame 30 and continuously pressed downward by a spring 5. Int-erposed between the frame 29 and the rocker arm 12 are two pivotally connected links'17 and 21, the former of which is bifurcated shaft 37 carrying at each end a pinion 15 and a ratchet wheel 14, these pinions being so disposed that one of. them will be adapted to mesh with the internal gear 32 on the shaft. of the motor at one side and that upon reversing the frame 29 the other pinion will be brought into mesh with the other side of this gear. Connected to the auxiliary shaft 37 is some torque-producing means, such as the spiral spring 13, which spring is connected at its ends respectively to the shaft 37 and to the pivotal connection between the links 17 and 21..

Assuming this spring 13 to be unwound, the tension in spring 16 will rock the arm 12 toward the left (Fig. 6), forcing the pinion 15 into mesh with a winding gear 31 fast upon the shaft of the motor 31. Then upon rotating the motor shaft by hand in a counter-clockwise direction, this gear 31 will drive the pinion 15- and wind up the driving spring 13, and owing to the links and their connections to the driving spring, the tension on the latter will set up forces F and G (Fig. 6) acting on the system of parts rocking about the pivot 20, these being in addition to the continuously operative force E, force G being the tension produced in the link 21 by resisting the pull of the spring 13 as applied at the juncture of the links 17 and 21. Forces E and F will both tend to rock the arm 12 toward the left, thereby. holding the gear and pinion intermeshed, while force G will tend to swing the arm 12 to the right and to carry the pinion out of mesh with the gear. However, these elements are so arranged that the torque produced about the axis 20 by the force G is greater than the oppositely directed effect of the force F. This difference increases as the tension in the winding spring is increased, until force G over-balances the effect of the other two forces and rocks-the arm 1..-to the right, thereby carrying the pinion 15 out of mesh with the gear 31. When this occurs, the torque of the winding spring would tend to spin the pinion 15 around, but the latter is promptly checked, by a'pawl 19 (Figs. 2 and 10) meshing with. ratchet wheel 11 which is also carried by the auxiliaryshaft 37. The torque upon this auxiliary shaft being thus taken up by the pawl, force F becomes inoperative, hence force G overbalances the opposing tendency all the more and there fore insures a quick and positive movement of the arm 12 toward the right or until stopped by the engagement of the armature pin. 3 with-the stop C on the upper projecting arm 7.

When thus stopped, the pinion 15 is out of mesh with the gear 31 and likewise out of mesh with an internal gear 32', which latter is carried by the shaft of'the motor and in alinement with the gear 31. However, during the slowing down of the motor, the centrifugal trip on the disk 11 will assume the position N 1), thereby raising the pivoted arm 4 and lifting the pin 3' clear of the stop C, thus allowing the rocker arm 12 to iove until the pin 3 engages the stop B, in which neutral position the elements are left when themotor is stopped. Then upon supplying current to the line wires of Fig. 10, the electromagnet 1 raises its armature, releasing the rocking support 12 and allowing the force (.1 (Fig. 6) to pull this rocker arm to the right until checked by the engagement of the pin 3 with the extreme stop it as in Fig. 7. This brings the pinion15 into full mesh with the internal gear 32, while also causing the pawl end 415 to strike pin 26., thus moving both pawls against the pressure of the springs 18 (Fig. 2) and releasing the pawls from the ratchet wheels, so hat th pinion-.15 m y be fr ly rotated hy the spring-.13 and may actuate the. in-

ternal gear for bringing the motor up. to

, motorfor the reason that thewindings of the-electromagnet 1 are in series with the motor windings. When the spring-actuated pinion is driving the internal gear as. in Fig. 7 ,1 this driving creates a forceF which cooperates "with the force G- due to the pull of-the spring. These two forces together so far overbalance the opposing effect of the tension spring 16 (which effect E is reduced by the shortening'o-f the. effective, lever arm between the spring and the pivot. 20. as shown by a comparison of Figs. 6 and 7) that the, spring 13 can spend substantially its entire force in accelerating the motor. As the-motor gains in speed, forces. G and F (Fig. 7) decrease until overbalanced by the" force E which then'moves the rocker arm 12 to the left, brin ing the pinion 15 .into mesh with the rewirding gear and also moving a contact block 8 into a position in which it bridges the magnet terminals. The magnet being thus short circuited. the full current is supplied to the motor which there- 'upon winds the spring until the force G (operating as before) moves the pinion to the entlrelv unmeshed or motor-running po- S1t 011. During both this rewindlng stage and the normal operation of the motor, the

trip 6 flies out to'a position parallel to the motor shaft, thereby clearing the armature arm 3.

When the motor is beingstopped and has s owed down to aspeed at which thepinion .15 may be safelv brought into me h with the internal ear 32. the. centrifu al trip. tilts (as at. N in Fi 1) and ralses the armature arm. thereby releasing the rocker arm 12 as before described and allowing the said .fast upon the shaft of the pinion, but with 'the respective pawls a half tooth apart,- so that when one pawl is at the point of dropping into mesh'the other is at least in half me h,- thus insuring a certain and substantially instantaneous checking of the secondary shaft at any point.

It will be obvious that by varying the resistance of the. magnet windings, the. initial current flowing to the motor may be. reduced to any desired fraction of the current required, by the motor when in normal opera tion, or at least may be kept down to this normal amperage. Consequently, my starter will be advantageous. wherever it is, desirable to avoid objectionable fluctuations on the circuit. It will also benoticed that my starter-requires no special windingof the motor, and'that itcouldreadily be built, as

an assembled whole andiattached to motors.

of various styles of makes, thus. (for example) permitting a low-currentstarting for a squirrel-cage or other rugged type of motor without employing special windings, commutators, or the like. However, while I have shown and described the starting appliance of my invention as applied to an induction motor, I do: not wish to be limited for its application. to this particular prime mover. Neither do I wish to be limited to. the particular arrangement or form ofthe various elements as herein disclosed, it being evident that the same might be varied in many respects without departing from the spirit of myinvention. i

I claim as my invention: v 1. The, combination with a primary shaft. of an external and an internal gear bot-h fast thereon, a torque-actuatedsecondary shaft, a

pair of pinions fast upon the secondary v9 shaft, and a carrier. for the secondary shaft, the said carrier being movable about an. axis intersecting the axis ofthe primary shaft to interpose the said pinions respectively between the external and internal gear at opposite sides of the primar Y shaft.

2., Mechanism as per claim 2, in combination with means associated with the carrier for moving the interposed pinion. into engagement with the, internal gear.

3. Mechanism as per claim 2, in.combina tion with means mounted on the carrier and responsive to the torque of" the secondary shaftfor bodily moving thev secondary shaft with respect to the main shaft.

4. The combination with a primary shaft, of a secondary shaft. extending parallel to and bodily movable with respect to the primary shaft. a gear fast on the primary shaft, a pairof pinions fast on they secondary shaft, an energy storing spring associated with the secondary shaft and arranged for storing energy upon the rotation of the latter in one direction. means for shifting the position of the secondary shaft from one sidev of the-primary shaft to the other and for thereby bringing one .or'the other of the said pinions into operative engagement with the gearv and means responsive to the tension of the spring for bodily moving the secondary shaft to annul the said operative engage-- ment. v I

5. The. combination, with a shaft and a gear fast thereon, of a pinion adapted to me h w t the ge a supp rt or th pin ion arranged for moving the pinion into or out of its said intermeshing with the gear, means tending to move the support in one di rection; and a coiled spring associated with the pinion and soarrangeol as to be wound by the rotation of the pinion in one direction, and connections whereby the tension of the spring during its Winding will move the support in a direction opposite to that first named and against the opposition'of the said means.

I 6. The combination with a shaft, of a gear fast thereon, a pinion adapted to mesh with the gear,a movable support for the pinion, means for moving the support in one direction, and common means for rotating the pinion and moving the support in the opposite direction, and latching means for bolding the support man lntermediate position.

7. The combination wlth a shaft, of an eX- ternal and an internal gear both fast there 7 on, a torque-actuated secondary shaft, a pinionfast upon the secondary shaft and adapted to mesh with either gear, means responsive to the torque actuating the secondary shaft, said means tending to move the pinion with respect to the gears, and latching means for holding thev pinion vout of mesh with both gears.

8. In a starter for an electric motor, a gear on the shaft of thermotor, a pinion meshing with the gear, and movable out of mesh therewith, means associated with the pinion for rotating the same and for moving the same into or out of mesh with the gear, a magnet in the motor circuit, and mechanism controlled by the magnet for limiting the movement of the pinion by the said means.

9.. The combination with an electric motor, of a torque-actuated secondary shaft bodily movable with respect to the shaft of the motor, interengageableelements carried by the respective shafts; means controlling the position of the secondary shaft, said means ineluding an electromagnet independentof the magnetic circuit of themotor, and common means, for bodily imoving the secondary shaft and for operatively disconnecting the electromagnet. p

10. The combination with a shaft, of a gear fast thereon, a torque-actuated secondary shaft, a pair of pinions fast upon the latter, and means supporting the secondary shaft and arranged for bringing the said pinions respectively into mesh with oppo' site sides of said gear, and means for latching the secondary shaft against rotation when neither pinion is in mesh with said gear.

11. The combination with a shaft, of a gear fast thereon, a pinion adapted to mesh 'with the gear, a movable support for the pinion. means for moving the support in one d1rect1on, and common means for rotating the p1n1on and movlng the support in the opposite direction, and means for affording three different limits to the movement of the support in the last named direction.

12. The combination with a shaft, of a gear fast thereon, a pinion adapted to mesh with the gear, a pivoted support for the pinion, an adjustable spring arranged for rocking the support in one direction about its pivot, and a spiral spring arranged for rotating the pinion and for rocking the sup port in the opposite direction. 7 p 13. The combination with a shaft, of a gear fast thereon, a pinion adapted to mesh with the gear, a movable support for the pinion, means for moving the support in one direction, and common means for rotating the pinion and moving the support in the opposite direction, means for limiting the movement of the support in the first named direction, and spaced means affording a series of stops for limiting the movement of thesupport in the last named direction.

14:. The combination with a rotor of an electric motor, of spring means for aiding theinitial acceleration of the rotor, a resistance in circuit with the motor during its acceleration; and means interlocking with the spring means after the latter has operated, for short-circuiting the resistance.

15. In a motor starter, the combination with a main shaft and a secondary shaft, of interengageable elements carried by the respective shafts, a source of power for rotating the main shaft, a separate source of power for rotating the secondary shaft, means tending to move the secondary shaft to bring the said elements into interengagement, and a latch for restraining the said means, said latch being released by the first named source of power.

16. A motorand starter combination as per claim 9, in combination with centrifugal means controlling the means which control the position of the secondary shaft.

.17. A motor and starter combination as per claim 14., in combination with centrifugally controlled means for restoring the said short-circuit when the motor comes to rest.

.18. The combination with an electric motor, of mechanical means for aiding the initial acceleration of the rotor, means for reducing the voltageof the current supplied to the motor during the said acceleration,

and meansresponsive to the depletion of the stored energy for thereafter annulling said voltage reduction.

19. The combination with an electric motor, of spring means for aiding the initial acceleration of therotor, a resistance in circuit with the motor during the said acceleration, and relatively interlocking means responsive to the depletion of stored energy for thereafter disconnecting said spring means and short-circuiting said resistance.

1 netic structure of the motor in imparting speed to the rotor, a detent for keeping the non-electric means from operating, and means for releasing said detent, said last named means including an electro-magnet having its winding in series with the motor so as to reduce the supply of current to the motor.

In a starter for an electric motor, nonelectric means for aiding the electromagnetic structure of the motor in imparting speed to the rotor, electromagnetic means controlling the operation of the non-electric means, mechanism for shortcircuiting the electromagnetic means when the rotor attains a given speed, and means for automatically rupturing said shortcircuit when the rotor is stopped, the electromagnetic means being in series with a winding of the motor so as to reduce the motor-actuating current while the said means are not shortcircuited.

23. In a motor starter, a main shaft, a secondary shaft, interengageable elements carried respectively by the two shafts, a movable carrier for the secondary shaft and the element carried thereby, and torqueeffecting means connected to the secondary shaft, said carrier being adapted to move the interengageable elements through a cycle of relative positions including a motor-starting, energy-storing and neutral positions; said carrier being so disposed as to be moved through its said cycle merely by the action of the said torque-effecting means and by the reaction on the carrier of the interengaged elements.

24. In a starter for a shaft, a secondary shaft, means for imparting rotation to the latter, interengageable elements carried by the two shafts, a ratchet for latching the secondary shaft against rotating in one direction, and ratchet'releasing means actuated jointly by the supply of energy for the first named shaft and by the said rotation-imparting means.

BENJAMIN B. JACKSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0.

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