US691358A - Means for driving dynamos from car-axles. - Google Patents

Description

No. 69l,358. Patented Jan. 2|, I902. J. L. CREVELING.

MEANS FOR DRIVING DYNAMOS FROM GAR AXLES.

(Application filed Aug. 30, 1900.) (No Model.) 2 Sheets-$heet l.

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J. L. CREVELING. MEANS FOR DRIVING DYNAMOS FROM GAR AXLES.

(Application filed Aug. 30, 900.

2 Sheets-Sheet 2.

(No Model.)

UNITED STATES PATENT OFFICE.

JOHN L. CREVELING, OF NEW YORK, N. Y.

MEANS FOR DRIVING DYNAMOS FROM CAR-AXLES.

SPECIFICATION forming part of Letters Patent No. 691,358, dated January 21, 1902.

Application filed August 30, 1900.

To all whom. it nutg concern:

Be it known that I, JOHN L. CREVELING, of New York, in the county of New York, State of New York, have invented new and useful Improvements in Means for Driving a D namo from a Car-Axle, of which the following is a complete specification, reference being had to the accompanying drawings.

The object of my invention is to produce improved means for driving a dynamo from a car-axle, whereby electricity may be generated for the purpose of lighting the car in conjunction, as usual in such systems, with a storage battery and wherein provision is made for driving the dynamo in one direction whether the car be moving in one direction or the other and in permitting the dynamo to run as a motor if the train should stop and the electrical connection between the motor and the storage battery remain unbroken. lVith respect to the last-named feature comprisedwithin the scope of my invention it may be observed that ordinarily in car-lighting systems in which electricity is generated by power taken from the axle provision is made for breaking the circuit between the storage battery and the dynamo when rotation of the armature falls below a critical speed or the car stops. The mechanism provided for this purpose, however, occasionally fails of operation, and in consequence the system is burned out or otherwise crippled by the discharge of the battery through the generator.

By my invention it the switch mechanism referred to fail to work the operation of the dynamo will simply be reversed until such time as the train be again set in motion and the armature attains critical speed.

In the accompanying drawings, Figure I is an elevation of a dynamo or generator mounted upon a car-body and connected with the axle in accordance with the principle of my invention, some of the parts being shown in section. Fig. II is a transverse section of the two driving-pulleys shown in Fig. I in connection with the armature-shaft pulley, some of the parts being shown in elevation. Fig. III is a side elevation of one pulley, and Fig. IV is a similar view of the other. Fig. V illustrates, diagrammatically, the arrangement of the generator and driving mechan- Serial No. 28,624. (No model.) {I

ism, whereby the generator is enabled to run as a motor when the train is at a standstill.

in the manner above described the brushes and commutator may be made accessible, as

through an aperture 8 in the car-floor,which may be covered in use, as by a cover or floorplate. 9. The shaft 6 is provided near its extremity with a fixed pulley. 10, audit is the object of my present invention to provide means for driving said pulley from the axle 3 in the same direction irrespective of the direction in which the axle 3 moves. Accordingly I provide upon the said axle a pair of fixed sleeves 14 and 15, secured, respectively, as by set-screws 16, to the axle. The sleeves being fixed to the axle, I provide between them a pair of loose pulleys 17 and 18, separated by an intermediate spacing-ring 19. Upon the respective pulleys I provide pawls 20 and 21, the curved face 22 of, each of which osculates the periphery of its respective sleeve 14 or 15. Each pawl being mounted upon a pin or bolt 24 is held normally in contact with its sleeve, as by the tension of a spring 25, secured at one end to the pawl and at the other end, as by a nut 26-, to a stud 27 on the web 28 of the pulley. 29 indicates a stop-pin projecting from the web 28 in the path of the movement of the pawl against the tension of its spring. 31 indicates a belt which, passing around the pulley 10 and the pulleys 17 and 18, is bent around an idler 32, supported as upon a spring-actuated frame 33. It should be noted in this connection that the pawls 20 and 21 are set so that they are adapted to move in opposite directions and also that each pawl is provided with a preponderance of weight or toe-piece 34 upon the side of the center of its pin 24: opposite the spring 25, by which through the action of centrifugal force, as well as inertia, if either of the pulleys be driven at an appreciable rate of speed in the direction opposite to that which causes ensleeve of the other pulley will engage. lgequently one of the pulleys, being affixed by gagement between the pawl and its sleeve it will throw the pawl out against its pin 29, and thus save wear between the parts designed in operation to engage when they are inoperative. By means of the belt-and-pulley connection above described it the shaft 3 be caused to revolve in one direction or the other it will rotate the sleeves l4 and 15 and one or the other of the sleeves will engage its pawl. If the axle move in one direction, the pawl and sleeve of one pulley will engage and if in the opposite direction the pawl and Con- ngagement of its pawl and sleeve to the axle 3, will drive the belt 31, and the movement ofthe belt will rotate the disengaged pulley idly upon the axle. The idle movement of the pulley will throw its pawl out of engagement with its sleeve, and thereby prevent wear, as above specified. Rotation of the axle 3 in either direction by the means above described will produce rotation of the shaft 6 in the same direction. If now the axle 3 become stationary and the shaft 6 continue to revolve in the same direction in which it would be driven by the movement of the axle -3, the movement of the belt 31 will cause both pulleys 17 and 18 to run loose upon the axle 3 and without other resistance to such movement than such as would be occasioned by the little friction between the pawls and their respective sleeves occasioned by the tension of the respective springs 25. If, therefore, in connection with the mechanism above described or equivalent mechanism for connecting the axle 3 and shaft 6 a generator be employed which, under the back discharge from the storage battery, would run in the same direction as a motor as it is driven as a generator, the stoppage of the car without breaking the circuit between the generator and storage battery could have no other effect than to convert the generator into a motor.

Apparatus which will operate in the manner specified is illustrated in Fig. V, in which, in connection with the parts previously specified, are illustrated the field-magnet 36 and upon it the differential series coil 37, which is connected, as through the lead 38, with the negative brush 39 of the commutator 40, and, as through mains 41 and 42, with the poles of a storage battery 43 and translating device or lam p system 44, respectively. From the other poles of said lamp system and storage battery a main 45 connects, through a switch 46, with the lead 47, communicating with the positive brush 48 of the generator. 50 indicates the field-excitation coil communicating, as by the wire 51, with the lead 38 and with the lead 47, as by the wire 52. The wire 52, if desired,

need not connect with the lead 47; but a wire 53, broken bya switch 54, as shown in dotted lines in Fig. V, may be substituted therefor, the wire 53 being connected to the main 45. If the wire 53 and switch 54 be employed, the coil 50 would derive current from the battery and the main switch would open, and thus the battery field-circuit might be opened at will by the switch 54.

In an application of mine, Serial No. 28,525, filed August 30, 1900, I have shown and described means for automatically operating the switch 54 by a centrifugal governor upon the armature shaft. Reference is herein made to said application as indicating a possible ground for the preference of employing the wire 53 and switch 54 instead of the wire 52.

In case it were considered preferable to use a direct compound rather than a differential compound machine the coil 37 could be suppressed and a coil 55, wound in opposite direction to the coil 37, could be substituted under certain conditions, which will hereinafter be explained. It is also obvious that a series coil might be omitted entirely, if desirable. These suggestions of difierent windings of the generator are intended only to indicate some of the variations which may be made in the generator without rendering it impracticable for employment within the scope of my inventionl The operation of my complete apparatus, as shown in Fig. V, is as follows: The main 47 being assumed to be in communication with the positive brush of the generator, the constant direction of rotation of the shaft 6 is indicated by the arrow on the belt 31. So long as the speed of the generator is such that its voltage is in excess of that of the battery the current, if the switch 46 be closed, flows through the lead 47, switch 46, main 45, bat-v tery and translating devices 43 and 44, mains 41 and 42, series coil 37, and lead 38 to the generator. At the same time ashunt-current flows from .the lead 47 through the wire 52, coil 50, and wire 51 to the lead 38 in the direction opposed to that of the differential coil 37. If now the motion of the axle be interrupted and the switch 46, through some accident, remain closedIcurrent from the battery would flow through the main 45, switch 46, lead 47, armature 49, lead 38, series coil 37, and mains 41 and 42 to the battery. The shunt-current would be made through the wire 52, coil 50, and wire 51 to the lead 38, the current in this case flowing through the shunt-coil 50 in the same direction as before and through the difierential coil 37in an opposite direction to that previously pursued by it, and consequently in the same direction as that taken by the current in the coil 50. The tendency of the combined currents is to strongly energize the field. Consequently the armature would be driven by the current from the battery in the same direction as a motor in which it was rotatedas a generator. This it would be enabled to do by the pulleys l7 and 18 slipping free upon the axle 3, as above specified.

If the compound coil 55 were used, as above suggested, in place of the differential coil 37, the current flowing back through the coil 55 would be opposed to that in the coil 50, and it is necessary, in order that the generator shall run in the same direction' when driven as a motor,that the coil 55 shouldbeweak as compared with the coil 50, so that the polarity of the field-magnet would not be reversed, although of course it would be weakened. If no compound coil were used, the generator would be driven as a motor as a plain shunt-machine, and consequently in the same direction as a motor asthat in which it is driven as a generator.

If the coil be connected with the main 45 by means of the wire 53 and switch 54, instead of to the lead '47, as by the wire 52, the action in case of failure of the switch 46 to operate would be the same as that above described. If the tendency of the generator when driven as a motor by the battery were to revolve in an opposite direction from that in which it is driven as a generator, the armature would become stalled and would form practicallya short circuit across the battery; but by the improvements herein shown and described the armature revolves freely. Consequently there would be kept up a counter electromotive force, and with no load upon it only small current would be wasted in running the generator as a motor.

I find with the differential field-coil 37 that the speed of the generator when driven as a motor is comparatively low, owing to the very strong field which is caused by the back discharge through the coil 37 and that with proper arrangement of the pawls 20 and 21 they may be 'made to stay in contact with the sleeves 14: and 15 at this speed, so that if the axle 3 cease to revolve and the switch 46 remain closed the generator will revolve as a motor,with its operative communications with the axle 3 unbroken. If'the axle start to revolve and increase its speed until in excess of that of the pulleys 17 and 18, they would be carried with it, and as this increases the armature 49 will pick up electromotive force in excess of the counter electromotive force developed therein while running as a motor, in'

which case it will begin again to charge the batteries, as before.

' hat I claim is- {r The combination with agenerator, of the type described, comprising an armature and its shaft, astorage battery and translating device in electrical communication one with the other, of a revoluble axle and means operatively connecting said axle with the armature-shaft, said means being adapted to communicate motion to the armatu re-shaft in one direction irrespective of the direction in which the axle moves, and to run free of the axle when the armature-shaft is independently rotated.

2. The combination with a generator, of the type described, comprising an armature and its shaft, a storage battery and translating device in electrical communication one with the other, of a revoluble axle, a pulley fixed to the armature-shaft, a pair of loose pulleys upon the axle, means for engaging said pul leys with the axle through their rotation in opposite directions, respectively, an idler, and a belt working around the pulley on the armature-shaft and the idler, across the peripheries of the pulleys upon the axle, all cooperative, substantially for the purpose speci fied.

In testimony of all which I have hereunto subscribed my name.

JOHN L. GREVELING.

Witnesses:

CHAS. E. RIoRDoN, J osnrn L. ATKINS.

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