US1152096A - Braking apparatus for electrically-propelled vehicles. - Google Patents

Description

P. N. JONES.

BRAKING APPARATUS FOR ELECTRICALLY PROPELLED VEHICLES.

APPLICATION FILED MAY I2, I913.

Patented Aug. 31, 1915.

3 SHEETS-SHEET I.

INVENTOR WITNESSES P. N. JONES.

BRAKING APPARATUS FOR ELECTRICALLY PROPELLED VEHICLES. APPLICATION FlLED MAY 12. 1913.

1,152,096. Patented Aug. 31, 1915.

3 SHEETSSHEET 2.

rrNEssEs INVENTOR J/ HM I W m WYQ WQ wrap s'rA'rEs PATENT OFFICE.

PEARL N. J'QNES, OF PITTSBURGH; PENNSYLVANIA.

BRAKING APPARATUS FOR ELECTRICALLY-PBOPELLED VEHICLES.

Specification of Letters Patent. Pa'bentd A g. 31, 1915 Application filed May 12, 1913. Serial No. 767,066.

' and useful Improvement in Braking Apparatus for Electrically-Propelled Vehicles, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of thisspecification, in which Figure 1 is a side elevation of a car body having my invention applied thereto, the parts embodying the invention being shown in full lines and the other parts of the figure being shown in dotted lines: Fig. 2 is a simplified wiring diagram of the motor circuits. Fig. 3 is a more complete wiring diagram of the same, and Figs. 4: and 5 are, respectively, side and plan views of mechanism for the manual operation of the motor reversing switch.

My invention has relation to braking apparatus for electrically propelled vehicles; and is designed to provide means of simple, convenient and efiective character. for enabling the propelling motors of the vehicle to be operated as generators to thereby exert a braking action on the vehicle. I

Myinvention provides means whereby the various circuit changes necessary to enable the motors to run as generators driven by the momentum of the vehicle may be effected, by

the manual operation of a single actuator.

Heretofore in apparatus of this character with which I am 'familiar, it has been necessary for the motorman in order to make use of the braking efiect of the motors run-'v ning as generators, to operate a plurality of different switches in order to eflect the necessary circuit changes. As'braking apparatus of this character is in the nature'of an emergency brake, the motorman in the excitement of the moment may fail to make the necessary combination of different switch -movements. My invention overcomes this and apparatus for the-control of electrical motors in which a plurality of motors are provided with a permanent series connection which is maintained at all times, the change from series to parallel relation of the motors being efi'ected while maintaining this series connection by establishing parallel circuits which are of a character to reverse the current flow through both armature and field of one or more of the motors. This general arrangement of the motors and their cir- I cuits is shown in Fig. 2, and a more complete wiring diagram is shown in- Fig. 3. Reference may be had to my said patent for a more complete understanding'of these fig ures.

The four series wound motors are marked, respectively, 1, 2, 3 and 4e. Their armatures are designated, respectively, A, A A and A and their field windings are respectively designated as F,-F F and F A, B, C, D, E, F, It and T designate switches or switch contacts which effect the various circuit changes.

R indicates external resistance. The switches A, B, G, D, E, F, R and T are shown as being of the solenoid type.

MC designates a master controller, 0 the contents carried by the rotary drum of this controller and f the contact fingers which connect these contactsin various ways in different positions of .the drum.

M R designates the master reversing switch havlng ahead and back positions, respectively. The contacts of thisswitch in its ahead position close the circuit of the soleand RS for the field windings of the respective motors.

In accordance with my present invention, I provide a switch member 5 which is pivoted at 6 at some suitable point'on the car and which, in one position (its normal position) is arranged to close the circuit between" two contacts 7 and 8 which completes the electric circuit between the trolley T and the master controller MC. In the other position of this switch member, the circuit between contacts 7 and 8 is opened and a circuit is closed between two other contacts?) and 10, thereby elfecting a ground connection for the motors. The motors being permanently grounded at the opposite side, as shown in Figs. 2 and 3, it follows that when the switch member 5 is moved to its last described position, the four motors, connected in series, are grounded at both sides. In efiect, therefore, they are in a closed circuit, and if either their fields or armatures be now reversed, they will run as generators, driven by themomentum of the car. The switch member 5 is designed to be manually actuated in any suitable manner to enable it to be moved from its first or normal position to its second position; and I prefer that such means shall be of a character which will permit this operation to be effected from any desired point or points on the car. Thus, this operation may be controlled either by the motorman or by the conductor wherever the latter may be stationed on the car; or it may be operated by both of them. .For this purpose I have shown a pull-cord 11 having a branch extending to each end portion of the car, and also another branch 11 at the central portion ofthe car where, in this particular instance, the conductor is stationed; (the particular car shown being a central side entrance car). This pull-cord 11 is connected to an arm 5 of the switch member 5. WVhen the cord is pulled the switch is moved from its normal position to its other position. This switch member is preferably inclosed in a box 12 which I have illustrated as being in the roof-portion of .the car. Although any suitable means may be provided for returning this switch member to its normal position, I prefer that in order to do this it shall be necessary for either the conductor or the motorman to open the box 12 and to move the switch member back to its normal position by hand. If desired, the box can be provided with a lock of any suitable character requiring a] special key, which may be the handle of the master controller. I also provide means whereby immediately after the switch member 5 has been thrown'from its normal to its other position, the reversing switch formed by the shaft S and its contacts will be thrown to'reverse the current flowing through the field windings of the motors. Any suitable mechanical connection may be provided, within the scope of my broader claims, for this purpose. 'Inithe arrangement shown in the drawings, the shaft S has fixed thereto a gear wheel 13 and also a cam disk 14. The gear wheel 13 meshes with the. teeth of a similar gear. wheel 15.

This gear-wheel is fixedto ashort shaft 16,

'journaled in 'a bracket 17 in which the shaft S 'is also" shown: "as being journaled'. :18 is another -"cam disk. whici1-is fixedrto the shaft 16-. 7 The cam 'diskx14 ":hasta single :tooth Tor shoulder'.l;9j which israrrangdtobe engaged by a pawl 20, and the cam disk 18 has a similar tooth or shoulder 21 which is arranged to be engaged by a pawl 22. The two pawls 20 and 22-are pivoted to two different studs 23 carried by a lever-arm 24 which is pivoted at one end of the shaft S". This lever-arm is also connected by a yielding lost motion device, such asshown at 25, and a flexible connection 26 with the pullcord 11. I

27 designates a guide through which the flexible connection 26 extends. In the drawings, the parts shown in Figs. 4 and 5, which have just been described, are shown as located below the bottom of the car and below the box 12. Each of the pawls 20 and 22 has connected thereto a pinion 28, these two pinions meshing with each other in the manner' shown in Figs. 4 and 5.

29 is a spring connected to the pawl 22 and to a lug of the lever arm 24. This spring acts to hold the pawl 22 in engagement with the tooth 21 when the parts are in the position shown in Fig. 4; but when the pawl 22 has been movedout of engagement with the tooth 21 in the manner hereinafter described, the line of action of this spring is moved to the opposite side of the center line of the pawl 22, and the spring then acts to hold this pawl out of engagement. The direct action of the spring through one of the pawls is also effective upon the other pawl by reason of the intergeared pinions 28. reversely, so that when one pawl is in engagement with one of the cam disks, the other pawl is out of engagement with the other cam disk.

30 is a spring connected to the lever arm 24 for the purpose of returning it to its normal position, shown in Fig. 4, after the device has been manually operated.

The operation is as follows: When it is desired to convert the motors into generators for braking purposes, either the motor- The two pawls are set man or conductor pulls on one of the I branches of the pull-cord 11. This immediately operates the switch member 5. to disconnect the motors from the trolley and make the second ground connection before described. The continued pull on the cord having taken up the lost-motion in the device 25, the lever arm 24 is next pulled mtg wardly, thereby rotating the shaft S su ciently to reverse the field winding connections of the motors This rotation of the shaft S is effected through the pawl 22, cam disk 14 and gears 13 and 15. As soon as the pull-cord is released, the spring 30 returns j-the lever arm 24 to the pos tion shown; in Fig. In moving. back to this meshing pinions 28, thr s the pawl 20 into engagement with the toot" of the cam disk in the appended claims.

14. If the pull-cord be again operated, the reversing switch shaft S is turned in the reversed direction through the action of pawl 20 and cam 14. When the lever arm 24: again returns to 'normal position the point is of the cam 14 will engage the pawl 20 and throw it out of engagement, simultaneously moving the pawl 22 into engage ment with its cam disk. This double pawl device is employed for three reasons; first, to enable the reversing switch to be thrown in the manner described, no matter which way the car is running; second, to provide means whereby the reversing switch may be returned to normal position by a second pull on the pull-cord. The third reason is that it may be necessary to utilize the braking action of the motors at a time when the car is going up hill. At such times when the power is cut 03 from the car, it will start to run backwardly down the hill by gravity and this, of course, makes it necessary to be able to again reverse the field windings of the motors by reason of the fact, that their armatures turn in the reverse direction when the car starts to go backward. It is, there'- fore, necessary in such cases to actuate the pull-cord a second time when the car commences to run backwardly. It will be un derstood that the reversing switch can be returned to its normal position by the op eration of the reversing switch of the master controller MS, after switch 5 has been thrown to its normal position, since the operation of the shaft S effected by this controller will turn the gears and the cam disks to effect the reversal of the'pawls and leave the parts in the same positions as they were before operation. The advantages of my invention will be apparent since it provides means of simple. and convenient character. whereby the mo tors may be utilized to exert a braking action on the car by a simple operation which may be carried out from any desired point on the car. i

It will be obvious that various changes can be made in the details of construction and arrangement of the parts as herein shown and described without departing from the spirit and scope of my invention as defined Thus, my invention may be used with various kinds of con trol systems; the particular character of the controlling and reversing switches may be changed, and changes may be made in the manual actuating connections for the switch member 5 and the reversing switch actuator.

What I claim is:

1. The combination with three or more electric motors for driving a vehicle, said tor circuit independent of said source of supply without breaking said series connection, a motor-reversing switch, and a single manually-operated actuating device connected to both-the said switches, substantially-as described.

2. Braking apparatus for electrically propelled vehicles comprising, in combination with the vehicle driving motors, a switch for disconnecting the motors from their source of current supply and for connecting them in a circuit independent of said source of supply, a motor reversing switch, and a single manually operated actuating device connected to both said switches, said device having means for first actuating the first named switch and for subsequently actuating the second named switch; substantially as described.

3. Braking apparatus for electrically propelled vehicles, comprising in combination a plurality of vehicle-driving motors, a

switch for disconnecting the motors from their source of current supply and for connecting them in a circuit independent of said source of supply, controlling means for the motors, a motor-reversing device, a master controller arranged to normally control the operation of the said reversing device,

and manually-operated means independent of the said master controller and having connections for operating the motor reverser .and also for operating said switch, substantially as described.

4;. Braking apparatus for electrically propelled vehicles comprising, in combination, a plurality of vehicle driving motors, a controlling means therefor, a motor reversing device, a master controller for controlling the operation of the reversing device, and

manually operated means independent of the said master controller and having con-- nections for operating the motor reverser, together with another switch arranged to disconnect the motors from their source of current supply andto connect them with a circuit independent of said source of supply, and having an actuating connection with the said manually operated means; substantially as described.

5. In apparatus of the character 'described, the combination with a motor reversing switch, of an actuating device therefor comprising a lever member, two sets of pawl and ratchet devices actuated by the lever member, and means for automatically and alternately throwing one or the other of said pawl and ratchet members into and out of operation; substantially as described.

6.1n apparatus of the character described, a motor reversing switchhaving a rotary shaft, a gear wheel fixed to said shaft, a second gear wheel meshing with the first named gear wheel, a ratchet member connected to each of the gear wheels, a lever,

two oppositely set pawls carried by the lever, each of said pawls being arranged to engage one of the ratchet members, connections between the pawls whereby one of them will be moved into engagement when a plurality of vehicle driving motors permanently connected in series, a switch for disconnecting the motors from their sourceof current supply and for connecting them in. a circuit independent of said source of supply without braking their series connection, a motor reversing switch, and a manually operative actuating device connected with bothsaid switches; substantially as described.

trolled vehicles, comprising a plurality 8. Braking apparatus for electrically coni vehicledriving motors, controlling means for controlling the normal driving opera-- tions of the motors, a reversing switch for reversing the motors, normally operated by the said controlling means, and a device for operating the reversing switch independently of the said controlling means, said device having means whereby successive op erations thereof in one direction cause the operation of the reversing switch in opposite directions, substantially as described.

In testimony whereof, I have hereunto set my hand.

PEARL N. JONES. Witnesses:

W. G. STERN, JAMES W. WELSH.

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