US623610A - Electric-third-rail system - Google Patents

Description

Patented Apr. 25, I899.

L. M. MAXHAM. ELECTRIC THIRD RAIL SYSTEM. (Application filad Apr. 6, 1898.) (No Model.) a Sheets-Shet l.

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No. 623,6!0. Patented Apr. 25, I899. L. M. MAXHAM.

ELECTRIC THIRD RAIL SYSTEM.

(Application m'ed Apr. 6, 1898.)

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LOXVELL MASON MAXHAM, OF BOSTON, MASSACHUSETTS.

ELECTRlC-THlRD-RAIL SYSTEM.

SPECIFICATION forming part of Letters Patent No. 623,610, dated April 25, 1899.

Application filed April 6, 1898.

To all whom, it may concern:

Be it known that I, LOWELL MASON MAX- HAM, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented a new and useful Electric Third Rail, of which the following is a full, clear, and exact description.

My invention relates to means wherebythe electric current can be transmitted to a car from an electric conductorwhich is normally insulated within a third rail; and it comprises, essentially, a hollow third rail having an electric conductor within it and normally out of contact therewith, a movable bar exterior to said third rail, means whereby the movement of said bar shall locally complete the circuit between said electric conductor and third rail, and a device carried by the car and adapted to properly operate said bar. Among the devices which Ihave invented for enabling the electric conductor to be put into contact with the-third rail is a series of rocking arms supported at opposite ends of the electric conductor and movable bar in such.

a manner that the depression of the bar shall automatically elevate and depress the electric conductor into pressing contact with the ceiling of the third rail, and thereby conduct the current to the shoe sliding on the upper surface of said third rail, which shoe is in electric circuit with the motor propelling the car. Another device comprises a laterallymovable slide carrying the electric conductor into contact with the interior of the third rail and adapted to be reciprocated by means of said movable bar.

Referring to the drawings forming part of this specification, Figure 1 is a cross-section of a third rail, the electric conductor located therein, the depressible bar, and the contactshoe and bar-depressing wheel. Fig. 2 is a side view of a section of the third rail and Fig. 3 is a plan view of the rocking lever or arm carrying the electric conductor and depressible bar. Fig. 4 is a side elevation of the sliding shoe and the bardepressing wheel carried therewith. Fig. 5 is a horizontal section of the sliding shoe. Fig. Gisacross-section of the third rail, showing the manner in which the depressible bar is enabled to move the electric conductor laterally into contact with said rail. Fig. 7 is Serial No. 676,629. (No model.)

a cross-section of the third rail, showing the electric conductor and depressible bar supported by a rocking arm, but with a spacingrail introduced between said third rail and movable bar. Fig. 8 is a perspective View of said spacing-rail. Fig. 9 is a perspective view of the pivot-spike designed for supporting said rocking arm. Fig. 10is a cross-section, upon a m uch smallerscale,of the third rail and allied parts, with the bar-depressing wheel slightly modified.

In all the forms of my invention illustrated, F indicates the third rail, A the electric conductor, and E the movable bar. M is the sliding shoe, designed to transmit the current from the third rail through the shoe-carrier N and the spring-supports O to the electric motor propelling the on r T.

The third rail F is in the form of a hollow arch or inverted trough, either rounded or flat internally, as in Fig. 1 or Fig. 7. Its top is usually fiat in order to better contact with the sliding shoe M. The electric conductor A (preferably a heavy copper wire or rod) is supported by one or two wooden strips a, suitably channeled to receive it, as in Fig. l, or by two wooden strips a ct, adapted to have the conductor clamped between them by the screw or bolt a as in Figs. 6 and 7. Referring now to Fig. 1 alone, the said conductor A is shown as resting within the channel of the wooden strip a, which in its turn is supported by the end of the rocking arm 13. Said arm is formed with a notch b, which fits loosely upon the rounded or bluntly-wedged head of the pivot-spike O and whose end Z) is engaged by the finger d of the post D. The lower end d of said'post fits loosely in the hole Z of the sleeper or other foundation-strip L, while its upper end is formed with knees or flanges 01 by which it is screwed to the under side of the bar E. The guard-rail K protects the said bar from being struck or depressed by any object narrower than the slot between said guard-rail and third rail F.

The wheel P, which is shown in Figs. 1 and t as carried by the sliding-shoedevices, easily enters the slot containing the bar E and by depressing the latter elevates the electric conduotor A into pressing contact with the interior surface of the third rail F. As said wheel rolls along the bar E new points of the conductor A are continually pressed into contact with the third-rail surface above them, while as the said wheel passes such contacting points return to normal positions. It is designed that the weight of the conductor A, the strip (l, and the enlarged end b of the rocking arms l3 shall more than counterbalance the bar E and the posts I), thereby causing the said conductor to sink to its normal position, as in Fig 7, when the wheel P has passed. I usually, however, more positively insure such return by providing each post D with a spiral spring S, adapted to raise the posts and bar E, as shown in Figs. 1 and 7.

In the modification illustrated in Fig. 7 the main differences over what has already been described consist in separating the bar E by means of an insulated spacing-rail G for a suitable distance from the third rail in order that the posts D may not have to be oifset, as in Fig. 1, and also when this third rail is used for street-railways that should a horses toe-calks enter the slot containing the bar E far enough to raise the conductor A into contact with the rail F the remainder of the shoe and hoof shall not touch the third rail and the horse be thereby electrocuted. To retain said spacing-rail in place, the third rail F is formed with an overhanging shoulder f and the rail G with several lugs g, which reach under the ledge 7c of the guard-rail K. A suitable insulating material 7L is introduced between said spacing and third rail of sufficient thickness to thoroughly insulate them when the third rail is alive.

Another modification illustrated in Fig. 7 is the substitution of the two strips a a for the single one previously described. Said strips are clamped together and to the notched ears b of the rocking arms B by means of the screw a and they so clasp the conductor A as to securely hold it in place. The main purpose for which I design them is to so bind the conductor between them as to keep it from coiling, kinking, or bending, and thereby bring itself into undesired contact with the interior of the third rail. To prevent the bar E and the posts D from beingsurreptitiously removed from their confining-slot,-I form the said posts with the lug d projecting laterally beneath the ledge 7a of the guard-rail K.

In the modification illustrated in Fig. 6 the clamping-strips a a, holding the electric conductor A, are bolted to the sliding block B, and the vertical motion of the bar E is made to communicate the desired horizontal reciprocation to said block by means of the pivoted elbow E the lower end of which engages an eye 13 in said block. A strong spiral spring S elevates the bar E and withdraws the conductor A from contact with the side of the third rail F. The spacing-rail G is here em- .ployed as in the construction shown in Fi '7 the only difference being that here the shelf q is provided for the support of said spring S. Herc also the opening Z in the sleeper L passes entirely through the same and serves for drainage purposes, it being located directly beneath the slot containing the bar E. The other forms of the invention are also furnished with similar drainage-openings, but cannot easily be shown on account of the post D. It will be noticed that the conductor A is here shown as hexagonal in cross-section instead of circular, as in the other figures. The main object of this is to provide a flat surface for contacting with the interior of the third rail, and thereby insure increased surface of electrical contact.

Turning now to Figs. 4 and 5, the construction of the sliding shoe M and its allied parts can be more clearly described. Said shoe is formed with upturned or runner ends, each one-half the width of the shoe. (See m in Fig. 5.) The carrierN for the shoe is formed with correspondingly-shaped ends n such ends being laterally perforated for the reception of the fastening-boltsa, by which the shoe and its carrier are secured together. The carrier N is further formed with the seats, upon which are bolted the lower ends of the S-springs 0, whose upper ends are bolted to the part T, which may represent the bottom of the car ora beam secured to the car-truck. The object of said springs is to hold the carrier and shoe in the correct position upon the third rail and at the same time permit the vertical oscillation to which the car-body is liable. Centrally above said carrier N projects a standard N, at whose upper end is an annular enlargement N within which is revolubly held the thiinble P Revoluble in said sleeve or thiinble P but eccentric with respect thereto, is the shaft P of the depression-wheel P.- The arm 4, formed of some non-conducting substance, as Wood, is rigidly connected to said thimble P by means of the hand r r, bolted thereto, and is oscillated through the agency of the rod R, controlled in any convenient way by the motorman. lVhen said arm is pulled by said rod, the cocentricity of the thimble and shaft causes the wheel P to descend into the slot containing the bar E; but when the said rod is pushed said wheel is made to rise out from said slotand the third rail made wholly dead. So, also, as the sliding shoe becomes thinner through the elfect of its rubbing contact with the rail it is not necessary to pull the rod R quite so far in order to lower the depression-wheel to the point of insuring contact between the conductor and third rail.

As shown in Fig. 1, thehand r r is bolted to the thirnble P through the slot 71 in the an- 11 ular head or enlargement N and said hand not only serves to turn said thimble P but to retain it in place therein.

In Fig. 10 I show a construction in which the wheel P is held separately from the shoecarrier N and in which said wheel is prevented froln descending too deeply into the slot containing the bar E, and thereby cause a too-heavy pressure upon the latter by means of the auxiliary wheel Q rotating independently thereof, bntpreferably mounted on the same axis. This auxiliary wheel rests upon the guard-rail K and so sustains the wheel P at the proper height in the bar-slot. In Fig. 1 I show the wheel P itself provided with a flange Q, designed to serve the same purpose.

It will be noticed that thehollow rail F contains the conductor A at so high a pointthat it will be difiicult-for water to reach the latter. The air in the upper part of the rail tends to prevent the water from rising therein, and thereby short'circuiting the conductor. To insure'greater protection, I insert suitable. elastic material between the ends of the rails, asf in Fig. 4, to prevent water and dirt from passing down between and entering the conductor-channel. So, also, I pro tect the slot through which the rocking arm enters the conductor-channel by surrounding said arm with a rubber collar If, as shown in Fig. 7, or other similar material. Although I have shown but a single rocking arm and post at any one point, it will be understood that said parts are designed to be located at suitable intervals throughout the entire length of the railway. These arms should be from three to four feet apart, depending upon the stiffness of the electric conductor and its supporting-strip and also of the bar E, The said bar should be stiff enough and the distance between the postsD short enough to retain the conductor A in contact. with the hollow rail F, even when the wheelP is midway between the posts. On the other hand, such flexibility and distance should be sufficient to enable said conductor to sag out of contact with the rail F at distances of three or four posts in either direction. In this way not more than one or two rails are kept alive at any one moment. i

The bar E being composed of separate sections touching end to end, the section immediately beneath the wheel P will be in its depressed condition, while the one following will be in its normal position. Hence the said wheel will meet the end of said latter section with a pronounced shock. To prevent this, I make the bar E practically continuous by means of strap-pieces e, fastened beneath the adjacent ends of the bar-sections by suitable screws 6. Thus arranged the depression of said bar will be a wave motion, wherein the wheel P will be at the hollow.

IVhatI claim as my invention, and desire to secure by Letters Patent, is as follows, to wit: 1. In an electric third rail, the combination of a normally-dead rail formed of conduct ing material and made hollow throughout its length, a naked conductor extending longitudinally through said rail, fulcrumed arms supporting said conductor out of electric contact with said rail and extending through to the exterior of the latter, and means for automatically actuating said arms and moving said conductor into contact with said rail.

2. In an electric third rail, the combination of the hollow conducting-rail, the movable electric conductor supported therein and normally out of contact tl1erewith,the practically continuous flexible bar located parallel with the said rail, means whereby the depression of a portion of the said barshall automatically move a corresponding portion of the said electric conductor into electric contact with the said rail, and means carried by a car for 10- cally depressing the said bar and for taking the electric current from the top of the said rail.

3. Inan electric third rail, the combination of the rail, the movable conductor normally out of contact therewith, the depressible bar adapted to automatically put said conductor and rail in circuit, the sliding shoe adapted to take the current from said rail, and the wheel traveling beside said shoe and adapted to depress said bar. 4. In an electric third rail, the combinatio with the hollow rail and the electric conductor located therein, of the bar having means whereby its depression shall complete the circuit-between said conductor and hollow rail, the spacing-rail resting beside said hollow rail and having the lateral lug, and the guard-rail having the ledge overhanging said lug and adapted thereby to hold the spacing-rail in 9 position, said lug being of sufficient length to give ample room for said bar between said guard and spacing-rail, substantially as and for the purpose set forth.

5. In an electric third rail, the combination of the hollow rail, the electric conductor located therein but normally out of contact therewith, the rocking arm supporting said conductor, the vertical post having the finger engagingthe outer end of said arm, the coiled spring for normally elevating said post, and the bar secured to the upper end of said post, substantially as and for the purpose set forth.

(5. In an electric third rail, the combination with the hollow rail and the electric conductor located therein, of the rocking arm support-- ing said conductor, the channeled insulatingstrip located between said arm and conductor, and means for depressing the outer end of said arm, substantiallyas and for the purpose set forth.

7. In an electric third rail, the combination of the hollow rail, the electric conductor normally out of contact therewith, the separable insulating strips provided with means for clamping them together and adapted to seto partially receive said conductor, the screw adapted to clasp said strips together and fasten them to said ear, and means for depressing the outer end of said arm, substantially as and for the purpose set forth.

9. Ihe combination with a normally-dead third rail adapted to be made temporarily alive by the depression of a bar located at one side thereof, of the sliding shoe pressing upon said rail, the revoluble wheel adapted to depress said bar and carried by said shoe, and means whereby said wheel can be raised or lowered at will.

10. In an electric third rail,the combination with the rail, the electric conductor normally out of contact therewith, and the depressi'ole bar located to one side of said rail and parallel therewith and adapted when depressed to put said conductor and rail in circuit, of the sliding shoe, the post rigidly connected therewith and having the annular head, the eccentric thimble loosely held in said head, the wheel having its shaft revoluble in said thimble, and means for partially turning said thimble,whereby said wheel can be raised out of contact with or lowered into a depressive engagement with said bar, for the purpose set forth.

11. In an electric third rail,the combination with the same, of the shoe slidable thereon, and having the upturned narrowed ends, the carrier having corresponding ends, the bolts for fastening said ends together, and an elastic connection between said carrier and the car, substantially as and for the purpose set forth.

12. The combination with the sliding shoe and the carrier holding the same, of the S- shapcd springs fastened at their endsto said carrier and to any support connected with the car, substantially as and for the purpose set forth.

13. The combination of the sliding shoe, the carrier having the post formed with the annular head slotted in its upper periphery, the eccentric thimble loosely held therein, the wheel having its shaft revoluble in said thimble, the hand secured to said t-himble in said slot, and the insulating-arm held thereby.

14. In an electric third rail,the combination of the electric conductor, the rail normally out of contact therewith, the guard-rail parallel therewith but at a short distance therefrom, the depressive bar located in the slot thus formed and adapted by its depression to complete the circuit between said conductor and rail, the wheel adapted to enter said slot and depress said bar and means connected with said wheel and supported by said guardrail whereby said wheel is prevented from depressing said bar below a definite limit, substantially as and for the purpose set forth.

15. In an electric third rail,the combination of the rail the guard-rail parallel therewith, the depressible bar beside said guard-rail adapted by its depression to put an electric conductor into contact with said third rail, the wheel adapted to roll upon said bar and depress it, and the auxiliary wheel rolling upon said guard-rail and adapted to prevent said bar from being depressed too far, substantially as and for the purpose set forth.

In testimony that I claim the foregoing invention I have hereunto set my hand this 22d day of March, 1898.

LOWELL MASON MAXIIAM.

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