US910805A - Car-brake. - Google Patents

Description

C. B. FAIRGHILD. GAR BRAKE.

I 91 0,805. APPLIGATION um APR' l 1903-' Patented Jan. 26. 1909.

2 SHEETS-SHEET 1.

G. B. FAIRGHILD.

GAR BRAKE.

APPLICATION FILED APR. 13,1908.

Patented .12.11.26, 1909.

2 SHEETS-SHEET 2.

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ru: NuRRls PETERS co., wAsmNcroN, n. c.

Uhllllllj STATES referir CHARLES s. rAracmLn, or New Yoan, Y.

can-enana.

Application le. April 13,

To all whom it may concern:

Be it known that l, CHARLES B. FAIR- oniLD, a citizen of the United States, and a resident of the borough of Manhattan, in the city, county, and State of New York, have invented certain new and useful Improvements in Car-Brakes, of which the following is a specification.

My invention relates to that class of car brakes in which the braking` action is effected, when it is desired to arrest or control the movements of the car, by forcing the brakeshoes against the peripheries of the car wheels until the stopping or control of such movements is effected.

ln Letters Patent of the United States numbered 696,901, which were granted to me April 1st, i902, l have shown and described a car brake of this character, in which the forcing of the brake-shoes against the car wheels is accomplished by a screw, which is operated from the platform of the car through appropriate appliances, and is constructed with a uniform pitch throughout. rlhis construction, while efficient in operation and requiring the application of but a small amount of force to arrest or control the movement of the car, has been found slow in operation when applied in practice, principally because of the fact that, in consequence of the uniformity of the pitch of the screw throughout its length, no considerable variation in the speed of movement of the parts operated from it is possible when taking up the slack or lost motion in those parts and when forcing the brake-shoes against the peripheries vof their cooperating wheels.

The object of the invention is therefore to remedy this disadvantage, and to provide a screw-operated car brake in which the taking up of the slack or lost motion in the parts operated from the screw will be more rapid T accomplished, and with less power, than when such parts are pressing the brakeshoes against the peripheries of the Wheels.

To these ends, my invention consists, first, in the employment of a screw, having a plurality of threads of different pitches, with the brake-shoes, whereby, when the screw is rotated to apply or set the brakes, the movements of the arts o erated therefrom will be more rapid wifxile ta ring up their slack or lost motion, than when forcing the brake-shoes against the wheels, but the ower exerted in accomplishing` the latter l be very much Patented Jan. 26, 1909.

lSS. Serial No. 426,769.

greater than it is in accomplishing the former second, in the means by which the mounting and connection of the screw with the brake-shoes are effected; third, in the means by which the rotation of the screw may be acccmplisned, and fourth, in various other combinations and arrangements of parts, all as will hereinafter more fully appear.

Referring to the accompanying drawings, which form a part of this specification, Figure l, is a side elevation of an end portion of a car, having one form of my invention applied in connection therewith, with certain of the parts broken away for purposes of illustration; 2, a side elevation, with parts broken awa y, of a portion of one form of my brake-operating mechanism, detached; Fig. 3, a detail, shondng a fragment of one end of the screw and the means by which it is mounted in its supporting frame, with a portion of one of the stirrup rods by which the nuts that cooperate with the screw threads are connected with the brake-shoes, broken anf'ay; Fig. 4, a face vie with parts broken away, of the frame in which the screw is mountech detached 5 Fig. 5, a side elevation of an end portion of a car', similar to that shown in i, .with the brake-operating mechanism located in a slightly different relationship with resect to the car body, and with a modified arrangement of mechanism for rotating` the screw, certain parts being broken away; Fig. 6, a plan view, with parts broken away, of a screw and cooperating nuts, and of the frame and stirrup in which the screw and nuts are respectively mounted and connected with the brake-shoes, showing a further modiiied arrangement of mechanism by which the screw is rotated, and an inclosing case therefor, and Fig. 7, a portion of the end of a car broken away, with my invention applied in connection therewith, but showing a still further modication of the mechanism by which the screw is operated.

ln all the figures, like letters of reference are employed to designate corresponding parts.

A indicates a sufficient portion of a car body to illustrate my invention, and B indicates one of the w reels upon which the car is mounted.

The car body is or may be constructed in any ordinary or preferred form, and is mounted upon any appropriate number of car wheels as may be desired. As shown in the drawings however, the car body is provided with an outwardly extending platform a for the accommodation of a driver or motor-man, with each of the car su porting wheels provided with a brake-shoe which is pivoted or otherwise supported in proper relationship with respect thereto. TWith the brake-shoes thus supported they are, in practice, normally held backward out of contact with the peripheries of their respective wheels by gravity or otherwise, but are capable of being forced forward with more or less pressure toward and in contact with them when the movement of the car is to be arrested or controlled. For forcing these brake-shoes forward into contact with the p'eripheries of the wheels B when required, l make use of a screw C, which, in order to impart a more rapid movement to the brake shoes in the earlier stages of their travel toward their respective wheels, and a slower movement when they approach and are pressed against the peripheries of the latter, with a corresponding increase in the power with which the screw operates, l construct the screw with a plurality of threads c, cl

' etc. of different pitches, which are progressively arranged thereon in such an order that the thread c, having the maximum pitch, will first be operative in carrying the brakeshoes forward towards their respective wheels, to be followed by the thread having a less pitch, and so on, following this order throughout the series, from the thread having the maximum pitch to that having the minimum. As thus constructed this screw cooperates with a nut E for each of the threads c and c1, to permit of which the screw C is rotatively mounted in a frame D. rThis frame, which may be constructed in various forms, is here shown as consisting of two end brackets d and (Z1, which are connected and held at the proper distance apart by rods d2, that extend between them and are disposed in parallel relationship with respect to one another. ith the frame constructed as thus explained the screw is journaled near one of its ends in a suitable bearing formed in the bracket al, while its o posite end is suported from the bracket l through a center 3, whereby to more effectively reduce the friction and to resist the strain imparted to the screw when the brake-shoes are being forced against their respective wheels in arresting or otherwise controlling the movement of the car. To this end, the center da is passed through and threaded within a suitable orifice d4 formed in the bracket d1, and is firmly held in adjusted position therein by a lock-nut d5 applied in connection therewith, as shown in the drawings. The screw C being thus mounted in the frame D, the nuts E are restrai-ned from rotation,when the screw is rotated, by the rods d2, which,

to effect such restraining action, extend through and are adapted to have suitable orifices e formed in or upon vsuch nuts, slide back and forth upoon them as required by the operation of the rake, and as illustrated in Figs. 2 and 6.

To permit of the nuts E coperating with their respective threads c, c1, etc., these nuts are arranged at the proper distance apart to insure of the one passing out of engagement with its respective thread, as the other is brought into engagement with its thread, being fixedly held in these positions by rods e2, which are passed through and firmly held in suitable orifices e3 formed in nuts E, and which, extending outward through suitable orifices formed in the bracket d1, are connected at their outer free ends by a bar e4, whereby, with such rods, to form a stirrup, with the rods e2 provided at their opposite ends with nuts e5 and e, which are respectively engaged with the outer side of the bar e4, and with the outer surface of the inner nut E. The nuts E being thus connected and rigidly held at the proper distance apart, will, when the screw C 1s operated, successively engage one after the other with their respective threads, with one passing out of engagement with its thread, as another is brought into engagement with its thread. To permit of this being accomplished, the portion of the screw containing the thread of the maximum pitch c is preferably constructed somewhat larger in diameter than that containing the thread of lesser pitch, which, if the series is continued, will be somewhat larger than that containing the minimum itch, whereby as the nuts are successive y passed over and o their respective threads, one after another will pass outward over the portion of the screw that extends beyond, and which, unprovided with a thread, is preferably constructed of a diameter slightly less than that of the interior of the nut that coperates with it, as shown more particularly at c2, c3, and c4 in Figs. 2 and 6. With the screw and nuts thus organized and operating, they may be applied to the car in various ways. In Fig. il have shown them as applied to the frame of the dash-board and occupying a vertical position, while in Figs. 5 and 7 they are located beneath the platform of the car and occupy a horizontal relationship. When applied to the frame of the dash-board they are or may be secured theretov by suitable bolts passing through the brackets d and d1 and engaging with it, and when thus applied the screw C is preferably operated by a crank F. On the ot -er hand, when applied to the under side of the platform a they will be secured thereto by bolts or screws, similarly passi-ng through orifices in the brackets d and d1 and entering or engaging with the floor or sills thereof, and in this case the screw will be rotated,

lOO

' ary of a vertical shalt F1, which,

either by an endless cord or rope H, which., passing around a suitable drum c5' upon the end ot' the screw and extending upward and over a pulley c6 secured to the root ot the car within easy reach oi' the driver or motorman, or by a crank ii"- through the intermedirotatively mounted in 'suitable bearings f and f1 respectively secured to the dash-board and formed in the platform, is operatively connected at its lower end with the screw through the intervention oi' bevel gears fl and f3. As thus mounted and operated in eitl'rer of the ways speciied, the nuts E may be connected with the brake-shoes in various ways. .l prefer however to effect this connection through the intermediary ot a which, fixedly attached at one end to an eye-bolt i secured in the bar et, is connected at its other end to the upper extremity ot' a lever L, whici'i is tulcrumcd intermediate its length upon a pin il, and is jointed at its lower end to the brake-shoes through the intervention of appropriate linlts i2.

When the screw and nuts are arranged beneath the platiorm ot the car, in a horizontal position, the chain l will extend directly trom the eye-bolt t' in the bar cL1 ot the stirrup to the upper end of the lever L in a strai line. if! hen however' these parts are ranged in a vertical position, s shown, instance, in Fig. l, then the chain, in tending from the eye-bolt to the upper end ot such lever, will pass around an idler-pulley i, journaled beneath the plattorm in a suitable hanger it.

As thus arranged and connected, thn operation oi tl e p arts w.-i be as iollows: il ith the brake-shoes held backward away from the peripheries oi their respective wheels, and in their normal position, whenever it is desired to arrest or control he movement of the car the screw will be rotated in the proper direction through the crank F or endless core El, when the nut E will be engagea with the thread c, having` the maximum pitch, and thc parts thereby moved to take up the slacl. or lost motion in them, with the maximum speed. YWith the slack or lest motion in the parts thus taken up, and the brake-shoes carried into close relationship to the peripheries et their respective wheels, the nut E will be carried oli. its respective thread c and the nut E appropriate to the thread cl brought into engagement with that thread, when the further movement oi the p arts will be continued and the brake-shoes forced int-o contact with the peripheries of their appropriate wheels at a slower rate of speed, but with a greatly increased power. The arrest or control oi the movement ci the car having been thus accomplished, and it be desired to start the car either forward or backward, the screw C will be rotated in an opposite direction by its crank or operating endless cord,

when the reverse of the movements above specified will result, and the nut appropriate to the thread cl will travel along the screw until the nut appropriate to the thread c is ongaged with that thread, when a more rapid movement oi theparts wid be occasioned,with the consequent e tiect t hat the brake-shoes in moving backward away-.from the peripheries oi their respective wheels will start at a slow rate of speed and be thereafter accelerated in their movement in their farther backward travel.

in the onstruction ot the screw C the diiference yetween the pitch of the various threads r f bc varied within wide lin `ts. ln practice have found that with a maximum pitch ot two inches and a minimum pitch oi tive eighths ci' an inch excellent results have been obtained, but this variation may be departed troni and the difference between the pitches of the dii/'ferent threads nay be otherwise varied the iudc'vient of the constructor or the eXig cies oi the screw may dictate.

lilith parts constructed and organized as above sot lorth l provide, as will be seen, a brake tor cars, which, inits operation to arrest or control the movements ot the Cars, acts with at rapidity during the maior port-ion ol the traY ot 'its 1warts, but with a very much reduced speed and greatly increased power, when forcing the brake-shoes u 'n t the peripheries et' the wheels, vhich ai l operation and results are reversed when brake-shoes are being withdrawn from periphe-y ci such wheels. Along wi h lrhe parts above described may be employed suitable casing nl in which various ot the parts ol the mechanism may be inclosed, as well as appropriate braces z, to aid in resisting the strain imparted to the trame E when the brake-shoes are being Aforced against the peripheriesol their wheels, as shown, for instance, in Fig. 5.

Having thus described my invention, and specilied certain ol' the ways in which it is or may be carried into effect, l claim and desire to secure by Letters Patent ol the United States,-

1. The combination, wi h a screw constructed with a plurality of threads ol' ditlerent pitches, and a nut l'or cooperating with each or such threads, of means by which a relative rotary motion between such parts may be e'tllected to successively bring one after another of such nuts into, or to carry them successively out of, operation, substantially as described.

2. The combination, with a car wheel, and a brake-shoe for cooperating therewith, ol a screw constructed with a plurality of threads of different pitches, nuts for cooperating with such threads, means for rotating said screw, and connecting devices intermediate the nuts and the bralre-shoe, whereby a progressively decreasing speed of movement with a correspondingly increasing power is imparted to the brake-shoe as it is carried forward toward and against the car wheel, substantially as described.

3. The combination, with a car wheel, a brake-shoe for coperating therewith, and a frame, of a screw constructed with a plurality of threads having the pitch oi' each succeeding thread decreased rotatively mounted in such frame, a nut for cooperating with each of the threads, and means for connecting these nuts with the brake-shoe, whereby the brake-shoe in moving forward and against the car wheel travels at different rates oi' speed and with an increasing power in differ# ent parts of its traverse, substantially as de scribed.

4. The combination, with a car wheel, a brake-shoe for cooperating therewith, a frame adapted for securement to a car, and a screw provided with a plurality of threads, the succeeding threads of which decrease in pitch i'rom one end of the series to the other rotatively mounted in such frame and constructed with portions at the ends of the several threads reduced in diameter, and means for rotating such screw, of a nut for coperating with each of the threads, rods by which these nuts are iXedly secured together and held at the proper distance apart, and means for connecting these rods with the brakeshoe, substantiallyT as described.

5. The combination, with a car body, a supporting wheel, a brake-shoe for coperating with such wheel, and a frame secured to such car body, of a screw equipped with a plurality of threads each succeeding thread of which is of less diameter and pitch than the preceding thread, a nut for each of these threads, a stirrup by which these threads are secured together and fixedly held at the proper distance apart, means for rotating said screw, and devices for connecting the stirrup with the brake-shoe, substantially as described.

6. The combination, with a car body, a supporting wheel, a brake-shoe for coperating with such wheel, and a frame secured upon such car body, oi' a screw equipped with a plurality of threads, each succeeding thread oi which is of less diameter and pitch than the preceding thread, a nut for each oi' these threads, a stirrup by which these threads are secured together and iixedly held at the proper distance apart, a vertical shaft, bevel gears by which this vertical shaft is connected with the screw, a crank on such vertical shaft, and means for connecting the stirrup with the brake-shoe, substantially as described.

7. rIhe combination, with a frame'adapted to be secured to a car body, and a screw equipped with a plurality of threads, each succeeding thread of which is decreased in pitch rotatively mounted at one end in a bearing formed in such frame and supported at its other end upon a center, of a nut for each of the threads, rods by which such nuts are connected and '.FiXedly held at the proper distance apart, a car wheel, a brake-shoe for cooperating therewith, connecting devices between said rods and the brake-shoe, and means for rotating such screw, substantially as described.

In testimony whereof have hereunto set my hand in the presence of two witnesses this 9th day of April, 1908.

CHARLES B. FAIRCHILD.

WM. H. APPLETON, WM. A. KNAPP.

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