US743966A - Brake for street-railway cars. - Google Patents

Description

No. 743,966; PATENTEE Nov; '10, 1903.*-

` J. WETZEEE E A. G-EEEN.

N0. Magee.

UNITED STATES aten'ted November 10, 1902i?.` l

PATENTA OFFICEe NEW YORK,'ASSIGNORS rTO COMPOUND MAGNET CORPORATION OF NEW JERSEY.

ERAKE ooMPANY, A

BRAKE FOR srREET-RAILWAY CARs.

SPECIFICATION forming para of :Letters Patent No, 743,966, dated Ntvembef 1o, ioo.' Application led November 1, 1902. Serial No. 129,697. (No modell .To all wiz/m t may concern.-

Be it known that we, JOSEPH WETZLER, residing at New York city, in the county of'NeW York, and ALFRED GREEN, residing at Rochester, in the county of Monroe, State of New York, citizens of the United States, have invented an Improvement in Brakes for Street- Railway Cars and other Vehicles, of which the following is a specification.

This invention relates to electric brakes, and more especially to the electricallybontrolled mechanism for actuating lthe brakes.

The object of our invention is to provide means for overcoming the diiiiculty in electric brakes as usually constructed attendant upon the slack and lost motion which results from the wear of the brake-shoes and other mechanism between the braking-surfaces and the electrically-actuated mechanism.

In magnets as ordinarily constructed with a single coil the effort which @aube secured at a sufcient distance or over a sufcient airgap to provide means for taking up the inlcreased slackrequires the use of an excessive magnetomotive force and an excessively large magnet. These difficulties we overcome by' means of the-arrangement shown in the actcompanyin g d-rawings,`thus providing a means for increasing the initial effort of the magnet :and at a greatly-increased-range, or, in other words, by our arrangement a given initial ef- I `fort may be secured at a much greater distance from that point in the path of the mov- .able member where that member ultimately' contacts, or nearly so, with its other coper- Aating member of the magnetic system.

rlhe essential features of our invention are illustrated and described in the accompanying drawings and specification and enumer-A ated in the claims annexed hereto.

The drawings are as follows: Figure 1 is a l'diagrammatic top View of one braking-magnet and parts connected therewith to apply the brakes to one pair of wheels of the car.' Fig. 2 is a side view of brake-staff b and the rod b' and parts carried thereby. Fig. 3 is a top view of the parts seen in Fig. 2'with all above the horizontal-plane passing through line y removed. Figs. 4, 5, and 6 are detail views of the magnet M, showing the core k in its initial, middle, and final position, respectively, when applying the brakes. Fig. 7 is a diagrammatic View oi' the circuits.

Similar letters refer to similarparts throughout the several views.

Referring to Figs. l, 2, and 3,' the brakestaff b is of the usual construction and is operated by the handle h. Ratchet-wheel fr and pawl t", secured to the door F of the car, are

provided, and a chain C is arranged to be wound on staic b when the brakes are set by hand. The right-hand end of chain c is c0n-. nected by the rod ot to the upper end of the equalizing-har a2, pivoted at lo to a support s, secured to the floor of the car. This bar a2 is connected, as indicated, by link a3 with brake-beam a4, carrying brake-shoes ff, arranged to bear upon the wheels w w when braking the car. The brake-stall b also carries a gear g,- meshing with a similar but larger gear g on rod b. Rod b carries a brush-arm e, which in turn carries a brush e', arranged to sweep over the contacts t when brush arm e is rotated to the left. The contacts e' are supported by and suitably insulated from each other on the base s2. As seen inFig. l, there is also secured to the upper end of bar a2 a link a', the left-hand end of which is attached to the core It of a magnet M, having a coil m. This core lt is recessed, as shown at 7o', so as to inclose a stationary core 7g2, as shown in Fig. 6. Au important result of-this construction is that at the start, as seen in Fig. 4, the attraction between core k2 and the thin tubular end of core k is'suflcient to move the core from the position shown in Fig. i to that shown in Fig. 5. This action is of course aided a little by the attraction between the core k2 and the body of the core k, and the motion just described is sufficient to bring the shoes ff up rmly to the wheels w w' and apply but little braking effort. By the time the core lr; reaches the position shown in Fig. 5 the pull between core k2 and the tubular portion of core la has become very small; but the pull between the core k2 and the body of core it has become suflicient to move the core lo from that point to the position shown in Fig. 6, and thereby to set the brakes completely. A turnbuckle t is provided in rod a', so that the brakes may be so adjusted that the core 7c willnot quite bottotn when the maximum braking effortis applied. Preferably two magnets of the type described are used, one on either end of the car, and are operated in parallel, as seen in Fig. 7. Other links a7, a6, and a5 are also pivoted to bar a2 and perform the same functions for the other end of the car as links a, a', and a3 perform, respectively, for the end of the car indicated in the drawings. I

As seen in Fig. 7, the trolleyT is connected vto one terminal of each of magnetcoils fm m, the other terminals of which are connected together and to one end of resistance R, from several points of which connections are made to the contacts i. Brush-arm e is connected to the wheel tu' and thence to the rail.

The operation of our mechanism is as follows: To brake the car, the handle h is rotated to the right and begins to wind tne chain c upon staii b. At the same time by means ot' gears g and g and rod b brusharm e,'witl1 brush e' thereon, is rotated to the left and makes Contact with the first contact t', by which action the magnetcoils m m are connected between the trolley T and wheel w/ in series with such a resistance R that a moderate current results in coils m m. As

vbrush e is advanced over contacts t' section after section of resistance Ris cutout of circuit, until on the last contact t' the full potential of the supply-circuitis impressed upon the coils m m and the maximum braking effortis secured. If for any reason the electric braking mechanism does not operate properly, the brakes may be set in the usual manner by continuing the rotation of handle h to the right and using the ratchet and pawl r and r.

Of course in using the electric brake any degree of braking is secured by moving the operating-handle h only so far as is necessary to increase the current in the coils m m to the amount required to effect the desired degree of braking.

It will of course be understood that the thin tubular extension c/ of core 7c constitutes but a very restricted path for the lines of force between cores 7a2 and 7c, so that when the core k2 is well within the tubular extension 71:' on core lo the main path for the magnetic lines is from core 7a2 to core la through the air-gap between them and in a direction nearly or quite parallel with the direction of travel of core 7c, whereby the main pull or effort exerted between the cores is not materially reduced by this thin tubular extension 71:2.

We have found it advisable to bevel the ends of the core 7a2 and tubular extension 7c', as indicated in the drawings.

What we claim isj 1. In a braking system, in combination with the two elements of an electromagnet and the energizing-coil therefor, one of such elements movable, connections between such movable element and the brakes, a source of electric energy and means for supplying energy therefrom to such coil, the elements of such magnet carrying projections arranged-to overlap each other at or about the time when the brake-shoes are brought into contact with their braking-surfaces, such overlapping projections constituting means for shortening the air-gap at the initial point in the motion of the movable element of such electromagnet and constituting also but a restricted path for the magnetic lines of force, in a direction at right angles or nearly so to the direction .of motion of the movable element of such magnet, from that point onward in its motion when such projections overlap each other.

2. In a braking system, in combination with the two elements of an electromagnet and the energizing-coil therefor, one of such elements movable, connectionsl between such movable element and the brakes, a source of electric energy and means for supplying energy therefrom to such coil, one of the elements of such magnet carrying a prismatic projection arranged to pass within a suitable opening therefor in a larger and hollow prismatic projection on the other element at or about the time when the brake-shoes are brought into contact with their brakingsurfaces, such overlapping projections constituting means for shortening the air-gap at the initial point in the motion of such movable element and constituting also buta restricted path for the magnetic lines of force, in a direction at right angles or nearly so to the direction of motion of such movable element, from that point onward in its motion when such projections overlap each other.

3. In a brakingsystem, in combination with the two elements of an electromagnet and the energizing-coil therefor, one of such elements movable, connections between such movable element and the brakes, a source of electric energy and means for supplying energy therefrom to such coil, one of the elements of such magnet carrying a cylindrical projection arranged to pass within the opening therefor in a hollow and larger cylindrical projection on the other element at or about the time when the brakeshoes are brought into contact with their braking-surfaces, such overlapping projections constituting means for shortening the air-gap at the initial point in the motion of such movable element and constituting also but a restricted path for the magnetic lines of force, in a direction at right angles or nearly so to the direction of motion of such movable element, from that point onward in its motion when such projections overlap each other.

4. In a braking system, in combination with the two elements of an electromagnet and the energizing-coil therefor, one of such elements movable, connections between such movable IIO element and the brakes, a source of electrick of force, in a direction at right angles or nearly so to the direction of motion of the movable element of such magnet, from that point onward in its motion when such projections overlap each other.

5. In a braking system, in combination with the two elements of an electromagnet and the energizing-coil therefor, one of such elements movable, connections between such movable element and the brakes, a source of electric energy and means for supplying energy therefrom tosuch coil, one of the elements of such magnet carrying a prismatic projection arranged to pass within a suitable opening therefor in a larger and hollow prismatic projection on the other element at a point between the two extreme relative positions of such elements, such overlapping projections constituting means for shortening the air-gap at the initial point in the motion of such movable element and constituting also but a restricted path for the magnetic lines of force, in a direction at right angles or nearly so to the direction of motion of such movable element, from that point onward in its motion when such projections overlap each other.

6. In a braking system, in combination with the two elements of an electromagnet and the energizing-coil therefor, one of suchelements movable, connections between such movable element and the brakes, a source of electric energy and means for supplying energy therefrom to such coil, one of the elements of such magnet carrying a cylindrical projection arranged to pass within the opening therefor in a hollow and larger cylindrical projection on the other element at a point between the two extreme relative positions of such elements, such overlapping projections constituting means for shortening the air-'gap at the initial point in the motion of such movable element and constituting also but a restricted path for the magnetic lines of force, in a direction at right angles or nearly so to the direction of motion of such movable element, from that point onward in itsv motion when such projections overlap each other.

net movable relatively to the other, such elements carrying projections arranged to overlap each other at a point between the two extreme relative positions of such elements, such overlapping projections constituting means for shortening the air-gap at the initial point in the movement of such movable element and constituting alsobut a restricted path for the magnetic lines of force, in a direction at right angles or nearly so to the direction of motion of such movable element, from-thatpoint onward in its motion when such projections overlap each other.`

8. In combination with the two elements Yof an electromagnet and an energizing-coil therefor and a source of electric energy and means for supplying energy therefrom to such coil, one ofthe elements of such electromagnet movable relatively to the other, one of the elements of such magnet carrying a prismatic projection arranged to pass within a suitable opening therefor in a larger and hollow prismatic projection on the other element at a point between the two extreme relative positions of such elements, such overlapping projections constituting means for shortening the air-gap at the initial point in the motion ofsuch movable element and constituting also but arestricted path for the magnetic lines of force, in a direction at right angies or nearly so to the direction of motion of such movable element, from that point onward in its motion when such projections overlap each other. v

9. In combination withl the two elements of an electromagnet and an energizing-coil therefor and a source of electric energy and means for supplying energy therefrom to such coil, one of the elements of such electromagnet movable relatively tothe other, one of the elements of such magnet carrying a cylindrical projection arranged to pass within the opening therefor in a hollow and larger cylindrical projection on the other element at a point between the two extreme relative positions of such elements, such overlapping projections constituting means for shortening the air-gap at the initial point in the motion of such movable element and constituting also but a restricted path for the magnetic lines of force., in a direction at right angles or nearly so to the direction of motion of such movable element, from that point onwardinits motion when such projections overlap each other.

JOS. WETZLER.

, ALFRED GREEN. Witnesses to Joseph Wetzler:

EDWARD HYANs, Y JEFFERSON WETZLER. Witnesses to Alfred Green: T. J. NIoHoLL,

LILLIAN M. TAFT.

IIC

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