US552047A - Car-brake - Google Patents

Description

(No Model.)

' J. O. DEVLIN.

OAR BRAKE.

No. 552,047. Patented Dec. 24, 1895.

AN DREW EGRAHAM. PMOTOUTHQWASMINGTDM. n c

- U ITED STATES PATENT Orricn.

JAMES CALVIN DEVLIN, OF HERNANDO, MISSISSIPPI.

CAR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 552,047, dated December 24, 1895.

Application filed September 2'7, 1895. Serial No. 563,878- (No model.)

To all whont it may concern;

Be it known that 1, JAMES CALVIN DEVLIN, a citizen of the United States, residing at Hernando, in the county of De Soto and State of Mississippi, have invented certain new and useful Improvements in Oar-Brakes; and I do hereby declare the following to be a full, clear, and exact description of the invention. such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to combined wheel and track brakes so arranged that the application of the wheel-brake automatically governs the action of the track-brake, the latter being applied with a force depending upon both the force applied to the wheel-brake and the momentum of the car, so that the greater the momentum the more powerful the retarding effect of the brake.

An especial object of the invention is to provide for keeping the track impinging shoes in approximately the same relation to the rails whether the track be straight or curved, in order that the shoes may operate although they have flanges at the inner sides of the rails, and also that the brake may not lose its effectiveness upon curves, where it is often most needed. The flanges are very desirable for the reason, among others, that they keep the brake in place in case the breakage or displacement of any part should allow it to fall, and thereby it is pushed along, doing no injury, instead of passing beneath the wheels and causing them to leave the track.

Figures 1, 2, and 30f the drawings, forming a part of this application, are respectively a plan view, a side elevation, and an end elevation of so much of the brake and the car to which it is attached as is necessary to show fully its construction and operation.

In the figures, A represents a portion of a car-wheel, and B a part of the truck-frame supported thereby. From the frame rise brackets C, from which the brake is suspended by sliding forked rods D, whose descent is resisted by springs E. At the lower ends these rods are pivotally secured to brakeblocks F, lying in the planes of the carwheels and rigidly connected by rods G and a bar I-I, all of which have threaded ends and are provided with nuts which press the brakeblocks against shoulders upon the bar and against the ends of sleeves G, which inclose the rods. A brake-beam I is pivotally mounted in the blocks, and the brake is swung toward the wheels by any suitable device for applying tension to the rod J, projecting toward the Wheels from the middle portion of the beam. Each brake-block bears a shoe K for impinging upon the car-wheel, and also a rail-impinging shoe K, provided with a flange K at its inner side.

The brake as a whole is sustained entirely by the springs E, and if it be drawn against the wheels by tension upon the rod J the friction of the wheels draws it downward, and the springs yielding the shoes K are forced against the rails. The friction upon the rails increases the friction upon the wheels and this in turn forces the shoe upon the rails with greater force, and so on, each augmenting the other. \Vhen, however, the strain upon the rod J ceases, the springs raise the brake from the rails and the brake becomes inactive.

The brake-blocks are always in planes substantially parallel to the longitudinal axis of the truck-frame, and evidently as the car passes around a curve they depart from the vertical planes of the rails to a distance varying inversely with the radius of curvature. Were the shoes K rigidly fixed to the brakeblocks they would in this case cease to be perpendicular to the radius of curvature passing through their middle points and would bear upon the rails at one end only, and moreover if they be flanged only slight departure would be possible without breakage. These shoes are therefore centrally pivoted to avoid the first difficulty and are arranged to remain immediately over the rails, although the brakeblocks move to one side to obviate the second. These results are reached by a construction to be described. The shoes are rigidly but detachably fixed to blocks M, which rest against the lower faces of the brake-blocks and are pivotally secured to a cross-bar P at O. The cross-bar projects to some distance beyond the brake-blocks and lies loosely partly in the brake-blocks, partly in the blocks M, in registering grooves cut in the meeting faces of the two members, but both it and the blocks last named are free from the brakeblocks. The cross-bar and the parts attached thereto are supported in position by clevislike loops Q passing over the bar H without being attached to it. Now when the car passes around a curve the brake-blocks move from their position over the rails, but the shoes K do not accompany them, for the bar H slides in the loops Q. At the same time the cross-bar P acts in precisely the same way as before, supporting the blocks and shoes, carrying them onward and pressing them, or allowing them to be pressed, toward the rails when the brake is swung toward the wheels.

The sliding just mentioned is made certain bythe flanges K, which pass between the rails and guide-rails, if there be guide-rails, and which in any case prevent the shoes from accompanying the departure of the brakeblocks from the plane of the rails. The shoes at the same time swing upon the pivots O and maintain themselves constantly perpendicular to the radii of curvature passing through their middle points, so that practically the whole shoe bears at all times upon the rail. The sliding of the bar H in the loops Q is resisted by a spring, which also aids in restoring the parts to position when the brake leaves the curve. As shown, this spring is a spring R coiled about the bar 11 between proj ections S, all lying in the same vertical plane. Loops T, similar to the loops Q and like them rigidly fixed to the crossbar P, closely bestride the bar H at the ends of the spring R, and rise far enough for the bar to pass freely over the upper projections. When the bar H tends to slide in the loops Q the one loop T presses the spring away from the adjacent projections and as the bar advances compresses it against the opposite set, and whenever the opposing force of the spring exceeds the sliding force it moves the parts in the contrary direction or toward their original positions.

It is plain that the construction may be varied without passing beyond the boundaries of my invention, and I do not, therefore, wish to limit my claims to the specific devices set forth.

\Vhat I claim is 1. The combination with a brake arranged to move toward and away from the rails, of rail-impinging brake shoes supported by the brake and arranged to slide bodily in a lateral direction with respect to their support, whereby they may follow the rails when such support moves toward one side'of the track.

2. The combination with a brake arranged to move toward and away from the rails, of a rail-impinging brake shoe pivotally supported from said brake to swing in an approximately horizontal plane, whereby it may remain perpendicular to the radii of curvature passing through its middle point.

3. The combination with a brake arranged to move toward and away from the rails, of a rail-impinging brake shoe carried by the brake and arranged to move laterally with reference thereto, and a spring arranged to oifer yielding resistance to such lateral movement.

4. The combination with a car truck, of a brake suspended therefrom by a downwardly yielding spring support and arranged to swing toward the car wheels, rail-impinging brake shoes arranged upon the lower part of the brake to move, with respect to the latter, in a direction transverse to the track, and a spring arranged to offer yielding resistance to such relative movement.

5. The combination with a brake arranged for vertical movement, of a transverse crossbar supported from the brake by devices permitting its longitudinal movement, rail-impinging brake shoes pivotally supported by said bar, and a spring arranged to resist such longitudinal movement.

6. The combination with the rigidly connected brake blocks arranged to swing toward the car wheels, of downwardly yielding springs supporting said brake blocks, a transverse bar extending between the brake blocks, a crossbar lying below said bar, devices sliding upon said bar and supporting said crossbar, brake shoes secured to the crossbar below the brake blocks, respectively, and a spring arranged to resist relative displacement of said bar and the parts supported thereby.

7. The combination with the truck frame, of the rigidly connected brake blocks forming the body of the brake, the spring supported rods pivotally suspending the brake blocks from the truck frame, a rigid bar extending between the brake blocks, a spring coiled about the bar between projections therefrom, sliding loops hanging upon said bar, a crossbarfixed to the lower ends of said loops and projecting beyond the brake blocks, devices projecting from the crossbar to press against the ends of said coiled spring when the crossbar slides longitudinally, blocks pivoted to the crossbar, in the planes, respectively, of the brake blocks, to swing horizontally, and brake shoes, in said planes, detachably secured to the pivoted blocks, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

JAMES CALVIN DEV LIN.

Witnesses E. B. MOHENRY, GEO. O. HALL.

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