US875543A - Automatic brake. - Google Patents

Description

No. 875,543. PATENTED DEC. 31, 1907. J. LYNCH. AUTOMATIC BRAKE. APPLIOATION FILED JUNE 29 1907 2 SHEETS-SHEET 1.

No. 875,543, PATENTED DEC. 31, 1907. J. LYNCH.

AUTOMATIC BRAKE- APPLICATION FILED JUNE 29 1907.

2 SHEETS-SHEET 2.

R m ma W W M N W W JAMES LYNCH, OF VAN BUREN, ARKANSAS.

AUTOMATIC BRAKE.

Specification of Letters Patent.

Patented Dec. 31, 1907.

Application filed June 29,1907. Serial no. 381,477.

To all whom it may concern:

Be it known that I, JAMES LYNCH, a citizen of the United States, and a resident of Van Buren, in the county of Crawford and State of Arkansas, have invented a new and Improved Automatic Brake, of which the following a full, clear, and exact description. This lnvention relates to automatic brakes,

.and the object of the invention is to produce .a brake of this class which is simple in construction and which can be controlled inits operation by pneumatic means.

More specifically, the purpose of the invention is to provide a brake which'is held unapplied by the air ressure in the service pipe, but which is applied by spring pressure when the pressure in the service reduced.

The invention consists in the construction and combination of parts to be more fully described hereinafter and particularly set forth in the claims.

Reference is to be had to the accompanying drawings forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures. V

Figure 1 is a plan of the brake mechanism at one end of a car, the body of the car being "indicated by dotted; lines, and the brake beingoperated by my invention; Fi 2 is a longitudinal central section througii the air cylinder and s ring box, which constitutes a feature of ti? an end view of the air cylinder, that is, it is a View of the left end of the mechanism shown in Fig. 2; and Fig. 4 is an elevation of the oppositeend of thedevice shown in Fig.2.

Referring more particularly to the parts, 1 indicates the car body in dotted lines. Near the middle portionof the car body at the pipe is sufficiently usual point where the brake cylinder is applied, I attach a bracketplate 2, to which my air chamber and spring box 3,is attached.

This air chamber and spring box is clearly shown in Fig. 2. It comprises an air cylinder 4 provided with a head 5 at one end, having an air nipple 6 through which the air sup plied to the cylinder passes into the interior thereof, as shown. Within this air, cylinder there is slidably mounted a piston head 7, and on the face of this head adjacent to the nipple 6, I provide a longitudinally projecting stem 8, the extremity whereof is slightly tapered as shown. The piston head 7 is e invention; Fig. 3' is suitably I a'cked so as to prevent leakage of air past t e head, and it is attached to a piston rod 9 which extends longitudinally in a cylindrical spring box 10 wh1ch is bolted to the end of the cylinder 4 as indicated. This spring box or spring barrel has the same internal diameter as the air cylinder or chamber 4, and within which there is provided a helical spring llyone end of wh1ch thrusts against the side ofthe head 7, while the other'end thrusts against a fixed head 12 which screws upon the remote end. of the spring barrel as shown. The piston rod 9 extends through the head 12, and'is provided at its extremities with threads 13 which facilitate its attachment toone of the main brake levers 14. This brake lever is connected by a link 15 with a similar brake lever 16 which has a fixed fulcrum at the point 17 on the bracket plate 2. The ends ofthese levers 14 and 16 are connected with links 18 which operate to apply the brake shoes 19 of the usual equalizing mechanism 20, illus- 'trated at the right in Fig. 1.

The nipple 6 is supplied with air through a branch pipe 21 leading from the train service pipe 22 as shown. It will be understood from an ins ection of Fig. 2, that the spring 11 constant y tends to pull the piston rod 9 into the spring barrel, which will apply the brakes, The "air pressure existing in the train service pipe exists also in the air cylinder, so that the head 7 isnormally held in the end'of the cylinder remote from the nipple 6. In this way the spring 11 is held in a compressed condition, and the brakes are maintained una'pplied'. When the pressure in the train service pipe is reduced, as is usual in applying the brakes when pneumatically operated, the spring 11 extends itself and ap lies the brakes.

n order to prevent too sudden an action of the spring in case the air hose should burst and the pressure in the service pipe be suddenly reduced to 'zero, I provide the stem 8, which has been referred to above. It will be observed that as the piston 7'moves toward the left, the end of the stem enters the bore of the nipple 6, and in this way the outward flow of the air. through the nipple forced out by the advancing-piston becomes choked. In this way I cushion the piston, when the spring suddenly applies the brakes, and thus I prevent any possibility of throwing out the head 5 ,or of injuring the brake mechanism VVhenthe cars are being shifted around the railroad yard and at other times, if necessary, the brakes of any car can be held unapplied by means of a-trans'verse pin 23 indicated in dotted lines in Fig. 2, which is removably received in a suitable opening through the piston rod 9. When this pin is in position it 'acts as a stop resting against the end of the barrel to hold the spring back.

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

'1. In a brake mechanism, in combination;

an air cylinder, a piston working therein, a

ing the said spring tending to move said piston within said cylinder to apply the brakes, means for admitting air to said cylinder to oppose the force of said spring, and means-for cushionpiston'when the-brakes are suddenly applie 2. In a brake mechanism, incombination, an air cylinder, a piston moving therein, a spring plressing said piston toward the end of said'cy 'nder and affording means for applyin the brakes, and means forchoking the efflux ofair from said cylinder when said spring advances said piston.

v 3. In a brake mechanism, in combination, an air cylinder, a piston working therein, and carrying a longitudinally disposed stem on the forward side thereof, said-cylinder having a head with an opening through which the air may escape in alinement with said stem,

and a spring forcing said piston toward said head and afiording means for applying the brakes, said stem aifording means for choking the flow of air throughsaid opening as said piston advances! 4. In a brake'mechanism, in combination,

- an air cylinder, a piston working therein and carrying a longitudinally disposed stem, said cylinder having a head with a vent openin therein through which air may escape, said vent opening bein in alinement with said stem whereby it wi lbe choked by said stem when said piston is adjacent thereto, a spring forcing said piston toward said head and affording means for applying the brakes, and

means independent of the air pressure for holding said piston againstp mevement by said spring.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses:

JAMES LYNCH. Witnesses:

SAM R. CHEW, 'OVERTON M. PARKS.

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