US265879A - Steam- b rake - Google Patents

Description

(No Model.)

T. J. SHELLHORN. STEAM BRAKE.

Patented Oct. 10, 1882.

UN TED STATES PATENT OFFICE.

THOMAS J. SHELLHORN, or HANCOCK, MICHIGAN.

STEAM- BRAKE.

SPECIFICATION formingpart of Letters" Patent No. 265,879, dated October 10, 1882,

' Applicationfiled February 18, [882. (No model.)

To all whom it may concern:

Be it known that I, THOMAS J SHELLHORN, of Hancock, in the county of Houghton and State of Michigan, have invented certain new and useful Improvements in Steam-Brakes 5 and I do hereby declare that the following is a full, clear, and exact description thereof, reference being bad to the accompanying drawings, and to the letters of reference marked thereon, which form part of this specification, in which- Figure 1 is a side elevation, partly in section. Fig. 2 is a vertical section through the steam-cylinder. Fig. 3 is a vertical section of the exhaust-valve.

This invention relatesto improvements which I have made on the locomotive and car brakes for which Letters Patent of the United States were granted to me bearing date September 5, 1876, and numbered 181,869.

My present invention has especial reference to a vertical cylinder which will admit steam or other elastic fluid through its bottom by means of a pipe properly provided for the pur pose, whereby the pressure will be from below upward, thus obviating the necessity of a stuffin g-box or gland for the piston-rod, and thereby avoid the friction due to a tight stuffing-box in relieving the brake. I also provide at the bottom or lower head of the said vertical cylinder means for the free escape of the waste steam and water of condensation; and I furthermore employ a certain novel combination of levers with brake-shoes and said cylinder and a piston therein actuated by a force from beneath of it, whereby I impart such compensating motion that the strain transmitted by the drive-wheels through inequalities in the track is transferred to the piston andcnshioned by the steam, in lieu of. being thrown upon the hangers.

I will show by the following description,

when taken in connection with the annexed drawings, that the entire weight of the brake mechanism is borne by the steam or other elastic force acting upward against the piston.

A designates the frame of a locomotive, and B B the drive-wheels on one side thereof.

0 G are two brake-heads, which are provided in the usual or most improved manner with brake-shoes adapted to press against the pcripheries or treads of their respective wheels. The brake-heads O G are connected at a a to fulcrum-pins of levers G O, the shortest arms of which are pivoted to a fulcrum-rorhl which is extensible by means of a nut, for the purpose of compensating for the wear of the brakeshoe's. The longest arms of the levers G C are connected bylinks to a pin, a, which passes transversely through ears formed on the upper end of a piston-rod, J. This piston-rod passes freely through the head of a cylinder, A, which is suitably sustained in a vertical position located below the axis of the wheels by the frame A of the locomotive. The vertical axis of this cylinder is equidistant from vertical planes intersecting the axes of the drive-wheels B B.

The piston B, which is suitably fixed to the piston-rod J ,is fitted with steam-packin g rings, thus obviating the necessityof using a stuffingbox or gland for the pistonrod J, where it passes through the head or top of the cylinder.

Steam is admitted to the cylinder Aat its lower end through a pipe, E, leading from the steam-space ot' the boiler, and which is provided with a suitable cut-off, which is under the control of the engineer in his cab. There is also provided a drip-valve or steam-outlet, located beneath the piston B, which has an automatic valve, 1;, that is opened by a spring, 2!, under the valve. WVhen the steam is applied to the brake the pressure of steam closes the valve, and when the steam is let off the spring opens the valve and holds it open until the steam is again applied to the brake.

The brake-heads are suspended by hangers a: 00, and the upper ends of the levers O O are connected by links or toggles w as directly to the upper end of the piston-rod J, as shown in Fig. 1. This form of toggle has special value for my purpose, as the motion of the piston ismore rapid at the time when the toggle-bars are starting from the point of their greatest flexion, and as they straighten out the power increases, and rate diminishes as the point of ultimate pressure on the brake-heads is approached. 4

The operation of the brakes on each side of the locomotive is as follows: Steam is admitted beneath the piston,which forces it upward. The piston-rod operates through the two links [00 w" to spread apart the two levers'c and to against the treads of the wheels.

press the brake-shoes with more or less force To release the brakes, steam is allowed to escape from the lower head of the cylinder A.

It will be seen that by the above-described combination of levers the entire weight of the brake mechanism is carried by the piston supported by the steam,by means of which rigidity and concussion are avoided and elasticity afforded. The release of the brakes is effected when steam is shutoff by the combined weight of the levers, thefulcrum-rod, the brake-head s, and the shoes thereof, the gravity of which will cause the piston to descend until it rests upon thebottom head of the cylinder A The brakeshoes will thus be movedfree from the'treads of the wheels, and when they are not in immediate action thereon they will not be subjected to wear. It is obvious that the mechanism hereinabove described as applicable to locomotives for the purpose of braking the drivers thereof is equally applicable to the trucks of cars.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent,is-

1. The combination of the suspended brake. heads 0 G, the hangers as :0 therefor, the vertical levers G O", pivoted thereto, the endwiseadjustable fulcrum rod F, pivoted to the lower vertical steam-cylinder, the steam inlet and outlet pipes, and the spring-actuated valve 12, connected to the supply-pipe, all arranged substantially in the mannerand for the purposes explained.

3. In a power-brake system, a vertical cylinder having a steam-tight piston and glandless heads, said cylinder being adapted to take steam from the lower end and exhaust it from the same end, in com binationwith arel'ief-valve connected to the steam-pipe, all constructed and arranged substantially as described.

In testimony that I claim the foregoing as my own I affix my signature in presence of two witnesses.

THOMAS J. SHELLHOBN.

Witnesses:

CHARLES H. SANFORD, It. H. BRELSFORD.

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