US32690A - Valve-geae - Google Patents

Description

UNlT @ad PATENT @FFlLE VALVE-GEAR OF STEAM-ENGINES.

Specification of Letters Patent No. 32,690, dated July 2, 1861.`

T0 all whom it may concern:

Be it known that l, ANDREW HARTUPEE, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Lifters for Puppet-Valves of Steam-Engines; and l. do hereby declare the following to. be a full, clear, and exactdescription thereof, reference being had to the annexed drawings, forming part of this specification, in which- Figure l, is a perspective view of my improved lifter detached from the engine. Fig. Q is a side view thereof as applied to a horizontal engine, neither of the valves being raised. Fig. 3 represents the lifter turned so as to raise one valve. Fig. a represents the lifter partly turned showing its action on the point of the lever.

My improvement consists in connecting the lifters, for the puppet valves of steam engines of such a shape that they will raise the levers of the valves by rolling contact or nearly so thus not only saving friction and avoiding the wearing away of the lever and lifter, but by applying` the force of the lifter at the commencement of the stroke to the end of vthe lever instead of near its center, effecting a saving of power and increasing the eflicieney of the engine.

To enable others skilled in the art to. make and use my improved lifter, l will proceed to describe its construction and operation.

In the drawings a is the shaft which earries the lifters Z), b. Each engine -has two lifters ofthe same size and shape, one of which Y) .works loose on the shaft a, and the other b, being fastened to the shaft works with it in the usual manner, in order to admit of the reverse motion necessaryto raise the lever of one of the said valves at-one end of the cylinder, while the lever of one of the exhaust valves is raised at the other end. ln the drawings one lifter and one pair of valves only are shown 'in each ligure and for the sake of illustration Fig. 2 may represent the valves and lifter on one side, and Fig. 3 the valves and lifter on the other side of the cylinder of the steam engine.

c, c, are the levers to work the exhaust valves, and (l (Z the levers to work the said valves.

The engine is of the ordinary construction, as my improvement applicable to almost any kind of engine.

My improvement in liftcrs consists in forming them of the shape shown in Fig. l, the upper surface or outline of the lifter being a uniform curve orv arc of a circle, the

vedge4 or tangential point of which, (midway from either end,) I place either exactly in the center or axis of the shaft a, which carries it, or near to the center, and within the circumference of the shaft a. The advantage of this arrangement will be seen, by reference to Fig. fl, to be, that when the shaft (t turns so as to raise one arm of the lifter l), instead of the face of the lever being applied first to a point in the lever, c, some distance from the extremity of th'e lever, the peint of the lever which rests on the curved surface of the lifter, near to the shaft (which is the center of motion), first receives the force of the lifter, and as the lifter rises, instead of rubbing along the under side of the lever it raises it to the point shown in Fig. 3, by rolling contact or nearly so, thus very materially diminishing the friction, saving power and causing the engine to work more smoothly as the levers are raised with less of a jerk. In lifters as ordinarily constructed the lifter exerts less power on the lever to raise the valve at the moment when it begins to rise, than afterward, while the reverse should be the case, as the greatest force needed just when the valve is first raised. And this l eect by my improvement which raises the levers from the point, while the ordinary lifters raise them at some distance from their extrelnity. My invention thus. renders the valves equal in eiliciency and easy of operation to balance valves, so that by the use of them the engineer has much greater control of hisengine, than with lifters of other constructions.

Having thus described my improvement what l claim as my invention and desire to secure by Letters Patent is,

The use of lifters for puppet valves of steam engines so constructed and arranged in relation to the shaft on which they are placed and by which they are operated, as

that their extremities shall. be inthe line of :1u nrc of u circle the tangential point of which, where it intersects Suid shaft, shall pass within the circumference of the shaft, und either through its axis or near thereto, for the purpose hereinbefore set forth.

In testimony whereof I have hereunto set my hand this fifth day' of August A. D. 185C.

ANDREV I-IARTUPEE.

Titnessesz /V. DUDLEY KING, AND. MCMASTER.

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