US238685A - Puppet-valve - Google Patents

Description

(N o Model.)

J. HEMPI-IILL. PuppetvValve.

N0. 238,685. Patented' March 8, |881.

N. PETERS. FHOTO-LlTHOGRAPNER. WASHINGTON, D t:A

UNTTED STATES PATENT EETEE.

PUPPET-VALVE.

,SPECIFICATION forming part of Letters Patent No. 238,685, dated March 8, 1881.

Application led September 20, 1880.

To all whom t may concern Be it known that I, JAMES HEMPHILL, of Pittsburg, county ofAllegheny, State ot' Pennsylvania, have invented or discovered a new and useful Improvement in Puppet-Valves; and I do hereby declare the following to be a full, clear, concise, and exact description thereof, reference being had to the accompanying drawings, making apart of this specification, in whichlike letters indicating like parts- Figure l is a sectional view of the steamcylinder of a vertical engine illustrative of the arrangement of the valves with reference thereto, as also of the construction of the valves themselves, the two upper valves being shown in elevation and the two lower in section. Fig. 2 is a sectional view, toasoinewhat larger scale, of one ot' the receiving or steamsupply valves, and illustrating its arrangement with reference to a horizontal cylinder; and Fig. 3 is a top view of the valve.

My present invention relates to certain improvementsin the old and well-known balanced puppet-valve, whereby I am enabled to secure a more perfect balanein g, greater compactness of construction, and amore equable and uniform motion, as well as greater facility in the inserting and removing of the valve in repairs, or for other purposes.

lo this end l make the body of the valve, between its seats, large enough for the making therein of one, two,or more steamports, which extend from end to end ot' the Valve, and I extend the steam-supply chamber around, or almost entirely around, the body of the valve, between its end seats, and also so construct the other parts of the valve-chamber that, the valve being seated at its lower end directly on the cylinder-wall, it shall, when u useated, admit steam through both seats or ports, as a result ot' which the valve is balanced by steamlpressure, and the ports through the valve give additional room for the passage of steam.

The cylinder of a vertical engine is represented at A, and A is its piston, and A2 the pistonstem. The steam-supply pipe may be connected at Bv and the exhaust-pipe at B. The passages b lead tothe valve-chambers BZ, and on the opposite side like passages, b', lead from the exhaust-valve chambers B3. In the (No model.)

steam-supply valve-chambers B2, I arrange the valves V, and I will tirst describe the construction and arrangement of these valves. Each valve is made with two seating-faces, a a', which, when the valve is seated, rest and make close joints on the seats s s. The upper seat (and by upper I mean the one most distant from the cylinder) has a slightly less diameter than the lower, and at least so much or such length ot' the body ot' the valve between its seating-faces as is intended in the motion of the valve to play through the upper seat is made slightly less in diameter than the seat itself, so that when the valve is unseated steam may not only pass under the valve through the port c and into the cylinder, but may also, and at the same instant ottime, pass between the body of the valve and the upper valve-seat into that part, d, of the valve-chamber which is above the valve, and thereby apply steampressure to both ends of the valve simultaneously, and so practically balance it; and also such steam, while thus acting in its progress as a balancing agent, may also pass along through the port or ports` e, which I make lengthwise through the valve, and so, passing through the port c,enter the cylinder. 1n order to get a good steam-supply and keep the Valve balanced laterally as well as longitudinally, I carry the passage b well around the valve at b2; and in order that the valve may be properly' guided at both ends I add guiding-ribs t', or equivalent device performing a like function, and in any desired number, around both ends of the valve. It will now be seen that when the valve is seated there will be a slight preponderance ot' downward or seating pressure, and when unseated the preponderance will be slightly the other way. Hence the positive motions ot unseating and seating, which are com municated. through any suitable means to the valve-stems c, are always against the pressure, which is a desirable feature in valves of this class. It is also an important feature that on the opening of the valve the application of a balancing-pressure to the upper end is as instantaneous as the application of luidpressure below the Valve, and

also that the ports through the valve operate as steam-supply ports to the cylinder.

I am aware that holes through puppet-valves IOO are old; but so far as I am aware they have been only organized heretofore so as to convey the balancing steam-pressure from beneath the valve to the balancing chamber or pocket above, there being in such construction, as heretofore practiced, a packing around the valve, which prevented steam from the pocket above the valve from passing into the cylinder. In such construction the practical difticulty is met with that the rst pressure of steam, when the valve is opened, is 011 the lower end of the valve, and this causes the valve to jump, as it is called.

My improved construction differs from this, among other respects,in supplying steam both above and below the valve simultaneously, so as to balance 'it at once, and so prevent jumping; and also in dispensing with the packing, and so organizing the valve that the holes or ports through the valve operate as steam-supply ports on the receiving-slide and exhaustports on the other side without at all impairing or materially lessening the balancing effect desired. Also, as a result of supplying steam both above and below the valve from a steam-space, b2, between the valve-seats, Iam enabled to set the valve directly on the port c, made in the wall or shell of the cylinder. As the lower end of this valve is the larger, I make provision for inserting it in and removing it from its chamber without making the body of the valve-chamber in separate parts, and this I do by the use of a bushing, a', the exterior diameter ot' which is at least equal to the exterior diameter of the largest part of the valve. The interior wall ot' this bushing above the valve-seat is provided with ribs, as shown, so as to act as a guide to the upper end of the valve, and also leavea steam-space between the upper valve and the bushing for the free ow of steam past the valve-head Vwhen the valve is unseated; but such guiding-ribs may be made on the valve-head itself and play against the cylindrical cavity of the bushing. The upper valve-seat is made in this bushing, and the latter is seated and held in place by a bevel-seat and shoulder, as at Then the valve and bushing can be putin and removed together.

The exhaust-valves V are of the same construction and operation, except that the upper end of the valve is slightly thelarger, and the upper valve-seat has a little the greater diameter, so that no bushing is needed, land also so that when the valve is seated steam-pressure, acting through the ports c, shall, in the chamber or pocket cl, balance the valve, with a slight preponderance of downward effect.4 Also, when the valve is unseated, steam passing through the holes or ports e will maintain a practical and substantial balance, and will also exhaust through said ports and through the partiallyopen port of the upper valveseat, as well as through the fully-open port of the lower seat.

While I'have described my improved valve as specially adapted to vertical engines, I do not limit myself to its use therewith, as it may be advantageously used with horizontal cylinders as well.

I claim herein as my invention- 1. In combination with a steam-port, c, made directly in the wall, body, or shell ot' a stealncylinder, a double-balanced puppet-valve seated directly thereon, without any intervening pocket, and a steam-port opening directly from between the valve-seatingfaces simultaneously through both valve-seats on the uuseating of the valve, substantially as set forth.

2. The double-balanced puppet-valve V, larger at the lower than at the upper end, in combination with a bush, sv, adapted to furnish a seat for the valve and guide the same in its motion to and from its seat by suitable interposed guides, substantially as set forth.

In testimony whereof I have hereunto set my hand.

JAMES HEMPHILL.

Witnesses:

R. H. WHITTLESEY, GEORGE H. CHRISTY.

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