US21682A - Joseph jobin - Google Patents

Description

UNITED STATES PATENT OFFIOE.

JOSEPH JOBIN, OF S'l. MAND, NEAR PARIS, FRANCE.

VALVE 0F STEAM-ENGINES.

Specification of Letters Patent No. 21,682, dated October 5, 1858.

To aZZ wlw/ml t may concern:

Be it known that I, JOSEPH JOBIN, of St. Mand, in the Department of the Seine and the French Empire, have invented certain new and useful Improvements in Steam-Engines; and I hereby declare that the following is a full, clear, and exact description, reference being had to the accompanying drawing.

The object of my invention is to avoid pressure produced by the impelling fluid of the valve in steam and other engines on the valve seat, and thereby diminish the requisite force to move the valve, an important consideration particularly in locomotive and marine engines.

The system I adopt to carry out the object above named is open to numerous modifications and applicable with advantage to existing motors as well as to those yet to be constructed.

The general principle of my invention consists in giving to the valve a prismatic shape, being in its cross-section for instance, of either of the forms shown in Figures 1, 2, 3, 4, of the accompanying drawing; and inclosing said valve in a case which serves as a guide to it in its reciprocating travel. The interior of this valve case is constructed with recesses arranged opposite the steam ports in the engine cylinder for the purpose of obviating lateral pressure. The valve is hollow to receive the steam within it from either or both ends of the chest in order that the valve shall be exposed to equal pressure on both ends.

In order to illustrate the advantages and peculiarities of this my improvement I show in the annexed drawing two modifications of it, as applied to horizontal steam engines.

Fig. 5, represents a vertical longitudinal section through a locomotive engine cylinder provided with my new improved sliding balance valve (A). Fig. 6 represents a transverse vertical section of the same. Figs. 7 and 8 are longitudinal and trans verse views of the valve detached; and Figs. 9 and l0, represent a face and edge view of a movable guide plate arranged and adjustable along one side of the chest against which the valve moves. The latter of these figures shows on one side of the guide plate a movable wedge serving the triple purpose, of adjusting said plate to meet wear of the valve of tightening said plate to the requisite pressure against the valve, and of obviating the necessity of removing the case for adjustment of parts, whereby the great advantage is derived of preserving the original joints.

By reference to the above figures it will be seen that the lower portion of the valve is of the ordinary D form having lips (a a) and exhaust opening (a2) corresponding with or serving to control the steam ports (Z, Z) and exhaust passage (Z2) but wherein this valve differs essentially from others is in its being surmounted by a prismatic cap, which cap is cast in one piece with the lower portion of the valve and provided with a longitudinal passage through it. rIhe lower portion of the valve that forms the base of the prism which in this instance is triangular, plays on the valve seat of the cylinder, while the upper sides of the prism are embraced by two corresponding sides of the chest which serve the valve as a guide in its reciprocating travel imparted to it by the valve rod (t). Instead of the valve chest being made of a shape corresponding to the prismatic form of the valve, it may be of the ordinary rectangular form fitted with a lid having a prismatic recessed protuberance entering the chest for the valve to fit and play against. Such construction it will be obvious, admits of my prismatic valve being applied to valve chests of engines now in use without requiring any alteration of the chest or disposition of its apertures.

The steam from the boiler enters the chest (B) either at one end (Z2) or as before mentio-ned, simultaneously at both ends, and traversing the hollow valve presses equally on both extremities of the valve andv thus balances it in the longitudinal sense or endwise.

The steam contained in the engine cylinder which has produced or is producing the pistons travel, pressing through the ports (Z or Z), on the face of the valve, has a tendency to lift the valve and press it against the upper portion of the case, but this effect I counteract by the grooves or recesses (0,0) which admitting steam produces a counteracting pressure thereto. The grooves, although opposite to the ports (Z Z) .do not communicate with the said ports.

The escaping steam entering the exhaust opening (052) in the valve, in its passage to the exhaust outlet (Z2), has a tendency also to lift the valve; this I counteract by allowing steam from the hollow valve, to pass y through the side of the valve by apertures (d Z d) and act with a downward force on the valve; these apertures are of area and number corresponding to the dimension of the valve. It is necessary even to give an excess of downward pressure, in order to keep the valve firm on the valve seat. Instead of the apertures (CZ al CZ) the exterior sides of the valve or interior sides of the valve casing may be grooved.

In varied or long stroke of the valve, it is desirable to avoid accumulation of dirt in the play of the valve, at its ends and roughening or wear of the ends of the valve, by constructing the valve case and valve seat with recesses (e e) as shown in Fig. 5. By such a construction of balance valve, the friction and consequently the wear of surfaces in contact is very little, almost none, but evidently infinitely less, than is the case with the ordinary steam valve.

To obviate difficulty and expense of adjustment, in the case of wear, I apply a mechanical means, consisting of a movable plate (D) shown in Fig. 9. Arranged along the side of the prismatic valve and which can be tightened to any required degree, by a wedge (E) and screw (Fig. 10) operated by nut on the outside of the case, the tightening of said wedge serving` to bear the valve down on its seat by reason of the angular or prismatic form of the valve and casing. In this case, the grooves (f f) which admit steam to counteract upward liftof the valve on the one side where the packing plate is arranged, are made in the plate itself, corresponding to the grooves on the other side in the steam chest. In case of want of room in the casing to insert a valve having a triangular cap, the top of the valve may beV truncated so as to give trapezoidal section to the valve, as shown in Fig. 4:. The sides of such trapezoidal form of valve, may be more or less inclined, for the purpose of insuring a balancing action, by the means hereinbefore described.

The following figures show another modification of my sliding balance valve, which consists particularly in the application of a` prismatical valve, having a square or rectangular cross section as indicated in Figs. 2 and 3. Fig. 11 represents a longitudinal section through the axis of the cylinder. Fig. 12, is an end view of the same, having the end plates of the cylinder and valve chest removed. Figs. 13 and 14 are details of the lower portion of the steam chest which incloses the valve and serves it as a guide. Figs. 15 and 16, are detail views of the upper part of said chest.

It is easy to see that this second disposition or arrangement answers the same purpose as the one previously described, of which this is but a modification.

The steam chest is made in two parts, the

first of which (B) rests and is bolted on the valve seat, while the second part (B) is jointed to the former by means of screws or bolts.

The valve A is a hollow tube throughout the who-le of its length and terminates at its extremities in two lips (a a) of square section, and which slide upon parts of a similar form in the base of the upper part of the chest.

Two grooves (c c) are provided in the chest to correspond to the steam ports (l Z) vof the cylinder (c) and a third larger groove (c2) is also provided corresponding to the exhaust opening Z2) ow, supposing steam enters Vthe chest through the pipe (o) which communicates with the generator, it will be readily seen that in order to fill the said chest, the steam has to travel through the interior of the valve before it can pass through the port (Z) to press against the piston (P) and drive it from the left to the right; the steam escaping from the opposite side of the piston enters the space (C2) and passes therefrom to the escape pipe (E). l

It will be seen that the valve during its movement receives equal and balancing pressures on its extremities and also on its lateral surface in as much as the steam is both in and outside. When the valve is moved so that the lips (a af) pass the ports and as they uncover the same, it will be seen that the steam takes an opposite direction to that which it before took, but the effects of pressure on the valve are the same, keeping it in equilibrium in the steam in such a manner, that in order to move it, there is no other friction to overcome besides that accruing from its own weight. To diminish this friction, the parts in contact may be greased and loss of steam from the chest avoided by use of stufng box (T) for the rod to play through.

This mode of constructing sliding balance valves is applicable to all steam engines, that is, to locomotives, portable engines, marine engines, as well as to stationary engines whatever be the impelling fluid used.

In Figs. 17 and 18 I show another modification, in which t-he steam instead of entering at one of the extremities of the chest, is made to enter by two orifices (o o) and to escape at the center of the chest by an outlet (02). In this case the valve (A) shown in Fig. 17, is not'hollow and terminates at its extremities in two square disks (i i) of the same form and description as the lips (a a) in Fig. 11. By this arrangement it is not necessary to close the ends of the steam chest consequently-no stufling box is required.

In Fig. 18. The steam is shown to enter the chest by a single opening (o) the escape taking place at (02). In this instance the form and guided in its reciprocating travel by and Within a steam chest open or closed 15 at its ends, but surrounding in a close Inanner the sides of said valve substantially as and for the purposes set forth.

In testimony whereof I have signed my name to this specication before two sub- 20 scribng Witnesses.

J. J OBIN.

Witnesses S. RICHARDS, MENGE A. MIENLIN.

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