US440965A

US440965A - Steam engine valve

Info

Publication number: US440965A
Authority: US
Publication date: 1890-11-18
Anticipated expiration: 1907-11-18

Description

(No Model.) 4 Sheets-Sheet 1.

J. ROSE.

STEAM ENGINE VALVE.

No. 440,965. Patented Nov. 18, 1890.

ATTORNEY 4 Sheets-Sheet 2.

(No Model.)

J ROSE STEAM ENGINE VALVE.

Patented Nov. 18, 1890. zzya waw Arron/5y (No Model.) 4 Sheets-Sheet 3.

J. ROSE. STEAM ENGINE VALVE.

No. 440,965. Patented Nov. 18, 1890.

WITNESSES: I

ATTORNEY (No Model.) 4 SheetsSheet 4,

J. ROSE.

STEAM ENGINE VALVE. No. 440,965. Patented Nov. 18,1890.

WITNESSES: IN VENTOH $21. 277%. Qygm A TTOHNE Y8 UNITED STATES P TENT OFFICE.

JOSHUA ROSE, OF TXVIOKENHAM, ENGLAND.

STEAM-ENGINE VALVE.

SPECIFICATION forming part of Letters Patent No. 440,965, dated November 18, 1890.

Application filed May 10, 1889. Serial No. 310,254. (No model.)

T at whom, it may concern.-

Be it known that I, JOSHUA RosE, a citizen of the United States, at present residing at Girton Lodge, Park Road, in the parish of Twickenham, county of Middlesex, England, have invented new and useful Improvements in Steam-Engine Valves, of which the following is a specification, reference being had to the annexed drawings, forming a part thereof, in which- Figure 1 is a longitudinal section of a steamengine slide-valve made in two sections, both T of which are shown in mid-position over the steam-ports and both receiving the steampressure on their backs. Fig. 2 is a longitudinal section showing the parts of the valve in the position they occupy when the supplyport is about to be opened to admit steam to the right-hand end of the cylinder. Fig. 3 shows a valve in a position which leaves the same port entirely open. Fig. 4: shows the same valve in a new position. Fig. 5 is a longitudinal section of a valve provided with auxiliary ports. Fig. 6 shows the same valve placed in the position it would occupy when thevalve travel is so reduced that it opens the port only to an amount equal to the lead, and Fig. 7 is a longitudinal section of the same valve with the parts in a different position. Fig. 8 is a longitudinal section of a griddle-valve provided with my improvement, and Fig. 9 is a similar view of a piston-valve provided with my improvements.

Similar letters of reference indicate corresponding parts in all the views.

My invention relates to the slide-valves of steam engines or motors, and has for its objects, first, to prolong the period of the expansion of the propelling-fluid for all points of the cut-off in engines or motors whose steam or fluid admission is effected or controlled by a single valve, whether the same be an ordinary fiat valve, a piston-valve, a gridiron valve, a circular valve, or a diskvalve, and whether it be balanced or unbalanced, by allowing the steam during certain periods of the valve travel to hold one part of the valve stationary upon its seat while the other part of the valve is actuated positively, by which prolongation of the period of expansion two important advantages are obtained:

(a) the power of the engine or motor is increased without increasing the consumption of steam, this being more especially the case when the live steam is cut off at an early point of the stroke-say one-half or less than one-half-and (b) the cylinder does not lose so much of its heat by radiation,because its exhaust-ports are open for a shorter time on the steam side, and hence the cylinder condensation is reduced; second, to render more nearly equal the points in the piston-stroke at which the release of the steam and also the points at which the compression of the steam shall Occur under varying points of cut-off; third, to provide in the travel of that part of the valve that effects the admission of steam to the cylinder periods during which it shall be greatly relieved of the duty of moving the exhaust part or section of the valve, thus rendering the valve more easily operated by the eccentric, cam, or other valve-driving device, and also to facilitate its control by means of the governor or other speed-regulator; and, fourth, to provide a means whereby an increased amount of steam-port opening may be obtained, more particularly at the shorter points of cut-off-as, for example, at half piston-stroke or less.

The valve is constructed in two parts E and D. The part E controls the steamedmission to, and the part D the exhaust from, the cylinder. The flanges ff of the part D (see Fig. 1) fit into recesses formed in the part E, but do not completely fill these recesses, spaces m and n being left at the ends of the part D to permit the part E to travel through a certain distance independently of the part D, leaving the part D behind, held to its seat by steam-pressure for a short period whenever it reverses its direction of travel. be described in connection with further ref erence to the drawings.

Referring to Fig. 2, the part E of the valve travels in the direction indicated by the arrow, carrying the part D, the flange f of which abuts against the end g of the part E, and the two parts of the valve will continue to move forward until the partE has completed its stroke, as shown in Fig. 3, and begins to travel. in the opposite direction, when the part The effect of this arrangement will E will leave the part D, while the latter remains stationary upon its seat, the steam on its back holding it still until the end g of the part E comes into contact with the flange f and causes the valve to travel in the direction indicated by the arrow in Fig. 3. Both parts of the valve then travel together until the stroke is completed. The valve in its movement from the position shown in Fig. 3 to the position shown in Fig. tholds the steam in the working end of the cylinder for a longer period than it would have been held in the cylinder if there were no play between the two parts of the valve, since the exhaust-edge r of the valve would have arrived at the point indicated by the dotted are 8, and the exhaust from the port I) would have begun. It is obvious therefore that the expansion will be prolonged by this construction until the edge I of the part D reached the position indicated by the dotted are 8.

In the modification shown in Fig. 5 the part E of the valve is provided with a recess or port (2, and the part D is provided with a reeess or port 0;, so that during the time that the part E is traveling in the direction indicated by the arrow shown in Fig. 5 the ports e and a: are closed; but as soon as the part E of the valve begins to move in the opposite direction, the said ports are opened, so that steam may enter the port I), as indicated in Fig. 7. This action will occur let the travel of the valve be reduced as it may to vary the points of cutoff, but it is more especially beneficial at the shorter points of cut-off. Thus Fig. 6 shows the port I) only open to the amount of the lead, while the valve is supposed to have traveled as far to open the port I) as it would, as is the case when a linkmotion is used and the link is placed in a middle position, so that as soon as the valve begins to move in the direction of the arrow shown in Fig. (3 the supplementary ports em will be opened, and when the part E has traveled back to the position shown in Fig. 7 the opening of the port I) by the part E of the valve and the opening of the supplementary ports e 00 will be equal, and when the part E has moved so as to close the port 17 the supplementary ports e a: will also close.

It is obvious that other arrangements of supplementary porting may be made-as for example, by double porting either or both parts of the valve.

In the foregoing explanation of the action of my improved valve it has been assumed that the part E of the valve has been moved positively, as by an eccentric and link motion, or by an eccentric Whose throw is reduced by a suitable mechanism, so as to reduce the valve travel and hasten the point of cut-off; but it is obvious that the exhaust portion D of the valve may also be operated positively by suitable mechanism, or the part E maybe worked by the part D. For late points of cut-off it will be found especially advantageous to drive the part D positively, as by an eccentric. This will give a greater steam-port opening than that of an ordinary slide-valve, inasmuch as that at the end of each valve-stroke, when the valve will have fully opened the steam-port, there will be a period of rest for the part E, while the lost motion between the part D and the part E is being taken up by the movement of the part D. Obviously also the amount of space between the fianges of D and the ends of E may be made equal to the width of the steam-port, and the part E may be actuated by mechanism such as is used in various automatic cutoif, engines, allowing the ports to remain fully open during the admission of steam to the cylinder without regard to the point of cut-off, while a dash-pot or its equivalent may be used to cause the part E of the valve to close and effect the cut-off at the desired point in the piston-stroke.

t is obvious that a small hole or series of holes 7o may be provided in the part E, as indicated in Fig, 2, so that the steam in the space between the ends of the parts D E may escape when the direction of the motion of the part E is reversed. It is also obvious that a spring or other buffer may be introduced to prevent shock or blow between the parts D E. It is also obvious that the outer part of the part E of the valve may be made with a back like that of an ordinary D-valve, thus preventing steam from acting directly on the inner part D.

When a valve is constructed in one piece, the points of release and the amount of compression of steam or propelling-fluid are determined by and bear a definite relation to the amount of steam or outside lap, the lead, and the travel of the valve, Whereas in my improved valve the amount of steam lap, the lead, and the valve travel having been determined the points of release and compression may be located and determined at will by making the flanges f f of suitable length, so as to project the required distance into the recesses in the part E.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. In a valve for motors, the piece E, substantiall y as described, for controlling the admission of the propelling-fluid, held to its seat by the propelling-fluid independently of the piece D, and having the recesses e e, which, in combination with piece D, having the recesses x, constitute a double-ported valve, substantially as set forth.

2. In a valve for motors, the piece D, held to its seat by the propelling-fluid independ ently of the piece E, and having the recesses 00, which, in combination with the part E, haw ing recesses 6, form a valve, which at each of its ends provides two ports, through which the propelling-fluid may pass into the cylin= der, substantially as set forth.

3. In a valve for motors, the combination of exhaust and compression may be regulated of the separate pieces D and E, either of which independently of the lap or lead of the valve, may be operated independently of the other, substantially as set forth.

and both having ports at their ends, the com- JOSHUA ROSE. 5 bination of the two forming a complete \Vitnesses:

double-ported valve, by means of which the WM. THOS. MARSHALL,

steam-supply is increased, while the points EDMUND S. SNEWIN.