US41758A - Improvement in valves for steam-engines - Google Patents

Description

UNITED STATES PATENT OFFICE.

FRANCIS W. CLOUGH, 0F SPRINGFIELD, MASSACHUSETTS.

IMPROVEMENT IN VALVES FOR STEAM-ENGINES.

Specification forming part of Letters Patent N0. 41,758, dated March 1, 1864.

To all whom it may concern:

Be it known. that I, FEANci-s W. CLoUeH, of Springfield, in the county of Hampden and Commonwealth of Massachusetts, have invented certain new and useful Improvements in Steam-Cylinders of Steam-Engines; and I do hereby declare that the following is a full, clear, `and exact description thereof, reference being had to the accompanying drawings, making a part of this specification.

In the application Aof steam as a motive power it is often necessary to so arrange 'the mechanism that the engine can be reversed. This has been accomplished in various ways, but it has been done by the application of some mechanism by means of which the motion of the valves could be reversed-as, for example, the link-motion;7 so called, which is a well-known mechanical contrivance for reversing the motion of the valves by changing the latter from one eccentric to another, or combining the motions of the two. Now, all these methods are easily applied to small engines, and are not difficult to operate; but when the valve to be operated is large and the -machinery `for operating itcorrespondingly heavy, then it is that the operation of reversing becomes an important item.

N ow, it is the object of my invention to reverse the engine-vl. e., to reverse the motion of the piston in the steam-cylinder-by means of a special valve for the purpose, in combination with suitable ports, and other valve or valves for performing the usual duties of the main valve ofa steamengine.

In the drawings to which reference is herein made, Figure l is a side view of a steamcylinder provided with my improvements. Fig. 2 is the same with the reversing valve and steam-chest removed, but having the form of the face of the reversing-valve drawn in red on the valve-seat, to aid in explaining the relative positions of the several parts. Fig. 3 is a longitudinal section of cylinder and valves. Fig. 4 is an end View of cylinder with the main valve removed and reversing-valve in section and the form of face of the "end or main valve drawn in red on the valve-seat. Fig. 5 is a face view of the reversing-valve.

A is the body of the steam-cylinder.

B is a steam-chest through which all the steam passes which enters the cylinder, and which chest contains a valve, C, which is the reversing-valve. As here shown, the re versing-valvc C is used in combination With the valves D D', as showing one style of valve to which it may be applied and in combination with which it may be used. The valves D D' are circular disks with suitable concavities or recesses in the under side of each. These valves D D' tit onto the heads E E' of the l steam-cylinder as seats, and are held in place by a nut, F F', or a stem, G G', extending from the cylinder-heads.

H H' are two ports extending from the steam-chest B to and through the head E'.

I I' are two corresponding ports running to and through the head E.

J J are ports through the heads E E', communicatin g with the interior of the cylinder.

K is the exhaustport having the openings a a' into the chest B.

L is the receiving-pipe.

The form of valve C is more clearly seen in Fig. 5, in which b b' are two ports or openings through the valve from top to bottom. c c' are two recesses on the under side of the valve, d d d d being the face or bearing-surface of the valve.

The construction of the valves D D' is similar to that of valve C, having the annular bearingce e c around the outside and bearings on the divisions or partitions ffff, thus forming four cavities or compartments, g g' g" g", under the valve. The partitions ff f j' are wide enough to cover the port J h IL' are pipes con necting opposite quarters or compartments of the valve D, to balance the pressure of steam on the valve, so as to relieve the nut F and stem Gr, from any unnecessary wear or sidewise strain.

Now,the operation is as follows: When the reversing-valve C stands in the position shown in Fig. 2, the port H is the receiving-port for the end E' of cylinder, and H is theexhaust-port for the same, communicating under the valve C with the exhaust-port a, and thence to K. Thus the steam passes from the steam-chest B, as shown by the arrow, through the port H, to and through the head E', under the valve D', thence through the port J in E' to the cylinder. Now, when the end E' is to exhaust, the valve D'havingreceived a slight rotary motion ,carrying it to the position shown by the red dotted lines in Fig. 4, the port J' is brought into connection with the port H', which (as vhas been stated) is in connection with the exhaust-port K. This same arrangement is employed on the other end of cylinder. Now, it is evident that if the valve C is rotated so that the port b, which now communicates with H, shall communicate With H', then H will be brought into connection with the exhaustport c', and the Whole arrangement of ports will be reversed, the receiving-ports becoming exhaust-ports, and the exhaust-ports becoming receiving' ports.

The advantages of the peculiar valves D D are as follows: First, thepressure is under the valve, so that there is no necessity for any more pressure on the valve-seat than just enough to make a steamjoint, all the pressure oi' the steam beingresisted and counteracted by the nut F, which takes its bearing so near the center of D, and consequently so near the axis in which it rotates, that the friction has but little power to resist the free movement of the valve; second, there is no necessity for any close covering to the valve D, therefore it is easily ascertained at any time if there is any leakage of steam and just Where it is; third, the valves are very near the point Where the receiving-port enters the cylinder, consequcntly there is 'very little Waste of steam 2. The pipes h h, in combination with the i valve D, having the compartments gg g g'f, when arranged and operating substantially in the manner and for the purpose described.

3. The steamchest B and valve C, in combination with the ports H H and exhaustport a, when applied to a steam-cylinder substantially in the manner and for the purpose herein set forth.

FRANCIS W. CLOUG-H.

Witnesses:

B. P. OoLToN, MILTON BRADLEY.

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