US1524271A - Slide valve of steam pumps - Google Patents

Description

' K. NAKAO SLIDE VALVE OF STEAM PUMPS Filed A rgl a, 1921- 5 Sheets-Sheet 1 4-5- 4.4. 5,"- 4i- I /4 1 /4 #0 /I 6 1' 40/11 4 1,5 4, 3+ f f 50 t 3 x I I was; 35

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' K. NAKAO SLIDE VALVE OF STEAM PUMPS Filed April 9, 1921 5 Sheets-Sheet 5 l'lgll V////////I//////////////%A ///////////////////A-- //////////4"'//////AZ WW K. NAKAO SLIDE VALVE 0F STEAM PUMPS Filed April 9, 1921 T Illllll 5 Sheets-Shet 5 Patented Jan. 27, 1925.

UNITED STATES PATENT OFFICE.

KINZABURO NAKAO, F TOKYO, JAPAN.

SLIDE VALVE OF STEAM PUMPS.

Application filed April 9,

certain new and useful Improvements in Slide Valves of Steam Pumps, of which the following is a specification.

The invention is an improvement in piston valves for steam engines, such as steam pump engines.

Heretofore, it has been customary to operate such valves by the fresh or live steam introduced into the steam chest. This has serious drawbacks, particularly the loss of heat energy used in driving the valve back and forth, and also complication in the mechanism.

The valve mechanism of the present invvention comprises a valve operated by the exhaust steam from the steam-cylinder of the engine subject to said valve, whereby the above-mentioned loss of heat energy is avoided. The invention also makes possible a simple form of construction, easy to adjust and repair.

More specifically, the invention comprises a valve mechanism wherein the valve member is driven back and forth longitudinally by the exhaust steam pressure from the steam-cylinder controlled by the valve mechanism, and is oscillated mechanically from the piston rod. I

The preferred embodiment will now be described.

In the accompanying drawings, illustrating a preferred embodiment of the invention Fig. 1 is a vertical longitudinal section through the valve and steam chest, taken on the line 11 of Fig. 2;

Fig. 2 is a central transverse section on the line 2-2 of Fig. 1;

Fig. 3 is a longitudinal section on the line 3-3 of Fig. 2, this view and Fig. 1 showing the valve member in a. central position Fig. 4C is a side view of the liner;

Fig. 5 is an end elevation, looking at the left hand end of Fig. 4;

Fig. 6 is a. side elevation of the valve member or piston;

Fig. 7 is an end elevation, looking at the left end of Fig. 6';

1921. Serial No. 460,027.

F ig. 8 is a longitudinal section through the liner and valve member taken in the same plane as Fig. 3, showing the valve member in its right-hand position;

Fig. 9 is a similar view showing the valve-member in its left-hand position;

Fig. 10, is a transverse section on the line 10-1O of Fig. 9;

Fig. llcorrespondsto Fig. 9,except that the valve member has been turned relatively to the liner (for convenience the plane of the section remains fixed as to the valve member and has been shifted as to the liner) Fig. 12 is a view corresponding to Fig. 11, except that the valve member has been moved to the right (Fig. 12 differing from Fig. 8 in the different angular relation between the valve and liner) Fig. 13 is a transverse section on the line 13-13 of Fig. 12;

Fig. 14 is a horizontal section on the line 14[llof Fig. 2, showing more particularly the starting valve;

Fig. 15 is a detail View of the starting valve member; and

Fig. 16 is an elevation of a steam-pump embodying the invention.

The steam-chest is marked a, and the steam-cylinder (Fig. 16) b. The steamchest has a live steam chamber and an exhaust chamber 13 at opposite sides. In the part of the chest which is applied to the steam-cylinder are passages 11 and 12, at opposite sides of the exhaust chamber 13.

The liner 6 is fitted tightly in the steamchest, and is provided at one end with three parallel circumferentially elongated ports 1,. 2, and 3, open, respectively, to the passages 11, 13 and 12. In the opposite side of the liner are two ports l: and 5, which are open to the live steam chamber 50 and which are spaced from each other at opposite sides of the transverse central plane and are also offset or staggered with respect to each other circumferentially of the liner. In the opposite end portions of the liner, near the top, are longitudinal slots, or end ports, 7 and 8 in circumferentially offset or staggered relation. A transversely elongated port 6' in the central upper part of the liner is in communication withthe exhaust steam chamber 13, through. a port 43 in the latter, a passage 41 leading from the port 43, a passage 44 leading at an angle from the passage 41, and a port 6 at the end of the passage 44 open to the port 6. In the bottom of the liner, in longitudinally spaced and circumferentially offset relation, are escape ports 9 and 10, in communication with passages 33 and 32in the wall of the chest, these last passages either being open to atmosphere or being connected with the condenser (not shown).

The sliding or piston valve 7 is mounted for longitudinal reciprocatory and rotary oscillatory movement in the liner. In one end it has a square socket having sliding but non-rotary engagement with the square end of a rock-shaft 52. The valve member has closed end walls and is divided interiorly by suitable walls 31 into three noncommunicating chambers 60, 61. 62.

In one side of the valve member are four parallel, circumferentially elongated ports 20, 21,22, 23, to cooperate with the liner ports 1, 2, 3; and in the opposite sides are two ports 24, 25, arranged in longitudinal alinement, at opposite ends of the transverse central plane, to cooperate with the longitudinally spaced and circumferentially offset ports 4 and 5 in the liner. The ports 20 and 24 are in communuication with each other through the right-hand end chamber 62. The ports 23 and 25 similarly communicate with each other through the left-hand chamber while the ports 21 and 22 constitute the opening to the central chamber 61. In the top of the valve member, not extending through its wall, is a longitudinal groove 26, which has continuous communication with the port 6 and is adapted to communicate alternately with the circumferentially otlset liner slots 7 and 8. Toward opposite ends of the piston valve member, and at opposite sides thereof, are circumferentially extending grooves 27 and 28 reaching from the bot-tom to near the top, and having at the bottom longitudinal, alined extensions 29 and 30 adapted to communicate alternately, respectively, with the liner ports 9. 10. The upper portions of the grooves 27, 28,, are adapted to cooperate with the liner slots 7, 8. V

The rock-shaft 52has a crank 53, which is pivotally connected with a longitudinally movable rod 54 carrying spaced, adjustable nut collars 56, 57 adapted to be encountered alternately by a tappet fork 55 on the piston rod 58 of the engine.

The operation of the parts above identified will now be described. Assume the pision valve member to be in the position of Fig. 8 and the piston of the steam cylinder 1) to be at the upper end of the stroke. The longitudinal groove 26 in the valve member now registers with the longitudinal liner slot 7, admitting exhaust steam from the port 6 through the groove 26 and slot 7 to the space at the right-hand of the iston valve member. At the same time, t e opposite end of the piston valve chamber is placed in communication with the atmosphere or the low condenser pressure through the liner slot 8, the groove 28, its extension 30 and the liner port 10. The result is to drive the valve member to the left, because the pressure of the exhaust steam is higher than that of the condenser or of the atmosphere, and suflicient to move the valve. The valve member will then assume the position of Fi 9. While the valve was moving toward the eft, its port 24 opened to the liner port 5, while the ports 20, 21, 22 opened to the liner ports 1, 2, 3, respectively. Consequently, in the position of Fig. 9, the lower end of the steam-cylinder is placed in communication with the exhaust through the ports 3 and 22, the chamber 61 and the ports 21 and 2. At the same time the upper end of the steamcylinder is placed in communication with the live steam through the ports 5 and 24, the chamber 62 and the ports 20 and 1. The downward stroke of the engine piston therefore takes place. At an appropriate point in such downward stroke, the tappet 55 comes in contact with the collar 57 depressing the same and the rod 54 and rocking the arm 53 and the shaft 52, which gives the valve member a partial turn in one direction, eventually bringing the valve member into the position of Fig. 11. During the turning movement of the valve, the port 24 is closed from the port 5, so that the steam ex ands in the steam-cylinder during the comp etion of the power piston stroke. At or before the time the piston has finished its downward stroke the valve has taken the position shown in Fig. 11. This turning movement carries the groove 26 out of register with the slot 7 and into register with the slot 8; and the same operation causes the oove 27 and its extension 29 to place the slot 7 in communication with the port 9 (to atmosphere or condenser) by way of passages 27, 29, 9 and 33, and to shift the groove 28 and its extension 30 so that the slot 8 no longer is in communication with the port 10. The exhaust steam from the port 6 is therefore admitted to the left hand end of the valve, and causes the same to be driven to the right, moving it to the position of Fig. 12. This causes the port 25 to open to the port 4, and the ports 21, 22, and 23 to open, respectively, to the ports 1, 2, and 3, while the port 20 is carried out of communication with the port 1.

Live steam will now pass by way of ports 4, 25, and chamber 60, and ports 23 and 3 to the lower end of the steam cylinder, while the upper end of said cylinder is open to exhaust by way of ports 1, 21, chamber 61, and ports 22 and 2. Consequently the piston ofithegsteam cylinder will ibedriven upward.

At, azcertain point'in thisstrokeithe.tappet the groove 27, 29 no longer connects the slot 7 with the port 9. The movement of the valve to the left then takes place, and the cycle of operations is repeated.

When starting, there is no exhaust steam in the. valve chest to operate the valve, and at this time the valve must be operated by live steam. For this purpose a manually operated starting valve, an illustrative form of which is shown in Figs. 14 and 15, is employed.

The channel 41 hereinbefore referred to is continued so as to communicate with the live-steam chamber 50, throu 'h a port 12-. A valve rod 40 is placed slidably and rotatably in this passage, having a handwheel 40 at its outer end and a screw portion 40 to cooperate with a corresponding fixed nut part. The part of the rod in the passage comprises fluted guide portions 40 and a cylindrical obturating portion 40. The last, in the normal operation of the valve mechanism, is disposed between the entrance to the channel 44 and the live steam port 42, preventing communication with the port 6. By turning the wheel 40". however, the plug portion 40 can be carried to the other side of the passage 44, so that live steam is admitted to the port 6, to operate the valve. After a few strokes of the piston under this condition, the starting valve may be restored to its normal position, seen in Fig. 141, after which the valve will be operated by the newly-produced exhaust steam.

What I claim as new is:

1. In a steam-engine, a steam-chest having a live-steam inlet chamber, an exhauststeam outlet chamber and a piston-valve chamber, a reciprocatory and. oscillatory piston-valve in said piston-valve chamber, with means for oscillating said valve mechanically, the piston-valve chamber having a wall or liner containing at one side a group of three ports to the opposite ends of the steam-cylinder of the engine and to said exhaust-steam chamber respectively and at another side two live-steam ports opening from said live-steam chamber, the piston valve comprising three parts or chambers adapted to cooperate with the said-ports in the liner to admit liveistefam to control the passage of steam to and from the steam-cylinder, the liner and valve-further provided with ports andpassages for alternately placing the endsof the valve chamber in communication with the. said exhaust-stea1n outlet; chamber as the valve is mechanically oscillated, so as to cause the valve to be reciprocated by exhaust steam from said outlet chamber.

2. The subject-matter of claim 1, further characterized by the provision of a channel between the said live-steam and exhauststeam chambers, and a valve in said channel movable at will to permit at starting the flow of live steam to the passages for reciprocating the valve.

3. A steam engine valve mechanism comprising a wall or liner having at one side a group of three ports to the opposite ends of the steam cylinder and to the exhaust, re spectively, and at another side two livesteam ports, and a reciprocatory and oscillatory piston valve divided into three parts or chambers and having at one side ports in the different chambers to cooperate with said group of three ports in the liner and at the other side two ports in the end chambers in staggered relation to the livesteam ports, said liner being provided with longitudinal end slot ports, an exhauststeam port, and escapeports, and the valve having a groove arranged to register alternately by oscillation with said end slot ports while communicating with said exhaust-steam port, and being provided with other grooves arranged to connect alternately by oscillation the said end slot ports with the escape ports.

4. A steam engine valve mechanism, comprising a wall or liner having at one side a group of three ports to the opposite ends of the steam cylinder and to the exhaust, respectively, and at another side two livesteam ports, and a reciprocatory and oscillatory piston valve divided into three parts or chambers and having at one side ports in the different chambers to cooperate with said group of three ports in the liner and at the other side two ports in the end chambers in staggered relation to the live-steam ports, said liner being provided with longitudinal end slots, an exhaust-steam port, and escape ports, and the valve having a longitudinal groove arranged to register alternately by oscillation with said end slots while communicating at the center with said exhaust-steam port, and being provided wiith other angular grooves arranged to connect alternately by oscillation the said end slots with the escape ports.

5. In a steam-engine, a valve mechanism comprising a wall or liner having longitudinal end slot norts, a central exhaust-steam port, and escape ports, a reciprocatory and oscillatory piston valve in the liner having a groove arranged to register alternately by oscillation with said end slot ports while communicating with said exhaust-steam port, said valve being provided with other grooves arranged to connect alternately by oscillation the said endslot ports with the escape ports, and means for oscillating the valve from the piston rod of the engine Without interfering with its reciprocation by the exhaust-steam pressure.

In testimony whereof I aflix my signature.

KINZABURO NAKAO.

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