US208797A - Improvement in direct-acting steam-pumps - Google Patents

Description

Pump.

Patented Oct. 8,'1878.

W. CRAIG. Direct Acting Steam No. 208,757.

l r l Ill l Iv\\\\\\\\\\\\\\\\\\\ N. PETERS. PHDTO-LITHOGRAPHER, WASHINGTON. D C.

UNITEDS'IATES PATENT OFFICE.

WILLIAM CRAIG, OF NEYV YORK, N. Y.

IMPROVEYMENT IN DIRECT-ACTING STEAM-PUMPS.

Specification forming part of Letters Patent No. 208,797, dated October r2, 1878 application filed July 17, 187s.

To all whom 'it may concern Be it known that I, WILLIAM CRAIG, of the city and State of New York, have invented certain Improvements in Direct-Acting Steamlumps, of which the following is a description, reference being had to the accompanying drawing, forming part of this specification.

Thisdnvention relates to that class of steampumps in which the main steam slide-valve of the pump is actuated by the steam without the intervention of eccentrics, cranks, or cams, an auxiliary slide-valve, actuated by the main steam-piston or piston-rod of the pump, being used to govern the action of the steam upon the main slide-Valve.

Although the invention will here be shown as applied to a vertical steam-pump, it is equally applicable to pumps arranged to work horizontally, obliquely, or otherwise, and Whether the pump be a sin gle-acting plunger one or a double-actin g piston one; but the invention is more especially intended to be used in connection with a vertical direct-acting steam-plunger or piston-pulnp having neither cranks, eccentrics, nor cams, and adapted for feeding boilers and other purposes, and which, besides being simple and cheap in construct-ion, shall act with greater certainty or more perfectly than other vertical directacting steam pumps having steammoved valves.

In carrying out my invention I employ an ordinary arrangement of a steam-cylinder land a pump-barrel in linewith each other, and either formed of a single casting or in different parts, properly secured together; also arrange, as in certain other direct-acting engines, the 'valvechest on the end or cover of the steam-cylinder opposite to that at which the pump-barrel is placed, such valve-chest, with its 4contained valves, being by preference placed concentrically and in line with the axis of the steam'- cylinder; but they may be placedfeccentri.`

cally with regard to said axis. .Y f

The steam-valves are of the sliding cylindrical kind, consisting of a main valve for gov'- ernin g the inlet and outlet of the steanito and from the steam-cylinder, and of fain? auxiliary valve, preferably arranged to ivorlmvithin the main valve, for governing the inlet and out'- let of steam to and from the facesforfendsof thc said main valve; and I sometimes' employ,

in connection with the aforesaid main steamvalve, a double set of ports and passages formed in the opposite sides of the valve-chest and communicating with the two ends of the steam-cylinder, whereby the said valve is more perfectly balanced, and for a given amount of travel it effects a greater opening of port or area of steam-passage than is usually obtained with this class of steam-valves; but such arrangement of double ports and passages forms no special feature of this invention.

In order to operate the auxiliary valve at the proper times to govern the admission of steam to and from the faces or ends of the main steam-valve when the main steam-piston approaches the end of its stroke, I employ a rod connected to the said auxiliary valve, and arranged to extend into a hole or recess formed in the piston and piston-rod or pump-plunger, such rod being acted upon by suitable part-s or devices connected to the piston: coming in contact with stops on the said rod. as the piston approaches the end ofy its' stroke in either direction.

The ports and passa-ges in the main steam and auxiliary valves are so arranged in relation toeach other and to the ports and passages in the valve-chest, andthesurfaces of the auxiliary valve are so adapted to those of the main steam-valve, that the reduced pressure consequent upon the exhaustion of the steam from one side or end of the main and auxiliary valves assists the steam-pressure acting on the other side or end of the main and auxiliary valves, tending to hold them both firmly and with certainty in their proper positions while the main steam-piston is making its stroke, and until the auxiliary valve is moved thereby preparatory to a fresh stroke of the main steam-valve. This effect is more prominent when a condenser is elnployed in connection with the steam-cylinder.

Figure 1 in the drawing represents a vertical section of a direct-acting steam-plunger or sin gle-acting pump constructed in accordance with Jmy invention, but having the steamvalves removed in order to show more clearly the steam and -exhaust ports in the valvechamber. Fig. 2. is a vertical section at right angles to Fig.!1,v\vith the valves in position. Fig. 3 is a horizontal section through the valves and valve-chest on the lineair. Figs.

4, 5, and (i represent longitudinal exterior views and alongitudinal section, respectively, and upon alarger scale, of the valves removed from the valve-chest. Fig. 7 is a vertical section of a double-acting-piston steam-pump, in part, with so much ot' the invention applied thereto as is necessary to explain its adaptation to such a pump.

Referring more particularly' to the first six igures of the drawing. A is the stean'i-eylinder otl the pump, and l its piston. t` is the pmnp-barrel, and l) its plunger. Said plunger l) passes through shitting-boxes li and F, as usual.

G is the valvechest. bolted orotherwise secured onto the end ot' the steam-cylinder.

H is the cylindrical main valve, for controlling the admission and exhaustion ot' the steam to and from the steam -cylinder A, such main valve H being actuated, as hereinafter explained, by stealn admitted to the ends thereof by the auxiliary valve I which latter is operated at the proper time by the rod J attached thereto. Said rod .l extends into a hole or recess, K, formed in the piston B and plunger l), Figs. 1 and 2.', and is acted upon by the tappct or catelrpieee L, screwed or otherwise secured within one end ot' the hole or recess l, as said tappet L comes in contact with a stop or enlargement, M, of the rod J, as the piston B approaches the end ot' its downward stroke, and against a stop or enlargement, X, as it approaches the end otl itsupward stroke.

The lnain cylindrical steam-valve 1I, which slides up and down within the valve or stealn chest G, has formed init two annular grooves, l1'l h2, which communicate by an opening, 0, at all times with the chamber I), into which steam enters from the boiler through the passage O. The grooves hl h2 also communicate with a chamber, R, opposite to the chamber l, conducting steam from the latter thereto, by which means the pressure ot' steam in the chamber P, acting against the surface of the main valve li, exposed at the opening O, is balanced.

S S are opposite exhaust -eavities in the main valve Il, corresponding` to duplicate exhaust-ports T T in the valve-chest, such exhaust ports or passages uniting into one passage, U, leading to the exhaust-outlet IV W are steam ports and passages leading to the lower end ofthe steam-cylinder, and X l X are steam ports and passages leading to the upper end ofthe steam-cylinder.

The auxiliary valve 1 is adapted to slide up and down in a cylindrical hole formed through the main steam-valve, and, as shown in Figs. 2, 5, and (i, may be divided transversely through its center or formed in halves for the convenience ofintroducing it within the main valve, suoli halves being united bythe rod .l passing through them and secured by a nut at the top, as shown. Said auxiliary valve I has formed at its ends heads or collars, which limit its longitudinal movement in the lnain valve.

Instead of tbrming the auxiliary valve in halves, it may be made mainly of' one piece by leaving' one ot' the heads or collars loose, and securing it to the body of said valve by screwing or otherwise at'ter the auxiliary valve has been passed into the main valve.

In the auxiliary valve I contracted passages fi z" and il i2 are formed and arranged to correspond alternately, accordingly as the auxiliary valve is moved in one direction or the other within the main valve, with small ports` y y and z .7 formed in the latter, for the purposes hereinafter explained.

The suction and delivery valve boxes of the pump are connected to the nozzles c in any manner that may be convenient and suitable.

rlhe action of the parts is as follows: When the piston B arrives at or near the end ot' its upstroke, the tappet L comes in contact with the stop N, and raises the rod J, and with it the auxiliary' valve I, until the ports and pas sages 1'l 'il communicate by branch or lateral apertures with the ports or passages y y in the main valve H. Steam then passes from the groove h through the passages 'il il into the space below the auxiliary valve I, and acting on the under side of the auxiliary and main valves raises them both until the groove hl comes opposite the steam-ports X X, thus admitting` steam to the top side of the piston B. The same upward movement ofthe main valve brings the exhaust-cavities S S over the steamports W W, thus opening communication between the exhaust-outlet and the under side of the piston B. When the piston l5 arrives at or near the end of its downstroke the tappet or eatelrpiece L comes in contact with the stop M and draws down the rod J, and with it the auxiliary valve I, until the ports or passages 1721'2 communicate by branch apertures with the ports or passages z z in the main valve. Steam then passes from the groove 112 through the passages i2 i2 into the space above l the auxiliary valve I, and acting on the upper side of the auxiliary and main valves presses them both downward until the groove h2 comes opposite the steam-ports y y, thus admitting the steam to the under side of the piston l. The same downward movement of the main valve brings the exhaust-cavities S S over the steam-ports s z, thus opening communication between the exhaust-outlet and the upper side of' the piston. In Fig. 2 the parts are shown in the positions last described, suitable for the ascent of the piston.

It will be understood that the movement ot' the auxiliary valve upward, which brings thel ports or passages il 1" in communication with the ports or passages 1/ 3/ in the main valve, so as to admit steam from the groove h* to the space below the said auxiliary and main steamvalves, also brings the ports or passages yi2 iz opposite ports or passages y y in the main valve H, which open into the exhausteavities thereof, by which means the steam which has acted above the auxiliary and main valves to press them downward is allowed to escape,

and that conversely the movement ot' the auxiliary valve downward, which brings the ports or passa-ges i2 il opposite the ports or passages z z, in the main valve H, so as to admit steam from the groove h2 to the space above the said auxiliary and main steam-valves; also brings the ports or passages il il opposite ports or passages z' z', in the main valve, which open into the exhaust cavity thereof, by which means the steam which has acted below the auxiliary and main valves to press them upward is allowed to escape.

In the arrangement above described and illust-rated in Figs. l and 2, a set of steam and exhaust ports and passages are used on opposite sides of the main valve, whereby, as hereinbefore described, said valve is more equally balanced than when one set only is used, and a greater opening of port for a given amount of valve travel may be obtained than is usual with this class of steam-valves; but I do not conne myself to such arrangement, as in some eases I employ only one set of such ports and passages, and then only one set of small ports, il i2, is required in the auxiliary valve; or, again, when it is not required that the main valve should be a balanced one, yet should operate in concert with a set of steam and exhaust ports or passages on opposite sides of it, the same may be divided longitudinally into halves, and said halves be connected by dowel-pins to move together longitudinally.

The passages W W may be provided with Aadjustable or regulating valves b b, to adapt the pump to different working conditions, as against or with pressure.

Cnshioning the steam at the end of the stroke of the steam-piston may be eected by causing the steam-passages to enter the cylinder at a short distance from the ends in the usual manner.

To enable the auxiliary valve I to be moved by hand when necessary, a rod, 2a, passes through a stuffing-box, 3a, at the top of the valve-chest, and carries at its lower end apin, 4, the head of which enters a recess in the rod J, a nut, 5, which screws onto the rod J, encircling the pin 41. The head of the pin may be made to act upon the rod J and consequently the auxiliary valve attached thereto, by drawing out or pushing in the rod 2, the play of the head of the pin 4 in the recess of the rod J allowing of the motion of the latter with the auxiliary valve when the pump is at work without giving motion to the rod 2f.

In the drawing the auxiliary and main valves and valve-chest are shown concentric with the steam-cylinder, and such arrangement is in most cases preferable, on account of simplicity and facility of manufacture; but they may be arranged eccentrically with regard to the axis of the steam-cylinder without departing from my invention.

Fig. 7 of the drawing shows the rod J of the auxiliary valve, which is operated by the main steam-piston B, as applied to a double-acting pump, a rod, D', from the pumping-piston l) connecting with the steam-piston and the recess K, within which the rod J enters, being arranged to pass through the steam-piston and into said rod, which, with its attached pumping-piston, corresponds to the plunger of the single-acting pump. So far as the construction, arrangement, and operation of the main and auxiliary valves, however, is concerned, there is no difference between the application of the invention to a single and a double acting pump, a tappet, L, connected with the piston, acting against stops on the rod J to start the auxiliary valve alternately in opposite directions, as in case of the single-acting pump.

I claim- 1. Theeombination, with the auxiliary valve, of its operating devices, controlled by the motion of the steam-piston, and arranged within the steam-cylinder and steam-chest of the pump, the same consisting of a rod, J, connected with the auxiliary valve, the piston and pump plunger or rod having a hole or recess, K, in them, the stops M and N on the rod J, and the tappet or catch-piece L secured to the piston, essentially as shown and described.

2. A direct-acting steam-pump provided with slide-valves arranged for operation in line with the steam-cylinder, and having its auxiliary valve operated by the movement oi' the steam-piston by means of devices contained within the steam-cylinder and valvechest, the whole being combined and arranged for operation, essentiallyY as specied.

WILLIAM CRAIG.

XVitnesses ALFRED BURHORN, T. J'. KEANE.

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