US122248A - Improvement in steam-engines - Google Patents

Description

4Shevekts--Sheet1.` Reciprocating Engines.

D. A. GREENE.. No. 122,248..

Patented Dec. 26, i871.

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l 4 She`ets``f$heet 2. Reciprocating Engines.

Patnted Dec. 26, i871 D. A'. GREENE.. No. 122,248..

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9732 352mm m D. A GRAEEN'. Reciprocating Engines.

No. 122,248. y Paienied Dec.26,1a71.

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Patented Dec.26,187i.

D. A.. GREENE. No. 122,248.

UNI'rnn STATES DARWIN A. GREENE,

or NEW YORK, N. Y.

IMPROVEMENT IN STEAM-ENGINES.

Speciiication forming part of Letters Patent No. 122,248, dated December 26, 1571.

To all whom it may concern:

Be it known that I, DARWIN A. GREENmof New York city, in the State of New York, have invented certain new and useful Improvements in Steam-Engines.

The invention relates to the general construction and arrangement of the parts by which the engineis made compact, easily accessible, more portable, and very nicely balanced; to peculiar means for operating the feed-pump, which alford marked advantages; and to peculiarities in the means for connecting and disconnecting the valve motion in starting and stopping.

The following is a description of what I consider the best means of carrying out the invention. The accompanying drawing forms a part of this specification.

Figure 1 is a front elevation, and Fig. 2 is a side elevation of the engine entire. Fig. 3 is a vertical section through my bed-plate on the line S S in Fig. 4. Fig. 4 is a plan view of the bedplate. Fig. 5 is a section of the bed-plateon the line T T .in Fig. 4. Figs. 6 and 7 are sections through the cylinder and adjacent parts on a larger scale. Fig. 6 is a central vertical section.

. Fig. 7 is'a horizontal section on the line S S in Fig. 6. Figs. 8 and 9 represent the pump mechanism in section and elevation. Fig. 8 is a vertical section on the plane of the axis of the pump. Fig. 9 is an elevation of the same parts. The remaining figures show details detached. Fig. 10 shows the hooking and unhooking gear in eleva- Fig. 11 shows the same in plan. Fig. 12 shows the beam in elevation, and Fig. 13 shows the same in plan.

Similar letters of reference indicate corresponding4 parts in all the figures.

A is the xed frame-work, considered collect ively, the several parts being indicated by A1A2,

&c., when necessary. B is the cylinder, mounted in an. elevated position, as represented. The piston-rodc extends downward therefrom, and connects with the cross-head C', running on slides A2, and communicating motion, through a short link, D, to a stout lever, E, turning on a center, c, near the base of the frame-work, but sufticien tly elevated to allow the beam to rock above the base of the bed-plate. The entire bed is formed in'one casting, A1, with a rim or raised ridge around its edge, as indicated by a. AThis con-- struction of the bed causes it to hold all the drippings of water, oil, or anything else, and retain them in a stratum over the bed, and allow them to be drained either constantly or at intervals through the drain-pipe a. This may be provided with a cock or other means of control, not represented. A connecting-rod, F, communicates motion from the beam E to the crank G1 on the main shaft G, which latter carries any-wheel, G'Sadapted to serve also as a pulley to communicate motion to the mill-work or-other work to be driven through the medium of a belt, not represented.

-The valve-chest is on the front of the cylinder,

and receives steam through a connection, H, from a pipe and boiler, not represented. The steamV is admitted to the cylinder by a slide-valve, I, which is reciprocated through the medium of a valve-rod, i, which communicates motion from a bent rock-shaft, J, in front of the beam at the bottom, and which is bent, as represented, to allow the keys and other work on the front of the cross-head and link D to project a considerable distance, if necessary. tThe rock-shaftJ is operated through the medium of its armsJ and an eccentric rod, K, leading from an eccentric, K, all in the usual manner, except in the provision Afor engaging and disengaging the parts. A hook is formed on the eccentric-rod adapted to engage with the pin on the rock-shaft arm. The hooked end of the eccentric rod is raised and lowered by means of a light link, k, which connectsa pin on the eccentric rod K to a piu on a revolving part, L, which is free to be revolved at will by turning loosely on the end of the rock-shaft J, being controlled by the short hand-lever L. To unhook or disengage' the eccentric rod from the pin on the rock-shaft the engineer pulls the handlever L', and turns it into the position opposite of that shown `in Fig. l0, and the engine is stopped. To hook on or make the connection the engineer turns the handle L by pushing it around so as to cause it to perform a half revolution. This lowers the link 7c and allows the hook on the eccentric rod K to en gage with the pin on the rock-shaft. Thus conditioned the eccentric maintains the proper rocking motion of the rock-shaft, and consequently imparts the proper motion to the slide-valve I. The arrangement of the parts requires a slight play on the link kat eachrocking motion. This `is allowed for making a short slot in the link k.

This slot may be either on the pin which connects this link to the revolving part L or on the other on the upper side, as indicated by il. One of its extreme highest position. It follows that it pin which connects it to the eccentric-rod K. It is sufficient in practice to allow a quarter of an inch or less for alarge engine. Without such j provision a slight lift would be given to the eccentric hook-at each revolution, and this, although slight, wou] d induce a iapid destructive wear and abrasion ofthe surfaces in contact. The device thus provided is very convenient and durable.

The slide-valve is liable to descend by gravity into too low a position when unhooked. This, if permitted, would induce various evilsnot theI least of which might be the moving ofthe rocker-arm J' into such a position that the hook on the eccentric-rod K could not engage with it. To prevent this an adjustable stop is provided inthe valve-chest by the screw d2, which is capable of being adjusted with very great delicacy. After setting the valve properly this screw is turned into such a position that at each descent of the valve the screw comes very nearly or quite in contact with the interior of the valve-chest at the bottom. It may be guarded against any possible derangement of position afterward by a jamnut, if Vsuch should be necessary. Y To avoid a liability to lift the valve too high when starting the engine by hand a similar screw is also provided these stops prevents the valve from being ever moved beyond its extreme lowest position, and the other prevents iti'rom being ever moved above cannotbeplaced by any unskillfulness or thoughtlessness in any position where the hook on me eccentric-rod is .not ready to engage with it when lowered forthe purpose. Y Y

` There is no joint in valve-rod. The motion of this member of the mechanism is nearly but not quite vertical. The upper end slides vertically, while the lower end describes a small arc. It has been common in small engines, and even in locomotives having long connections between the valve and rocker-arm, to make the valvestem'without a joint, and to cause it to spring sufficiently to allow for its slight deviation from a constant line. This would involve difficulties on an engine as compact or with as short connections as this. I avoid them by a verysimple device. The valve-stem is made rigid or with a moderate degree of elasticity, and the Obliquity of its position is allowed for in the gland of the stuffing-box at the base of the steam-chest. The surface on the interior at the base of the steamchest is elevated around the valve-rod, and at the extreme upper end of this elevation it fits quite closely. Below this it is filled with packing, which is intentionally and necessarily a yielding material and will allow very completely for its slight deviations of positions to one side and the other. vThe feed-pump Mis of the ordinary solid-plunger variety, and is mounted directly below the overhanging end of the main shaft. The engine is intended to run very rapidly, and it is important to the smooth and successful working ofthe pump that it shall reciprocate at only a moderate speed. I employ a friction-gearing to reduce the motion, and have adapted it to perform in its ordi- 'u frictional contact. The pump-pluri germ is worked by means of a connection', m1, whichreceives motion from a pin, m2, xed in a radial slot, M2,

vin the wheel M1. This pin m2 may be set out and in, so as to give the pump-plunger the required amount of throw. l

Iconstruct the parts capable of adjustment to pump a much greater amount than is needed to supply the. boiler, so that the surpluswater may Vbe used to supply an elevated tank, or for other purposes; and it can be adjusted exactly at the center in any case, when necessary, so that the pump will remain absolutely motionless. The

main resistance to the motion of the pumpis during the descent of the plunger m. Itis a peculiarity of my arrangement that it provides for an increase of friction between the friction-wheels at this period without inducing any excess of friction at other times, whatever may be the resistance to the descent of the plunger m; and this will vary according to theA pressure of the steam. A corresponding increase of friction is induced between the large friction-wheel M1 and the small friction-wheel. It follows that the contact of these friction-wheels is always just suf-l The pipe which drains the base of the cylinder is marked S, and its cock s. The pip'e which drains the bottom of the steam-chest is marked R, and its cock fr.

I propose, in large'engines, to apply some compact form of water-trap in place of the controlling means r and s here represented; but for small engines the screw-valves shown are amply sufficient. 'The'parts beingall properly proportioned to afford proper strength and stiffness, it is usually or invariably found that the weight of the piston and its connections exceeds the weight of the connecting-rod and crank. I compensate for this difference by giving an excess of weight to the beam at the end which connects to the crank, as shown in detail in Figs. l2 and 13.

Some of the advantages due to certain features of the invent-ion may be separately enumerated, as follows: First, by reason of the arrange-- ment of the elevated cylinder and shaft with the single-loaded beam below, connected as represented, to make an inverted beam-engine, I am' able to mount the shaft at a just suflicient elevation, and to employ a large iy-wheel Without cutting through the iloor or ceiling. It also a-llows the employment of a continuous bed-plate under the entire engine, and the pillow-blocks being mounted on aV rigid frame-work, and connected together by the bed-plate, holds the work more strongly and reliably in line. The entire framing is a unit, and the engine is remarkably compact and stiff, while every part is easily accessible. Second, by reason of the employment of the friction-gears M1 and pin m2, adjustable in the slot M2 for variably operating the pump plunger, as speciiied, I am able to vary the quantity pumped Within Wide limits with very simple and noiseless mechanism. Third, by reason of the mounting of the friction-gear Wheel M1, slotted and carrying an adjustable pin, m2, and pump-connections, as represen ted, with the Wheel M1 on a spring bearing directly in line between the friction gear-wheel M1 and the pump, I am able to render available the vari able resistance of the pump to increase the contact of the frictiongears at the right momentwithout any considerable excess at any time, as herein specified. Fourth, by reason of the construction and ar rangement of the revolving part L with its 11andleL and link L, connecting it to the eccentric rod Kl, I am able to hook and unhook the engine by very simple and efficient mechanism, and to hold the hook efficiently in or out of connection Withoutinducin g any appreciable friction or Wear.

I claim as myinventionl. The within-described inverted-beam engine having the elevated cylinder and shaft, and single loaded beam below, connected and adapted to operate within a rigid castiron 'aming, substantially as herein specified.

2. rIhe rictiongears M1, slot M2, and adjust'- able pin m2, arranged, as represented, relatively to the main shaft and to the pump M m., and connection m1, for thepurposes specified.

3. The arrangement of the friction-gears MI in line with the pump, andthe mounting of the wheel M1 on the spring-bearing', so as to induce a selfacting adjustment of the frictional contact varying with the change in the resistance of the pump, as specified.

4. The turning piece L L' and link 7c, arranged and operating relatively to the eccentric hook K and the rcck-shaft arm, as and for the purposes set forth. z

In testimony whereof I have hereunto set my name in presence of two subscribing witnesses.

DARWIN A. GREENE.

Witnesses:

C. C. LIvINGs,

A. HOERMANN, `(150)

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