US105941A - Improvement in direct-acting comfottnd engine - Google Patents

Description

Pazntfed-Aug-2, 1879.`

DIRECT AGTINGJGOMPOUND ENGINE-@v the following is aspeciiication.

, This'nvention is intended as an improvement upon '.I IvILLI AM` M.,- IIENDEnsoN, or PHILADELPHIA, PENNSYLVANIA] Letters Patent Ivo. loactnfdated August 2, '1370.A

IMPRovEMeNrrN manor- ACTING coMPo'UND ENGINE.

,f The` Schedulereferred to in `these Lettere y*Patent and making part of the same L I, `WILLIAIYI M." Hersonissos', of Philadelphia, St-ate tof, Pennsylvania, have invented certain improvements inDirect-Aiction yCompound=Steam-Engines, of which thepatent granted to myselfV by the United States vPatent O ce, dated ,April 5, 1870,ND.`101,617,`for

ari- Improvement in, Direct-Action Compound Steam- Engmes, the improvement referring exclusively to the mode of operating thesteam-valves when it is desired `to Work `the engines singly, and notin pairs, as set forth in the patent above referred to, theAv same being directly applicable to the construction of single direct- Yacth'm, engines, as commonly employed for pumping.v purposes, which engines'invariably take' full-pressure i steam throughout the entire stroke, a consequence at- `tendant upon the general' means employed to operate 'thersteam-valve,:whicht is alternately reversed'by a I motion comm unicated fromcthe `steam-piston or its rod, at orabont the termination ot each stroke, in a variety ot'tfways, eachftlie subject of an individual patent.

The result 1ct' `thewhole is identical `in theone fea-1 ture, that no gain from expansion can ever be obtained, a matter overlookedas ot minor importance, so long as the valve can be reversed, but in reality ofy great I significance, especially Ysowhen an engine of .consider- 1 able size isreqnired, where economy of fuel is a desid- 'eratum. In this engine the means employed to'eect this end is by the use of combined high and low pressure steam-cylinders, fitted with slide-valves of a peculiar form, connected with small steam-pistons, which valves areentirely free from contact with the main pistons or rod, and moved exclusively by the duid em" ployed as a motive power, the valves controlling the motion of the main pistons, and said pistons control- -ling the necessary motion' of the valves at theright time, to cause the u /hol'etov nperateantomatically with any degree of determinedexpansiom 4allfof which will,

' be hereafter more fully described, reference lie-inghad I tothe accompanyingdrawing, 'and' to the letters. of.'

reference marked thereon, which shows alongitudinal section of this improvement, exhibiting the combinedcylinders, with the general arrangementpf-,the-fpistons,

ports, and valves, and means for operatm A is a steam-cylinder, closed at e'ac` i B B, and divided into two lequal parts b'y' an abutment, O, formed into a stuug-boir, and packetlwith n'letal-v lic packing-rings, as sho\vn.

Dis a hollowtrunk, turned to suit the -boreof this `E E', ata distance apart equal tothe length of the.

` stroke of the engine, added to the width Vof the central abutment, and'the clearance allowed'.A 4Each pistoncylinder engines, in order to'permit each piston, E E', to have the stroke determined-upon. i` n i The piston-rodFis-attached to the tinnkD,`-as shown, and passes through a stuiing-box in the front ,cylinder-head B'.

G G are polts for admittingv the live steam from the steaxmchest to the annular cylinders' H H', formed by. the above-describedA combination ot'l parts.

- lI Il are transfer portsfor conducting the steam'frorn the annular-or high-pressure cylinders to the low pressure cylinders A A', -and `J vJ are eduction ports for exhausting the spent steam, v j

KK are two similar slide-valves, connected and moved together by'arod, L, which is furnished with a yoke, as'sllown, fitted with a slidingblOcE'intowhicli a wrist-pin of a crank-arm, M, projectspthegshaft of this crank passes through a stuing-box to the outside I vIn each "end ofthe valvechest is formed' a small cylinder, bored true vin linewith each other, and tted with steam-pistons N N', packed with metallic packidg"-rings. Theinner ends of these cylinders are open i to the steam within the valve-ches,t, and consequently balance-each other, being both exposed to thel same pressure. The outer ends `of the cylinders are closed by heads O 0.', 'as shown. These pistons are attached tothe valves K K by rods P P", and fconstitnte `the v mechanism by which the slide-valves are opera-ted.l

' Steam`passag`es,'fQ Q', are cut through from these small cylinders in'to the transferports I IY', as indicated. The 'rods P1 are continued through studing-boxe's'in :the `heads O- 0", and their extremities ttedwith dash. 'j'

pots, t'o break theA -force ofthe movement ofthe valves,

by cushioning, in any of the well-known jrnethods.'y 't Each slide-valve has'a' steamf-passage o r'port cored through it, to establish, at the properAtime, a comrnu nication between the .ports G and I, for the purpose of conducting the live steam from the highfpressure to vthe low-pressure steam-cylinders, .as before dev scribed. fj In'other respects the faces 'of these valves'- -are made to coincide with the .ports over which they play v iid'vofthe boreof the cylinder A, ct down to the level of the counter-bore, the apen; 0f the V of each -poutingtoward each other; `these are cushioningpassages for arresting the pistonsll E'at the vends (aftheir stroke, and at the saine time are aiso thev steamports f oradmitting the; steam to the valve-pistons, cause areversion ofthe position of the slide-valves',

, the main pistons acting at thatl time asA the slide-valve y for the small'pistons.

W is where the steam` enters the chest fromthe boiler, and itsy `distribution is-eftected as follows; i

Referring to the drawinmwe nd the pistonailier?1 R' are small V-shapefl cavities arranged at each' ingjust completed the stroketo the left. Live steam' has been admitted by the port G, while the spent 'steam from the other side oi' the piston E has beeii` exhausted through the port J into tlieexhaust-chamber S, thence conveyed away by afpipe, T, in the usual manner,'to the condenser, or dischargedl into the atmosphere, as the case may be. b

It will lat the saine time be observed that the charge of live steam from the previous stroke, after imp'clling thepiston E to the right, has been transferred by the poits G', K', and 1', to the low-pressure cylinderAi',

where it has been assisting the-efforts of the live steampressing upon thel piston-head E, by exerting its expansive force upon the greater area presented by the face of the piston lIE.

The eiective area alici-ded here is reduced to that of the trunk only,-as the steam, in expanding within the 'low-pressure cylindei,reacts with a back pressure upon the annular or higl'i-pressnre cylinder, as will be at once .apparent by au examination of the action of the valve K. This, however, does no harm; lnothing is lost in consequence, and we only require to make the low-pressure cylinder somewhat larger `to compensate for it'.

The present position of the poits shows that the -piston E has just passed over the exhaust-port J, ef

fectually shutting oif all communication between the end of the.cylinder A and the condenser or atmosphere',

' the engine being condensing or iioii-coiidensing, and

that, immediately following upon this, the inner edge of the same piston-head passes over the ciishioningpassage R, permitting the live steam to tiow to the' greater area presented by this piston, as indicated by Athe arrow, thus bi'iiigingthe stroke to yan end. This' same steam immediately rushes up thetiansfer-port I,

and through the passage Q,-to the. endof pistou N.

Now, by virtue of the fact that the steam contained within the cylinder A' has -becomereduced hyexpainsive working, in the proportionof the relative capacities o t' the annular cylinder H' to that of the lowpressure cylinder A', the pressure acting'upon the other piston,:N', is inferior to that just admitted to piston N, consequently the slide-valves must be carried to theriglit by this superior force, which, changing the'dircction of the currents of the s team. by a reversion of position of the slide-valves, thereturn Vstroke will be made, afterward :tobe Iarrested,landftl iej valves'again reversed precisely in a similar mannerto that just desciibed, which, being repeated-at the. end of each stroke, will cause alternate reciprocation' of the pistons and valves ad infinitum, so long as the. steam is admittedto the engine. It is obvious that the exhaustports should be surely closed vby the piston-heads before the established cushion-.passages permit the steam to pass to the ends of y the cylinders', otherwise there would vbe a waste. of

steam'; as'it is, no loss is entailed, as the little steam 'that is passed to perform'lthe functions of 'arresting the pistou and reversing the valve is merely an ad, vance of the' main body, which, immediately after the valve is reversed, pours over, by th'eport in the valve.

K, to continue its further service of expansion.

Byv arranging the V-shaped passages as described, with the apex of each pointing 4toward each'other, the cushioning is effected in a very gradual manner,

and the pistons will notl be so suddenly checked, as

would be the case if these passagesopened abruptly. i

- With a further view of regulating tbecushioning."

ports to a greater degree of nicety,the 'steam might be conveyed by la' closed passage, iittedl with a valve,

in place of the countersunkVfpassage just described.

I claim as my invent-ion- 1, In a compound engine,.as described; where they opposite faces ofeach piston presents an unequal area,

the arrangement of the passagesR R', eduction-ports J J and steam-passages Q Q', or their equivalent/s., in combination with the main pistons E E' and wilyer pistons N N', iii such manner that' the live, steam, upoiifthe completion of each stroke, will pass directly.

from 'the annular cylinders to the valve-pistons N, by the passages R and Q, for the purpose of operating.'4 thevalves, as described.,

2. Tn@ siidevaives, admitting me impeiiing'agnt employed tothe m""ii pistons, which, ii1turn,"aud at l the proper time, become'valves for controlling the acq" tion of the slide-valve pistons, the one admitting the impelling agent tothe other alternately, substantially'.

inthe' manner and for the purposes repiesented.-

, l WILLIAM 'M. HENDERSON. Witnesses:

Josnin H. WARRINGToN, Ro'r. F. LYTLE.

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