US166848A - Improvement in balanced valves - Google Patents

Description

4 Sheets Sheet I.

W. B. CHURCH. Balanced-Valves.

Patented Aug. 17,1875.

w. c. cnuncn. Balanced-Valves.

PatentedAug fi, 1875.

-PETERS. PHOYO-UTHOGRAPHER WASHINGTON. 1 c4 4 Sheets--Sheet 2.

'4Sh eets--Sheet3.

Patented Aug. 17,1875.

W. C. CHURCH.

' Balanced-Valves Illl l 4 Sheets--She6t 4.

W. 6. H U RGH.

Balanced-Valves.

Patented Aug. 17,1875.

MIMI/ t UNITED STATES PATENT OFFIGE.

WALTER CHARLES CHURCH, OF LONDON, ENGLAND.

IMPROVEMENT IN BALANCED VALVES.

Specification forming part of Letters Patent No. [66,848, dated August 17, 1875; application filed March 2, 1874.

To all whom it may concern:

Be it .known that I, WALTER CHARLES CHURCH, of 39 Lombard street, in the city of London and Kingdom of England, engineer, have invented Improvements in Steam-Engines, (parts of which improvements are applicable to hydraulic rams and pumps,) of which the following is a specification The object of my invention (for which a British patent, No. 563, was issued on the 19th day of April, 1872) is a slide-valve for steamengines, constructed as described hereafter, so as to prevent undue friction, unequal wear, and: the waste of steam.

I propose, according to my invention, to

. employ a peculiar construction and arrangement of equilibrium slide-valve for steam-engines, such valve being of a circular in lieu of theordinary rectangular form, and capable of rotating within a circular buckle or clip, such as is hereinafter described, when running with or without steam.

The peculiar construction of slidevalve hereinafterdescribed admits of the removal or balancing of the pressure on the valve more effectually and easily than when an ordinary rectangular-shaped valve is used. I propose to balance or remove the pressure acting on the back of the valve by the employment of a cap or ring of smaller diameter than the valve itself, fitting over a junk-ring secured by a central bolt to the back of the valvean Lrshaped packing-rin g, which is equally applicable to pistons ot' steam-engines, rams of hydraulicpresses, pistons and plungers of pumps, and toother similar purposes, being interposed between the under side of a projecting flange on the upper surface of the said junk-ring and the body of the slide-valve, and pressed against the inner parallel bored surface of the l cap and against the junk-ring by the pressure of the steam in the valve-chest, thus making the said surfaces in contact steam-tight.

The cap is. kept pressed against the steamtact-surfaces of the metallic packing-ring.

The pressure of the steam, when in the valve-- chest, against the annular area of the cap nextthe valve keeps the said cap firmly against the steam-chest cover, and thus reduces the area subject to pressure on the back of the valve. The same arrangement of the cap, junk-rin g, S-shaped spring, and metallic packing-ring, used either singly or in. duplicate, may be applied to a rectangular slide-valve. The said metallic packing-ring is cut through on one side, and is disposed so that the surface in actual contact with the internal bored parallel surface of the cap shall have a less area than the inside annular area of the said packingring, which is subjected to the direct pressure of the steam admitted behind thering, whereby I obtain an excess of expanding force tending to press the packing-ring outward against the internal bored parallel surface of the cap over that which tends to press it inward, and hence I prevent leakage. In conjunction with this action the steam also exerts a pressure which forces the reduced annular area of the packingring against the under or inner side of the projecting flange of the junk-ring. A segmental joint-piece, such as is hereinafter described, is to be placed across the joint in the packing-ring, in order to make good the joint and prevent leakage through the same.

And in order that my said invention maybe fully understood, I shall now proceed more particularly to describe the same, and for that purpose shall refer to the several figures on the annexed six sheets of drawings, the same letters of reference indicating corresponding parts in all the corresponding figures.

Figure 1 of my drawings represents a trans verse section of a sixteen-inch locomotive-engine cylinder with my improved slide-valve. Fig. 2 is a longitudinal vertical section of the same. Fig. 3 is a view 01' the back of the improved slide-valve, the cover of the valve-chest being removed; Figs. 4 to 7, detached views of parts of the valve.

A is the cylinder, which, with the exception of the steam and exhaust ports a a and I), and steam-passages, as hereinafter described, may be of the ordinary construction. 0 is my improved circular equilibrium slide-valve, which is of peculiar construction. It is left free to revolve during its travel within the clip or buckle D on the valve rod or spindle E, by which arrangement the relative surfaces of the valve and portfaces are continually varying, thereby preventing the formation of grooves, and consequently producing a greater uniformity of wear and a longer duration of both valve and port faces, whether worked as an equilibrium or as an ordinary valve. The circular slide-valve may be economically made by turning it up and facing it. In the lathe F is a junk-ring, (shown in detail plan in Fig. 7,) which is also turned in a lathe. This ring is fixed onto the back of the valve by a central bolt and nut, G. Above and around this junk-ring there is adjusted the loose cap H, also turned up and faced in the lathe, which cap slides against the face of the steam-chest cover, thereby preventing the pressure of steam or other fluids from acting on the area contained in the inside diameter of the cap H, in contact with the metallic packing-ring g.

A steam-tight metallic packing-ring is established between the junk-ring and the top of the valve and the inner parallel bored surface of the cap H by the interposition of the L-shaped packing-ring 9, (shown in detail plan in Fig. 6,) the said ring being forced outward, and at the same time forced against the under or inner side of the projecting flange of the junk-ring, so as to maintain a tight joint and prevent leakage of steam by the pressure of the steam in the valve-chest. When the steam is out of the valve-chest the cap H is held in contact with the steam'chest cover by the S-shaped spring I, (shown in section in Figs. 1 and 2, and in plan in Fig. 3,) which spring is placed centrally on a stud or tap turned on the end of the bolt G, while the extremities of its two arms, which are beveled or inclined, so as to fit the inner beveled or inclined surface of the cap, are made to press against such beveled or inclined surface, and, consequently, the horizontal and vertical tension of the spring forces upward the said cap. The said S-shaped spring can be cast either in gun-metal, iron, orsteel, or forged out of ordinary spring-steel, as may be required, and

is made larger in diameter acrossthe arms remaining arm still retains its elastic action both horizontally and vertically, as, the spring being bored out centrally to fit on the stud or tap turned on the end of the bolt G, it forms a kind of fulcrum for the action of each arm, so that one can work independently of the other. I have found it necessary in practice to make the metal of the metallic packing ring or rings 9 of the valve much softer than either that of the cap H orjunk-ring F-that is to say, if the cap H and the junk-ring F are made of gun-metal, the metallic packing ring 9 should be made of soft brass, so as to prevent the outer surface of the metallic packing-ring g from wearing or forming grooves in the internal parallel bored surface of the cap H, as well as in the surface of the projecting flange of the junk-ring F, by reason of the extension and compression of the rings while working. In the center of the steamchcst cover a pipe, K, is fitted, leading into the atmosphere, such pipe forming the vent for any steam that may escape between the cap H and the valve-chest cover, or may leak past the packing-ring g. A number of holes or radial slots are made round the edge of the junk-ring, as shown in Fig. 7, to allow of the I free escape of any steam that may momentarily leak past the surfaces of the metallic packing-ring when the steam first enters the valve-chest, and other openings are made through the cap H, such openings communicating with an annular groove or channel, h, Fig. 3, made in the sliding face of the cap, which groove or channel, in conjunction with other channels or sunk parts at t' i, also serves as a free vent for any steam that may leak behind the cap H when first put to work on the engine.

It will be seen, by referring to the plan, Fig. 3, that the clip or buckle D, surrounding the circular slide-valve G, is bored out, so as to be an easy fit over the back part of the valve, to allow the valve to rotate freely within it.

The semicircular ends of the buckle D are struck with the same radius as the diameter of the valve-face 0, each being struck from a separate center, for the purpose of giving a greater sectional area on the-longitudinal cen-' ter line, the section of which is shown in the longitudinal section, Fig. 2, so as to keep the buckle D from springing, and thereby allow the valve 0 to rotate freely within the buckle D during the reciprocal motion of the valve. A flat surface is provided on each side the total depth of the buckle D, so as to form a guide between the projecting surface h on each side of the steam-chest, to keep the valve (3 always central over the ports, and thus prevent any lateral motion of the buckle D by the rotation of the valve 0. These projecting surfaces h h are suitably faced on the inner side, and also serve to impart a rotary motion to the slide-valve when traveling without steam, by reason of the periphery of the face of the valve rolling against one or other ofthe said surfaces. The same rotatory motion of the valve 0 is also obtained when under steam, if one side of the valve-face orport-face should become dry for want of more lubrication than the other side, as a greater amount of friction will be caused on that part of the port-face or valve-face through a deficiency of lubrication, thereby creating a greater amount of cohesion between the parts in contact, and by the reciprocal motion of the val e 0 this excess of cohesion on one side of the valve-face over the other will cause the valve 0 to rotate in its buckle D, thereby causing a uniformity of wear between the surfaces in contact.

masas I a The following proportions of the acting surfaces of the metallic packing-ring g for a twelve-inch circular slide-valve constructed according to my invention will be foundto answer well in practice: The outer reduced annular area of the metallic packing-ring g in contact with the internal parallel surface of the cap H is about nine square inches, and the inner area of the metallic ring exposed to the pressure of steam in the steam-chest is about thirteen square inches, showing an excess of about four square inches for forcing the outer reduced annular area against the internal parallel bored surface of the cap H by the pressure-of steam in the steam-chest. The reduced annular area of the metallic packing-ring g on the upper side, next the junkring F, is about six square inches, and the area of the lower side of the ring, next the valve exposed to the pressure of steam in the steam-chest, is about seventeen square inches, showing'an excess of about ten square'inches for forcing the upper reduced surface of the ring against the projecting flange of thejnnkring F by the pressure of steam in the steamchest.

By these means I insure a perfectly tight contact, and thus prevent any escape of steam or other fluids past the said surfaces when working. The proportions will vary, and consequently the areas, according to the width, depth, and diameter of ring or rings adopted.

Fig. 8 of my drawings represents a transverse vertical section of an ordinary rectangular slide-valve, the back pressure on which is avoided or reduced by the application thereto of my improvements, consisting of the junk ring, cap, S-shaped spring, and metallic packing-ring, acting as hereinafter described. Fi 9is a corresponding plan or view of the back of, the slide-valve with the valve-chest cover removed, showing a duplicate arrangement of caps, one cap being in its working position, and the other cap removed. In cases where the rectangular slide-valve is nearly square, a single arrangement of cap, junk-ring, packing-ring, and S-shaped spring maybe used. 0 is the rectangular slide-valve, which is connected to thevalve-rodE by eyes D D, formed on the back of the valve, through which eyes the rod E is passed, and is secured therein by a'nut at one end, and a loose collar at the other, as shown in plan in Fi 9.

It will be seen that the valve-spindle E is flattened on the top side in the center part of the valve, as shown in section in Fig. 8, and in plan, Fig. 9, for the purpose of allowing thecaps to be placed closer together, and thereby obtaining a greater area for displacement of steam on the back of the rectangular valve, due to the inside diameter of the caps H, or, more strictly speaking, the line of contact between the outer diameter of'each metallic packing -.ring 9 and the internal diameterv of its cap H. A pair of junkrings, F F, are secured by means of the bolts Gr G to the back 'ofthe-valve, andincombination with each junk-ring there is provided a cap, H, and S'shaped spring I, and a metallic packing-ring, g, all arranged and op- .eratin g precisely as and for the purpose hereinbefore described in reference to the circular slide-valve. K K are the two ventpi1.)es, one for each junk-ring and cap, one of which I have also previously referred to.

When either the circular or the rectangular slide-valve is under steam, the steam in the steam-chest presses upon that part of the annular area of the cap or caps H next the valve,

which area is due to the difference of its inner and outer diameters 5 and as this annular area is greater than that on the top of the cap or caps H, which is outside the' annular channel or groove h h, Figs. 3 and 9, the steam consequently forces the cap or caps H tight against the steam-chest cover, and by the position and formation of the annular groove h h any steam-' pressure from small leakage, caused by the surfaces not accurately fitting one another when first put to work on the engine, is prevented from being realized on the additional wearing surfaces on the cap face pressed against the steam-chest cover, and contained within the annular channel or groove h, since such leakage will pass off by the channels 11 to the vent pipe or pipes K. The surfaces of the cap or caps H and steam-chest cover, after working-for a short time, will become perfectly tight.

Should. the spring I not force the surface of the cap-face tight against the surface of the steam-chest cover when the steam is shut off from the steam-chest, the moment the steam is readmittedinto the steam-chest the pressure of steam, acting upon the annular area of the said cap or caps next the valve, instantly forces the cap or caps against the steam-chest cover by reason of the annular area of the cap or caps next the valve being greater than the annular area on the cap-face pressed against the steam-chest cover, which is outside the annular groove h h. All leakage is carried off by the annular groove h h and sank parts t" i, and escapes through the-pipe or pipes K into the atmosphere, as shown on the drawings, Figs. 2 and 8, there being always a free communication through the pipe or pipes K to the atmosphere when the valve 0 is working. as an equilibrium slide-valve, thereby gaining the remaining area or areas contained within the groove h or passages t on the cap-face H for additional wearingsurface, and diminishing the friction and pressure per square inch between these surfaces. I thus increase the durability of the cap-face, as the total areas of the cap-face sliding on the steamchest cover are greater than the annular area of the cap H next the valve, 0, exposed to the steampressure in the steam-chest.

It will be seen from the drawings that the cap or caps H are kept central by their inner parallel part fitting over the junk ring or rings F, either on the circular or rectangular valves,.and are independent and free to have a rotary motion round the;

junk ring or rings F when traveling Wlbh out steam, especially on 1ocom0tive-engines,

since'one side of the S shaped springv will,

in practice, press one side of the cap orf caps H against the steam-chest coverwith a greater pressure than theother. By this means a greater amount of cohesion is produced between the surfaces. in contact, andby the reciprocal motion of the valve 0 this vexcess of cohesion on. one sideofi-theeap overv theotheriwill canse the caper, caps H to rotate aroundthe junk ring or rings F, thereby causing a uniformity of-wearbetweentheisur:

faces of thecapor caps H antlthe snrfaceof, the.

steam chest covert Thesa ne rotatory motion oti-the cap or caps H isobtained when, under steam, if one sigle of the cap or caps in contact with the steam-chest cover should become dry for-[want of lubrication, as at greater-amount; of friction is thereby cansedon that partof.

thecap or caps, thus .creatinga greater amount of 'cohesion between the partsin contact, and

byl thei reciprocal motion-of thevalve-O this 0f he J'uhhe he fines-1F wh -sure a a rJm Q m W f ar betw enh r hheh in, 1 act, hesz hapesi nrl le; ttin o e y onto 'a c'e'n max stud o tap tnrne 0n thehead hi otate thtthe cap or capstif required.

y y a ning ot e. l awiaFi e L'Ziahd 8, it will be seen. that,bytthe formation of the m hll tcopa khi zrih y eu perr hqedarea of the said ring is pressetl against. the, under side of he innihqt h eh e 9f; hei nk- 'gQF, istl s} he the r B PQ QfltQstedh, pressure on the du cegl external ar eav which. is".presseglagainst the inter'l allparallelbored: surface of themapv or ps. ;ian t thehie ll packih r'ih y' '9, hi h r lso; t h nes e is; a by owh had h theplah, F g- M6 0 mhh h r h h v, l fil w hh hhnlhv rabhet, orrecess, .onth-e top side. of the ring, as shown in I ig ti. The said segmentalpiece heteledt i htly lo i g n re l n th-and.

pth .7 n e thr id 9 at. i s r ht rhr length and depth shall, not, bear; against the.

hidh'lp ir le ir' hhelo -t e a r; ma

thereby. linsnring a uniform 1 contact between a he he b red h zhllel rface ollhhe th n a wllthe 'p h a t pf he u er" acted. area' ofthe paelringging, even should the surfaces. of" the port-face. and ,steam-cl 1est cover not be perfeetly parallellg As the segmental" p c 6 is P I ht a ihstt e,proi htih flangeofthe junk ring or rings F itv prevents any steam from escaping at thepar t Where, thecnt in thc ringg is;.made.- The holesor radial slotsin the edge of the junkring, (see Fig. 7,) for carrying ofl';any 'leakageof steam that may escapepast the surt'aces of the me tall ic packing ring or rings 9 throughthe pipe on one sidev over the other, ,;.0r..caps. torotate around the e ext-[ e alvell h;

;.K in the steam-chest-cover-to the atmosphere,

are so drilled. that the inner edges of these holes orslots are about three: thirty-seconds of an inch clear ofi the outside annular bearing:

snrfaee of the packing-ring, which is. pressed 7 pagalhe e nhoj ct ngh hne E he nj nk ring -o'r rings F, so; asto prevent any leakage; st mrp fi lh hr gh he-open ng o ut in the ring g andl whichlis .notcovered'by the;

segmental piece 0, before described, since, they said segmental piece e, only fills, the recess; =,w. hich is" turned. onv the side; of themetallic,

packing ring opringagnext the junkrring,

which .reeess will varyin, widthand depth acqr ihet he ize f h asl p hdh pr s-t e f: teele c n h h an ular m an cap or. caps H-next the valye will hold them h h h hstthe. eamz es o r n h pressnre, acting oathe larger annular area of;

metallic packingring .Or ringsg .next the valve will hold them also tight vagainst the-- inner snrfaceofi the projecting flange tot! the .i hhr n ing F, her by pro d n ain any ant Qf' hmlle i lh w enith -m ace and hwh hestlcqven othatby't ee'wl ra cal motion of the valve 0 the cap or cap slll ill when hemse resf y r; he-oh ertdim ete of v he, m l ic. packin ne-.o rlnesa and:

hus.ac mihosl ta hms lv w l y n f parallel x' i w i hay e i tvbQtw-eeh he fhhesl f he ot lhqeahs the tea s h stchw er, hereby I reyeh lh t he rface flz h.ecan=- 1 org-cap H mz e hg sp eed fromrthe surhhe t z he teahh hestcqy r, nd mut ng-Y ht.p ht ct betwchh 1 t e-s escr ed: a. t wi lobe-see ,nnlrh er inette ha rhn n st he ir u ar.v m t hhtah hlan slideal s hetbh .areal-0ni heba wft he-twelve new h m;ihu her= map w e t nh er-v i h ,ohthe cap =or.caps.-H,or, more strictly. 9%.. he;l l qualzt the rQabQuQd Qby h contaet betw. en,;t e outerrdian eter ot'o @QIQQ- pqu, y hepres 9. th e hal ht no a h t L; nthl ihh w n j rill, ;ohr u hy and. the. n e

P T YlSlQh m l n omp esh o n h y u1 6 3- hifllllOQIItDlffiiQ ihhhhhhdab h M l v-F mi a-Ory-an vafifi lll l lfl lq o ldfihsetl; water.infthecylintler when.- the engine is first: u s arted, :h a lQa iwh i i g allewedhetsgeem th t p w th? i nkw ngl hslt e derhlde; of the cap or capsH, alsobetyveenthz.top-side;

of .the valve Q anti/the lower annular edge- 0f he whic or-wps- -hepressure o st amr nt hem-s h h-hh st, acbl hn h-n a o er 1 m l, ?@:-.0 he iw ps ext the v lv will hol he hldi niorv ap fight ainst-- the steam-chest. cover, so that when; comprem onto theport-tacewithontmoving the surface;

.hl ihh eteh f;,thecan awn H-r t l lso-whee ,Figs- ,1, 2 nd v8, hat her is t of the cap-face H from the surface of the steam-chest, cover, thereby preventing the surface of the cap or caps H from being displaced from the surface of the steam-chest cover, and insuring a tight contact between the surfaces described.

It will be seen, on referring to the drawings, that in my improved slide-valves there is no communication between that portion of the back of the valve inclosed by the cap or caps H and the exhaust-port b in the port-face of the cylinder for the passage of any leakage that may take place from defects in the surfaces of the cap or caps H and metallic packing ring or rings 9 into the exhaust, as this leakage would pass through the pipe or pipes K into the atmosphere; but should there be any such leakage as would cause a waste of steam from the'engine, the attendant, by closing a tap or taps attached to the pipe or pipes K in the steam-chest cover, allows the pressure of the steam escaping from the steamchest to be exerted on that portion of the back of the valve inclosed within the cap or caps H, thus reducing the valve for the time being to an ordinary slide-valve.

In a rectangular valve, (J, supposing one tap only to be closed from the causes before described, the inclosed area within the cap H would be acted upon by the pressure of steam in the steam-chest; but if both taps were closed from the causes before described, the pressure of steam would act upon the back of the valve in the same manner that it would with a slide-valve of the ordinary construction. Thus, it will be seen that under the most unfavorable circumstances (as in case of accidents) my improved equilibrium slidevalves can never become more objectionable than the ordinary slide-valve at present in use, as they can either work as equilibrium or ordinary valves until an opportunity can be obtained for rectifying any part or parts that may have become deranged, thereby insuring their certainty of working, in all cases and on all classes of engines, either as equilibrium or ordinary slide-valves.

The advantages to be derived from the adoption of my peculiar circular equilibrium slide-valves, compared with the rectangular valves now in ordinary use, maybe exemplified to a certain extent by taking a circular valve of twelve inches diameter, as shown in Figs. 1, 2, and 3, containing an area of about one hundred and thirteen square inches on the back of the valve, having steam-ports for admitting steam on the lead, fourteen inches in length, with an area of about thirteen square inches, the area of the exhaust-port being about thirty-seven square inches. The rectangular valve now in use, which is taken as a comparative example, is sixteen inches long and nine and three-fourths inches wide,

having an area on the back of the valve of one hundred and fifty-six square inches, with steam-ports only thirteen and a half inches in length, about eighteen square inches area, the exhaust-port being about thirty-seven square inches area.

On comparing the above dimensions it will be seen that my circular slide-valves steamport is half an inch greater in length on the lead or opening than the rectangular one, with an area of about forty-three square inches less on the back of the valve to be acted on by the pressure of the steam in the steamchest, which diminishes the power required for working it as compared to an ordinary rectangular slide-valve of the dimensions given, at the same time gaining, where most required, a large amount of steam-supply to the cylinders, as well as economizing its consumption by reason of the formationof the ports through diminishing the width and length of the steam-passages into the cylinder.

I make no claim in this application to the arrangement of ports shown in the drawings, as this feature forms the subject of a separate application for Letters Patent 5 but I claim- 1. The combination of the reciprocating frame D and the valve 0, having a lateral hearing, by" frictional contact with which an intermittent rotation is imparted, as described.

2. The combination of the valve 0, loose ring H, sliding in contact with the top of the valve-chest, ring F, secured to the valve, and an L-shaped packing-ring, g, bearing upon the rings F and H, substantially as and for the purpose set forth.

3. The packing-ring H, groove h, and channels c i, and recesses communicating with the groove, as and for the purpose-set forth.

4. The combination of the valve-ring H, having a beveled inner edge, and spring I, bearing against said beveled edge, substantially as set forth.

5. The combination of the valve 0, ring F, and metallic packing-ring g, confined between the two, and reduced to diminish its bearing on the ring F, as set forth.

6. The combination, with the L-shaped packing-ring g, adapted to bearing-surfaces at right angles with each other, of the overlapping segmental piece 6, filling the recess or rabbet on the lateral side of the Lshaped ring, all as set forth.

In witness whereof I have'signed my name to this specification in the presence of two subscribing 'witnesse's.

WALTER CHARLES CHURCH.

Witnesses:

OHAs. thus,

47 Lt'ncolns Inn Fields. FREDK. O. DYER,

47 Lincolns Inn Fields.

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