US2401545A - Throttle valve control - Google Patents

Description

c. R. BRIGGS THROTTLE VALVE CONTROL 2 Sheets-Sheet l Filed Feb. 17, 1944 1HE, E

June 4, 146. c. R. BRIGGS THROTTLE VALVE CONTROL Filed Feb. 17, 1944 2 Sheets-Sheet 2 y IVENTOR. CARL I?. BR/qs.

5% mi@ v Y ATTORNEYS.

Patented June 4, 1946 THRO'ITLE VALVE CONTROL Carl R. Briggs, Mantua, Ohio Application February 17, 1944, Serial No. 522,705

7 Claims. 1 The invention relates to steam engine valve mechanism and more particularly to throttle valve mechanism.

One object of the invention is to provide novel and improved throttle valve means for admitting steam, or other iiuid power medium, to the engine valve chest and constructed and arranged to be smoothly, positively, and readily cracked in the presence of maximum boiler pressure. Another object is to provide a throttle valve, prefern ably of piston form, which is statically and dynamically balanced in all positions in such manner that it is readily operated manually so as to seat or unseat or for graduating adjustment despite the opposed head of pressure in the boiler. Another object of the invention is to provide novel mechanism of the nature indicated, readily adapted to an improved lubricating means and method.

Further objects of the invention in part are obvious, and in part will appearmore in detail hereinafter.

In the drawings, which represent one suitable embodiment of the invention V Fig. 1 is a sketch, in outline, of the housed assembly of a throttle control, a valve chest and power cylinder.

Fig. 2 is a central longitudinal section of my improved throttle valve assembly in its housing.

Fig. 3 is a fragmentary section showing a portion of the left end of Fig. 2, some parts being in a different operating position.

Fig. 4 is a top plan view of the apparatus shown in Fig. 2.

Fig. 5 is a side elevation of the perforated bearing sleeve.

Fig; 6 is an end view of the sleeve shown in Fig. 5.

With reference to the following description of a preferred embodiment of my invention, the power cylinder and main valve chest of the steam engine are not shown in detail since they may be of conventional design, although I prefer to use a main valve system of the character illustrated and described in my copending application, Serial No. 517,215, filed January 6, 1944, which application may be referred to, if desirable or necessary, for a more particularized description of said main valve chest and cylinder. The present invention is devoted solely to a control for the throttle valve, one manner of disposition of said valve and control with respect to the steam chest and cylinder being shown in outline in Fig. 1.

Those skilled in the art are familiar with the effort Vwhich must be exerted to crackthe throttle valve of a steam engine manually, since in many throttle Valve arrangements previously regarded as efficient and practical, opening movement of the valve is opposed by the pressure from the steam head. The effort thus required makes it difficult to open the valve with those preliminary gradual increments so necessary for smooth starting, especially since with the usual valve type, such as a poppet valve, the first incrementY of unseating motion is against practically full fluid pressure. The invention now to be described permits cracking of the valve by normal manual effort, either rapidly or slowly as needed, and aiords positive control of minute increments of pressure change, in a manner substantially iinproved over throttle valves heretofore available.

With particular reference to Fig. 2, the pre-n ferred embodiment of my invention comprises a housing I5 having a cylindrical bore or chamber I6l for the reception of `a reciprocable throttle valve. The housing is provided with a steaminlet port I1 and an outlet port I8. The inlet port, which is in communication with a steam supply (not shown) may be provided with an inlet Valve or check 'valve I9, seating toward the engine, and the outlet port I8 is in communication with the main steam chest 25. `In the embodiment shown I have provided inlet valve operating means` comprising a lever 23, operated, as will be described, by the reciprocable throttle valve, and disposed to open the aforesaid inlet valve I9. 1' have also provided operator cperatable means 24 formoving the throttle valve.

The reciprocable orslidablethrottle valve member is in certain structural respects similar to the piston valve shown inmy aforesaid copending application, Serial No. 517,215. It consists of a pair of matched and balanced pistons 25 and 25a aflixed atspaced points to the piston rod 2t which conveniently may be 'an extension ofthe operating rod 24, or is operatively connected thereto.` Pistons 25 and 25a are simultaneously slidable to the left or right (Fig. 2) `in bearing sleeves or linings 2| and Zia respectively, the sleeves being fixed with respect to .the cylindrical wall of chamber it. The operating rodfzcl passes through a centrally disposed aperture in the end wall 27 of the housing I5, being packed by a con ventional stuffing box assembly 28.

The piston rod 2t has been diametrically rei duced in successive steps 26a, 26h, 26e, from left end to right end (Fig. 2) to facilitate assembly thereon of the parts now to be described. Pis

piston comprises a stationary head 30 seated against a rigid collar 33 on the left end of the rod, and an adjustable head 32 slidable on the rod and adjustable by a nut 3| capable of rbeing locked. The several elements of the piston just described, as well as of piston 25a, and of cam 49 (later to be described) are assembled from the right end of the rod over operating stem 24 as will be understood from an vexamination of Fig. 2. Heads 30 and 32 are provided with telescoping sleeves 34 and are normally urged apart by a spring 35. In the cavity or space between the heads are mounted suitable resilient split sealing piston rings 36 outwardly expansible against the bearing sleeve 2| which provides the necessary sealing or bearing face. To support the sealing rings 33 and provide additional resiliency I have provided suitable spring backing means, which, in the embodiment illustrated, comprises a wide split ring 31, although two or more may be arranged concentrically one within the other. The :nut 3| is-adjusted to advance head 32 towards head 30 until the assembled parts are in operative relationship, due regard being had to the rise in temperature occasioned by contact with the steam. In such operative relationship the rings have a close mutual fit, but contracting surfaces are readily slidable on each other. On

each piston, that head which is presented to the livesteam (head 32 in vthe form shown) is provided with a small port or opening 40 to permit access of full steam'pressure to the cavity within the piston so as to equalize the pressures internally and externally of the rings.

n The inlet port I'I may be provided with Valve means responsive to movement of the piston-like throttle valve. Such valve means is shown in Fig. 2. The inlet valve I9, here shown as a poppet valve, is seated at 42, in the steam line between intake port I'I and the chamber I6 of housing I5, and is biased to normally closed position both by a'spring 44 and by the head of steam pressure transmitted through port I1. The

left position. It will be immediately obvious that when the piston is moved to the left, the steam outlet area is increased by increments as each successive aperture 53 is uncovered by piston 25.

From the foregoing description it is apparent that the steam pressure transmitted to the main valve chest may be increased or decreased by definite and minute increments by simple sliding motion of the throttle valve operating rod.

Operation of the device is apparent from the preceding description but may be brieiiy out, .lined as follows.

Assuming` the parts to bein the position shown in Fig. 2,'the inlet valve I9 is Y ing on the spacing of the annular groove 52 with.

stem of the valve I9 extends downwardly into chamber I6 between pistons 25 and 25a, where it abuts an operating lever 23,- pivoted at one end 45 in the bifurcated head of a stud 4'|, secured in the housing I5. The free end of the lever has a curved or beveled end face 48 adapted to be operatively engaged by a suitable cam portion l49 of rod 26. Movement of the piston assembly to the left interengages the respectively cooperating cam portions 48v and49 vof lever 23 and rod 23 and initiates an upward swing of lever 23, producing immediate abutment of'an intermediate portion of the lever against the free end of valve stem 45 so as to unseat the inlet valve and admit steam to chamber I6'. The rela-V means to prevent deflection of rod 26, the means in the embodiment shown consisting of a stud 50 adjustablyA seated in a boss,`i`n the bottom of housing I5, in such manner that its free upper end contacts the under side of rodg26. If desired the contacting surface portions of stud and' rod may be suitably shaped to provide a bearseated, and the engine is at rest. Port I1 is in communication with a head of steam. The operator moves operating rod 24 to the left so that cam follower 48 begins to ride up on cam track Y 49 as the piston valve assembly begins to move,

thereby initiating opening movement of -the inlet valve to admit steam to chamber IB. At the same time, or as soon thereafter as desired depend respect to the lapping peripheral face offpiston 25, the apertures 53 are successively uncovered...

permitting v steam in chamber I5 to leave by port I8 and thence enter' the main valve chamber. At full open throttle (liig) all apertures 53ers Y uncovered.

I have also provided a novel and improved lubricating system especially adapted for use withr apparatus of the character described'. Aclearance space 6I)v at the left end of'housing I5 is in communication with thevlike space 60a at the right end, through a conduit 6I running from port 62 to a port' 62a. A T connector 63 leads to a source of lubricant (not shown) Movement of the piston assembly to the left transfers excess lubricant through conduit 6| to space 60a, the excess being returned to space 6I) over the same path when the piston movement is reversed.

The rings 36 serve as leak proof barriers between the steam space 43 'and the' clearance spaces 60 and 60a. 1 Y Y The whole apparatus herein described and illustrated is simple and sturdy, and the balanced' character of the moving parts, permits easy and smooth operation of the main throttle valve', supplementing the same with an auxiliary gate valving effect if desired. The construction is durable and efcient in operation. Other advantages willl be apparent to those skilled: in the art.

What I claim is:

1. Throttle mechanism for controlling the flowY operating rod extending `to the outside ofthe chamber for operation thereof, said device comprising two pistons spaced upon said rod, one on either side of said inlet port, an internal surface portion of said housing near one end being provided with an inwardly opening peripheral channel, a cylindrical sleeveA overlying, said channel and having ,its inner surface engageablewith the with respect to the longitudinal axis oi Ysaid,

sleeve, said channel being in communication with said outlet port whereby movement of the last said piston in one direction within said sleeve successively uncovers each of said apertures, so,

as to permit passage of steam from said chamber through said outlet port and into said valve chest in progressive increments, and `wherebyreturn movement of said piston successively seals said apertures,` and progressively cuts off steam from said outlet port, an inlet valve in said inlet port, a lever; pivotally carried within and by said housing and having a portion thereof operatively engaging said inlet valve, and having another portion thereof operatively engaging saidpistonlike valve means, whereby movement of said piston like valve means in one direction causes opening movement of said inlet valve.

2. Throttle mechanism for controlling the ilow of steam to the valve chest of a steam engine, comprising a housing having a cylindrical chamber provided near one end with an outlet port in communication with a valve chest, and, intermediate its ends, with an inlet port in communication with a steam supply, a piston-like valve device slidable in said chamber and including an operating rod extending to the outside of the chamber for operation thereof, said device comprising two pistons spaced upon said rod, one on either side of said inlet port, an internal surface portion of said housing near one end being provided with an inwardly opening periph- 4eral channel, a cylindrical sleeve overlying said channel and having its inner surface engageable with the sliding ycylindrical bearing face of one of said pistons, said sleeve being provided with a plurality of peripherally spaced apertures in communication with said channel, and helically disposed with respect tothe longitudinal axis of said sleeve, said channel being in communication with said outlet port whereby movement of the last said piston in one direction within said sleeve successively uncovers each of said apertures, so as to permit passage of steam from said chamber through said outlet port and into said valve chest in progressive increments, and whereby return movement of said piston successively seals said apertures, and progressively cuts off steam from said outlet port, a poppet valve in said inlet port having a depending stem, a lever pivotally carried within and by said housing, and having a portion thereof adjacent the pivot point in engagement with said valve stem, the free end of said lever operatively engaging said piston-like valve means whereby opening movement of said piston-like valve means produces opening movement of said poppet valve.

3. Throttle mechanism for controlling the flow of steam to the valve chest of a steam engine, comprising a housing having a cylindrical chamber provided near one end with an outlet port in communication with a valve chest, and, intermediate its ends, with an inlet port in communication with a steam supply, a piston-like valve device slidable in said chamber and including an operating rod extending to the outside of the chamber for operation thereof, said device com- 6 prisms two pistons spaced upon Saidrodmne on eitheruside otsaid inlet port, an internalsurface portion of, said housing near one endbeing provided with an inwardly opening `peripheral channel, a cylindrical sleeve overlying said channel and having its inner surface engageable with the sliding cylindrical bearing face of one of said pistons, said sleevefbeing, provided `with a `plurality of peripherally spaced apertures in communicationwith said channel, and helically disposed with respect to the longitudinal axis of said sleeve, said channelbeing in communication with said outletfi'neanswhereby movement of the last saidgpistonin one `direction within4 said sleeve successively uncovers each 0f saidfapertures, so as to permit passage of steam from said chamber through said outlet port and into said valve chest in progressive increments, and whereby return movement of said piston successively seals` said aperturesL and progressively cuts oi steam from said outlet port,"an inlet valve in said inlet port, a lever pivotally carried within and by said housing, and having a portion thereof operatively engaging saidV inlet valve means, and said pistonlike valve means and said `lever having mutually engageablecam-.like elements whereby movement oflsaid piston-like valve ,means in, one direction produces engagement of said cam-like elements, and causes opening movement of said inlet valve.

4. Throttle mechanism for controlling the flow of steam to the valve chest of a steam engine, comprising a housing having a cylindrical chamber provided near one end with an outlet port in communication with a valve chest, and, intermediate its ends, with an inlet port in communication with a steam supply, a piston-like valve device slidable in said chamber and including an operating rod extending to the outside of the chamber for operation thereof, said device comprising two pistons spaced upon said rod, one on either side of said inlet port, an internal surface portion of said housing near one end being provided with an inwardly opening peripheral channel, a, cylindrical sleeve overlying said channel and having its inner surface engageable with the sliding cylindrical Vbearing face of one of said pistons, said bearing face comprising a plurality of resilient, expansible piston rings, spring biased outwardly to contact with said sleeve, and said piston having a cavity therein communicating with the steam supply whereby sealing contact between said bearing face and said sleeve is augmented, said sleeve being provided with a plurality of peripherally spaced apertures in communication with said channel, and helically disposed with respect to the longitudinal axis of said sleeve, said channel being in communication with said outlet means whereby movement of the last said piston in one direction within said sleeve successively uncovers each of said apertures, so as to permit passage of steam from said chamber through said outlet port and into said valve chest in progressive increments, and whereby return movement of said piston successively seals said apertures, and progressively cuts oilE steam from said outlet port, an inlet'valve in said inlet port, a lever pivotally carried Within and by said housing, and having a portion thereof operatively engaging said inlet valve means, and said pistonlike valve means and said lever having mutually engageable cam-like elements whereby movement of said piston-like valve means in one direction produces engagement of said cam-like elements, and causes opening movement of said inlet valve.

5. Engine throttle valve mechanism compris- 7 ing avcasing provided with a cylindrical charnber-,an operating rod extending along the Vaxis of said chamberand through an opening in one end offsaid casing, two pistonsspaced apart on said rod and slidable in said chamber by rod motion, one thereof serving as a valve, said casing being provided with a uid supply opening between said pistons and with a fluid discharge opening near one end, inlet valve means controlling the ilow of iluid through said supply opening,` a lever pivotally carried within and by said chamber, and

having av portion thereof operatively engaging'saidl rod between said pistons, whereby movement of said operating rod causes opening movement ofsaid inlet valve.

6. Engine throttle valve mechanism comprising a casing provided with a cylindrical chamber, an'l operating rod extending along the'axis of said chamber and through an opening in one end of said casing, two pistons spaced apart on said rod and slidable in said chamber by rod motion, one thereof serving as a valve, said casing being provided with a fluid supply opening between said pistons and with a -iiuid discharge opening near one end, inlet valve means controlling the flow 25 of .fluid through said supply opening, a lever pivotally carried within and by said chamber, an inclined cam like surface rigid with said rod ben tween said pistons, Vsaid lever being operatively ing a casing'provided with a cylindrical chamber, ari operating rod extending along the axis of said chamber and through an opening in one end of said casing, two pistons spaced apart on said rod and slidable in said chamber by rod motion,V one thereof serving as-a valve, said casing beingl provided with a uidsupply opening between said pistons and with a Huid discharge opening near oneend, inlet valve -means controlling'thev ilow of Vfluid through said supplyopening, a lever piv-v otally carried within and by said chamber, an inclined cam like surface rigid `with said rod between said'pistons, said lever being operatively engageable with said cam like surface whereby move-- 20T ment of said operating rod causes opening movement of said inlet valve, means carried by the interior wall of said chamber, and abutting the surface of said rod between said pistons, and slidably engageable with the rod surface in diametric opposition to said cam like surface to prevent deiiection thereof during operation.

CARL R. BRIGGS.

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