US1786918A

US1786918A - Relief valve

Info

Publication number: US1786918A
Authority: US
Inventors: Ranck Edward Bruce
Original assignee: Individual
Current assignee: Individual
Priority date: 1928-05-16
Filing date: 1928-05-16
Publication date: 1930-12-30
Anticipated expiration: 1947-12-30

Description

uec. 30, 1930. RANCK 1,786,918

RELIEF'VALVE Filed May 16. 1928 s Sheets-Sheet 1 Patented Dec. 30, 1930 V UNITED STATES EDWARD BRUCE RANCK, or ALTOONA, PENNSYLVANIA RELIEF VALVE Application filed May 16,

This invention relates to relief valves for steam engine cylinders, and particularly to such valves for the cylinders of locomotives.

It is a general object of the present invention to provide a novel and improved (iiorm of relief valve for steam engine cyliners.

More particularly it is an object and feature ofthe invention to arrange a relief valve for an engine cylinder substantially entirely within the cylinder head.

The relief valve of the present invention is of the type wherein the pressure within the cylinder opposes that'from the boiler applied over a larger area, so that only excessive cylinder pressures, resulting from high compression or condensation will be effective tounseat the valve. .The boiler pressure may be applied directly from the boiler or from the drypipe, in which latter case it drops ofl to zero when the throttle is closed, and for this reason resilient means are provided to maintain the valve on its seat at such times.

'The present invention is particularly illustratedand described as appliedto a railway locomotive, although it will beobvious to those skilled in the art that it maybe applied with equal facility to almost any type of steam cylinder, and it isthe intent of the claims to so cover the invention. Features of novelty not specifically referred to will be apparent to those skilled in the art upon a consideration of the accompanyingdrawings and following specification, wherein are disclosed two exemplary embodiments of the invention, with the understanding, however, that such changes may be made therein as fall within the scope of the appended claims, without departing from the spirit of the invention.

In said drawings:

Figure 1 is a side elevation of a cylinder and valve assembly of a locomotive showing relief valves constructed according to the present invention applied thereto;

Figure 2 is a front elevation thereof;

Figure 3 is a longitudinal vertical section through a .reliefvalve and the associated portions of; the cylinder;

1928. Serial No. 278,223.

' Figure 4: is. a horizontal section on line H of Fig. 3; I

Figure 5 isa vertical section on broken 5-5 of Fig. 3;

Figure 6' is a view similar to Fig. 1 but 1 showing a different live steam piping ,arrangement; and

Figure 7 is a front elevation of the modification shown in Fig. 6.

Referring first to Figs. 1 and 2, there is disclosed at lOthe cylinder of a. locomotive having the cylinder heads 11 suitably applied thereto. Above the cylinder is the valve chamber 12 preferably formed integral with thesteam chest 13, having the flanged f3 pipe 14 adapted'to'be' connected to the customary drypipeor other means of supplying steam to the cylinder. Each cylinder head isprovided witha relief valve, generally indicated at 15, arranged at 'substan-i. tially the lowermostportion of the head and housed therein. The valve proper is best shown in Figs. 3, 4 and 5.

The cylinder head 11 is secured to the end line - of the cylinder in'the customary way by the studs 16. The head construction departs slightly from the customary so that it includes, preferably integral therewith, a chamber 17 divided into the

compartments

18 and 19 by means of suitable partition'walls and. the sleeve later to be described. This chamher has as its outer wall the outer wall of o the cylinder head, and as its inner wall the sloping partition wall 20, which maybe of such shape as to conform to the usual piston configuration, so as not to unduly increase the clearance. The top wall 20 closes the chamber. In the connecting rod head, space "is readily found surrounding the piston rod packing for this chamber. The front head imposes no limitations on its form. The sleeve above-referred to is indicated at 21 andis a cylindrical tube formed of suitable metal having the peripheral flange 22 at its outer end adapted to abut against the outer surfaceof the cylinder head. This flange is more or less rectangular and is head. The studs may conveniently pass through the flange 24 on the spout 25 which projects out from the cylinder wall and serves to deflect downwardly any liquid which may be ejected from the valve, to thus hold the spout in position.

As before stated, the sleeve 21, together with the rear wall 20 and the walls 26, divides the chamber in the cylinder head into two parts. The compartment 18 is partially above the sleeve and opens into the rear end thereof and is adapted to be supplied with live steam. The compartment 19 is in communication through the ports 27 with the interior of the cylinder. Between the outer end of the sleeve and the front end of the wall 26 the sleeve is provided with a plurality of ports 28 which place the compartment 19 in communication with the interior of the sleeve. It will thusbe seen that'the sleeve is the separating means which divides the chamber 17 into the

compartments

18 and 19, and forms the sole communicating passage between these compartments. Communication, however, is prevented, in the complete valve, by means of the piston 30 having an operating fit in the sleeve.

The piston is preferably an integral casting, hollow as shown and having at its inner end the portion 31 forming a steam-tight sliding fit with the sleeve and at its outer end the reduced tubular portion 32. A head 33 closes this reduced portion and has a circumferential chamfered surface 34: which is adapted to engage with a seat 35 formed at the outer end of the sleeve on the inwardly turned flange 36. When this head engages the seat it closes off communication between the compartment 19 and the atmosphere, but when open allows steam from within the cylinder to pass through the

ports

27 and 28 and thence out to the atmosphere through the spout.

When in its seated position the piston does not interfere with the passage of steam through the ports 28 by virtue of its reduced diameter at the outer end. A coil spring 37 is housed in the reduced portion of the piston and its rear end abuts the wall 20 and is seated in a recess 38 therein and normally holds the head against the valve seat. The rear end of the spring is prevented from distorting by the ribs 39 formed integral with and proiecting inwardly from the part 31 of the piston. I

In operation, steam is supplied to the compartment 18 at a pressure at least as high as that in the cylinder and is effective over the total area of the inner face of the piston to thus maintain the head 33 seated against the seat on the sleeve. Steam from within the cylinder acts on the annular area 40 of the piston equivalent to the difference in area of the whole piston and that of the reduced diameter portion thereof. The head of the that tending to open the same, but on the occurrence of excessive pressure within the cylinder for any of the well known reasons, the valve will be opened, for the cylinder pressure would be sufliciently greater than that of the live steam in the compartment 18 to overcome the differences of piston areas to thus move the piston and open the valve.

As shown in Figs. 1 and 2, steam for the compartment 18 is obtained by means of the pipe 41 from the dry pipe 14 or some part of the steam system on the cylinder side of the throttle. This means that under operating conditions the pressure in the compartment 18 is at least as great as, and probably always greater than, that in the cylinder, due to the throttling action of the cylinder valve. hen the locomotive is standing or when the throttle valve is closed as under certain coasting conditions, there Will be no pressure in the compartment 18 and the spring 37 will maintain the valve seated and prevent the same from acting as a drifting valve. This seating action will be assisted by the cylinder vacuum acting on the annular area 40 of the piston.

Under some circumstances it may be desirable to supply steam directly to the compartments 18 without having the throttle valve interposed and in this case the steam may be conveyed directly from the steam dome by means of the pipe M as shown in Figs. 6 and 7 This pipe may branch at 45 so as to supply both sets of cylinders. Pipes 46 lead from the branch pipes to the opposite ends of the respective cylinders and connect to the relief valves.

The valve of the present invention is extremely compact and adds but few parts to the cylinder construction. It is very effective in operation and can be made quite large in diameter without becoming cumbersome or without being in the way so that there will be no question of its ability to handle any quantity of condensed liquid which may be in the cylinder in a sufliciently short space of time to prevent any damage on the starting of a cold engine.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a steam engine, in combination. a cylinder, a cylinder head, a chamber in said head, a lining sleeve passing into said chamber to divide the same into two compartments, means to supply steam at substantially boiler pressure to one of said compartments, means connecting said other compartment with the space in the cylinder, a piston slid able in said sleeve and having oppositely disposed faces exposed one to each compartment and a valve between said cylinder connected compartment and outside of said cylinder, said valve being controlled by said piston.

2. In a steam engine, in combination, a cylinder, a cylinder head, a chamber integral with said head, a sleeve passing thru the outer wall of said head into said chamber and dividing the same into two compartments, one connected to the cylinder space, means to supply steam at substantially boiler pressure to the other compartment, the outer end of said sleeve being open to atmosphere, a valve seat adjacent the open end, a piston operable in said sleeve, and exposed on opposite facesto the respective pressures in said compartments, means on said piston to cooperate with said valve seat and to reduce the area of piston exposed to cylinder pressure and means providing communication between said compartment connected to the cylinder and the interior of the sleeve adjacent said valve seat.

3. A water relief valve for a steam engine cylinder including, in combination, a chamber in the head of said cylinder, means dividing said chamber into two compartments, a passage connecting said compartments, a piston slidable in said passage, means connecting one compartment to steam at substantially boiler pressure, means connecting said other compartment to the interior of the cylinder and to atmosphere, a valve normally closing said atmospheric connection, said valve being operatively connected to said piston.

4. A Water relief valve for a steam engine cylinder, including in combination, a chamber in the head of said cylinder, means including a sleeve dividing said chamber into two compartments connected only thru said sleeve, means to supply steam to one of said compartments, means connecting said other compartment to the interior of said cylinder, a piston in said sleeve having a larger area exposed to said first compartment than said second, a passage from said second compartment to atmosphere and valve means actuated by said piston to normally close said passage.

5. A water relief valve for a steam cylinder, including in combination, means forming a chamber having an inlet from said cylinder and an outlet, a piston movable adjacent said chamber, a projection onsaid piston to normally close said outlet, the difference in area of said piston and projection being exposed to the pressure within said cylinder and means to apply steam pressure to the whole area of said piston opposite said proj ection to maintain said projection in normal position.

6. A water relief valve for a steam cylinder, including in combination, a cylinder head, a chamber formed in said head, an open ended sleeve passing thru an outer wall of said chamber and into the chamber to divide the same into two compartments, one opening into the inner end of said sleeve, a valve seat adjacent the outer end of said sleeve, ports thru said sleeve inwardly of said seat and leading to said other compartment, a piston in said sleeve between said ports and inner end, an extension on said piston adapted to co-operate with said valve seat to cut off communication from said ports to atmosphere, means to supply live steam to said first mentioned compartment,

said other compartment being in commumcation with the interior of said cylinder.

7. A water relief valve for a steam cylinder, including in combination, a cylinder head, a chamber thereon, a sleeve passing into said chamber and dividing the same into two compartments, one in communication with the inner end of said sleeve, a valve seat at the opposite end of said sleeve, a port thru said sleeve intermediate its ends leading to said other compartment, a piston in said sleeve between said port and inner end, and means movable by said piston to engage said valve seat and close said sleeve, said means reducing the effective area on the port side of said piston.

8. A water relief valve for a steam cylinder, including in combination, a cylinder head, a chamber thereon, a sleeve passing into said chamber and dividing the same into two compartments, one in communication with the inner end of said sleeve, a valve seat at the opposite end of said sleeve, a port thru said sleeve intermediate its ends leading to said other compartment, a piston in said sleeve between said port and inner end, means movable by said piston to engage said valve seat and close said sleeve, said means reducing the effective area on the port side of said piston, and a spring to retain said means against said valve seat when there is no steam pressure on said piston.

9. The combination with a steam cylinder head, of a steam chamber formed therein, a sleeve dividing said chamber into two compartments one connected to each end of said sleeve, a piston in said sleeve, a valve seat at one end of said sleeve and a valve member actuated by said piston to normally rest on said seat.

10. The combination with a steam cylinder head of a compartment formed in said head,

a sleeve in said compartment and passing through a wall thereof to atmosphere and ED'WARD BRUCE RANGK.