US2387363A - Automatic valve mechanism - Google Patents

Description

Oct. 23, 1945. c. M. TERRY AUTOMATIC VALVE MECHANISM Filed June 17, 1943 CHARLES M TERRY Patented Oct. 23, 1945 AUTOMATIC VALVE MECHANISM Charles M. Terry, Decatur, Ill., assignor to A. W. Cash Company, Decatur, 111., a corporation of Delaware Application June 17, 1943, Serial No. 491,100

8 Claims.

This invention relates to automatic valve mechanisms, and more particularly to the construction and arrangement of a valve which will operate to maintain a substantially constant drop in the pressure of the fluid traveling therethrough.

In certain installations of oil cooling equipment there is need for an automatic valve for use in a by-pass line. The viscosity of oil varies greatly with its temperature, and if an oil cooler is designed for a normal pressure drop of say eleven pounds, it will be found that when starting up with the oil cold the pressure drop may run as high as forty or fifty pounds. This high pressure drop may be avoided by allowing a considerable portion of the oil to by-pass the cooler through a suitable valve, which should preferably open automatically to the required extent.

It is accordingly one object of the invention to provide an automatic valve mechanism of simple, inexpensive and dependable construction which will restrict the flow of fluid in such a manner as to maintain a substantially constant drop in the fluid pressure. v

It is a further object of the invention to provide an automatic valve mechanism arranged to respond to variations in a fluid pressure diilerential and so constructed as to operate steadily without surging or fluttering.

It is a further object of the invention to provide an automatic valve mechanism arranged to respond to changes in the pressure drop across the valve and so constructed that a slight increase in the said pressure drop will cause the valve to open to a comparatively large extent.

It is a further object of the invention to provide an automatic valve mechanism arranged to maintain a substantially constant drop in the fluid pressure and capable of handling fluid at a rate of flow which is very high in proportion to the size of the mechanism.

With these and other objects in view, as will be apparent to those skilled in the art, the invention Fig. 4 is a fragmentary sectional view showing a further modification.

The embodiment illustrated comprises a hollow body or casing I0, preferably of integral construction, which is divided internally by a partition II to provide an inlet chamber I2 and an outlet chamber I 4. The body I0 is provided on opposite sides with external openings l5 and it which communicate with the inlet and outlet chambers respectively, these openings being surrounded by flanges ll so that the body may be readily connected to inlet and outlet pipes (not shown). The partition I l is shaped as a horizontally positioned U, with the interior of the U forming a portion of the outlet chamber 14. Each of the two horizontal branches: of the U is provided with a cylindrical port It, the two ports being vertically aligned and of the same diameter. Within these ports there is mounted a vertically slidable valve member I! of the balanced type having two cylindrical portions or disks 20 to control the flow through the ports, these disks being connected by a vertical stem 2 8. Guide wings 22 depend from each disk 20 to engage the walls of the ports and maintain the valve member in proper alignment with the ports. Upward movement of the valve member open the ports for increased flow of fluid therethrough.

Means is provided to steady the movements-of this valve member and prevent surging or fluttering thereof. For this purpose the body in is shaped to provide a vertical cylindrical bore 24 directly beneath the lower port l8 and aligned therewith. A plate 25 is secured to the bottom of the body to close the lower end of this bore Within the bore 24 there is mounted a vertically slidable piston 25 which is connected to" the lower disk 20 of the valve member by means of a verti cal stem 28. A restricted port 29 extends through the piston 26 to form a by-pass. This construcsteadying effect is obtained.

In order to control the operation of the valve in accordance with the fluid pressure drop across the same, the body [0 is shaped to provide an opening in the form of a vertical cylindrical bore 3| directly above the upper port it and aligned therewith. This bore preferably has substantially the same diameter as the port. The upper end of the bore 3| communicates with the interior of a chamber 32 which is secured to the top of the body. A piston 33, forming a fluid-pressure re sponsive device, is vertically slidable in the bore 3!, and in the embodiment shown in Fig. 1 this piston is integral with the valve member IS. The

piste; 33 and valve member I! are urged downward! by means of a vertical coiled compression spring 35 which extends upwardly into the chamher 3;. The upper end of the spring engages a button 38 on the lower end or a vertical screw 31 which is threaded through the top of the chamber 3'2. A ca 33 is mounted on the upper portion of the s rew to engage the top of the spring chamber and prevent any leakage of fluid. The interior oi the spring chamber is connected with the outlet chamber l4, and for this purpose a passage til extends downwardly through the center of the upper disk 20 and the stem 2| to intersect with a passage 4| which extends diametrically through the sham 2'.

It will now be apparent that the valve member i3 is -irged upwardly toward its open position by the p-essure of the fluid in the inlet chamber i2, this pressure being eilective beneath the dashpot piston 26 and the lower valve disk 20. This upward force is opposed by the downward force of the spring 35 and by the fluid pressure inside the chamber 32, this pressure being effective above the pi. ton 33 and being equal (under static conditions) to the pressure in the outlet chamber. Thus the valv will remain closed so long as the fluid pressure differential between the inlet chamher the outlet chamber is below a predetermined value which is dependent upon the adjustment of the screw 31. Whenever the pressure differential exceeds the said predetermined value, the valve member will be raised to allow flow through the ports l8.

Preferably the construction is such that a comparatively slight increase in the pressure differential will open the valve widely and thus allow large volume of fluid to flow through the valve. This is accomplished by utilizing the flow of the J cause a reduction in the pressure above iston 33 as compared with the pressure in outlet chamber I4. For this purpose I prefer ze the fluid flowing through the upper port treate an aspirating effect on the passage indicated by the small arrows in Fig. 1, id entering the outlet chamber l4 through per port l8 tends to travel at comparatively locity downwardly along the stem 2 E. Diabove the passage 4| this stem is provided baflle plate in the form of an outwardly ng flange or rib 43 which preferably comsurrounds the valve stem. This baffle direct the downwardly flowing fluid in an ,1 d direction away from the stem, and this 3 effect of reducing the pressure beneath stile and thereby aspirating fluid out of the in; er 32 through the passages 40 and 4!. -esult the pressure above the piston 33 is i, causing the valve to open much farther would otherwise, and permitting a much flow to take place. The lower surface baiile 43 forms a downwardly facing s of the larger sizes are of course conte to larger pipes, and these pipes are so d heavy that in some cases they may impreciable mechanical stresses on the valve and distort the same slightly. The dash- ;on 26 will ordinarily be made a rather t in its bore 24, and hence will always l eely. The valve disks 20 and the upper 33 should however fit rather closely in their ive bores in order to minimize leakage of id any appreciable distortion of the valve ght cause them to bind. In order to avoid sibility, the piston 33 in the larger valves BEST AVAILABLE COPY may be made separate from the valve disks 20, as shown in Fig. 3. With this construction the piston merely rests on the upper valve disk and is free to move laterally thereon, so that slight misalignment of the bores will not prevent free sliding of the valve member and pistons.

In Fig, 4 there is shown a further modification showing a slightly diflerent arrangement for obtainlng the desired aspirating eflect. In this embodiment the valve stem I9 is somewhat reduced in diameter to provide a downwardly facing shoulder 46 beneath the upper valve disk 20 and adjacent to the valve stem. The passage 40- of Fig. l is replaced in Fig. 4 by one or more substantially vertical passages 41 which extend through the upper disk 20, with their lower ends opening through the shoulder 46. When the valve is open, the fluid traveling downwardly through the upper port l8 will create a zone of relatively low pressure directly beneath the shoulder 46, and fluid will therefore be aspirated out of the chamber 32 through the passages 41. This will cause the valve to open much farther and permit th rate of flow to increase considerably.

The operation of the invention will now be apparent from the above disclosure. The screw 31 will be adjusted so that the valve will start to open at a desired pressure differential of say fifteen pounds. So long as the pressure differential is less than fifteen pounds, the fluid pressure above the piston 33 added to the force of the spring 35 will hold the valve closed against the fluid pressure beneath the lower valve disk 20.

35 If however the pressure diflerential exceeds flfthrough the upper port will travel downwardly along the stern l9 until it encounters the baflie 43, which will deflect the fluid outwardly away from the stem and thereby aspirate fluid from the passage 4| beneath the baflle.- This will reduce the pressure above the piston 33 to a value appreciably below the pressure in the outlet chamber 84, and cause the valve to open much farther than it would otherwise. As a result flow can take place at a comparatively high rate with only a slight increase in the pressure differential. In order to ascertain the efiect of the baifle 43, tests were run on a valve mechanism 1% inch nominal pipe size both with and without the baille. In each case the valve was adjusted to start opening at a pressure difierential of 14 pounds per square inch. Without the baffle an increase of 3 pounds in the pressure differential produced a flow of 22 gallons per minute, whereas with the baiiie the same increase in the pressure differential produced a flow of gallons per minute. Thus the addition of the baille increased the capacity of the valve five-fold under these particular conditions, with the pressure differential across the valve l7 pounds. Without the bafiie it was found that the pressure differential had to be increased to 20 pounds to produce a flow of only 42 gallons per minute. The practical advantages of this feature will be apparent to those skilled in the art. The mechanism operates smoothly at all times, the dashpot 26 serving to prevent surging and fluttering. The bores 3|, i8 and 24 in the valve body are all aligned and of the same diameter. They can all be machined at one set up, greatly decreasing the cost of manuiacture. The entire mechanism is simple, inexpensive and dependable. The operation or the embodiment shown in Fig. 4 is similar to that of the Fig. 1 construction. The fluid flowing downwardly i'rom the upper port It will creates 'low pressure zone beneath the shoulder ll similar to the low pressure zone beneath the baille n at Fig. 1. Thus fluid will be aspirated from the passages 41, and the pressure above the piston I3 willbe reduced, causing the valve to open and allow an increased flow oi fluid tor a given pressure diiierential.

Inthe claims, certain terms such as upper," "lower." vertical." "horizontal," and the like are employed. It should be noted however that the apparatus can be mounted in positions other than that illustrated, andsuch terms are not intended as limitations except as they describe the relative positions of the various parts.

.Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: g

1. Automatic valve mechanism comprising a hollow-body, a partition shaped as a horizontally positioned U dividing the interior of the body a into an inlet chamber and an outlet chamber, the

interioroi the U forming a portion of the outlet chamber and each branch oi the U having a port therein withthe ports vertically aligned, a

vertically reciprocable-valve member having two with the space above the piston, means to utilize the fluid flowing through the upper port to aspirate fluid from the passage and thereby reduce the pressure above the piston. and a sprin urging the valve member downwardly.

2. Automatic valve mechanism comprising a hollow body, a partition shaped as a horizontally positioned U dividing the interior of the body into an inlet chamber and an outlet chamber,

the interior of the U forming a portion of the outlet chamber and each branch of the U having a port therein with the ports vertically aligned, a vertically reciprocable valve member having two vertically spaced disks thereon connected by a central stem, the disks being associated with the respective ports to control the flow therethrough andgclosing in a downward direction, the body 3 tically spaced disks thereon connected by a central stem, the disks being associated with the report, a piston slidable in the bore and connected to the valve member, the valve member having a e therein which extends through the stem, the upper end of the passage communicating with the space above the piston and its lower end communicating with the outlet chamber, and means-to utilize the fluid flowing through the p r port to aspirate fluid from the lower end oi the passage and thereby reduce the pressure above the piston, and a spring urging the valve member downwardly;

4. Automatic valve mechanism comprising a hollow body. a partition shaped as a horizontally positioned U dividing the interior of the body into an inlet chamber and an outlet chamber, the interior of the U forming a portion of the outlet chamber and each branch 01' the U having a port therein with the ports vertically aligned, a vertically reciprocable valve member having two vertically spaced disks thereon connected by a central stem, the disks being associated with the respective ports to control the flow therethrough and closing in a downward direction, the body having a vertical bore therein above the upper port, a piston slidable in the bore and connected to the valve member, the valve member being shaped to provide a downwardly racing shoulder adjacent the stem and a passage connecting the -space directly beneath the shoulder with the space above the piston, whereby fluid flowing downwardly from the upper port past the shoulder will aspirate fluid from the passage and reduce thepressure above the piston, and a spring urging the valve member downwardly.

3. Automatic valve mechanism comprising a hollow body, a partition shaped as a horizontally positioned U dividing the interior of the body into an inlet chamber and an outlet chamber, the interior of the U forming a portion or the outlet chamber and each branch or the U having a port therein with the ports vertically aligned, a vertically reciprocable valve member having two verhaving a vertical bore therein above the upper port, a piston slidable in the bore and connected to the valve member, the valve member having a passage therein which extends through the stem, the upper end 01' the e communicating with the space above the piston and its lower and opening laterally into the outlet chamber, a baille on the stem arranged to direct'the fluid which flows downwardly along the stem from the upper port away from the lower end oi? the passage and thereby reduce the pressure above the piston, and a spring urging the valve member downwardly.

5. Automatic valve mechanism comprising a hollow body, a partition shaped as a horizontally positioned U'dividing the interior of the body into an inlet chamber and an outlet chamber, the interior of the U forming a portionoti the outlet chamber and each branch of the U having a port therein with the ports verticallyaligned, a vertically reciprocable valve member having two vertically spaced disks thereon connected by a central stem, the disks being associated. with the respective ports to control the flow therethrough and closing in a downward direction, the body having an opening th'erein above the upper port, a vertically movable fluid-pressure responsive device closing the said opening and connected to the valve member, the'valve member having a passage therein which connects the outlet chamber with the space above the said device, means to utilize the fluid flowing through the upper port to aspirate fluid from the passage and thereby reduce the pressure above the said device, and a spring urging the valve member downwardly.

6. Automatic valve mechanism comprising a hollow body. a partition shaped as a horizontally positioned U dividing the interior of the body into an inlet chamber and an outlet chamber, the interior or the U forming a portion of the outlet chamber and each branch of the U having a port therein with the ports vertically aligned, a vertically reciprocable valve member having two vertically spaced disks thereon connected by a central stem, the disks being associated with the respective ports to control the flow therethrough and closing in a downward whereby fluid flowing downwardly irom the lip-- per port past the shoulder will aspirate fluid from the passage and reduce the pressure above the said device, and a spring urging the valve member downwardly.

7. Automatic valve mechanism comprising a hollow body, a partition shaped as a horizontally positioned U dividing the interior of the body into an inlet chamber and an outlet chamber, the interior of the U forming a portion of the outlet chamber and each branch of the U having a port therein with the ports vertically aligned, a vertically reciprocable valve member having two vertically spaced disks thereon connected by a central stem, the disks being associated with the respective ports to control the flow therethrough and closing in a downward direction, the body having an opening therein above the upper port, a vertically movable fluid-pressure responsive device closing the said opening and connected to the valve member, the valve member having a passage therein which extends through the stem, the upper end of the passage communieating with the space above the said device and its lower end communicating with the outlet ea set chamber, and means to utilize the fluid flowing through the upper port to aspirate fluid from the lower. end of the passage and thereby reduce th'e pressure above the-said device, and a spring urging the valve member downwardly.

8. Automatic valve mechanism comprising a hollow body, a partition shaped as a horizontally positioned U dividing the interior of the body into an inlet chamber and an outlet chamber,

the interior of the U forming a portion oi the outlet chamber and each branch of the U having a port therein with the ports vertically aligned, a vertically reciprocable valve member having two vertically spaced disks thereon connected by a central stem, the disks being associated with the respective ports to control the flow therethrough and closing in a downward direction, the body having an opening therein above the upper port, a vertically movable fluid-pressure responsive'device closing the said opening and connected to the valve member, the valve member having ,a-passage therein which extends through the stem, the

upper end of the passage communicating with the upper port away from the lower end or the passage and thereby reduce the pressure above the said device, and a spring urging the valve member downwar ly.

Y CHARLES M. TERRY.

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