US2204191A - Flush valve - Google Patents

Description

June ll, 1940. w. E. sLoAN Er AL FLUSH VALVE 2 Sheets-Sheet l 7mm/ms IML/#M552 06f/V J//A/[fMH/v BY m. f/D

ATTORNEY Filed April 4. 1938 June 1l, 1940. w E, SLOAN ET AL 2,204,191

FLUSH VALVE Filed April 4, 1938 2 Sheets-Sheet 2 6&9 644%- ATTORNEY Patentes June 11', 1940 UNITED STATES FLUSH VALVE William E. Sloan,.River Forest, and John I. Bellamy, Brookfield, Ill., assignors to Sloan Valve Company, Chicago, Ill., a corporation of Illinois Application April 4, 1938, Serial No. 199,812

Claims.

'GENERAL DESCRIPTION As commonly used, a flush valve is designed to 15. operate properly from a source of supply oi only a few pounds pressure to the square inch, and no objectionable noises are generated by the flush valve operation when the supply pressure is in the neighborhood of the pressure for which 20 the flush valve is designed to operate. Keeping in mind the actual pressure conditions prevailing in Water supply systems wherein pressures from sixty to onel hundred pounds to the square inch are not uncommon, it will be seen at once 2 that the flush valve must be adaptable to meet the higher pressure conditions when they arey encountered. The most common practice is to install a shut-od or stop valve immediately preceding the flush valve, which answers the pur- 30 pose of shutting oi the supply temporarily when the ush valve is to be inspected or repaired, as

well as the further purpose of limiting the maximum rate or" flow through the ush Valve, and consequentlythe pressure supplied to the ilush 35 valve during the main flushing operation. With the stop suitably throttled in each case of high pressure supply to cut down the rate of flow vto about that delivered when the flush valve is operating from an unthrottled low pressure sup- 40` ply, the `actual pressure condition obtaining at the iiush valve during the main ushing operation is about the same under all pressure conditions. However, whenv the flush valve reaches the point in its operation when the full fdushing rate of flow is being reduced to the relatively low refill rate oi flow, the pressure at the flush Valve builds up until it is a. large fraction of the supply pressure. The pressure remains about the same from this point on until the flush valve 50 seats, at which time the pressure at the flush valve equals `that of the supply line, for there is then no further pressure drop through the controlling stop valve.

The problem of quietly `throttling the main flushing flow at the controlling stop has been more orless satisfactorily solved heretofore by providing an adjustable throttling device Wherein `the water passes between roughened walls and thus has its velocity reduced below the critical 50 noise-making velocity. The application of this principle to the iiush valve to keep the velocity below the critical noise-making value during the approach to the reiill position and during the refilling operation of the flush valve has not heretofore been generally satisfactory. The reason for this seems to be that each pressure drop requires a denite minimum amount of length or overlap to the roughened-Wall restriction, and the objectionable noise is made while the throttling piece in the flush valve (commonly known as the reiill head) is entering the cooperating` port, and before it has entered far enough to begin to give suflicient overlap or length to the roughened wall restriction to aiord quiet throttling. Our invention herein disclosed oifers several forms of a solution to the problem. In one form, the approach from the flushing rate of ilow to the refill rate of flow is made by a lost-motion throttle piece, slidable upon the main valve, which has a tapered form and comes into cooperation with a tapered or flared entrance to the guide barrel of the flush valve, whereby the full amount of overlap between the parts, or full length of passage between the cooperating roughened Wall surfaces, is realized before substantial restriction takes place, in which case the approach is made with relative quietness and the main valve can travel any desired further distance before it reaches the main seat in order to deliver the desired amount of water for refilling the receptacle `being ilushed after the usual syphon has terminated at the end of the main flushing rate of flow.

In another form of theinvention, the parts which cooperate to bring about the reduction of the rate of flow to the refill rate are of such a large diameter compared to the rate of flow being handled that the parts come very close together before the restriction between them is great enough'to build up a considerable back pressure, in which case a minimum of overlap suffices to keep the velocity below the critical noise-making value. Moreover,- this large diameter of the parts by which the approach from flush to rell is made induces the iiush valve to travel at a relatively high rate during the approaching operation, tending to reduce the duration of the approach noise and thereby render it much less objectionable.

Other objects and features of the invention, mostly subordinate to the foregoing, will become apparent upon a further perusal of the specification.

Description of drawings stood,

Figures 1 and 2 show a top view and a front view at a reduced scale of an installation of the improved flush valve;

Figure 3 shows the controlling stop and flush valve of Figs. 1 and 2, in section, with the parts turned suiciently from actual installed positions to enable the cutting plane to pass through the center of them;

Figure 4 is a sectionallview taken along the line 4 4 of Fig. 3, looking upward, to illustrate the guiding arrangement of the throttle piece 39; and

Figures to 8 each show a desirable modification of the flush Valve as illustrated in Figs. 1 to 4.

` DETAILED DESCRIPTION The invention having been described generally, a detailed 4description of the apparatus shown will now be given.

Figures 1 to 4 Referring to Figs. 1 to 4, the flush valve 5 and the controlling stop 3 are mounted adjacent a wall inthe customary manner. The supply pipe 2 comes from the wall and encounters the inlet II of the stop or valve 3, whence the water is supplied from the outlet of the stop through the nipple or tail piece 4 to the inlet 2| of the ush valve 5. From the ush valve 5, the Water passes through the discharge ytube 1 to the receptacle (not shown) to be ushed.

The stop 3 has the throttle plug I3 which can be adjusted more or less within the discharge barrel I2 to give the desired rate of ilow under a wide range of pressure conditions, the setting being controlled by the handle I5 in the usual manner. The throttle plug I3 can be withdrawn entirely from the barrel I2 to give a large, free waterway for a flow under a low pressure condition, and which can be introduced into the barrel a desired distance to provide for quiet throttling of the maximum rate of flow through the flush valve under a condition of intermediate or high pressure. A further adjustment by means of the handle I5 brings the travelling seat lIll against the shoulder around the entrance to the barrel I2 to close off the stop entirely when desired.

The illustrated stop 3 is designed to give a rate of ow of from twelve to fteen gallons a minute with substantial quietness from any pressure up to slightly in excess of one hundred pounds to the square inch. The desired rate of ow of about twelve gallons a minute is delivered from a supply pressure of one hundred pounds when the handle I5 is opened one turn from the fully closed position. In order for the stop 3 to give the desired rate of flow quietly from intermediate and high pressures, the clearance between the plug I3 and the inside surface of the wall I2 is in the neighborhood of .015 inch on the side, a total diiference of diameter of about .030 inch. Moreover, the inside surface of the passageway I2 and the outside surface-of the plug I3 are provided with roughening which may conveniently take the form of threading or similar scoring, thirty-six threads to the inch of standard Whitworth form, with the top of each thread flattened somewhat to give a at surface about .008 inch wide. The stop 3 is Shown adjusted to about the position which would be occupied to give a rate of ilow of twelve gallons a minute from a supply pressure of seventy to eighty pounds to the square inch.

The inlet of the nipple 4 and the outlet of the stop 3 are provided with the usual ground-jointunion facilities, being removably held together by the coupling nut I6.

Upon reference to Figs. 1 and 2, it is to be noted that the ilush valve 5 is actually installed with the actuating push button 55 extending to- Ward the front, and with the inlet 2| on the side,

` and that the inlet II of the stop 3 is actually horizontally to the rear of the stop. However, in order to simplify the detailed showing in Fig. 3, the inlet 2l of the flush valve has been indicated at the rear instead of at the side, and the stop 3 has been shown with its inlet II and the supply pipe 2 coming up from below.

Construction of the ,flush valve 5, Figure 3 The flush valve 5 has a main valve or piston 24, which is normally seated on the main seat 23, and which is provided with a leather cup 28. Cup 28 makes sealing engagement with the cylinder walls, and divides the interior of the ush valve into a lower or supply chamber 8 and an upper or controlling chamber 9. The main valve is normally maintained firmly on its main seat v25 by the pressure in the upper chamber 9, above the leather cup 28, the full line pressure being transmitted to this upper chamber through the bypass assembly 25 and the vertical supply channel 3I. The by-pass assembly 25 includes a by-pass tube 26 with a small, arcuate opening through its nose and the protecting strainer disc 21. The leather cup 28 isy held in place by the back plate 29, held in turn by screws such as 30. Ihe bumper 32 engages the bottom of the cover 5I at the top of the stroke of the valve, and thus establishes the upper limit of the stroke. The hori- Zontal groove or slot 33 is provided to deliver water from passage 3l into the upper chamber 9 during the time the valve is at the' top of its stroke.

Briey, when the iiush valve is to be actuated,

the actuating push button 55 is operated against the force of the restoring spring 5E and against the pressure in the upper chamber, transmitted to the end of the push-button relief valve through the vertical channel 69. When this occurs, water ows out between the relief valve and the seat 59 and passes through the holes 58 in the bushing 54 to the relief-discharge chamber 51, lying around the bushing 54. The vertical channel 44 allords communication between the relief-discharge chamber 51 and the main discharge chamber 4I of the flush valve, permitting the water to be discharged quickly from the upper chamber. The discharge of the water from the upper chamber takes place because of the unbalanced condition that exists when the pressure is reduced in the upper chamber by the actuation of the button' 55, because the line pressure against the piston at the diameter of the cup 28 is acting upwardly over a substantially greater area than that over which it is acting downwardly.

When the flush valve reaches the top of its stroke, push button 55 may be released,whereupon the relief valve reseats on the seat member 59 to prevent further escape of water from the upper chamber. rIhe upper chamber 9 thereupon slowly reills with water from the supply chamber 3, passing through the restricted opening in the bypass tube 26. As the upper chamber slowly refills, the main valve travels slowly to its seat. When the main valve again reaches its seat, the pressure in the upper chamber 9 again becomes as large as the pressure in the lower chamber 8.

In the flush valve illustrated, the area of the net opening between the surface of the guide 34 and the inside surface or the guide barrel 22,

around the guide wings 35, is preferably on the order of .2 square inch, in which case a pressure of less than five pounds in the lower chamber 8 gives a maximum discharge rate in the neighborhood of twelve gallons a minute.

The lost-motion piece 39 has its conical surface roughened by circular scoring. This scoring may conveniently be of the usual thread form, with a slightly flattened top, as described in connection with the surface of the plug I3 and the inside of the barrel l2 of the stop 3. Also, the conical surface at the entrance 38 to the guide barrel 22 is similarly roughened so as to force the water to flow between the two roughened surfaces when the valve is approaching its refill position, as will be explained.

The flush Valve 5, as illustrated, has a stroke of about one inch, half of which may be designated flush stroke and the other half refill Stroke.

The lost-motion piece 39 is normally lying by its own weight in contact with the entrance 38 to the guide barrel l2. When the Valve is flushed, the lost-motion piece 39 is carried up with the valve, but not until the valve has completed about half of its upstroke. The sloping upper part of the guide wings engages the underside of the piece 39 at about the mid-point of the upstroke, carrying the piece 39 upward during the remaining half of the upstroke. The carrying of piece 39 away from the entrance 38 to the guide barrel leaves a large opening between the parts for the water to iiow from the lower or inlet chamber 8 to the discharge chamber M, and thence out through the discharge tube 1, the rate of flow for a given pressure in the inlet chamber 8 being controlled by the net area of about .2 square inch between the guide wings, as previously brought out.

Additionally, as long as the main, valve is unseated, water is free to flow between the refill head or portion 36 of the guide stem 34 and the inside surface of the central opening through the lost-motion piece 39. The surface 36 is provided with scoring or roughening which may be of the character of the roughening previouslydescribed, in order to reduce the velocity of the water flowing through the central opening in the piece 39. The inside surface of the piece 39 need not be roughened in order for a silent flow through the central opening from any line pressure up to and slightly in excess of one hundred pounds per square inch, provided the clearance is not more than .007 or .008 inch on the side. The part 39 is guided for movement over the vscored surface 36 by the integral ribs such as 49 (see Fig. 4). The discharge rate, during the refilling operation, through the central opening in the piece 39 and around the scored surface '35 has been found to be from three to five gallons minute when the supply pressure is at one hundred pounds and the stop 2 is suitably throttled to give a rate of flow of about twelve gallons a minute during the main flushing operation.

Operation of the flush valve value 5, Figure 3 Assuming the silent stop 3 to be adjusted to give a maximum rate of flow through the flush valve 5 of about twelve gallons a minute from a supply pressure of about one hundred pounds to the square inch, a complete operation of the flush valve 5 is about as follows:

With the Vmain valve 24 on its main seat 25, no flow is taking place through the flush valve.

As a result, the full line pressure of one hundred pounds is available in the lower chamber 8 and is transmitted, through the opening in the by-pass assembly 25 and the vertical passage 3l, to the upper chamber 9. This full line pressure existing in the upper chamber 9 is transmitted through the relief passage 69 to the relief valve, seated on the relief-valve seat 59.

Sta/rt of upstroke When the push button 55 is actuated to unseat the relief valve from itsy seat 59, water is free to flow out of the upper chamber and through the relief valve and thence by way of the relief-discharge passage 44 to the outlet of the flush valve. The pressure in the upper chamber is thus lowered. Under this condition, the high pressure existing in the lower chamber 8 acts against the underside of the leather cup 28 and the supporting means thereof, causing the main valve to rise somewhat rapidly toward the full open position.

As soon as the main valve 24 leaves its main seat 23, water'commences to flow through the refill passageway in the space between the surface 46 and the` inside wall of the throttle piece 39, but no substantial flow takes place between the tapered outer surface of the piece 39 and the flared entrance 38 to the guide barrel until the main valve has completed about the first half of its upstroke and has engaged and unseated the piece 39.

Since the rate of flow through the flush valve during the first half of its upstroke is very small compared to the full flushing rate of flow which takes place when the flush valve has fully opened, the pressure in the lower or inlet chamber 8 remains at a large fraction of the full line pressure throughout the rst half of the upstroke. This pressure adds to the weight of the piece 39 to keep this piece firmly seated in the flared entrance 39 to the guide barrel until it is positively engaged by the top of the wings 35.` Any tendency for the two pieces to rise together prematurely (such as may be caused by small particles of foreign matter temporarily lodged between them) is thus positively overcome.

From the foregoing, it will be seen that the first half of the upstroke is completed very rapidly under the high pressure condition assumed.

Preparing for selfcleam'ng As the first half of the upstroke is completed, the sloping top of the guide wings 35 engages the correspondingly shaped, outwardly flared bottom of the lost-motion piece 39, so as to carry the piece 39 bodily up with the main valve during the remaining part of the upstroke. By this time, the self-cleaning groove 31, located between the upper and lower sections of the scored surface 35, has been carried entirely through the lost-motion piece 39, so that it is exposed around the upper entrance to the central passageway through the piece 39. This groove is thus in position to receiveany particles of foreign matter which might be too large to pass through the passageway between the scored surface 36 and the inside wall of the piece 39, and carry these particles through the piece 39 to discharge them below at the end of the flushing operation.

Opening throttle 39 As soon as the piece 39 is lifted substantially from its normal position of contact with the barrel entrance 38, the discharge area through the flush valve is increased sufliciently that the pressure in the inlet chamber 8 becomes only a small amount (less than ve pounds to the square inch), for then the water is discharged at substantially the full rate for which the stop 3 is set, the controlling restriction in the flush valve from then on being the area around the guide wings 35, much greater than the net area through the throttled stop 3.

With the pressure in the inlet chamber 81 of the flush valve thus lowered, the travel of the main valve through the remaining part of its upstroke is at a very much lower rate. As a result, the top of the stop boss 32, carried by the main valve 24, engages the central portion of the cover 5l quietly, for the velocity of the main valve is then comparatively low.

The main valve remains at the top of its stroke as long as the push button 55 is held actuated. In the ordinary use of the device, the push button 55 is actuated only momentarily (say for about a second). Under this condition, the push button 55 is released and is allowed to reseat shortly after the arrival of the main Valve at the top of its stroke.

The flush. stroke When the push button 55 is released, and the relief valve reseats on the seat 59, the escape of water from the upper chamber 9 is stopped The accumulation of pressure in the upper chamber as kwater ilows into the upper chamber 9 through the bly-pass member 26 causes a slow descent of the main valve.

During the first or fiushing half of the downstroke of the flush valve, the throttle piece 39 is supported out of engagement with the flared entrance 38 to the guide barrel, and the water is thus permitted to be discharged at the maximum rate. The low pressure condition in the inlet chamber 8 thus prevails during about the first half of the downstroke of the main valve. The first half of the stroke is therefore performed rather slowly because the flow of water through the by-pass element 26 is comparatively slow when there is a relatively low pressure in the inlet chamber 8.

' The approach When the main valve is nearing the mid-point of its downstroke, the piece 39 begins to approach close to the surface 38, and the effective areal throughv the flush valve begins to be sharply restricted. This, however, does not occur until the piece 39 has arrived fairly close to the position it occupies in the drawings. relative to the surface 38. At this time, the length of overlap between the tapered scored surface of the piece 39 and the tapered scored surface 38 is approximately one-half inch, while the separation between the two walls is a small fraction of an inch. At this point, the pressure in the inlet chamber 8 begins to rise sharply.

The main valve now starts.to travel faster toward its seat, the increase in the speed of travel being attributable to two factors: (l) the pressure in the inlet chamber 3 builds up as the net discharge area through the flush valve begins to be restricted; and (2) the lifting area is decreased to the difference between the area of the cup 28 and the area of the top of the throttle piece 39. As a result of the second factor, the pressure in the upper chamber 9 drops much further from inlet pressure and closer to discharge pressure. -The lost-motion throttle piece therefore travels switfly to rest position on the wall of the flared portion 38, quickly reducing the flow from flush rate to rell rate.

The above described operation, which takes place from the time the rate of flow begins to be substantially reduced until the part 39 comes to rest, is commonly referred to as the approach. It is readily apparent that the approach of the flush valve from the full flush rate of flow to the greatly reduced rell rate of fiow can give rise to a great amount of noise, for the velocity tends to become very high toward the end of the approach, when the pressure in the inlet chamber 8 of the ush valve becomes a large fraction of the line pressure. The construction illustrated in Fig. 3 substantially eliminates the approach noise, as will now be particularly pointed out:

It has been determined by experiment that the stop 3 delivers a preferred rate of flow with substantial silence when the inside diameter of the barrel l2 thereof is about one and one-quarter inches and when the gap between the inside wall I2 and the outside surface of the plug i3 is about .015 inch. It Will be observed that the diameter at the entrance of the flared portion 38 in the guide barrel 22 of the flush valve is about the same as the inside diameter of the barrel I2 of the stop 3. Therefore, it will be seen that the same rate of flow which is passing through the stop 3 could pass quietly into the entrance of the liared portion 38 when the throttle piece 39 is only about .015 inch away. Keeping this in mind, the tapered portion of the throttle piece 39 is made sufficiently atter than thev tapered entrance 38 to the guide barrel that the crevice widens toward the outlet enough that the area between the piece 39 and the tapered entrance 38 is substantially uniform throughout the entire overlap of about one-half inch when the two parts. are separated by about .015 inch. Under this condition, the approach throttling in the flush valve is comparatively noiseless, for the throttling accomplished by the stop 3 is gradually taken over in the flush valve as the piece 39 approaches the ared surface 38,` and the entire length of about one-half inch is fully effective at the parts 38 and 39 when the width of crevice at the entrance to the flared portion 38 is substantially the same as the width of the crevice through the stop 3.

Since the crevice at this time is a few thousandths inch wider at the point Where the lower end of the flared portion 38 of the barrel 22 joins the straight portion of the barrel, the fully effective length of overlap offered by the approach of the throttle piece 29 to its rest position is progressively shortened, until only the first few rings of scoring are effective at the point of largest diameter just as the part 39 comes nally to rest. At this time, there is still substantial separation at the lower end between the surface 38 and the tapered surface of the part 39. This progressive decrease in the effective length through which the flow is actually restricted is of no moment, for it is offset by the increased effectiveness of the approaching surfacesv to reduce the velocity as the gap between them is reduced.

Keeping in mind that the velocity of the move.. ment of the flush valve toward the main seat is substantially increased during the approach operation just described, it will be seen that Whatever sound is emitted as a result of the approach operation is extremely short. The approach is therefore both comparatively silent and very short.

` assembly 25 to the upper chamber.

The refill` .stroke With the part 39 at rest on the surface 38, the flush valve still has about one-half inch of travel left before the main seat 25 is reached. During this final one-half inch of travel, the rate of flow is only three to five gallons a minute from high line pressure, being only that which can pass through the small opening,` only about .007 inch wide, between the scored surface 36 and the inside of the central opening through the lost-mon tion throttle piece 39. This final onenhalf inch travel of the flush Valve is referred to as the refill travel, and it is accomplished ata travel rate intermediate between the relatively slow travel rate during the main flushing operation and the comparatively swift travel rate during the approach operation.

Since the lost-motion throttle piece 39 is now seated on the surface 38, the lifting area of the flush valve is the entire area represented by the outside diameter of the leather cup 2B, minus the small area represented by the diameter of the central opening through the piece 39, or the outside diameter of the scored surface 36. As a result, the pressure n the upper chamber 9 rises to a point nearly equal to the pressure in the inlet chamber 8, causing the water to flow only slowly through the small opening in the by-pass The upper chamber thus fills slowly to produce a slow travel of the valve toward its main seat. This slow travel duringA the refill operation, coupled with the relatively low rate of refill flow, causes the valve to have a prolonged slow refill ow. This characteristic is highly desirable, since it insures the delivery of an ample refill to the receptacle being hushed, even allowing for some refill loss during a final syphoning out of the receptacle after the refill flow commences.

With further reference to the relative travel rates of the hush valve in its three stages (flush, approach, and refill) of operation previously discussed, ythe travel rate during the full flushing operation is substantially uniform independent of the line or supply pressure, provided the stop 3 is set for the preferred rate of flow at all cases. On the other hand, the travel rate during the refillingoperation, although comparatively slow, is dependent upon the line pressure. The refill travel rate is therefore higher when the line pressure is high, for the pressure in the inlet chamber 8 of the flush valve rises to a large fraction of the line pressure by the time the refill operation begins, as previously explained. It will be seen therefore that, although the relatively small. closing area during refill represented by the inside diameter of the throttle piece 39, gives rise to a relatively slow rate of travel, because the pressurein the upper chamber 9 is allowed to approach the pressure in the lower chamber 8, the difference between the pressures in the chambers 8 and 9 is somewhat greater during the refill operation than it is during the flushing operation forall medium and high line pressures.

Self-cleaning It was previously noted tha-t the groove 31 in the guide stem 36 is exposed above the top of the throttle piece 39 during the main flushing operation, so that it is ina position to receive particles too large to pass through the refill crevice. During the refill stroke, the groove 31 is carried down through the piece 39 until it is exposed just below the bottom of piece 39 by the time the valve closes. In this way, any particles carried through the self-cleaning groove 39 are free to fall out or be washed out of the groove by the time the valve closes.

Quiet closing The flush valve `closes quietly at the end of the refilling operation, the explanation for the quietness being about as follows:

Keeping in mind that the maximum rate of iiow during the refill, even with high line pressure, is only from three to live gallons a minute and that the mean diameter of the main seat 25 is in excess of one and one-half inches, with a mean circumference of nearly five inches, it will e seen that the valve 24 comes extremely close to the main seat 25 before it begins to substantially restrict the refill flow. High velocity therefore cannot be induced between the valve and the main seat 25 before the valve 25 is almost upon its seat. By this time, the separation between the valve and the main seat is so very close that the friction offered to the water passing between the two opposed surfaces at the point of sea-ting is so great that high velocity cannot be mainY tained, causing the final seating to be made in almost complete silence. The close separation between the valve and its main seat before substantiall restriction of the rate of flow begins to be effected has a further effect tending toward silent closing, in that it causes the stream tending to have high velocity to' be so extremely narrow that the force of it is quickly taken up by its friction with the relatively nonemoving water lying just within the inside diameter of the malin seat 25 and above the top surface of the piece 39. These two effects thus combine to give the practically silent final closing previously mem tioned.

Figure 5 Referring now to Fig. 5, the modification of the ush valve 5 of Fig. 3 shown therein will now be described. The parts of Fig. 5, which correspond to parts illustrated in Fig. 3, have the same numbers applied in Fig. 5 as in Fig. 3, except that each number in Fig. 5 has the digit5 prefixed for purpose of identification. It may be notedthat the same prexing arrangement is carried out also in Figs. 6, 7, and 8, in that the prefixes 6, 7, and 8, respectively, are used therein.

The distinguishing diierence between the arrangements of Fig. 5 and Fig. 3 is that the lostrnotion throttle piece 539 is provided withV ears or lugs such as 50| and 502, which engage the recess inside the main seat 525 just before the scored, tapered surface of the piece 539 comes to rest on the flared, scored barrel entrance 535. By this arrangement, the scored surface of the piece 539 is kept separated from the scored surface 53B sufficiently that the preferred refill rate of flow of from three `to five gallons a minute can take place between these two surfaces after the lugs 50| and 502 have seated, whereby the provision of a refill crevice through the central opening in the piece 539 and around the portion 536 of the guide stem 534 is unnecessary. The surface 536 is therefore made smooth, as is the inside surface of the piece 539, and the clearance between the two is only sufficient for a smooth sliding action; Such leakage ow as may occur be* tween these surfaces is unimportant, as it is ne g ligible compared to the refill flow taking place between the tapered, scored surfaces, and it genfl erates no noise because of the low velocity imposed upon it bythe closeness of the surfaces between which it passes.

Except as noted, the flush valve of Fig. 5 is similar in construction and operation to the flush valve of Fig. 3.

Figure 6 Referring now particularly to Fig. 6, the flush valve shown therein is generally similar to the flush Valves of Figs. 3 and 5, differing, however, in the specific arrangement employed to secure a relatively silent and rapid approach and a prolonged slow refill. In the flush valve of Fig. 6, the total travel is in the neighborhood of one inch, of which about half is allotted to the delivery of water at the full flushing rate and about half to the delivery of water at the slow refill rate. The arrangement in Fig. 6 is based on the discovery that a flush valve with a scored throttle piece (called a refill head) with straight sides, cooperating with an inside-Scored barrel with straight sides, can be inserted into the cooperating barrel to reduce the flush rate of flow to a desired refill rate of flow with a satisfactory degree of silence, provided the diameter (and consequently the circumference) involved is sufficiently large with respect to the full flushing rate of flow that the parts come very close together before substantial restriction is offered to cause substantial back pressure to be built up. If this condition is carried out, it` will be found that the separation between the parts is so small at the time substantial back pressure begins to be built up that the stream discharged is so thin that its energy is lost yin friction against the defining walls and against the relatively stationary Water through which it must force itself, without the generation of a substantial amount of noise.

The primary refill head 639 and the cooperating enlarged barrel portion 638, each of which has its surface roughened by scoring, have a diameter and consequently a circumference sufriciently large to provide a quiet approach from the full flushing rate of flow of about twelve to fourteen gallons a minute from high pressure to provide the substantial silent approach above discussed.

With the large diameter represented by the primary ref-lll head 639, the lifting area of the flush valve is so reduced that the pressure in the discharge chamber 609 falls so near the pressure in the discharge chamber 64| that the rate of ow through the by-pass assembly :B25 is so high that the time during which the rell flow occurs is entirely too short, unless the length of the rell travel is greatly increased. This fast rate of travel which would occur throughout the refill operation if the valve of Fig. 61 were provided only with the large primary refill head 639 compares with the momentary fast operation of the valves of Figs. 3 and 5 previously described as occurring during the approach operation.

In order to cause the travel through the major portion of the distance allotted to the ref-lll flow to be at the desired relatively slow rate hereinbefore discussed, the flush valve of Fig. 6 is provided with the secondary rell head 636, of small diameter. This secondary refill head 636 is somewhat shorter than the distance between the top of the small portion of the guide barrel 622 and the top of the enlarged portion of the guide barrel. By this arrangement, the secondary refill head 636 does not enter the small portion of the guide barrel until slightly after the primary rell head 639 has entered the enlarged portion 638 of the guide barrel. The primary approach operation has already been performed, as described, by the primary refill head 639 to reduce substantially the rate of flow before the small secondary refill head 636 enters its cooperating barrel 622. By this time, the rate of flow has been reduced to such an extent that the secondary scored head 636 enters likewise with substantial silence for reasons pointed out in connection with the substantial silence of the entry of the primary head 639.

The clearance between the primary head 639 and the cooperating barrel surface 636 is preferably such that the preferred rate of fiow of about twelve gallons a minute is reduced to a rate of flow in the neighborhood of six to eight gallons a minute for high line pressure, and the clearance between the secondary refill head 636 and the inside scored sur-face of the reduced barrel portion 622 is preferably such as to further reduce the rate of flow to about three to five gallons a minute from high line pressure. With the clearances arranged to give the results above enumerated, the relatively high rate of travel occurring during the approach operation when the primary head 639 is approaching and entering the inside surface 638 is sharply reduced to a slow travel rate when the small secondary head 636 approaches and enters the barrel portion 622, as it shortly does.

The restriction offered at the secondary refill i head 636 is sufficiently greater than the restriction offered at the primary refill head 639 that the restricting effect of the primary head 639 can be practically ignored after the secondary head 636 enters. Therefore, the travel during the remaining part of the rell operation is at the preferred slow rate for reasons discussed in connection with the valves of Figs. 3 and 5.

Figure 7 Referring now particularly to Fig. 7, the modification disclosed therein will be described. The flush valve of Fig. 7 utilizes the lost-motion principle of Figs. 3 and 5, as well as the principle of Fig. 6, wherein the` approach is made quietly with minimum overlap of restricting surfaces because of the large diameter at which it is performed relative to the rate of flow before reduction. The guide stem 134 of Fig. '7 has the scored surface 136, just below the center of which is the self-cleaning groove 13?, corresponding to the parts 36 and 31 of Fig. 5. The approach throttle piece 39, however. differs from the tapered approach piece 39 of Fig. 5, in that it cooperates with the inside diameter of the recess provided in the body in which the main seat '|23 lies, the height of the recess being suitably increased to accommodate the flange portion of piece 139.

The total stroke of the flush valve of Fig. 7 may be about one inch, as in the case of the other illustrated flush valves. The tapered top ofthe guide wings F35 engages the correspondingly flared bottom portion of the piece 139, about the middle of the upstroke of the valve,v whereby the piece 139 is `carried upwardly throughout the second half of the upstroke. The piece l39 may be guided for movement relative to the surface 136 by guide wings as described hereinbefore for the piece 39 of Fig. 3, illustrated best in Fig. 4.

It will be seen, therefore, that a full flushing rate of flow is secured between the main seat 123 and the bottom of the flange portion of the piece 739. The control point at which the amount of back pressure developed within thelower chamber 108,during the main flushing .operationis preferably between the outside diameter of .the vertical portion of the piece 139 and the inside diameter of the guide barrel within which it operates. In this way, the pressure in. the inlet chamber 708 is available to hold the piece 139 down rmly on the guide wingsl while the flush valve is in the upper half of its stroke. This control area, as previously pointed out, is` preferably on the order of about .2 square inch for the preferred rate of flow of twelve gallons a minute.

At the end of about the rst half of the downstroke, the periphery 10| of the flange portion of part |39 approaches and comes within the pre viously mentioned body recess in which the main seat 123 lies, sharply reducing the rate of ow. An instant later, the part 139 seats on the main seat 123, entirely shutting off the flow except for the refill flow which occurs between the scored surface 136 and the inside surface of the central opening through the part 139. The approach from. the full flushing rate of flow to the rell rate of flow is thus made in two stages. The primary stage of the approach occurs as the periphery of the flange portion 'lill is entering the mouth of the recess in which the main seat 23 lies, at which time the bottom of the ange portion is some small distance away from the seat 23. The primary stage of the approach is made more nearly silent and can effect a greater reduction in the rate of flow with substantial silence when the short Vertical surface defining the periphery of. the ange part '10i is scored or otherwise roughened. Good results may be obtained when the clearance between the periphery of the flange and the inside wall of the recessv in which the main seat 723 lies is suiliciently close that the preferred rate of flow of twelve gallons a minute from. a supply pressure of one hunn dred pounds to the square inch is reduced to a rate of flow of about six to eight gallons a minute. Then, when the bottom. or seating portionof the flange cornes to rest upon the main seat 123, the secondary stage of the approach operation is performed between the bottom. of the flange and the top surface of the main seat 123. This secondary approach operation can rbe made almost completely silent because, by the primary approach operation, the rate of flow between the main seat and the throttle piece has been cut down to such a small value that the throttle piece is almost upon the main seat 123 before further restriction takes place. The close separation between the parts is therefore sufficient to keep the velocity of the ilow from reaching its critical noise-making value.

It will be understood, of course, that the refill flow between the scored surface 13B and the in side wall of the central opening through the piece 139 is quiet, as explained before in connection with scored. surface 36 and piece 39 of 3. Also, the self-cleaning groove '537, being exposed above the top surface of the piece '139 during the upper half of the stroke of the flush valve, and. carried entirely through the central opening in the piece '139 by the time the valve finally seats, serves to carry through particles which might otherwise lodge in the refill crevice `and cause binding of the parts.

At the end of the refill operation, the rubber seat 102 carried by the ush valve cornes to rest on top of the flange portion of the throttle piece 139, closing off the refill flow. This flow is closed off with almost complete silence because of its low rate. As hereinbefore pointed out, when the rate of ilow 'is low compared to the seating circumference, the parts come so close together be fore further substantial restriction is made that the critical noise-making velocity cannot be reached because of the great friction offered by the closely separated parts to the flow of water between them.

Figure 8 Referring now to Fig. 8, showing a desirable modification of the arrangement in Fig. '7, it will be noted at once that the parts in Fig. 8 are suitably rearranged to enable the traveling seat 102 of Fig. 'l to be dispensed. with, simplifying the construction to this extent. This simplified construction has one advantage in that the closing of the flush valve at thc main seat shuts off all flow without depending upon a tight closing of a secondary main seat such as 102.

The characteristic of the arrangement of Fig. 8 which distinguishes it from the arrangement of Fig. 'i is that the main seat 823 has an enlarged outside diameter and a greatly enlarged inside diameter in order to give room within the inside diameter of the main seat 823 for the lost-motion throttle piece 839 and its horizontal flange 80| to operate to give the two-stage approach operation from the full flushing rate of flow to the refill rate. Except for this difference, the arrangement of Fig. 8 operates substantially the same as the arrangement of Fig. 7 with one exception: The arrangement of Fig. 8 has a somewhat reduced capacity for giving a quiet approach from a high flushing rate of flow at high line pressure to the low rell rate, as will be at once apparent upon observing the relationship between the approach diameters in Figs. l and 8. Experiments have demonstrated, however, that the arrangement of Fig. 8 has ample capacity for the preferred rate of flow of twelve gallons a minute from a line pressure of one hundred pounds to the square inch, whereas the capacity of the arrangement of Fig. 7 is proportionately in excess. of this.

With reference to the operation of the ar? rangement of Fig. 8, it suffices to point out that the top of the guide wings 9.35 engages the bottom of the piece 839 at about the middle of the upstrokea-nd carries the piece 839 out of engagement with the recess in the casing in which, it normally lies. The lifting of the piece 839 gives the opening through the flush valve necessary for the discharge at the full iiushing rate as previously described. i

As the main valve and the part 839 supported thereby descend, the periphery of the flange portion 8l!! approaches and starts to come wi in the cooperating recess in. the casing, preparatory to seating on `the bottom of the casing. The approach and entrance of the periphery of the flange 80| into the recess constitutes the primary stage of the approach operation. sharply reducing the rate of now to a point intermediate between the flushing rate and the refill rate. This primary approach operation is rendered snhstanH tially quiet by providing scoring or other roughening around the periphery, as pointed out in connection with the iiange portion 'ii of the piece 139.

The secondary approach operation occurs as the bottom of the flange portion 80! approaches and comes to rest upon the bottom of the recess in which it normally lies. This second approach operation entirely stops the flow through the path provided for the flushing flow, leaving open only the refill passage through the central opening in the piece 839 around the scored surface 836.

The refill How takes place through the refill passage with substantial silence, as hereinbefore pointed out, and the renll flow continues through the remaining part of the downward travel of the flush valve, until the flush valve approaches and comes to rest upon the main seat 823. The final closing occurs with no audible disturbance because of the large circumference of the seating surface compared to the relatively low rate of refill flow.

It will be apparent that, by using the values for clearances, rates of flow, and other pertinent data given hereinbefore, keeping in mind the proper ratios hereinbefore given, ush valves may be constructed which will operate with substantial silence for practically any rates of ow desired.

Although the roughening of surfaces, such as the surfaces 36, 38, 636, 639, and the surface at the perimeter of flange ll, are described as preferably produced by threading, or by scoring to produce a thread form, it is to be understood that other forms of roughening may be employed with similar results, and that the particular form of roughening used on surfaces requiring it is largely dependent upon the ease with which a desired form of roughening may be applied, keeping in mind machining and similar problems.

What we claim is:

1. In a flush valve, a valve member reciprocable between a closed position and an open position, a throttle member surrounding a section of said Valve member intermediate the ends thereof, said throttle member being slidable longitudinally of said valve member, and means for limiting the sliding movement suiciently to enable said throttle member to be carried by said valve mem- 40. ber between a throttle position and a non-throttle position, said throttle member reaching its throttle position before the valve member reaches its closed position, said throttle member substantially sealing around its outer periphery when in its said throttle position there being sufficient clearance between the throttle member and the valve member where the latter member encircles the former member to enable a substantial but reduced flow to occur after throttling and before seating, the said clearance between the throttle member and the valve member being only a small fraction of an inch, and said throttle member extending longitudinally of said valve member a sufiicient way to provide a length of passageway for the said reduced flow of several times the width of such passageway, whereby the velocity of the fluid through the said passageway during the said reduced flow is greatly retarded to promote quietness.

2. In a valve, a valve member reciprocable between an open position and a closed position, and a throttle device surrounding an intermediate portion of the valve member and reciprocable between a non-throttle position and a throttle position, said throttle member having a movement of less extent than the movement of the valve member, whereby there is relative movement of the two members, the eiective dimension of the throttle member in the direction of movement being less than the relative movement of the members, said valve member having a groove eX- tending around it exposed on the upstream side of the throttle member when the valve is in open position and carried through the throttle member to an exposed position on the downstream side of the throttle member by the time the valve member reaches seating position, whereby particles which would not otherwise pass between the members may be earried through in the travelling groove.

3. A valve for controlling the ow of liquid from a high-pressure source, including a casing having a passageway therethrough for liquid iiow, and a valve member mounted in said passageway for movement between an open position and a closed position, said passageway including a tapered portion having inside walls generally defining a truncated cone with the small end downstream of the large end, and a throttle piece having a tapered form enabling it to approximately nest within said tapered portion and being mounted for movement away from and into nesting relationship therewith, said throttle portion having its taper enough flatter than the taper of the conical portion of the passageway that the inlet area of the passageway between the tapered surfaces in a selected position of the throttle piece is equal to the outlet area.

4. In a flush valve, a casing having a passageway therethrough including a central portion connected with the discharge end of the passageway by a guide cylinder of smaller cross section than the central portion, there being a shoulder around the upstream end of the guide cylinder, a valve member located in said central portion and reciprocable between an open position and a closed position, said valve member having a` stem extending into the guide cylinder, guide wings on the remote end of the stem cooperating with the cylinder walls, and a throttle slidable on said stem within the cylinder, said throttle having one portion engaged by said guide wings while the valve element is opening and another portion engaging said shoulder when the valve element reaches an intermediate point in its closing movement.

5. In a flush valve, a valve member reciprocable between aniopen position and a closed position, a throttle member operable with said valve member and reciprocable between an open position and a throttle position, the relation between said members being such that the throttle member reaches its throttle position before said valve member reaches its closed position, said throttle member including a travelling shoulder cooperating with a xed shoulder to throttle the flow in the said throttle position, the stationary part of said flush valve including also a pre-throttle cylinder through which the flow takes place when the valve is in open and unthrottled position, and a pre-throttle portion on said throttle member positioned so as to enter said pre-throttle cylinder before the said throttle position is reached, the clearance being such that the rate of ilow is sharply reduced from its unthrottled value upon the entry of the pre-throttle portion into the prethrottle cylinder and is further reduced when the throttle member reaches its said throttle position, the said ow bein-g discontinued entirely when the said valve member subsequently reaches its closed position.

, WILLIAM E. SLOAN.

JOHN I. BELLAMY.

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