US2189330A

US2189330A - Automatic flow control means

Info

Publication number: US2189330A
Authority: US
Inventors: Charles H Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-12-13
Filing date: 1938-12-13
Publication date: 1940-02-06
Anticipated expiration: 1957-02-06

Description

Feb. 6, 1940. c, H. Mm; 2,189,330

AUTOMATIC FLOW CONTROL MEANS Filed Dec. 15, 1958 3 Sheets-Sheet 1 Fig.1

INVENTOR. 5 CHARLES/v. SM/v'H ATTORNEY Feb. 6, 1940. c Sm-m AUTOMATIC FLOW CONTROL MEANS 3 Sheets-Sheet 2 M ww ggw m a R A TTORNEY Feb. 6, 1940. c sMlTH 2,189,330 AUTOMATIC FLOW CONTROL MEANS Filed Dec. 13, 1938 5 Sheets-Sheet 5 INVENTOR. HA R1. 55/). 5/4/71 4 A TTORNEY Patented Feb. 6,1940

i STATES rTEN-T OFFICE Charles H. Smith, PortlandfOreg. I Application December 13, I938, Serial No. 245,408 I v 10 claims, (01. 137- 8) I This invention relates to automatic flow control means-for hydraulic systems and is peculiarly adapted for use in controlling the amount of flow from laterals into a main trunk sewer in 5 sewage disposal systems in large cities and it will be so illustrated and described for the purpose of this'disclosure. t 1

It isan object of the present invention to devise mecl'ianisin to regulate fiow volume in arelatively predetermined proportion from a plurality of laterals into a trunk line, insuch manner that each will contribute its predetermined part of the whole capacity of the trunk line, regardless of the hydraulic head tending to dump the entire 5 flowage of. one lateral into the trunk, at the expense of carrying capacity to be apportioned to other laterals further along the trunk towards.

the point of final disposal.

In sewagadisposal systems the gathering of sewage "from criginalsources isaccomplished by branched lateral systems of pipes, laid to a hydraulic gradient according to limitations imposed by topography. For example, if a considerable area to be drained lies along the bank of a river, ;say for a distance ot several iniles'thelriver grade forms the natural drainage outlet. for that district. The laterals, however, owing to surface irregularities, must-in general benormal to the river, reaching it at a number of separated points 0 along its bank, the logical and only place for the trunk sewer if gravity flow is to be depended upon to any extent. Maximum storm-water conditions usually connote overfiow, as clear as may be from the semi-solids. 3 l

': As is well-known, the semi-solids from the laterals will tend to the bottom of the laterals, especially if an enlargement or basin be provided to check the velocity of the flow at the terminus or point or juncture with the trunk. Overflow outlets will be provided to dispose of storm water surplus but it is very important that each lateral have reserved its allotted portion of the whole capacity of the trunk, that the semi-solids shall for the most part at least go tothe trunk; and not 5* into the river through the overflow, during excess water periods. 7

Apparatus to admirably'accomplish the functions hereto-fore set out are illustrated in the accompanying drawings and described in the spec- 50 ificatlon, but are not intended as limiting the invention to the one embodiment, the; scope of the invention to be ascertained from the claims which follow. a Drawings of the particular embodiment chosen to illustrate the invention herewith, are in three assumed to be about the center of the drainage sheets consisting of six related figures, as follows:

Fig. I is a vertical sectionof a preferred form, t to be described in detail l t L Fig. 11 is a plan view of FigrI; 5 t Fig. III is a section on the line III-J11, Fig. I; Fig. IV is a section taken on the line IV--IV of Fi I; l

Fig'V is a section on V-V of Fig. I; and Fig. VI is a section on VIVI, Fig. I. j ,l'u In the drawings, i is a conduit communicating with anadjacent trunksewennot shown, and 2 is a lateraLthe entire flow from which is to be delivered to the conduit I, under normal conditions, and 3 is a valve opening through which 15 the now takes place. Under expected normal conditions, the valve 4 will be at rest'in about the position shown, that is to allow full capacity of the opening 3. r

This lateral 2 will be only one of a number of 20 lines that are designed to discharge into the trunk and for purpose of illustration it will be district served. Thus under abnormal conditions, if the laterals above it have not been con- 25. trolled, the trunk carrying capacity, will have been satisfied by laterals discharging from -a higher level; hence the particular one shown would have to overflow its entire volume.

Each of the other laterals will, however, have 3!), beenequipped with controls similar though per- 1 haps. varying in the sizeof the valve opening 2 and its cooperating valve 2. Mechanism to operate the valve flow and deliver apredetermined quantity of fiow to the conduit i will now be described. 3;:

The lateral discharges into the chamber 6 which breaks the flow velocitygjtending to keep the semi-solid parts of the flow at the bottom.

As the flow begins to exceed thecarrying capac ity of the valve opening 3, a hydraulic head devel- 40 ops in the chamber 6, being reflected in the float well I, in communication therewith by the screenedopening 8. y

. A float 9 is provided with guides such as H],

H and E2. The fioat rises with the liquid in the well l. The float Q is provided with a central opening in which is fixed a plural thread nut l3 which is an easy fit on the threaded shaft M, the

threads in this case being quadruple. I

The shaft I4 is mounted revolubly in the lower 7 bearing l5 and the upper bearing l6 and carries a rigidly fixed worm ll that engages with the double roller head It, made rigid with the lever Hi. It will be noted that the worm l1 andr the double roller head I8 have the same relationship as a relative low pitch worm with sector of a worm gear, that is the worm runs the gear easily but the locking characteristic of a worm and gear is present to oppose revolution from oppositely acting forces. This constitutes a very effective irreversible reducing motion between the float and the valve.

The thread of the worm l l is made with a differential or changing pitch to give a faster motion when the valve 4 starts to close than when it is further along towards closure, because the friction of fluid passing between the valve 4 and the valve seat 4a increases as the square of the velocity; hence a uniform closing of the valve will not result in a maintained volume which is corrected by the variable pitch. This variable pitch must be computed for each size of valve and seat; therefore the indication is diagrammatic and suflicient for the engineer skilled in such design when his attention is called to its necessity.

The lever I9 is fulcrumed on the standard 20. which is movably attached to the base 2| by cap screws 22, or other preferred means. It passes through the sleeve 23, provided with trunnions 2 3 rockably engaged by the standard 20; hence-the relative length of the two arms of the lever It? may be changed for adjustment to operate valves 4 of varying size.

The operated arm of the lever |9a is pivotally connected .to the valve stem 25 by the trunnioned sleeve 26 which is quite similar to the one shown at 23. The valve stem 25 is constrained to lineal vertical movement by suitable bearings such as 21 and 28; hence any rise of the float 9 causes the worm l! to turn proportionately to such rise, which turning movement is translated into a downward movement of the valve stem 25, reducing the area of the annular opening 311', carefully designed to have the same carrying capacity as the opening 3 when the relative position of the valve 4 is as shown. If the apparatus is properly designed, each increment of increase of hydrostatic head over the valve 4 will be reflected as a corresponding rise ofthe float 9, which, as explained, will be translated into a relative closing movement of the valve 4 with respect to the opening 3a and the actual flow therethrough will be the same within close limits whether the float is up, down or in any intermediate position. The actuating mechanism is so proportioned that complete closure of the valve 4 never occurs.

Counterbalance means for the valve stem 25 is shown by the weights 30 attached tocables 3i passing over the pulleys 32 and attached to the clamp 33.

Since the buoyancy lift of the float 9 will ordinarily be less than its weight, an equalizer is shown as the drum 35, the cable 36, the pulley 31 and the counterweighttfi so arranged as to assist the turning moment of the shaft M when the hydrostatic head tends to raise the float 9.

The exemplification' as described is for a sewage system. but quite obviously it can be arranged without substantial change to deliver a relatively fixed amount of Water from a main irrigation ditch to a lateral, with a varying head in the main ditch. It has many other applications which will be at once apparent to the hydraulic engineer.

The devices of the'present exempliflcation of the invention have been explained with a considerable attention. to detail, sothat the art may fully understand the principle of operation, but it'is not intended as markingthe boundaries of the claims.

What I claim as new and desire to secure by Letters Patent is- 1. Automatic flow control means comprising a valve, a lever that is arranged to control said valve and a float that is arranged to actuate said lever, characterized by a transmission between the float and the lever that includes a worm. revoluble by movement of thefloat and a worm gear sector that is in engagement with the worm.

2. In a flow control apparatus of the character described wherein a variable hydrosatic head above an outlet orifice is controlled for stable delivery capacity, a supply conduit, a receiving conduit, a divisional wall therebetween that is provided with an orifice, a valve positioned to vary the eflective area of said orifice, a float chamber connected to the receiving conduit, a float that is movable therein under the influence of liquid level, speed reducing transmissions between the float and the valve that are effective sensitive to hydraulic head above said valved conduit and a transmission between the valve and the float that is in part a differential reducing motion device that is effective to move the valve to maintain substantially uniform discharge capacity thereof under varying hydraulic heads.

4. In a flow control means, a chamber that is positioned to receive flow from a conduit, a needle valve adjacent the bottom of the chamber, a con duit positioned to receive discharge from the valve, a float well positioned adjacent the said chamber that is in hydraulic communication therewith, a float in said well, means constraine ing the float to vertical reciprocating movement. a threaded nut carried by said float, a threaded shaft that is rotatable by said nut and transmission means between the shaft and the valve that are effective to transform rotative motion thereof into varying reduced reciprocating motion of the valve.

5. Float control means for reciprocating a valve in reduced differential movement with re spect to the movement of the float, comprising a means limiting movement of the float to reciprocating vertical motion, a rotative shaft, helical cooperative connections between the float and the shaft that are effective to rotate the shaft when the float moves, a wormof varying pitch made rigid with the shaft, a worm gear sector engaged with the worm, a needle valve, and transmissions operatively arranged between the sector andthe valve that are effective to move the valve proportionately to the movement of the sector. v

6. A float controlled valve for a water system comprising a valve seat member provided with an opening, a cooperative valve, a float positioned adjacent said valve that is sensitive to supply volume for said valve, anddifferential transmissions between the said float and said valve that include a worm rotatable under the influence of the float and a worm gear sector that is in engagement with said worm, whereby the flow through the valve is substantially constant under varying hydrostatic heads thereabove.

'7. A float controlled valve for a water system comprising a valve seat member provided with an opening, a cooperative valve, a float positioned adjacent said valve that is sensitive to supply volume for said valve, transmissions between the'said float and said valve that include a worm rotatable under the influence of the float and a wormgear sector that is in engagement with said worm, characterized by a thread of differential pitch on the'worm to compensate for varying friction coeflicients of water passing throughthe valve. I

8. Flow control means comprising a valved flow portal, a float positioned adjacent the portal on the intake side thereof, guide means for restricting float movement to a verticalplane, a

rotative member operatively' connected to said float that is rotatable in synchronism with the movement of the float and a differential transmission mechanism operatively arranged between ;of the float, a' differential thread on the worm, a worm gear sector engaged with the thread of the worm. and transmissions operably connected to the said sector that are effective to differentially vary the flow volume through the portal underthe influence of the thread.

10. In hydraulic flow control means, a valve,

a float that is positioned to be sensitive to the a supply head above said valve and reducing transmission mechanisms between said float and said valve that tend. to close the valve as the head above it increases, characterized by a differential portion of said transmission that is effective to compensate forythe difference in flow friction through-the valve as the same tends to be limited by action of the float.

CHARLES H. SMIETH. 2s