US1096788A

US1096788A - Flushing apparatus.

Info

Publication number: US1096788A
Authority: US
Inventors: Patrick J Madden
Original assignee: Individual
Current assignee: Individual
Priority date: 1909-07-17
Filing date: 1909-07-17
Publication date: 1914-05-12
Anticipated expiration: 1931-05-12

Description

P. J. MADDEN.

FLUSHING APPARATUS.

APPLICATION FILED JULY 17, 1909.

1,096,788. Patented May12, 1914.

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P. J. MADDEN.

FLUSHING APPARATUS.

APPLICATION rum) JULY 11. 1909.

1,096,788. Patented May 12, 1914.

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onrrni) sTA'irns PATENT ornioa.

PATRICK J. MADDEN, OF CHICAGO, ILLINOIS.

FLUSHING APPARATUS.

To all whom it may concern:

Be it known that I, PATRICK J. MADDEN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Flushing Apparatus, of which the following is a specification.

The present invention relates to an apparatus having a tank, means for automatically starting the discharge of the liquid contents thereof when said liquid reaches a given level and allowing the discharge to continue until the tank is emptied or practically emptied of its liquid contents, means for thereupon automatically conditioning the tank to refill to the aforesaid level at which the preceding discharge started, and means for thereupon again automatically starting the discharge, thereby producing an intermittent discharge.

The term tank as used in this specification comprehends receptacles of any desired construction having any desired number of separate compartments, chambers or sub-tanks so long as they will meet with the requirements of the invention.

As practical examples of the use of such automatic, intermittently discharging flushing tanks, mention may here be made of flushing tanks for plumbing fixtures of various kinds and used for various purposes, filter beds and tanks used in systems for the treatment of sewage for purifying it, and tanks, generally, for whatever purpose they may be used, which it is desired to automatically and alternately fill and empty, so that the discharges will be intermittent.

The object of the invention is to provide for any of the purposes above mentioned, an efficient flushing apparatus that will operate automatically and that is of simple construction, having a minimum number of moving parts that can by any possibility get out of working order.

The invention consists in the features of novelty that are hereinafter described with reference to the accompanying drawings, which are made a part of this specification, and in which Figure 1 is a vertical section of a flushing apparatus embodying the invention in its preferred form, the section being taken on the line 1-1, Fig. 2. Fig. 2 is a view there- Specification of Letters Patent.

Application filed July 17, 1909.

charged thereinto.

Patented May 12, 1914.

Serial No. 508,186.

of looking downward, one half being shown in plan and the other half in horizontal section on the hne 22, Fig. 1. Fig. 3 is a vertical section of a flushing apparatus of In Figs. 1, 9. and 3, portions of the tank are broken away for the purpose of indicating indefiniteness of size and dimensions. From this it will be understood that the tank may be of any desired capacity and may also be of any desired dimensions or shape that will meet the requirements. It should also be understood that the invention does not relate to the tank per se, but only to the combination with a tank proper, of the other parts necessary to bring about the automatic, intermittent action hereinbefore mentioned and hereinafter more particularly described.

The flushing apparatus embodying the invention comprises two tanks or chambers, A and B, hereinafter called the priming tank and the main tank, respectively, which may be of any form and capacity that will meet the requirements, it being essential, however, that the priming tank shall be of sufficient capacity to contain a sufficient quantity of liquid to prime the discharge siphon of the main tank when it is dis- A partition A common to both chambers forms the bottom of the priming tank and the top of the main tank and the two tanks are separate and without internal communication with each other, excepting for certain openings for the passage of air or water, or both, as hereinafter described, a siphon, D, being used to draw off the liquid contents of the main tank.

The liquid for priming the siphon D is introduced into the priming tank by a supply pipe, C, which pipe, in the form shown in Figs. 1 and 2, is provided with a suitable valve, 0, adapted to be ope'ated manually for regulating or controlling the rate at 'which the liquid flows into the priming tank, it being the intention that this flow shall be constant, whatever its rate may be.

In the form of the invention shown 1n Fig. 3, the supply pipe is provided with a similar valve 0, but instead of being provided with means for operating it manually the rise and fall of the liquid in the main tank.

Rising from the main tank, and forming an upward extension thereof, is a tube E which forms a passage registering with an opening a formed through the bottom A of the priming tank and which rises upward within said tank, or the main tank may be vented through a tube F, or through both of said tubes.

This upward extension of the tube also constitutes means for forming a hydrostatic column extending upward above the surface of the liquid in the main tank, when the liquid in the main tank rises up in said extension. The tube E also constitutes an overflow for carrying off the water which is discharged into the priming tank, in the event of a stoppage due from any cause which prevents the apparatus from operating as intended.

In addition to the tube E, the apparatus as shown in Figs. 1, 2, and 4 of the drawings also has a tube, F, which will perform all of the functions of the tube E, so that either one may be omitted, if desired. When the tube, F, alone is used, as shown in Fig. 4, a tight joint is formed between the siphon,

D, and the bottom, A, of the priming tank Here the bottom of the priming tank has an opening through which the siphon extends upward into the priming tank, and the tight joint between them is formed by providing the siphon with an outwardly extending flange, d, which contacts with the under side of the bottom of the priming tank around said opening, a suitable packing or cement being interposed between them. The term tube as herein used is intended to comprehend any passage or duct through which air or liquid may pass, however said passage or duct may be formed.

When only the tube F is used, and the tube E omitted, as shown in Fig. 4, a tight joint is formed between the siphon D and the bottom A of the priming tank. Here the bottom of the priming tank has an opening through which the siphon extends upward into the priming tank, and the tight joint between them is formed by providing the siphon with an outwardly extending flange cl which contacts with the under side of the bottom of the priming tank around I said opening, a suitable packing or cement being interposed between them.

The upper end of the tube F preferably terminates in an inclined plane, or is of such other shape that it provides a low point at which the liquid overflows into it, so that the liquid will hug the wall of the tube and trickle down the inside thereof without any splash and consequent noise. The avoidance of a noise may be still further aided by carrying the lower end of the tube to within a short distance of the bottom of the main tank, as shown in Fig. 1, and still further by providing the tube with an internal shoulder f on the low side or the side at which the water enters it, as shown in Figs. 1 and 4, and still further by providing the tube with a series of perforations f, as

shown in Fig. 1.

example, in Fig. 4, the downwardly projecting portion of the tube, F, tendsto trap a body of air in the top of the main tank,

;and if the main tank is not otherwise vented .to atmosphere, the liquid will rise up in the tube, F, forming a hydrostatic column, which will put the entire fluid contents of the main tank under pressure and this Pressure will, of course, exert itself in all directions. It is also true that if the tube, F,

be entirely omitted, the liquid rising up in zthe tube, IE, will in like manner form a hydrostatic column that will put the fluid contents of the main tank under pressure which will act in all directions. It is this upward pressure that is used for unseating the valve which closes communication between the priming tank and the main tank,

preferably cast in one piece and comprising four vertical side walls and a bottom 9, which constitutes the bottom or" the main tank, and a horizontal partition A which divides the interior of the box G into two compartments and forms the bottom of the compartment which is in fact the priming tank A and the top of the-compartment which is in fact the main tank, B. This partition is supported at its edges by a shoulder G which surrounds the box on the interior thereof and is preferably integral therewith and the partition is secured in place on the shoulder by bolts or screws g or other suitable means and preferably a packing or cement g of any suitable material is interposed between them for the purpose of forming a liquid tight joint. In this form of the invention the vent and fill-- ing tube E is cylindrical in horizontal section and is preferably integral with the partition A and the crown or upper part of the siphon D projects upward into the tube E leaving between the siphon and tube E a space a which, in this instance, is annular.

In all instances the dam, (Z, or top of the overflow wall or partition, between the two legs of the siphon, must be located at such a level that when the contents of the priming tank is rapidly discharged into the main tank it will raise the level of the liquid in the short or uptake leg of the siphon and cause it to [ill the crown of the siphon and overflow into the long or downtake leg in a su'll'icient volume and with sufficient rapidity to prime the siphon and set it in action.

In the preferred form of the invention the siphon is made up of concentric tubes I and I. The bottom of the outer tube I terminates in a bell '21 and is in open communication with the interior of the main tank, near the bottom thereof, and its upper end is closed by a dome i. The inner tube I is located concentrically within the outer tube, and the upper end of the inner tube is in internal communication with the interior of the outer tube, within the dome 2". The inner tube is provided, near its lower end and within the bell i, with a downwardly increasing enlargement I terminating at bottom in an inwardly extending flange i, which has the double purpose of providing an internal shoulder presented upward and an external shoulder presented downward. The internal shoulder has the eiiect of deflecting inward and across the outlet opening of the inner tube, the downwardly flowing liquid, whereby said outlet opening is partially closed or choked at the entrance to the short pipe or nipple J which forms a downward continuation of the inner tube 1. The effect of thus partially closing or choking oi? the outlet opening of the inner tube is to prevent the air from rising upward in the inner tube and thereby retarding the complete establishing of the siphonic action. The descending volume of water drives the air downward before it, and thereby produces by its downward suction a partial vacuum in the long log of the siphon and the choking referred to prevents this partial vacuum from being supplied from below. This closing or choking of the outlet of the siphon is augmented by a lip or shoulder j formed by the upper end of the tube or nipple J and projecting upward above the level of the inner shoulder formed by the flange Q7. The tube or thimble is externally threaded and screwed into the lower end of the inner tube 1, whereby the tube or thimble may be adjusted to regulate the height of the lip or shoulder j.

The outer and inner tubes constitute, respectively, the short or uptake leg and the long or downtake leg of the siphon. As shown in Figs. 1, 2 and i, the inner tube forms, a common wall or partition which separates the two legs of the siphon, as it were, and the top of this inner tube forms a dam, (1, over which the liquid flows, from the uptake to the downtake leg, and this dam, cl, which determines the overflow level 01 the siphon, is located at a sul'liciently high level to prevent the liquid from slowly trickling over it, from the uptake into the downtake leg, in advance of the action which primes the siphon and sets it in action, as hereinafter described. This is true of all of the several forms of the invention shown in the drawings, and as to each of them it may be said that this overflow dam may be located anywhere between the lowest level at which the water cannot flow over it, at the rate it is supplied to the priming tank, in advance of the action which primes the siphon and the highest level to which the water will flow when the action which is intended to prime the siphon takes place. The volume of water discharged from the priming tank into the main tank and the rapidity of its discharge are factors which .must be taken into consideration in determining the highest level at which the top of the dam may be located in order that the priming action may be ellective.

A packing ring J is interposed between the downwardly presented shoulder formed by the flange 5 and the upper surface of the bottom 9 of the main tank and a similar packing ring J is interposed between the lower surface of said bottom and a clamp ing nut J turned onto the tube or thimble so that when the nut is turned up the parts are drawn together and a liquid tight joint formed.

A screw K extends through the dome z" and projects downward into engagement with a spider K carried by the tube I whereby the upper ends of the two tubes are held concentrically and whereby said tubes may be adjusted longitudinally relatively to each other for the purpose of bringing the lugs 2' into engagement with the upwardly presented shoulder a ll'orded by the enlargement 1 and the outer tube thereby supported.

In the forms of the invention shown in Fig. 3, all parts of the siphon are preferably cast integrally and the siphon comprises two parallel branches L and L, forming, respectively, the uptake and the downtake legs, said branches or legs being united at their upper ends by a U shapcd bend Z and separated by a dividing wall or partition Z. The downtake or long leg communicates with a horizontal, lateral branch L which may communicate with a pipe taking any desired course or direction.

As before suggested, the priming of the siphon is accomplished by causing the priming tank to discharge into the main tank a sufficient volume of liquid at a sufficiently rapid rate to cause the liquid to rise up in the uptake leg of the siphon, fill the crown of the siphon and overflow into the downtake leg in a sufficient volume and at a sufficiently rapid. rate to set the siphon in action. To this end the priming and main tanks communicate through an opening formed through the wall which separates themthe bottom A of the priming tank so that when said opening is unobstructed the liquid may flow from the priming tank into the main tank. This opening is sufficiently large to permit a sufiicient volume ofliquid to pass through it at the necessary rate. It is surrounded by a valve seat adapted to receive a buoyant valve, which islocated in the priming tank, or so as to be under the influence of the liquid therein and may be variously constructed as hereinafter described.

The unseating of the valve N is accomplished partly by its buoyancy and partly by producing and subjecting it to a pressure, acting upwardly immediately upon its under side, said pressure being produced automatically by the rising up of the liquid in the main tank. T he force or pressure acting downward upon the valve and tending to hold it seated is made up in part of the weight of the valve itself and in part of the Weight of the column of liquid resting upon it.

For the purposes of this specification, it is not necessary to here state with mathematical accuracy the various factors which must be taken into consideration in designing and constructing a flushing tank that will have the mode of operation contemplated by the invention. On the contrary the foregoing general statements taken in connection with detail descriptions of the mode of operation of the several species or modifications shown in the drawings of the mechanism for bringing about the priming action will suffice. As the liquid continues to rise above this level it will fill the main tank and rise up in the vent and supply tube E or F and also in the uptake leg of the siphon, to a common level in all of the said parts, thus augmenting the displacement and consequently the buoyancy of the valve and forming a hydrostatic column the base of which is the level of the lowest point of the valve, and the height and weight of which must be sufiicient to produce upon the valve an upward pressure, aided by the augmented buoyancy of the valve, which is sufiic ent to overcome the downward pressure of the superincumbeiit column of liquid upon the valve and the weight of the valve itself. 5

less of the liquid contents of the priming tank to flow into the main tank at a sufficiently rapid rate and in asufiicient'quantity to raise the level of the liquid in the uptake leg of the siphon until it fills the crown of the siphon and flows downward into the long leg thereof. In this connection, it should be borne in mind that the dam d, or in other words, the overflow level of the siphon must be above the top of the column of liquid which unseats the valve, else an unseating column of the necessary height could not be formed, as the liquid would simply trickle over the dam of the siphon without priming it.

hen the tube F is omitted the levelof the top of the tube E will be the normal level of the liquid in the priming tank and when it reaches this level it will overflow the top of the tube E and flow downward through said tube and into the main tank filling it and rising up in it and iii the tube E and the uptake leg of the siphon as just above described. Thereafter the unseatiiig of the valve for controlling the opening through which the priming tank and the main tank communicate is brought about precisely as above described. 7

The preferred form of the valve for controlling this opening is shown in Figs. 1 and 2. Here, 0 represents a short tube which is externally threaded and screwed into an opening through the bottom of the priming tank. Its upper end is flared and shaped to form a seat 0 for the buoyant valve N, While its lower end extends downward from the valve seat sufliciently far to form beneath the valve an air-pressure chamber 0 of suificieiit depth aiidcapacity for the purposes hereinafter described. The valve is prefei'ably made of soft rubber and is hollow in order to give it the necessary buoyancy. It has through its top and bottom walls oppositely located openings through which pass a stem or rod Q, provided with a shoulder 6 preferably in the form of a threaded nut turned onto it, which bears against the bottom of the valve and a threaded nut g which is'turned onto the upper end'of the rod and bears against the top of the valve. If the valve is made of soft rubber, or even of light weight sheet metal, so that it has a tendency to collapse between the nuts, a tubular strut a through which the rod Q; passes, may be arranged within the valve so as to brace it and prevent it from collapsing.

This strut may be of rubber and molded integrally with the walls of the valve, or it may be a separate tube made of metal or other suitable material which will give it the necessary rigidity, in which case the walls of the valve, immediately surrounding the openings aforesaid are clamped be tween the ends of the strut and the nuts 1] and q, respectively.

The rod Q acts as a guide for guiding the valve in its movements toward and from its seat, and also as a stop for limiting the movement of the valve away from its seat. To these ends a spider R is arranged in the short tube or thimble O and from this spider depends a tube B, through which the rod passes and whereby the valve is guided, and the rod is provided with a shoulder, preterably in the form of a threaded nut Q turned onto it and adapted to contact with the lower end of the tube R, thereby forming a stop for limiting the movement of the valve away from its seat. In the operation of this device the liquid rising up in the main tank never comes in direct contact with the valve N, although the column formed by this ris- :ing up of the liquid in the main tank, the uptake leg of the siphon and the vent tube, E or F, or both, does exert an upward pressure upon the valve with practically the same results as already described, but this upward pressure upon the valve is exerted through the medium of a body of air which is trapped and confined in the air-pressure chamber 0 when the liquid in the main tank reaches the level of the lower end of the tube 0. The valve is held to its seat by the superincumbent column of liquid exerting a downward pressure upon it. Then the valve is seated it closes the upper end of the air-pressure chamber and prevents the upward escape of air therefrom. It is manifest, therefore, that when the level of the liquid reaches the lower end of the tube 0 it seals it and prevents the entrance of liquid into the air-pressure chamber, excepting as the air therein is compressed. As the liquid continues to rise in the main tank, the uptake leg of the siphon and the vent tube, E or F, as the case may be, it forms a hydrostatic column of which the level of the bottom of the air-pressure chamber is the base. As this column increases in height the upward pressure upon the air in the air-pressure chamber also increases until the column reaches the height necessary to produce upon the air in said chamber, and through it upon the under side of the valve, suflicient fluid pressure to unseat it.

The term fluid is used in this specification in its customary sense, as comprehending generically all aeriform and liquid substances, of which air and water are species, respectively. When air is used for pressing immediately against the valve, its sudden release is explosive-like and of considerable force. In fact this explosive force is so great that even if the valve be of greater specific gravity than the liquid, it will be blown from its seat. This mode of operation is important in a flushing tank used in a sewage system, because it prevents the liquid contents of the main tank, which may contain more or less solid matter, from reaching and fouling the valve seat. This is because, the instant the valve leaves its seat the water will commence flowing from the priming tank into the main tank, and thereby instantly start a downward current of clean water which not only overcomes any tendency of the liquid to rise up from the main tank into the priming tank, but also washes the valve-seat and keeps it clean.

In the valve-device shown in Fig. 5 the valve proper consists of a solid block N of wood or other material of less specific gravity than the liquid in the priming tank and it does not project laterally beyond its seat 0", so that its buoyancy has no tendency to lift it from its seat although its buoyancy will hold it oil of its seat when once it is unseated. Excepting for the difference due to this difference in the construction of the valves shown in Figs. 1 and 5 they both have the same mode of operation. The solid valve does not require, nor does it have an internal strut for preventing it from collapsing, but otherwise its appurtenances are of practically the same construction as those of the valve N shown in Figs. 1 and 2, and in both, similar parts are indicated by simi lar letters of reference.

It will be noted that in the forms of the invention shown in Itgs. 1 and 2, inclusive, the entire body olliquid passing through the apparatus whether it be clear water, sewage or any other liquid, is first discharged into the priming tank and thence into the main tank, either through the filling tube of the main tank and then through the valved outlet opening of the priming tank, or else (should said valve and the filling tube F of the main tank become obstructed) through the tube E, alone acting as an overflow. There is no objection to this-in fact it is preferablein an apparatus for flushing water closets or other plumbing fixtures or apparatus where only clean, clear water is to be dealt with. This form of apparatus may however be used in sewage systems, but in such case there isa possibility of stoppage in the filling tube F, and hence the advantage of an additional overflow tube (E) the upper end of which terminates at a level. above the normal high water level which is determined by the filling tube, as in Figs. 1 and a.

The preferred form of the apparatus for use in sewage systems is shown in Fig. 3, the

parts here shown which are similar to" parts outer end. of which is jointed by a pin a to the upper end of a rod T extending downward through the tube E which tube, in this instance, has two possible functions, to wit: venting the upper portion of the main tank and conducting water from the priming tank to the main tank should the valve for controlling the opening through which the water is discharged into the main tank for priming the siphon, not be unseated before the water in the priming tank reaches the level of the top of the tube E. A tube T passes through the tube E and is supported therein by a spider T, and the rod T passes through this tube whereby it is guided and confined to an endwise, upward and downward, practically rectillinear movement. The guiding tube T extends completely through the tube E and projects upward and downward therefrom at its upper and lower ends, respectively. Its upper and lower ends acting in conjunction with nuts 23 and t turned onto threaded portions of the rod T,

form adjustable stops for limiting or arresting the closlng and opening movements of the valve, respectively. The opening of the valve is efl'ected by the buoyancy of a float U which is adjustably secured to the rod T between the nut 25 and a second nut t. The closing movement of the valve is effected by the weight of the float U, and the stop nut 25 may be adjusted to such position that the valve may be completely closed, thereby completely cutting oif the supply of water from the pipe G into the priming tank, or arrested at any intermediate point in its permitted range of movement, thereby permitting a stream of water of greater or less volume to flow constantly from the pipe G into the priming tank. The opening move ment of the valve 0 is effected by'the upward movement of the float, due to its buoyancy, when the liquid in the main tank rises to a sufliciently high level to submerge it, more or less, and the extent of this opening of the valve may be regulated or stopped by adjusting the nut 25 to the proper position with relation to the lower end of the guiding tube T. The float U must be of suflicient buoyancy or displacement to open the valve 0 as far as desired and at the same time the float and other parts must be so constructed and proportioned that the necessary quantity of water for priming the siphon will have been delivered into the priming tank at least as soon as the column of liquid for unseating the valve which controls the opening through which the water for priming the siphon flows from the priming tank into the main-tank is formed, however this column may be formed. To be more specific, as to the construction shown in Fig. 3, as the liquid rises in the main tank and reaches the lower end of the tube 0 it will trap the air in the chamber 0 and then continue to rise up, as already described with reference to Fig. 1, and form or build up, as it were, the unseating column until it reaches the necessary height. This column will then unseat the valve N (or the valve N or N or the valve for performing the same function, whatever its construction may be) and this unseating will take place regardless of the quantity or level of the liquid in the prim ing tank, but at the time the valve N is unseated the priming tank must contain a sufiicient quantity of water to prime the siphon, regardless of its level in the priming tank. It may stand at a level below the top of the tube E, or it may stand at a suffi ciently high level to overflow the top of said tube and flow downward into the main tank and thus augment the quantity of liquid in the main tank and assist in forming or building up the unseating column. It is desirable that this latter condition should not take place before, or at any rate, not much before the valve unseats, because the primary object of the present invention is to discharge the liquid contents of the main tank, while the object of the priming tank is a secondary one, namely, to start the discharge of the liquid from the main tank. Hence a minimum quantity of water for priming the siphon should be need, because whatever quantity is used, adds to the cost of maintenance.

here the valve has an appreciable buoyancy, its buoyancy will assist in unseating the valve, but its buoyancy is not in allcases a necessary factor. For example, where the main tank has a chamber, such as 0, in which a body of air is trapped and compressed as the liquidrises in the main tank, the instant the necessary pressure to overcome the downward pressure of the valve is produced the confined compressed air will free itself with an explosive force that will blow the valve from its seat, whether it be buoyant or not; In this instance, if the valve be buoyant, the only efl'ect'of its buoyv ancy will be to prevent the valve from re seating.

The term buoyant valve as used in this I do not herein claim specifically that form of the apparatus which is shown in Fig. 3, the specific features of which form the subject of an application of even date herewith, Serial No. 508,965.

It will be observed that in all instances the pressure of the fluid acts in'nnediately against the under side of the valve for unseating it and this term is intended to distinguish and differentiate from other devices in which the pressure produced by the rising of the liquid in the main tank acts upon the valve mediately or through the medium of some mechanical device or part, as, for example, a float which rises and falls with the liquid and whose movements are transmitted to the valve by a stem, a lever, or other mechanical appliance. In order that this ac tion may take place, it is necessary that the liquid in the .main tank, or the upward extension thereof, shall form a hydrostatic colmnn of sufficient height to produce sullicient pressure to unseat the valve after the liquid in the main tank reaches the level at which it commences to exert an upward pressure upon the valve. For example, as in the pre- 'l'erred form of the invention as shown in Figs. 1 and 2, when the liquid in the main tank reaches the level of the bottom of the tube 0, it commences to exert an upward pressure upon the valve through the medium of the trapped body of air and this level represents the base of the hydrostatic column. hereinhefore referred to. This column must rise high enough to produce the necessary pressure and if the lower end of the tube 0 is not sufficiently below the top of the tank to produce this necessary pressure before the liquid reaches the level of the top of the tank proper, the liquid will continue to rise in the tube E until the necessary pressure is produced.

In all instances, also, the dam of the siphon must be sutliciently high to prevent the liquid from trickling over it in advance of the unseating of the valve, otherwise the liquid will flow through the siphon and escape at the same rate as it is introduced into the priming tank. In this form of the invention it will be observed that the overflow level of the priming tank is above the top of the valve, so that the valve will become submerged by the liquid in the priming tank without being unseated by its buoyancy. This is because there is but a very small surface of the valve that is presented downward to the upward pressure of the liquid as it rises to the level of the maximum diameter of the valve. As the liquid continues to rise in the priming tank, a column will be formed above it and act downwardly upon it so that it is held downward by a force or weight which gradually increases until the level of its highest point is reached. Nhen the liquid begins to overflow into the main tank, it will gradually rise until it reaches and seals the air chamber 0. As it continues to rise in the main tank and in the tube E, and until the level of the maximum diameter of the valve is reached, it will exert an upward pressure upon the valve, so that the entire surface of the valve, excepting insofar as it is covered by the valve seat, is subjected to counter forces which are practically balanced. As the liquid continues to rise in the tube 11], it will increase the height of the hydrostatic column thereby producing a downward pressure upon the liquid in the main chamber and this pressure converted into upward pressure immediately against the under side of the valve. This upward pressure, combined with the buoyancy of the valve, will unseat it before the level of the liquid reaches the dam (Z.

It will be observed that, in a broad sense, the main tank A constitutes a passage-way through which the liquid for priming the siphon flows when the aim of the outlet opening of the priming tank is unsealed and that this passage is oil such capacity that it will contain the liquid which flows backward through. the siphon upon the breaking of the siphonic action and it will also be observed that this passage-way is vented to atmosphere, so that although the liquid flowing backward will have a tendency to produce a fluid pressure within the passageway, this tendency is made ine'l'l'ective by the venting of the passage to the atmosphere either thrmigh the tube I!) or the tube ll. It will also be observed that the level at which the fluid pressure begins to act upwardly immediately against the valve is a considerable distance above the level of the intake of the siphon so that when the siphonic action breaks, the liquid flowing backward is not sut'ficient in, quantity to rise up in the main tank and exert against the under side of the valve a sufficient pressure to again unseat it.

What I claim is new and desire to secure by Letters Patent is- 1. In a flushing apparatus, the combination of a main tank, means for discharging liquid thercinto, a priming tank having an opening communicating with the main tank, a float valve for controlling said opening, the under side of the valve being immediately exposed to the fluid pressure within the main. tank, means for trapping a body of air immediately against said exposed under side of the valve, whereby as the liquid .rises in the main tank it will compress the air and produce a sutlicient fluid pressure upward immediately against the valve to unseat it, a siphon for discharging the liquid contents of the tank, and means for dis charging into the priming tank a suiiicient quantity of liquid to prime the siphon when the valve is unseated as aforesaid.

2. In a flushing apparatus, the combination of a main tank, means for discharging liquid thereinto, a priming tank having an opening communicating with the main tank, a float valve for controlling said opening, said valve having a buoyant part exposed to the liquid in the priming tank, the under side of said valve being immediately exposed to the fluid pressure within the main tank, a siphon for discharging the liquid contents of the main tank, means for discharging into the priming tank a sufficient quantity of liquid to prime the siphon, and means for trapping a body of air immediately against the exposed under side of the valve, said main tank being open to atmosphere whereby as the liquid rises therein a body of air will be trapped immediately against the under side of the valve and there compressed sufficiently to automatically unseat it and permit a quantity of the liquid contents of the priming tank sufficient to prime the siphon to flow into the main tank.

3. In a flushing apparatus the combination of a main tank, a priming tank having an opening communicating with the main tank, a float valve for controlling said opening, the under side of said valve being immediately exposed to the fluid pressure within the main tank, means for forming beneath the valve an air-pressure chamber communicating with the interior of the main'tank, a siphon for discharging. the liquid contents of the main tank, means for discharging into the priming tank a sufficient quan tity of liquid to prime the siphon, and means for discharging liquid into the main tank, said main tank being open to atmosphere whereby as the liquid rises therein a hydrostatic column is formed of suficient height above the level of the bottom of the air-pressure chamber to produce within the tank a sufficient air pressure acting upward immediately against the valve to automatically unseat the valve and thereby permit a quantity of the liquid contents of the-priming tank sufficient to prime the siphon to flow into the main tank.

I 4. In a flushing apparatus, the combination of a main tank, means for discharging liquid thereinto, a priming tank having an opening communicating with the main tank,

a valve seat surrounding said opening, a float valve adapted to said seat, means for forming an air-pressure chamber surrounding said opening and extending downward into and communicating with the main tank, the under side of the valve being immediately exposed to the pressure of the air in said air-pressure chamber, produced by the rising of the liquid after it reaches the level of the bottom of said air chamber, a siphon for discharging the liquid contents of the main tank, and means for discharging into the priming tank a sufficient quantity of liquid to prime the siphon, said main tank being open to atmosphere whereby the liquid may rise therein and seal the bottom of the air-pressure chamber and thereafter continue to rise and form a hydrostatic column extending upward above the level of the bottom of the said air-pressure chamber a sufficient distance to produce within said air chamber a sufficient air pressure acting upward immediately against the valve .to automatically unseat it and thereby permit a quantity of the liquid contentsof the priming ,tank sufficient to prime the siphon to flow into the main tank.

5. In a flushing apparatus, the combination of a main tank, means for discharging liquid thereinto, a priming tank having an opening communicating with the main tank, a tube occupying said opening and having at its upper end a valve seat, its lower end being in communication with the main tank,

thereby forming an air-pressure chamber, a Y

float valve adapted to said seat and closing said air ressure chamber at to a si hon" for dischar ing the liquid contents of the main tank, and means for discharging into the priming tank a sufficient quantity of liquid to prime the siphon, said main tank being open to atmosphere, whereby asthe liquid rises therein it first seals the bottom of the air-pressure chamber and then forms a hydrostatic column extending, upward above the level of the bottom of said airpressure chamber a sufficient height to produce a sufficient pressure upon the air therein, acting upward immediately against the 'valve to automatically unseat it and thereby permit a quantity of the, liquid contents of the priming tank sufficient to prime the siphon to flow into the main tank.

PATRICK J. MADDEN. Witnesses: r i o L. M. Horxrns, R. H. HUNTSMAN.

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