US3441696A - Delayed action hydrostatic switch - Google Patents

Description

United States Patent 3,441,6596 DELAYED ACTIQN HYDROSTATEC SWITCH Axel L. Nielsen, 1316 E. Elza, Hazel Park, Mich. 48030 Filed Aug. 28, 1967, Ser. No. 663,718 Int. Cl. Htllh 35/24 U.S. Cl. 200-81 5 Claims ABSTRACT OF THE DISCLOSURE A delayed action hydrostatic switch is disclosed which provides for the rapid force draining of a receptacle, such as an accumulating sump, a basement floor riser, a laundry tray or tub, and the like, by a motorized pump. The switch is disciplined or controlled to delay its deenergization and that of the pump motor, once pumping has commenced, until the receptacle is substantially dry. Thus, water is drained by the pump from the receptacle in a very fast way, indeed.

The result is brought about by maintaining within the receptacle a column of liquid distinct from the liquid being directly pumped from the receptacle. This liquid column surrounds the lower end of an upright pressure transmitting tube and traps therein a column of air acting on a flexible diaphragm of the switch. The upper end of the outer tube, into which the liquid initially enters in substantial volume and at a flooding rate from the main liquid body in the receptacle, is at an elevation no less than that at which the liquid Within the inner tube will sufliciently drop the compression of the trapped air column to permit opening of the motor switch and terminate pumping. Actually, and as disclosed herein, the upper end of the outer tube will be well above this level, in the interest of securing a more extended period of pumping.

An essential feature resides in the fact that the outer tube has valve or equivalent restriction means, as at its lower portion, to insure that the columns of liquid in it and in the inner tube will drain therefrom much more slowly than the dropping of liquid level in the remainder of the receptacle by pumping. This is to such an extent, preferably, that the sump, riser, tub, tray, or other receptacle will normally be wholly emptied before the level in the inner tube has dropped enough to lower the hydrostatic-pressure on the switch diaphragm and stop the pump. The cycle repeats after both tubes have drained empty and the liquid level in the main receptacle has risen sufiiciently to raise hydrostatic-pressure on the switch diaphragm to start the pump again.

A simple adjustment of the valve or like drain control restriction of the outer tube permits a reliable regulation of the rate of draining of the outer tube, for a tube of any given inner diameter and height.

Background 0 the invention Difliculties have heretofore been experienced in the force-pumping of basement flood or seepage accumulator sumps and floor risers, also laundry tubs, and the like, in which initiation and termination of the operation of the pump motor is under control of a pressure responsive switch, usually of the diaphragm type. Briefly, it has been found that as time goes on the commencement and duration of pumping lack uniformity in succeeding pumping cycles, with the result that many customer complaints have been received.

The present invention provides a method of rapidly force-draining a receptacle, employing a delayed action, hydrostatic pressure-responsive, diaphragm type switch 3,441,696 Patented Apr. 29, 1969 whose control provisions reliably and accurately time the uniform commencement and termination of pumping, hence eliminate the cause of complaint. Furthermore, they insure a very rapid and complete emptying of the receptacle.

Gross reference to related application The improvement is related in a general way to that of my copending application, Ser. No. 371,293, filed June 1, 1964, now abandoned and entitled Drainage Accumulator and Pumping System.

In my U.S. Patent No. 2,922,854, Jan. 26, 1960, I have disclosed a sump pump control which utilizes a control means to alter the rate of vertical rise of liquid entering a tube, such as the tube 70 hereof. The present invention may be incorporated into such structure, if desired.

Summary of the invention The invention relates to a method and equipment for repeatedly draining a receptacle of liquid with great rapidity and in pumping cycles of uniform duration. A hydrostatistically responsive pump control switch housing is variably pressurized in a pressure chamber thereof through a first upright tube, thus to actuate a pump motor control switch as the tube is increasingly pressurized. This occurs when the liquid level in the receptacle rises predeterminedly. However, the deactuation of the switch is caused to be substantially delayed notwithstanding a drop in the receptacle level under pumping, in fact until the receptacle is wholly pumped out.

This result is bad by providing a second tube of larger diameter surrounding the first tube and filled from above with liquid at a predetermined receptacle level. The second tube has a restricted gravity discharge at its bottom, and thus maintains a head of water about and in the lower end of the first tube. The restricted discharge then occasions a much slower drop of head in the tubes than the drop of the level in the receptacle being pumped; and this in turn produces the desired increase in time of the pumping operation.

Brief description of the drawing FIGURE 1 is a side elevational and vertical sectional view of the delayed action hydrostatic switch as mounted on tub type of receptacle;

FIGURE 2 is a top plan view of the switch; and

FIGURE 3 is a schematic view of the electrical system employed with the switch.

Description of a preferred embodiment Referring to the drawing, it will be noted that the delayed action hydrostatic switch 10 is mounted to a laundry tub or like receptacle 12. However, it is to be understood that the switch is equally applicable in the force draining of a sump, a flood or seepage accumulating floor riser (as in my copending application identified above), etc. The receptacle 12 is provided with an outlet or basket 14 in its bottom wall 16; and a centrifugal pump 18, illustrated diagrammatically, is connected to the outlet for rapidly draining the tub to a sewer or other main drain under a pressure head greater than that provided by gravity.

The hydrostatic switch 10 includes a U-shaped support member 20 which serves to carry the working components of the switch structure and to secure the structure to the receptacle 12. As will be noted, the upper edge portion of the tub side wall 22 is received within the cavity defined by the support 20; and a clamping screw 24 is threadedly received in an opening provided in the outer wall 26 of the support 20. The screw 24 engages the outer surface of the side wall of the tub and, with the end wall 28 3 of the support 20, causes the switch structure to be firmly secured to the tub.

A diaphragm and switch housing 30, which is of known type comprising upper and lower halves 32, 34 is secured to the support 20 by means of screws 36. A flexible diaphragm 38 extends across the interior of the housing and divides the housing into an upper switch receiving portion. The diaphragm 38 is secured between the housing halves by means including an annular gasket 42, to make the housing fluid-tight, and screws 44.

The upper housing half 32 is provided with a central internally threaded boss 46 which threadingly receives an externally threaded tubular portion 48 of a normally open pressure sensitive electrical switch 50; and an electrical cable 52 leads from the switch 50 to a power source, as will more fully be described in connection with the electrical diagram illustrated in FIGURE 3. The switch 50 has a downwardly depending actuating element 54 which serves to open and close the switch, the element 54 being shown in a position to cause the switch to be open. It downwardly contacts a pad 56 on the upper surface of the diaphragm 38. Upward movement of the diaphragm will, at a predetermined pressure therebelow, cause the element 54 to be depressed to close the switch and energize the motor which drives pump 18.

The switch 50 is of a conventional type in that it takes a pressure of, for example, eight ounces, to depress element 54 and close the switch. The element 54 will not return to its initial position until the pressure has been reduced to a lower value, as for example four ounces.

A female electrical connector 58 is mounted on the upper housing 32; and this connector is adapted to receive a male connector (not shown) through which the motor of pump 18 is energized. Another cable 60 leads from female connector 58 to the switch 50. A manual offon override switch 62 is also mounted on the housing, with an operating element 64 thereof being externally accessible for arbitrarily turning the pump 011 and on by overriding switch 50.

The lower housing portion 34 has a central internally threaded boss 68; and an elongated tube 70 having a threaded portion 72 on the upper end thereof is received in the bore 68. The tube 70 extends downwardly towards the bottom of the receptacle 12, terminating a short distance from the latters bottom surface. A fitting member 74 is threadedly connected into the housing boss 68 and secured to the top of tube 70 to make a union in this zone.

An outer tubular drainage control member 76 surrounds the lower portion of the tube 70, the upper portion of the outer tube 76 may be closed by a screen 78 which perrnits free, in fact a flooding, overflow passage of liquid into the top of outer tube 76 at a predetermined liquid level in receptacle 12, but filters solid materials.

The inner, pressure transmitting tube 70 terminates at a point short of the lower end of the control tube 76 and perforated spacer 80 is provided at the lower end of the tube 70 to secure the latter in the proper position and to provide support for the outer tube 76, at the same time keeping the two tubes in free communication with one another at the bottom of the innermost.

An annular resilient plug member 82 is inserted in the outer tube 76 at the lower end thereof, which plug member 82 may be removable to permit cleaning of the unit. In any event, it has a central aperture 84, or some equivalent means, which serves as a restriction to the gravitational flow of liquid out of the outer tube 76, hence also out of the tube 70. This essentially is the basis of the delayed drainage contemplated by the inventor. Typically, for the purpose a closure element 86 is provided on the undersurface of the plug 82, being secured by means of a nut and bolt device.

Thus the closure member may be pivoted about the axis of the nut and bolt structure to partially cover or fully expose the aperture, so that a variable restriction to the flow of liquid from the outer tube is provided. This enables an adjustment of the duration of the force drain operation.

The electrical circuitry of the system is illustrated in FIGURE 3. Three leads, namely positive lead 92, ground lead 94 and negative lead '96 extend from a source of power. The ground and negative leads 94, 96 are directly connected to pump 18. The positive lead 92 is connected to a terminal 98 of the pressure sensitive switch 50. A lead 100 extends from the other terminal 102 and is connected to a terminal 104 of the manual override switch 62. A lead 106 extends from the terminal 98 of switch 50 and is connected to a terminal 108 of the switch 62. A lead 110 extends from the terminal 104 to the pump 18.

As will be appreciated from the above-described circuit, the switches 50, 62 are arranged in parallel. Closure of either switch will thus cause the pump 18 to be activated. When the switch 50 is closed by the diaphragm 38, the pump will begin operation. A similar result may be achieved by manual closure of the switch 62.

In the operation of the improved switch and system, reference being had to FIG. 1, a rise of liquid in the receptacle 12 will eventually fiood the outer tube 76 from above; and it will be assumed that when the columns of liquid therein and in the inner tube 70 rise to a 'height indicated, for example, at 90 the air trapped in the tube '70 becomes sufficiently pressurized to operate diaphragm 38 and close the normally open switch 50, thus causing the motorized drive of pump 18. A rapid forced evacuation of receptacle 12 ensues, but the drop of level in tubes 70 and 76 proceeds much more slowly, until it reaches a level, say, at 112 at which the air column in tube 70' is sufficiently decompressed to permit switch 50 to open.

By this time, receptacle 12 will have been completely drained, and the restriction valve 86 may be adjusted so as to delay pumping still more, if desired. At any rate, the tubes 70 and 76 continue to drain gravitationally, until the lower end of the pressure transmitting tube 70 is wholly exposed, whereupon it refills with air preparatory to the next tub pumping cycle.

While the outer control tube 76 is shown as being of a quite extended height, for a considerably protracted pumping period, it will be understood that, pursuant to the principle of the invention, the outer tube need be of a height only to exceed the critical lower level, for example at 112, at which diaphragm 38 is depressurized and pumping terminates.

What I claim as my invention is:

1. A delayed action hydrostatic switch comprising a housing providing a hydrostatic pressure chamber, a first open-ended tubular member in communication with said chamber and extending from said housing for disposition in a receptacle from which liquid is to be drained, said chamber being variably pressurized in accordance with the level of liquid in said tubular member, and a second tubular member surrounding at least the lower portion of the first member and adapted to receive liquid from said receptacle at a predetermined liquid level in the latter, there being a liquid flow restriction in at least one of said tubular members acting to delay draining thereof during draining of the receptacle.

2. The switch of claim 1, in which the upper portion of the second tubular member is exposed to liquid in the receptacle to permit rapid filling of said second member when the liquid level in the receptacle rises predeterminedly, and further comprising a pump connected to the receptacle to drain the latter, and pump-controlling switch means on the housing operated in response to pressurization of said chamber by a rising level of liquid in the first tubular member to operate the switch means and actuate the pump, a relatively slowly falling level of liquid in the second tubular member reducing the pressure in said first member and chamber to a predetermined point to deactuate the pump in delayed time relation to the draining of the receptacle.

3. The device of claim 1, in which said liquid flow restriction is adjustable.

5 4. The device of claim 1, in which said liquid flow restriction is on said second tubular member.

5. The device of claim 2, in which said liquid flow restriction is on said second tubular member and is adjustable in 'area.

References Cited UNITED STATES PATENTS 2,514,632 7/1950 Flubacker 200-8391 XR 3,043,225 7/1962 Nielsen ZOO-83.91 XR 3,055,994 9/1962 Lundeen 20083.91 XR 6 3,250,872 5/1966 Hellman 20083.1 3,363,075 1/1968 Jordan et a1. ZOO-83.1 3,200,389 8/1965 Damico et a1. 200-81 XR 5 ROBERT K. SCHAEFER, Primary Examiner.

H. BURKS, Assistant Examiner.

US. Cl. X.R.

Images