US2739536A - Submersible sump pump control - Google Patents

Description

March 27, 1956 E. .1. SCHAEFER SUBMERSIBLE SUMP PUMP CONTROL Filed July 31, 1952 INVENTOR.

lduarciJfic/zaefer jlmaf 7 M I United States Patent O SUBMERSIBLE SUMP PUMP CONTROL Edward J. Schaefer, Fort Wayne, Ind.

Application July 31, 1952, Serial No. 301,951

6 Claims. 1 (Cl. 103-26) This invention relates generally to sump pumps and more particularly to a novel control means for a sump pump of the submersible type.

In my copending U. S. Patent No. 2,662,206, issued December 8, 1953, I have described and claimed a sump pump arrangement wherein the electric motor for the pump unit is of the submersible type and is positioned immediately adjacent to the pump. unit. The motor is rendered submersible by meansof a generally cylindrical shell or enclosure. which includes a flexible diaphragm means adapted to actuate a control switch for the motor in response to changes of water level outside the enclosure. Preferably, the-diaphragm means constitutes an end portion of the motor enclosure and, in addition, the diaphragm means is preferably arranged so that the entire motor enclosure functions as .a float control.

With the sump pump arrangement comprising my earlier invention the pump is. automatically turned on when the water in the sump reaches a. predetermined maximum level suflicient to deflect thediaphragm means and actuate the control switch. The-pump continues to operate until the Water in thersump recedes to a minimum level such that the head: of water in the sump is 'insufli? cient to deflect the diaphragm. means or lift the float whereupon the control switch ultimately returns to its normal off position. Thus, it will be seen that. the device functions to maintain the waterin the sump at a cer-' tain minimum level but inno case is the sump actually pumped to substantialemptiness.

In my copending application S. N'. 211,544, filed February 17, 1951, now U. S.- Patent No. 2,625,107, issued: January 13, 1953, I have described and claimed a; control means adapted to be used in combinationwith. a sump pump arrangement of thetype disclosed in my earlier copending application forthe purposeofinsuring continued operation of the pump until the sump; is substantially dry. The present invention relates to a dilferent type of control means foraccomplishing the same general result.

Accordingly, a primary object of my invention is to provide a novel sump pump. arrangement adapted to. empty a sump or the like to substantial dryness.

A further object of the invention is. to provide novel auxiliary control means fora float controlled. sump pump which insures continued operation of the pump for a predetermined time after the level in the sump falls below the minimum level for actuation of the float control.

Another object of the invention is to provide a novel submersible sump pump arrangement having a motor enclosure including main control means for the motorand an auxiliary control device adapted. to cooperate with the main control means for insuring operatiorrof the pump until the sump is substantially empty.

Other objects and advantages of the invention will become evident from the subsequent detailed description taken in conjunction with the accompanying drawing wherein:

Fig. 1 is a vertical sectional view of a sumppump arrangement comprising one specific embodiment of my invention; and

Fig. 2 is a view similar to Fig. l but showing amodifled form of the invention.

, 2,739,536 Patented" Mar. 27, 1956' Referring first to Fig. 1 of the drawing, wherein one specific embodiment of my invention is shown merely by way of illustration, the devicecomprises an electric motor 6 of a conventional type having a rotor'shaft 7de'pending therefrom. Disposed below" the motor 6'and immediately adjacent thereto is a centrifugal pump unit 8'of aconventional type havingan inlet 9' and an outlet 10 and arranged so that the pump casing-supports the weight of the motor. The device is shown as disposed at the bottom of a sump 111 The'pump impeller, indicated at 12, is secured at the lower end of 'theshaft 7"andthe latter is provided with a suitablerotating= seal 13" to prevent entry of water to the motor through the shaft outlet.

Surrounding the motor 6 for rendering the lattersub= mersible-is an enclosure, indicated generally at '14, which comprises a cylindrical body portion16'supported'on the motor 6-by means of a pair of substantially identical upper and lower end portions designated generally by the refer ence numeral 17. The bodyportion 16 is-preferably formed from relatively thin corrosion resistant metal such as stainless steel Each of the endportions 17 of the enclosure 14 comprises a deflectable diaphragm means including a relatively thin annular element 18 which maybe of metal. The outer marginal or peripheral edge of each of the elements 18 is turned inwardly toward the motor 6" to provide a flange or rim 19' which'is rigidly secured and sealed, preferably by welding, to'the inner periphery-of the body portion 16' of the-enclosure 14'. The inner marginal or peripheral edge ofeach element 18 is turned outwardly away from themotor '6, as at "21', and is flexibly attached to the motor 6 bymeans of an annular connecting collar, indicated generally at 22. Thecollars 22 are preferably formed from a resilient material such as-rubberorthe like andare generally U-shaped in crosssection'. Thus, each of the collar-s22 is formed. with relatively heavy concentric inner and outer ring portions 23 and 24, respectively, which are interconnected adjacent their outermost edg'es- -by a relatively thin" integral connecting portion 26. The collars 22 are secured to the elements 18 by means of the outwardly-turned edges 21 of the latter which are flared outwardly to a'slight extent in order to provide a snug engagement with the inner periphery of the collar portions 24. The inner portions 23 of the collars 22 fit snugly around the upper and lower hub portions'of the motor 6', as indicated at 27'and '28, respectively.-

Thus, the combination of the enclosure 14' with the upper and lower end portions or diaphragm means 17' forms a water-tight casing which renders the motor 6 submersible and at the sametimeconstitutes a float which is free for limited movement in a' verticaldirection upon flexing of the connecting portions 26 of 'thecollars 22, as hereinafter described.

For automatically regulating the operation of the motor 6, a control switch 29 having a depressible spring-pressed operating member or button 31 is mounted adjacent the upper portion of the motor 6 with the operating button 31'facing the upper annular element 18 in operative relation therewith. The switch 29 is of the toggle or snap action typein which a spring normally urges the toggle arrangement toward oneofits over-center positions and a substantial force sufficient to overcome the spring pressure is required to effect movement of the toggle to its opposite over-centerposition. It will be understood that the enclosure 14, which. is sealed to the upper and lower ends of the motor 6 by the end diaphragm means 17, will function as a float when the motor and pump unit are disposed at the bottom of a sump. Thus, .as the water level in the sump,ris es, .the. enclosure 14 containing trapped air is lifted upwardly relative to be repeated here.

the motor 6 by the buoyant effect of the water, the flexibleconnecting portions 26 of the collars 22 permitting this upward movement. Upon upward movement of the enclosure 14, the upper element 18 also moves upwardly and permits the operating button 31 to move outwardly under spring vactionwhereby to complete the electrical circuit for the motor 6 and thereby start the pump 8 in operation. Similarly, as the water level in the sump recedes during operation of the pump 8, the weight of the enclosure 14 causes the latter to move downwardly whereupon the upper element 18 engages the switch button 31 and ultimately the force applied to the button 31 depresses the latter to shut off the motor.

Means comprising a bridge-member and guide screws (not shown in detail in the drawing) is provided at the upper end of the motor for guiding and limiting the vertical movement of the float enclosure 14 relative to the motor 6. Details of this structure are described fully in my aforementioned Patent No. 2,662,206 and need not A dome-shaped cover 32 is detachably mounted over the upper end of the device with the depending skirt portion thereof fitting over and frictionally engaging the upper end of the body 16 of the enclosure 14, as at 33. A handle 34 is fastened to the cover 32 for raising and lowering the entire unit. Suitable electric wires, indicated at 35, are also provided for conducting electric current to the switch 29 and the motor 6, the

wires 35 entering the motor enclosure through suitable seal means (not shown).

As the motor 6 heats up during operation, the temperature of the air trapped inside of the enclosure 14 may vary as much as 50 C. Under such circumstances it is desirable to compensate for varying air pressure in order to avoid the possibility that an increase in air pressure inside the enclosure might cause movement of the enclosure relative to the motor and thereby effect the operation of the device independently of any change of water level. However, the provision of substantially identical diaphragm means 17, i. e. diaphragm means having substantially the same exposed areas, at the top and bottom of the cylindrical portion 16 of the enclosure 14 balances out the effect of varying air pressure within the enclosure and leaves the upward and downward movement of the enclosure 14 dependent solely upon external pressure. In other words, even if the pressure of the air surrounding the motor 6 and within the enclosure 14 should increase, the net force tending to move the enclosure 14 relative to the motor 6 will be zero because the force acting against the upper diaphragm means 17 tending to move the enclosure 14 upwardly will be counteracted by a substantially identical force acting against the lower diaphragm means 17 tending to move the enclosure 14 downwardly. .The cover 32 is provided with suitable means (not shown) for permitting drainage of water from the space between the cover 32 and the upper diaphragmmeans 17 and also for preventing air from being trapped in this space.

From the foregoing description it will be seen that the main control means for the sump pump unit comprises the diaphragm means 17 which are deflcctable in response to changes in liquid level outside the enclosure 14 for actuating the control switch 29. Withthis main control means alone the pump shuts off at a predetermined minimum water level in the sump which corresponds to the level at which the buoyant or lifting eifect is lost and the weight of the float 14 shuts oi? the switch 29. Such operation is satisfactory in many cases, but in other situations it may be desirable to have the sump emptied to substantial dryness. The primary feature of the present invention involves an auxiliary control means which supplements and cooperates with the main control means to insure continued operation of the pump until the sump is substantially empty, as hereinafter described in detail.

- Broadly speaking, the auxiliary control means which constitutes the principal feature of my invention comprises an auxiliary liquid receptacle or sump disposed ad jacent the lower end of the float enclosure 14 and adapted to maintain a predetermined liquid level therearound for holding the float enclosure 14 in its raised position even after the level in the main sump 11 has receded below the minimum level otherwise required for actuation of the main pump control switch 29. The auxiliary liquid receptacle or sump is provided with an orifice or gravity discharge opening of predetermined size so that the liquid drains from the auxiliary sump rather slowly thereby insuring operation of the pump until the main sump is substantially empty.

Thus, it will be understood that the slowly receding liquid level in the auxiliary sump provides a means for the delayed actuation of the float enclosure 14 and the control switch 29 independently of the liquid level in the main sump 11.

In the embodiment of the invention illustrated in Fig. l of the drawing, the auxiliary liquid receptacle or sump is provided by means of an upright wall 36 which extends around the upper portion of the pump housing to define a relatively shallow open reservoir or sump 3'7. As will be clearly seen from the drawing, the upper end of the auxiliary sump wall 36 extends upwardly beyond the lower end of the float enclosure 14 so that the latter is subjected to the buoyant effect of the liquid level in either the main sump 11 or the auxiliary sump 37. A discharge orifice 38 of predetermined size is provided adjacent the bottom of the auxiliary sump wall 36 to permit liquid to drain slowly from the auxiliary sump 37. By proper selection of the size of the orifice 3 5, it will be understood that the drainage time for the auxiliary sump 37 can be readily controlled in order to obtain continued operation of the pump for a sufficient period of time to empty the main sump 11.

When the water level in the main sump 11 is relatively high such as to cause the float enclosure 14 to be lifted upwardly and thereby actuating the switch 29, the water contained in the auxiliary sump 37 will have no particular effect on the operation of the unit since the efiect of the high water level in the main sump is sufficient to keep the pump in operation. However, as the water level in the main sump 11 recedes, the tendency is for the float enclosure 14 to move downwardly, as described above, with the result that the switch 29 would eventually be shut off if there were no other force acting on the float enclosure 14. By means of the present invention when the Water level in the main sump 11 recedes below the upper end of the auxiliary sump wall 36, the buoyant efiect of the liquid retained within the auxiliary sump 37 continues to urge the float enclosure 14 upwardly thereby insuring continued operation of the pump unit 8 until the level in the auxiliary sump 37 becomes so low that it no longer actuates'the float enclosure 14. During this continued or prolonged operation of the pump unit 8, the main sump 11 is pumped to substantial emptiness and ultimately the float enclosure 14 moves downwardly to shut oh the motor.

As previously mentioned, the size of the auxiliary sump 37 and the drainage orifice 38 will of course be proportioned in accordance with the size of the main sump 11 so that the prolonged'period of operation of the pump unit 8 is adequate to permit the main sump 11. to be substantially emptied. The relatively small amount of water which will continue to drain from the auxiliary sump 37 into the main sump 11 after the motor 6 has been shut ofi will be relatively inconsequential. As a practical matter, the effect of the auxiliary sump arrangement is to impart a time delay in the operation of the pump unit, and the auxiliary sump and its discharge orifice can be constructed initially to insure prolonged operation of the pump unit 3 for a suificient time to drain the maximum size sump in which the unit is likely to be installed.

Fig. 2 of the drawing illustrates a slightly different means or" dicharging liquid from the auxiliary sump, the structure of the unit being otherwise the same as in Fig.

l. The same reference numerals are employed in Fig. 1 and Fig. 2 to illustrate similar parts of the devices. In this form of the invention the discharge orifice, indicated at 39, is provided in the bottom wall of the auxiliary sump which also constitutes the upper wall of the pump housing. In addition, the orifice 39 is positioned substantially above the outer periphery of the impeller 12. When the pump is in operation, it will be understood that as long as suflicient liquid is present in the main sump 11 to be drawn in through the suction 9 of the pump unit, there will be little or no tendency for liquid to drain by gravity from the auxiliary sump 37 through the orifice 39. The fluid pressure of the liquid within the pump chamber under the centrifugal influence of the rotating impeller 12 will ordinarily be greater than the pressure induced by the small head of water in the auxiliary sump 37 so as to prevent drainage of liquid from the auxiliary sump 37 through the orifice 39. However, after the main sump 11 has been pumped to substantial dryness, the pumping chamber of the pump unit 8 will be empty and liquid can then readily drain from the auxiliary sump 37 through the discharge orifice 39 until the auxiliary sump level is low enough to permit the float enclosure 14 to shut oil the motor 6. Thus, in this embodiment of the invention the auxiliary sump is drained only after the water in the main sump has been removed to substantial emptiness.

As a result of the combination of the main control means comprising the deflectable diaphragm and the auxiliary control means constituting the principal feature of the present invention, I am able to control the operation of the pump to insure that the sump is pumped to substantial dryness. The main control means functions primarily to reduce the water level in the sump to a certain minimum point and thereafter the float enclosure surrounding the pump motor is actuated by the liquid retained in the auxiliary sump. Consequently, it may be said that the main control means functions in response to changes in liquid level in the sump, whereas the auxiliary control means functions independently of the liquid level in the sump. Thus, the auxiliary control means constitutes an important adjunct to a submersible sump pump of the type described in the present application and in my earlier copending application. This feature is of particular importace in a situation wherein it is desirable to maintain a sump in a substantially dry condition rather than merely maintaining the water level at some predetermined minimum.

Although the invention has been described in connection with certain specific structural embodiments, it will be understood that various modifications and equivalent structures may be resorted to without departing from the scope of the invention as defined in the appended claims.

I claim:

1. In a motor driven sump pump adapted to be disposed at the bottom of a sump, a pump unit, an electric motor connected to said pump unit, a casing structure around said motor to render the same submersible, a control switch for said motor Within said casing structure, said casing structure including diaphragm means disposed in operative relation with said switch and deflectable in response to changes in liquid level outside said casing structure for actuating said switch, and an auxiliary liquid chamber having an upright wall with a fully open top and disposed around the lower portion only of said casing structure for maintaining a quantity of liquid around said lower portion independently of the liquid level in the sump, said chamber having a discharge opening adjacent the bottom thereof for permitting liquid to drain slowly from the chamber after the liquid level in the sump has receded below its minimum effective level whereby the liquid in said auxiliary chamber effects prolonged operation of the pump to permit pumping of the sump to substantial emptiness.

2. The device of claim 1 further characterized in that said discharge opening is provided in the upright wall of said chamber to permit 11'; uid to drain from the chamber into the sump.

3. in a motor driven sump pump adapted to be disposed at the bottom of a sump, a pump unit, an electric motor connected to said pump unit, a control switch for said motor, casing structure around said motor to render the same submersible, main control means for said pump unit comprising a flexible diaphragm constituting an end portion for said casing structure and defiectable in response to changes in liquid level outside said casing structure for actuating said switch, and auxiliary control means comprising an open liquid reservoir with a fully open top and an upright wall disposed around the lower portion only of said casing structure and adapted to maintain a supply of liquid therearound independently of the liquid level in the sump, said reservoir having a discharge opening permitting liquid to drain slowly therefrom whereby the liquid level in said reservoir is adapted to eilect deflection of said diaphragm after the liquid in the sump has receded below its minimum effective level whereby to eflect prolonged operation of the pump unit until the sump is substantially empty.

4. In a motor driven sump pump adapted to be disposed at the bottom of a sump, a pump housing containing a pump, an electric motor mounted above the pump housing and connected to the pump, a casing structure surrounding the motor to render the same submersible, a control switch for said motor within said casing structure, said casing structure including diaphragm means disposed in operative relation with said switch and defiectable in response to changes in liquid level outside said casing structure for actuating said switch, and an upright wall extending from the upper portion of said pump housing and having a fully open top disposed in radially spaced relation around the lower portion only of said casing structure whereby to define an auxiliary liquid reservoir adapted to contain a supply of liquid in operative relation around the lower portion of said casing structure and independently of the liquid level in the sump, said reservoir having a discharge opening permitting liquid to drain slowly therefrom whereby the liquid level in said reservoir i adapted to efiect deflection of said diaphragm means after the liquid in the sump has receded below its minimum effective level whereby to permit prolonged operation of the pump until the sump is substantially empty.

5. In a motor driven sump pump adapted to be disposed at the bottom of a sump, a pump, an electric motor connected to said pump, a casing surrounding said motor to render the same submersible, a control switch for said motor within said casing, said casing including diaphragm means disposed in operative relation with said switch and deflectable in response to changes in liquid level outside said casing for actuating said switch, and structure defining a housing for said pump and an auxiliary liquid reservoir around the lower portion of said casing, said reservoir being adapted to maintain a liquid level around the lower portion of said casing independently of the liquid level in the sump, and said structure having a fluid passage between said reservoir and the interior of said pump housing to permit liquid to drain from the reservoir into the pump housing.

6. The device of claim 5 further characterized in that said pump comprises a rotating impeller and said fluid passage opens into said pump housing adjacent the periphcry of said impeller.

References Cited in the file of this patent UNITED STATES PATENTS 1,929,754 McCord Oct. 10, 1933 2,424,657 Goodman July 29, 1947 2,625,107 Schaefer Jan. 13, 1953 2,662,206 Schaefer Dec. 8, 1953

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