US3902028A

US3902028A - Pressure responsive switch

Info

Publication number: US3902028A
Application number: US450787A
Authority: US
Inventors: David L Tremain
Original assignee: Houdaille Industries Inc
Current assignee: STANWICH INDUSTRIES Inc 781 NORTH STREET GREENWICH CONNECTICUT 06830 A DE CORP
Priority date: 1974-03-13
Filing date: 1974-03-13
Publication date: 1975-08-26
Anticipated expiration: 1992-08-26

Abstract

A control switch mechanism for controlling a submersible sump pump, not provided with an integrally associated control mechanism, in which a housing is provided with electrical plug-in contact adapted to be inserted in a common electrical power outlet, for example of the wall type, with the housing structure supported thereat, the housing structure also containing an electrical outlet socket into which the electrical connecting cord of the sump pump is inserted. The plug-in contacts and outlet socket of the structure are adapted to be operatively connected by means of a pressure responsive switch, which is adapted to be actuated by means of a small continuously-operating air pump, for example of the vibratory type, which also is contained within the housing, the air pressure at the pressure switch being controlled by a vent line which is adapted to operatively extend to the liquid to be pumped by the sump pump, with normal air flow through the vent line being sufficient to prevent sufficient pressure at the pressure switch for actuation thereof and operation of the sump pump, until air flow through such vent has been restricted, by pressure of the liquid to be pumped, has increased to a predetermined value sufficient to cause said pressure responsive switch to be actuated by the air pressure thereat.

Description

United States Patent Tremain Aug. 26, 1975 PRESSURE RESPONSIVE SWITCH [57] ABSTRACT [75] Inventor? David Tremainv Sterling A control switch mechanism for controlling a sub- [73] Assignee: Houdaille Industries, Inc., Buffalo, merslble Sump P not Provided w integrally associated control mechanism, in which a housing is provided with electrical plug-in contact adapted to be [22] Flled: Man 1974 inserted in a common electrical power outlet, for ex- [21] Appl. No.: 450,787

[52] US. Cl. 200/81 R; 200/51 R; 200/83 R;

340/245; 339/117 R [51] Int. Cl. HOIH 35/24 [58] Field of Search 200/81 R, 81.9 R, 81.9 M,

200/83 R, 83 L, 51 R, 84 R, 84 C; 317/112; 339/117 R, 117 P, 35; 340/240, 244 R, 244 A, 244 B, 244 D, 245

Primary Examiner-Gerald P. Tolin Attorney, Agent, or Firm-Hill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson ample of the wall type, with the housing structure supported thereat, the housing structure also containing an electrical outlet socket into which the electrical connecting cord of the sump pump is inserted. The plugin contacts and outlet socket of the structure are adapted to be operatively connected by means of a pressure responsive switch, which is adapted to be actuated by means of a small continuously-operating air pump, for example of the vibratory type, which also is contained within the housing, the air pressure at the pressure switch being controlled by a vent line which is adapted to operatively extend to the liquid to be pumped by the sump pump, with normal air flow through the vent line being sufficient to prevent sufficient pressure at the pressure switch for actuation thereof and operation of the sump pump, until air flow through such vent has been restricted, by pressure of the liquid to be pumped, has increased to a predetermined value sufficient to cause said pressure responsive switch to be actuated by the air pressure thereat.

10 Claims, 5 Drawing Figures 52 43 l l/g.

l 47 l l a /C E l Er J2 llll 55 i ll Z 9 A1 t q, U 5 '11 w 2 l l a PATENTEB AUG 2 61975 PRESSURE RESPONSIVE SWITCH BACKGROUND OF THE INVENTION The invention is directed to a pressure responsive structure adapted to be employed for the control of sump pumps and the like which have no integrally associated control means, i.e. pressure responsive means for actuating such sump pump upon a predetermined rise in the liquid to be pumped.

Many sump pumps are provided with a built-in pressure responsive switch which is adapted to actuate the electric motor of the pump when the liquid level to be pumped reaches a predetermined height. Pressure responsive switches of this type are usually employed with submersible types of sump pumps, while the vertical or stand-up type of sump pump, in which the motor is disposed well above the liquid level of the fluid being pumped, usually employs a float-actuated type of switch mechanism, with the switch normally being disposed at the very top of the structure, for example suitably carried by the motor. It will be appreciated that where a submersible pump is involved, the pressure switch structure, lines thereto etc. all must suitably be sealed with respect to the liquid being pumped and if the switch fails to properly operate, the pump must be removed or repaired. This in turn would normally also entail disconnection of the discharge line, often in the form of a rigid or semi-rigid metal or plastic type, necessitating a down period during which the pump is inoperable.

The present invention therefore is directed to the provision of a pressure responsive switch mechanism, adapted to be operated by changes in height of liquid to be pumped, in which the control mechanism may be readily operatively interposed between an electrical wall outlet or the like and the power cord of the pump involved with the control mechanism being remote from the pump structure itself and at a location convenient for replacement or repair. The mechanism thus is completely divorced from the pump structure itself so that the pump, in an emergency, may be operated without the automatic control mechanism.

The pressure responsive switch, in turn, is adapted to be controlled by fluctuation of the level of the liquid to be pumped, by means of a relatively small tube or conduit which extends from the control unit to a convenient location at which the free end of the tube is so disposed with respect to the liquid to be pumped that upon rise in the liquid level to a predetermined height such liquid will so impede air flow through the tube that air pressure at the switch will effect actuating thereof.

The entire structure may be quite compact, readily enabling its mounting at the wall, or other type ofoutlet socket, with the air pump employed preferably being of small and inexpensive construction, as for example a vibrator type pump of the type commonly employed to supply air to small home aquarium tanks and the like. It will be appreciated that by eliminating the immersion of the switching mechanism into the liquids to be pumped, in addition to the elimination of sealing problems, corrosion and/or other deterioration of parts from the liquid contacting any exposed portions of the switch is also avoided.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings wherein like reference characters indicate like or corresponding parts:

FIG. 1 is a semi-diagrammatic view of a submersible pump structure and the application of the present invention thereto;

FIG. 2 is a transverse cross-section through the pressure responsive mechanism taken approximately on the line II-lI of FIG. 3;

FIG. 3 is a plan section taken approximately on the line III-III of FIG. 2; and

FIG. 4 is a transverse sectional view taken approximately on the line IVIV of FIG. 2; and

FIG. 5 is a semi-diagrammatic view of the air bell l5 and associated structure.

DETAILED DESCRIPTION OF THE INVENTION General Construction Referring to the drawings and more particularly to FIG. 1, the reference numeral 1 indicates generally a control structure adapted to control a submersible type pump or the like indicated generally by the numeral 2, having a pump body 3 adapted to be powered by a suit able electric motor 4, with the pump body having a plurality of liquid inlets 5 and a discharge port to which is operatively connected a discharge pipe or conduit 6, with the pump 2, in the example illustrated being disposed at the bottom of a suitable sump indicated generally by the reference numeral 7, from which liquid is to be pumped.

The electric motor 4 is provided with a connecting power cord 8 terminating at its free end in a standard electrical plug 9, which normally will be of the three prong type with the third terminal providing a grounding connection.

As illustrated in FIGS. 2 and 4, the structure I is provided with plug-in type contacts, indicated generally by the reference numeral 10, which generally correspond to the comparable contacts carried by the plug 9 and which are adapted to be inserted directly into a wall type socket or the like, such as the socket ll illustrated in FIG. 1 which may be of the usual wall type and mounted directly on a wall surface 12, and having a cover plate 11.

As hereinafter described in detail, the housing 1 is adapted to contain a pressure responsive switch, the operation of which is controlled by a sensing tube or conduit 13 extending from the housing I with its free end adapted to be operatively disposed with respect to the liquid 14 contained within the sump 7, the free end of the conduit 13 in the example illustrated being connected to an inverted cup-shaped air bell 15, illustrated in the present example as being supported by the motor 4, with the lower end of the bell disposed in the liquid.

In operation, upon a predetermined rise in liquid level with respect to the adjacent end of the conduit 13, the pressure responsive switch contained in the housing 1 will be actuated to complete electric connection from the outlet 11 to the electric motor 4 and actuate the pump. Such operation will continue until the liquid level in the sump 7 drops to a predetermined level with respect to the end of the conduit 13, at which time the pressure responsive switch will open thereby discontinuing operation of the motor 4.

It will be appreciated that with this construction all of the control mechanism is contained in the housing l, remote from the pump structure as well as from the liquid to be pumped, with the control mechanism merely requiring interposition between the plug 9 and the outlet 1 1, and the tube 13 operatively disposed with respect to the liquid to be pumped.

In the event of failure of the control mechanism to properly operate, it may be readily replaced, the pump being operated continuously, if desired, merely by inserting the plug 9 directly into the outlet 1 l, or likewise may be repaired without shut-down of the pump.

As the control structure is remote from the liquid being pumped, it is not subject to corrosive or other deteriorative action, for example, as a result of condensation in the switch mechanism, etc.

Details of Construction Referring to FIGS. 2-4 the housing 1 is constructed from two base components, a base member 16 and a cover member 17, formed in suitable manner from a suitable material, as for example as molded plastic components, which are adapted to be secured together by suitable means such as screws 18 extending through the base member and threaded into enlargements 19 disposed at the corners of the cover member 17. The plug-in contacts comprise a pair of spring contacts 100 and 10b and a ground pin 100 which are suitably supported from an enlargement 20 formed on the base member, the contacts 10a and 1012 being secured to the member 20 by screws 21 threaded therein. The contact 10a is integrally formed with socket contact 11a, socket contact 1112 also being provided which is secured to the molded enlargement 22 of the cover member 17 .by a suitable screw 21. As clearly illustrated in FIG. 2 the contact 10c is provided at its upper end, as viewed in FIG. 2, with a split socket portion 110 which is adapted to receive the ground pin of the usual cord plug 9.

Mounted on the base 16 by means of a switch supporting member 24, is a pressure responsive switch indicated generally by reference numeral 25, the pressure switch being of standard construction, commercially procurable, the details of which therefore form no part of the present invention. The switch 25 is secured to the base 16 by a plurality of screws 26 extending through radially extending projections on the pressure switch 25, passing through cooperable bores in the supporting member 24, and threaded into the base member 16, a gasket 27 being interposed between the opposed horizontal faces of the pressure switch and the supporting member 24. In the embodiment illustrated, the switch supporting member 24 may be suitably cemented or plastic welded to the face 16 to form a sealed joint therebetween with each being formed with one-half of a conduit engageable nipple 28, adapted to receive and support the adjacent end of the conduit 13. It will be noted that cooperable portions of the base 16, switch supporting member 24, and the pressure side 25' of the switch define an air chamber 29 which communicates through passageway 30 extending through the nipple 28, with the interior of the tube or conduit 13.

As will be apparent from a reference to FIGS. 2 through 4, the pressure switch 25 is provided with contacts 31b. and 31b which are adapted to be operatively connected by the pressure responsive mechanism of the switch 25 when the pressure in the chamber 29 exceeds a predetermined value. Contact 31b of the switch is operatively connected over a conductor 32 with the contact 1012 of the plug 10 while contact 31b is operatively connected by a conductor 32' to the contact 11b of the socket 11.

Also disposed within the housing 1 is an air pump, indicated' generally by the reference numeral 33, comprising a pump structure 34, adapted to be actuated by a vibrating armature 35 which is energized by a cooperable coil 36 which includes a winding 37 and cooperable core 38, with the vibrator arm 35 being actuated by a permanent magnet 39 carried thereby, cooperable with the core 38. The pump member 34 is provided with an air outlet stem 40 which is disposed in a bore 41, formed by cooperable semi-circular depressions in the base member 16 and the switch supporting member 24, with the member 40 being secured in sealed relation to the base and switch supporting member, with air thus being supplied by'the pump to the chamber 29. In addition, the pump body 34 may be secured by cement or the like to the adjacent face 42 of the base member.

As illustrated in FIGS. 3 and 4, the armature 35 is provided with an end portion 43 adapted to be fixedly retained in projecting means 44 carried by the base 16 and cooperable projecting means 45 carried by the cover member 17, such projecting means having complimentary indentations to receive the adjacent portions of the vibrating arm and firmly retain the same in operative position. In like manner the core 38 of the coil 36 is adapted to be firmly retained in operative position by projections 46 carried by the base member 16 and

projections

47 and 48 carried by the cover member 17, with

projections

46 and 47 being positioned in cooperable slots in the core structure 38.

Thus upon passage of an alternating current through the winding 37, a magnetic flux will be produced, cooperable with the magnet 39 to vibrate the armature 35 and through a suitable projection 49 on the armature 35, actuate the diaphragm of the pump member 34. The winding 37 is adapted to be continuously energized during operation of the device and thus has one end of the winding operatively connected, over a conductor 50, to the conductor 32 at the terminal 31b, and the opposite end connected by a conductor 51 to the contacts 10a and 11a.

FIG. 5 illustrates details of the air bell 15, which likewise can be constructed of plastic or other suitable material, and consists of a generally inverted cup-shaped member 52 open at its bottom and provided with a tube-connecting stem 53 to which the free end of the conduit 13 is operatively connected. The air bell 15 is provided with a mounting bracket 54, illustrated as being integrally formed with the bell member and constructed to receive one or more mounting screws 55 which, in the embodiment illustrated, are threaded into the body 3 of the pump 2.

Thus, the air pressure in the bell 15 and consequently in the chamber 29 will be dependent upon the height 1 of the water level above the bell member, and when the water level is low, as illustrated in FIG. 5, the pressure in the chamber 29 will be insufficient to actuate the pressure responsive switch 25, and the pump motor 4 will remain inoperative. However, upon such the water level rising to a predetermined height, as determined by the output of the pump 33 and the height of the water level above the bell 15, a point will be reached at which the pressure within the chamber 29 is sufficient to actuate the pressure responsive switch 25, closing its contacts and thereby completing the electrical circuit from the plug 10 to the socket 11. The pressure responsive switch 25 preferably is of the overcenter type so that once the switch has been actuated to closed position, it will not be opened until a restoring force acting against the diaphragm is operative at a sufficiently low pressure level to overcenter the switch mechanism in the reverse direction, opening the electrical circuit and disconnecting the power source from the pump. Thus, energization and de-energization of the pump will take place within a suitable operating differential therebetween.

in pressure responsive switches of the type illustrated, the biasing force thereon can be adjusted by means of a suitable set screw or the like and by suitable proportioning of the air pump capacity, pressure switch adjustment and size of the air bell various combinations of operating parameters may be derived. It will also be appreciated that the operating parameters will also depend upon the nature of the liquid to be pumped. In the event water is not involved, as actuation in re-set pressure levels for the switch are commonly calibrated in inches of water a correction, taking into account the specific gravity of the liquid involved, must be made for the inches of liquid level above the discharge end of the air tube required for actuation and reset of the switch.

It will be appreciated from the above description that I have provided a very compact, relatively simple and yet highly efficient pressure responsive control mechanism for'the operation of a submersible pump, which may be employed within a wide range of pumps of varying capacities, etc. limited substantially merely by the current carrying capacity of the pressure responsive switch and associated current conducting members, with the control mechanism not only being disposed remote from the pump structure and out of the liquid being pumped, but also disposed directly at the point of connection of the pump with the supply line, eliminating all electrical cables, etc. for the connection of the control mechanism and employing merely a single, relatively small tubular conduit which may be suitably proportioned to enable its usage over relatively long distances and requiring a very simple installation.

Having thus described my invention it will be obvious that although various minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent granted hereon all such modifications as reasonably, and properly come within the scope of my contribution to the art.

I claim as my invention:

1. A control switch mechanism for controlling a sump pump having no integrally associated control mechanism, comprising a housing structure having electrical plug-in contacts extending therefrom, and inserted in an electrical power outlet, with the housing supported from such an outlet, an electrical outlet socket structure carried by said housing, into which the electrical connecting cord of a sump pump to be controlled is to be inserted, means, including a pressure responsive switch, disposed in said housing for selectively completing operative connection between said electrical plug-in contacts and cooperable electrical outlet socket, a self-contained electrical air pump disposed in said housing, said pump having an air inlet, and an air outlet operatively connected to the actuating pressureside of said pressure switch, with said air pump being operative to discharge air at a pressure sufficient to actuatesaid pressure switch, said housing having an air vent port operatively communicating with the actuating pressure side of said switch, of a size to accommodate unrestricted flow of sufficient air to reduce the air pressure at said switch, resulting from the operation of said air pump, to below that required to actuate said switch, and tubular means operatively connected to said air vent port, said tubular means having a relatively open free end and being of a size to permit such unrestricted air flow through said air vent port, the open end of said tubular means being adapted to be so disposed with respect to the liquid to be pumped by said sump pump that such liquid will exert a pressure in said tube opposing the flow of air therethrough, whereby the liquid pressure at a predetermined liquid level will sufficiently restrict such air flow through said vent port thatsufficient air pressure will exist at said pressure responsive switch to effect actuation thereof.

2. A control switch mechanism according to claim 1, wherein said housing is provided with means cooperable with the pressure responsive switch to form an air chamber at the actuating pressure side thereof, said air outlet of the air pump and said air vent port communicating with said air chamber, whereby operation of said pressure responsive switch is controlled by the air pressure in said chamber.

3. A control switch mechanism according to claim 1, wherein said plug-in contacts are mounted on said housing, the latter being provided with means adapted to receive a mounting screw, which means is so positioned with relation to said plug-in contacts that when the latter are engaged with an electrical power outlet, such a mounting screw may be substituted for the usual mounting screw of an electrical power outlet cover plate, with the housing thus fixedly connected with such a power outlet socket.

4. A control switch mechanism according to claim 1, comprising in further combination, an air bell, comprising an inverted cup-shaped member having an open bottom end, and provided with an air inlet at its upper end, said tube means having its free end connected to said air inlet whereby air discharged from said housing is conducted to said air bell, said open end having a cross-sectional area considerably greater than that of said tubing means.

5. A control switch mechanism according to claim 1, wherein said air pump comprises an electrical pump having a diaphragm-type pumping mechanism, a vibratory armature operatively related to said pumping mechanism for actuating the same, and an electrical coil structure, comprising a winding and a paramagnetic core, disposed to effect vibration of said armature, said winding being operatively connected to said plug-in contacts, whereby said pump, in use, will be continuously operated.

6. A control switch mechanism according to claim 5, wherein said housing comprises a base member and a cover member connected thereto, said vibrator armature being mounted on said housing in interlocked relation with cooperable elements on both the base and cover members.

7. A control switch mechanism according to claim 6, wherein said electrical coil structure is retained in operative position with respect to said armature by cooperable elements on both the base and cover members.

8. A control switch mechanism according to claim 7, wherein said base is provided with means adapted to 10. A control switch mechanism according to claim 8, comprising in further combination, an air bell, comprising an inverted cup-shaped member having an open bottom end, and provided with an air inlet at its upper end, said tube means having its free end connected to said air inlet whereby air discharged from said housing is conducted to said air bell, said open end having a cross-sectional area considerably greater than that of said tubing means.

Claims

1. A control switch mechanism for controlling a sump pump having no integrally associated control mechanism, comprising a housing structure having electrical plug-in contacts extending therefrom, and inserted in an electrical power outlet, with the housing supported from such an outlet, an electrical outlet socket structure carried by said housing, into which the electrical connecting cord of a sump pump to be controlled is to be inserted, means, including a pressure responsive switch, disposed in said housing for selectively completing operative connection between said electrical plug-in contacts and cooperable electrical outlet socket, a self-contained electrical air pump disposed in said housing, said pump having an air inlet, and an air outlet operatively connected to the actuating pressure-side of said pressure switch, with said air pump being operative to discharge air at a pressure sufficient to actuate said pressure switch, said housing having an air vent port operatively communicating with the actuating pressure side of said switch, of a size to accommodate unrestricted flow of sufficient air to reduce the air pressure at said switch, resulting from the operation of said air pump, to below that required to actuate said switch, and tubular means operatively connected to said air vent port, said tubular means having a relatively open free end and being of a size to permit such unrestricted air flow through said air vent port, the open end of said tubular means being adapted to be so disposed with respect to the liquid to be pumped by said sump pump that such liquid will exert a pressure in said tube opposing the flow of air therethrough, whereby the liquid pressure at a predetermined liquid level will sufficiently restrict such air flow through said vent port that sufficient air pressure will exist at said pressure responsive switch to effect actuation thereof.

8. A control switch mechanism according to claim 7, wherein said base is provided with means adapted to receive a mounting screw, which means is so positioned with relation to said plug-in contacts that when the latter are engaged with an electrical power outlet, such a mounting screw may be substituted for the usual mounting screw of an electrical power outlet cover plate.

9. A control switch mechanism according to claim 8, wherein said plug-in contacts extend from said base member and said electrical outlet socket is carried by said cover member, with said contacts and socket being disposed on a common axis.

10. A control switch mechanism according to claim 8, comprising in further combination, an air bell, comprising an inverted cup-shaped member having an open bottom end, and provided with an air inlet at its upper end, said tube means having its free end connected to said air inlet whereby air discharged from said housing is conducted to said air bell, said open end having a cross-sectional area considerably greater than that of said tubing means.