WO2009013593A1

WO2009013593A1 - Fluid-tight electric connection device, in particular for supplying and controlling a submerged pump

Info

Publication number: WO2009013593A1
Application number: PCT/IB2008/001899
Authority: WO
Inventors: Dino Chirumbolo
Original assignee: Itw Industrial Components S.R.L. Con Unico Socio
Priority date: 2007-07-24
Filing date: 2008-07-22
Publication date: 2009-01-29
Also published as: ITTO20070549A1

Abstract

A fluid-tight electric connection device including a tubular body formed by electrically insulating material, a first and a second opposite open ends of which delimit therein a first and a second cup-shaped seats, separated by a common bottom wall obtained transversally to, and integrally with, the tubular body and throughly crossed by a plurality of blade contact elements;; and a casing including at least two reciprocally and fluid- tightly coupled half shells and accommodating therein the first end of the tubular body through a first end thereof, f luid-tightly fixable in use to a case of a submerged pump, and throughly crossed by the tubular body, the casing displaying a second end provided with through, fluid-tight inlet means in the casing of at least one electric cable. The bottom wall is entirely coated, bya layer of sealing resin in which the blade elements are embedded and the tubular body is laterally and externally provided with an annular flange abuttingly cooperating against the first end of the casing to be sandwiched in use between the latter and the support to which it is fixable.

Description

FLUID-TIGHT ELECTRIC CONNECTION DEVICE, IN PARTICULAR FOR SUPPLYING AND CONTROLLING A SUBMERGED PUMP

TECHNICAL FIELD The present invention relates to a fluid-tight electric connection device, particularly indicated for connecting the electric supply cable and the control cable (generally coming from a float level indicator) to a pump intended to operate in a submerged manner, i.e. immersed in the liquid to be pumped.

BACKGROUND ART

It is known that in such a type of applications, die-cast wirings are used, which form a single body with the case of the pump and which are then connected to the electric supply cable and the possible control cable, coming from a float, by means of head connectors of the fluid-tight type commonly available on the market, formed by two or more screwed elements. Such a type of connection is disadvantageous and expensive and does not allow to intervene on the wiring, thus actually obliging to replace the pump in case of any type of fault.

DISCLOSURE OF INVENTION

It is the object of the present invention to solve the drawbacks of the known described devices, by providing a device with high reliability, low production and assembly cost and small dimensions. The present invention thus relates to a fluid-tight electric connection device as defined in claim 1. In particular, the device according to the invention comprises: a tubular body formed by electrically insulating material, a first and a second opposite open ends of which delimit therein a first and a second cup- shaped seats, separated by a common bottom wall obtained transversally to, and integrally with, the tubular body and throughly crossed by a plurality of blade elements having opposite ends thereof which overhangingly protrude, from opposite sides, within the first and second seats to define blade contacts, preferably of Faston type, in the same; and a casing comprising, in turn, at least two reciprocally and fluid-tightly coupled half shells and accommodating therein the first end of the tubular body through a first end thereof, throughly crossed by the tubular body and fluid-tightly fixable in use to a support, in this case to the case of a submerged pump .

The casing displays a second end, opposite to the first, provided with fluid-tight through inlet means in the casing of at least one electric cable and the common bottom of the tubular body is entirely coated, internally to at least one of said first and second cup-shaped seats, by a sealing resin layer in which the blade elements are embedded; in combination with this feature, the tubular body is laterally and externally provided with an annular flange abuttingly cooperating against the first end of the casing so as to be sandwiched in use between the latter and the support (in this case, the case of the submerged pump) to which the first end of the casing is fixable.

According to an aspect of the invention, the first end of the casing is laterally and externally provided with a flange equipped with fixing means to the support and with a flat seal which mimics the profile of the flange and of the first end of the casing; the annular side flange of the tubular body abuttingly rests directly against the first end of the casing and is at least partially surmounted by the flat seal, caught and sandwiched between the same and the first end of the casing. Furthermore, the casing is formed by a first and by a second asymmetrically shaped half shell so that the first half shell entirely delimits the first end of the casing and only one first half of the second end of the same; while the second half shell delimits a second half of the second end of the casing; between the first and the second half shells a peripheral seal is interposed and the half shells are reciprocally fixed and sandwiched by means of at least one screw arranged at the second end of the casing, so that the second half shell serves as a cable clamping element on the fluid-tight through inlet means into the casing of the mentioned at least one electric cable.

In this manner, a device which is very simple, cost- effective to be produced and easy to be assembled and disassembled is obtained, displaying at the same time high reliability and excellent water- and humidity- tightness, even the humidity possibly caused by internal condensation. In particular, the sealing resin layer confers a capillary tightness at the electric contacts, i.e. precisely in the most critical point of the device. BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention will be apparent from the following description of a non-limitative embodiment thereof, with reference to the accompanying drawings, in which: figure 1 diagrammatically shows a top three- quarters perspective view of a fluid-tight electric connection device made according to the invention;

- figure 2 shows the device in figure 1 turned by 180° with parts removed to allow to appreciate the internal structure thereof; and

- figure 3 shows a perspective view of a component of the device in figures 1 and 2.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to figures 1 and 3, numeral 1 indicates as a whole a fluid-tight electric connection device, in particular for supplying and controlling a submerged pump 2 of a known type and therefore only diagrammatically and partially shown with a dashed line in figure 1.

The device 1 comprises a tubular body 3 formed by electrically insulating material, typically a synthetic plastic injection-moulded material; the body 3 (figure 3) displays a first open end 4 and a second open end 5, reciprocally opposite, which delimit therein a first cup- shaped seat 6 and a second cup-shaped seat 8, respectively, which are separated by a common bottom wall 9 (figure 3) obtained transversally to, and integrally with, the tubular body 3 and throughly crossed by a plurality of blade elements 10 formed by a electrically conducting material and having opposite ends 11 and 12 thereof which overhangingly protrude, from opposite sides, within the first 6 and second 8 seats, respectively, to define electric blade contacts, preferably of Faston type, into the same.

The device 1 further comprises a casing 20 (figure 1) comprising in turn at least two reciprocally and fluid-tightly coupled half shells 21 and 22, and accommodating therein (figure 2) the first end 4 of the tubular body 3; in particular, the end 4 is fluid-tightly accommodated in the casing 20 through a first end 23 of the casing 20, fluid-tightly fixable in use to a support 24, e.g. consisting of an external case of the submerged pump 2, provided with a through seat 25 for receiving the device 1.

In particular, the end 23 of the casing 20 is throughly crossed by the tubular body 3, while a second end 26 of the casing 20, opposite to the end 23, is provided with fluid-tight through inlet means 28 into the casing 20 of at least one electric cable 30, in this case a supply cable 30a and a cable 30b adapted to convey an electric control signal for the pump 2.

According to an aspect of the invention, the common bottom wall 9 of the tubular body 3 is entirely coated, internally to at least one of the first and second cup- shaped seats 6 and 8, respectively, by an electrically insulating sealing resin layer 33, e.g. of the same type as that used for embedding the windings of a transformer. The blade elements 10, which are throughly accommodated through the wall 9, through specific openings made in the same, are in use embedded in the resin layer 33, thus obtaining three different results at the same time: a mechanical fastening of the elements 10 to the tubular body 3 and to the corresponding bottom wall 9 for the seats 6 and 8 without the use of the traditional snapping fasteners; the reciprocal electric insulation of the electrically conducting elements 10; and the reciprocal fluid-tight sealing, with capillary tightening, of the two cup-shaped seats 6 and 8, even at the passage openings in the wall 9 for the blade elements 10.

In combination with this feature, the tubular body 3 is laterally and externally provided with an annular flange 35 abuttingly cooperating in use against the end 23 of the casing 20 so as to be in use sandwiched between the latter and the support 24, to which the first end 23 of the casing 20 is fixable in a known manner, e.g. by means of screws 36.

The sealing resin layer 33 is preferably arranged inside the cup-shaped seat 6, partially filling the same, and therefore from the part of the end 4 of the body 3 which is accommodated within the casing 20; the blade elements 10 overhangingly protrude from the sealing resin layer 33, within the cup-shaped seat 6, by a sufficient length to define in the cup-shaped seat 6 itself, with its ends 11, corresponding electric blade contacts of the Faston type.

Furthermore, the annular flange 35 of the tubular body 3 is arranged essentially flushed with the common bottom wall 9 of the cup-shaped seats 6 and 8 and the ends 4 and 5 of the tubular body 3 are preferably reciprocally asymmetric and are delimited by opposite segments of a side wall 40 of the tubular body 3, which are shaped so as to define, along with the blade contacts formed by the ends 11 and 12 of the elements 10 internally carried by each end 4 and 5, corresponding multiple connectors 41,42 of a standard type, to which corresponding connectors 43,44 electrically connected in a known manner (not shown for simplicity) to the cables 30 and to the actuating motor of the pump 2 (not shown) through the through seat 25, may be connected in use. According to a further aspect of the invention, the first end 6 of the tubular body 3 defines, along with the corresponding ends 11 of the blade elements 10, a pair of standard connectors 14 placed side-by-side, for a connector 43a of the power supply cable 30a of the pump 2 and a connector 43b of the control cable 30b of the pump 2, respectively, the latter being generally connected to a level gauge (float), known and not shown, external to and separated from the device 1.

Furthermore, the first end 23 of the casing 20 is laterally and externally provided with a flange 45 equipped with fixing means 46 to the support 24 (in this case, consisting of through holes 46 for screws 36) and, on an external side thereof, with a flat seal 48, which mimics the profile of the flange 45 and of the first end 23 of the casing 20; the side annular flange 35 of the tubular body 3 abuttingly rests directly against the end

23 of the casing 20, in this case, against the flange 45, and is at least partially surmounted by the flat seal 48

(figure 1), caught and sandwiched between the same and the end 23 with the corresponding flange 45 of the casing

20. Moreover, according to a further aspect of the invention, the casing 20 is formed, as a whole, by a single pair of reciprocally asymmetric half shells 21,22 so that a first half shell 22 entirely delimits the end 23 of the casing 20, but only a first half 26b of the second end 26 of the same; while a second half shell 21 delimits a second half 26a of the second end 26 of the casing 20; a peripheral tightening seal 50 is further interposed between the half shells 21 and 22 (figure 2) . In particular, the two half shells 21,22 are reciprocally separated at a plane which is transversal to a laying plane of the annular flange 35 of the tubular body 3 and obliquely oriented to the same in the direction of longitudinal extension of the tubular body 3, as well shown in figures 1 and 2, so that the half shell 22 is in use arranged essentially parallel to the plane on which both cables 30 lay.

The half shells 21, 22 are reciprocally fixed and sandwiched by means of at least one screw 60 arranged at the end 60 of the casing 20, in this case by means of four screws 60 arranged in pairs on both the ends 23 and 26, so that the half shell 21 serves as a cable clamping element on the fluid-tight through inlet means 28 into the casing 20 of the electric cable 30. For this purpose, the fluid-tight through inlet means 28 into the casing 20 of at least one electric cable 30 (in this case of the pair of cables 30a and 30b) consist in at least one bellow-shaped ring 60 (in this case a pair of rings 60, one for each cable 30) made of an elastomeric material and snappingly inserted into an annular through seat 62 obtained across the second end 26 of the casing 20.

In use, when the half shell 21 is removed, the cables 30 may be introduced into the casing 20 and connected by means of the connectors 43 to the pair of connectors 41 placed side-by-side as defined by the body 3. Thus, by fixing the half shell 21 in place, the casing 20 is fluid-tightly closed with the end 4 of the tubular body 3 therein, which end is electrically connected with the cables 30. The connector 44 is then fitted on the opposite end 5 of the body 3, left outside the casing 20, and the device 1 thus formed is fixedly mounted on the support (pump case) 24 once the connector 44 and the corresponding end 5 of the body 3 have been introduced into the through seat 25, thus bringing the flange 45 and the corresponding flat seal 48 in contact with the support 24; by fastening the screws 36, the device 1 is not only fixed in place on the pump 2, but even the fluid-tight sealing of the through seat 25 and, therefore, of the connector 44 and of the corresponding connector 42 mating with it and defined by the end 5, and above all of the flange 35 against the end 23 of the casing 20, is obtained.

All the electric connections required between the cables 30 and the pump 2 are thus obtained simply and rapidly, with small dimensions and, above all, with a very high fluid-tightness reliability against any seepage of water or humidity towards the inside of the pump 2.

Claims

C L A I M S

1. A fluid-tight electric connection device, in particular for supplying and controlling a submerged pump, comprising a tubular body formed by electrically insulating material, first and second opposite open ends of which delimit therein a first and a second cup-shaped seats, separated by a common bottom wall obtained transversally to and integrally with the tubular body and throughly crossed by a plurality of blade elements having opposite ends thereof which overhangingly protrude, from opposite sides, within said first and second seats to define blade contacts, preferably of Faston type, in the same; and a casing comprising in turn at least two reciprocally and fluid-tightly coupled half shells and accommodating therein the first end of the tubular body through a first end thereof, fluid-tightly fixable in use to a support, e.g. a case of said submerged pump, and throughly crossed by the tubular body; said casing displaying a second end, opposite to the first, provided with fluid-tight through inlet means in the casing of at least one electric cable; characterised in that said common bottom wall of the tubular body is entirely coated, internally to at least one of said first and second cup-shaped seats, by a sealing resin layer in which the blade elements are embedded; and in that, in combination, the tubular body is laterally and externally provided with an annular flange abuttingly cooperating against the first end of the casing so as to be sandwiched in use between the latter and the support to which the first end of the casing is fixable.

2. A device according to claim 1, characterised in that said sealing resin layer is arranged inside said first cup-shaped seat of the tubular body, partially filling the same; said blade elements overhangingly protruding from the sealing resin layer and within the first cup-shaped seat for a sufficient length to define corresponding blade contacts in the first cup-shaped seat .

3. A device according to claim 2, characterised in that said annular flange of the tubular body is arranged essentially flushed with said common bottom wall of the first and second cup-shaped seats; said first and second ends of the tubular body being preferably reciprocally asymmetric and being delimited by opposite side wall segments of the tubular body shaped so as to define, along with said blade contacts internally carried by each end, corresponding multiple connectors of standard type.

4. A device according to claim 3, characterised in that said first end of the tubular body defines, with the corresponding ends of the blade elements, a pair of standard connectors placed side-by-side for a supply cable and a control cable, respectively.

5. A device according to any one of the preceding claims, characterised in that said first end of the casing is laterally and externally provided with a flange equipped with fixing means to said support and with a flat seal which mimics the profile of the flange and of said first end of the casing; said annular side flange of the tubular body abuttingly resting directly against said first end of the casing and being at least partially- surmounted by said flat seal, caught and sandwiched between the same and the first end of the casing.

6. A device according to any one of the preceding claims, characterised in that said casing is formed by a first and by a second asymmetrically shaped half shell so that the first half shell entirely delimits said first end of the casing and only one first half of the second end of the same; while said second half shell delimits a second half of the second end of the casing; a peripheral seal being arranged between the first and the second half shells .

7. A device according to claim 6, characterised in that said first and second half shells are reciprocally separated at a plane transversal to a laying plane of said annular flange of the tubular body and obliquely oriented to the same in the direction of longitudinal extension of said tubular body.

8. A device according to claim 6 or 7, characterised in that said first and second half shells are reciprocally fixed and sandwiched by means of at least one screw arranged at the second end of the casing, so that the second half shell serves as a cable clamping element on said fluid-tight through inlet means into the casing of at least one electric cable.

9. A device according to any one of the preceding claims, characterised in that said fluid-tight through inlet means into the casing of at least one electric cable consist of at least one bellow-shaped ring formed by an elastomeric material and snappingly inserted into an annular through seat obtained across the second end of the casing.