US3454291A - Raintight electrical connector - Google Patents

Description

lJuly 8, 1969 N.'Go|..DsoBl-:L `Emi. 3,454,291 l v RAINTIGHT ELECTRICAL CONNECTOR Filed Feb. 1'5, 1967 Tlc/L. NT3.

Mivar INVENToRs A//HA/vapsoaa United States Patent O 3,454,291 RAINTIGHT ELECTRICAL CONNECTOR Norman Goldsobel, Commack, and Jonah Eidelberg,

Huntington Station, N.Y., assignors to Electrical Fittings Corporation, Farmingdale, NY., a corporation of New York Filed Feb. 15, 1967, Ser. No. 616,241 Int. Cl. F16l 77/00, 19/00, 21 /02 U.S. Cl. 285--371 Claims ABSTRACT OF THE DISCLOSURE This invention relates to an electrical connector for attachment to electrical cable conduit, and in particular, wherein connectors of the type contemplated herein are designed to prevent seepage of rain water into the conduit interior.

Heretofore electrical connectors for attachment to electrical cable conduit of the set screw and crimp type as contemplated herein have not been raintight and thus could not be employed for installation requiring raintight attachments to such conduit. The present invention provides a connector with an interior sleeve fitted within the connector body to form a water-tight seal adjacent the bottom of a conduit receiving chamber. The sleeve eX- tends beyond the end of the body a predetermined length to form a differential or headf Hence, water, such as rain or spray, entering the connector between the connector body and conduit, will propagate between the outside wall of the conduit and the inside wall of the body until it reaches the seal. The water then will propagate upwardly between the inside wall of the conduit and the outside wall of the sleeve to about the same height as the connector body, but in no case higher than the sleeve portion extending beyond the body length. The differential in length of the body and the portion of the sleeve extending beyond the body end prevents water entering the conduit. Therefore, it is the principal object of the invention to make conventional connectors raintight.

It is another principal object of the invention to provide an electrical connector for attachment to electrical conduit wherein the connector incorporates an inner sleeve member. The foregoing is designed to provide a liquid pressure head differential at one end of the connector, and a liquidtight seal within the connector so as to prevent moisture and seepage of rain water into the interior of the attached conduit.

It is a further object of the invention to provide a raintight electrical connector as described hereinbefore wherein the connector body may be the conventional set screw connector.

Further objects and advantages will become apparent from the following description of the invention taken in conjunction with the figures, in which:

FIG. 1 is an exploded view of a connector in accordance with the claimed invention;

FIG. 2 is a vertical elevational view in section of the connector illustrating same attached to an electrical junction box;

FIG. 3 is a fragmentary section in vertical elevational view illustrating a modified embodiment of the connector to include a rainwater drain hole;

FIG. 4 is a fragmentary section in vertical elevation illustrating a further modified embodiment of a connector in accordance with the invention;

FIG. 5 is a fragmentary section in vertical elevation of another modified embodiment of a connector employing the invention; and

FIG. 6 is a sectional view in elevation showing still a further modification of a connector in accordance with the invention.

Reference is made to FIGURES 1 and 2 for an electrical connector 10 incorporating the invention claimed herein. Connector 10 is essentially a tubular body 11 with opposite open ends and a through bore 12 therebetween. In FIG. 2, connector 1.0 is shown mounted vertically to an electrical junction box 13 (shown fragmentary in FIG. 2) or other electrical unit. Electrical cable 14 from a conduit 15 feeds into box 13. Connector 10 has a lower threaded end 16 attached at a box knockout by a locknut 17. A watertight sealing ring 18 is clamped between a connector fiange 19 and the box wall.

Connector bore 12 has an enlarged inner diameter section 20 and a reduced inner diameter section 21. A bore shoulder 22 appears at the junction of said sections 20, 21.

A concept of the invention involves supporting a hollow tubular insert 23 in body bore 12. Insert 23 is made of `pliable material such as plastic and has uniform inner and outer diameter surfaces 24, 25. As used hereinafter, OD means an outer diameter surface, and ID means an inner diameter surface. The dimension of insert OD 25 is selected to require a force press t with respect to lower bore section 21 upon assembling insert 23 into connector 10. The foregoing force fit relationship creates a liquidtight seal along the section of insert OD 25 in contact with bore section 21. The upper section of insert OD 25 is spaced peripherally from the upper bore section 20 and thus provides a clearance for receiving the end of conduit 15 therebetween.v

Shoulder 22 serves as a limit stop when the lead end of conduit 15 abuts against same. The upper end of insert 23 protrudes a distance H above the horizontal plane P of the upper body end. The insert lower anged end 26 abuts against the lower end of connector body 11. A set screw 27 clamps conduit 15 to connector 10.

As seen in the figures, connector bore surface 20 is in contact with a contiguous section of the conduit OD 28. These contacting surfaces are not watertight. The figures show an exaggerate space between the bore ID 20 and the conduit OD 28 to emphasize that lthe space therebetween is not normally watertight. For an outdoor installation, rain or other spray of liquid, as depicted by arrow 29, will enter connector 20 at its top end and result in propagation of water downwardly between surfaces 20, 28. Such water seepage is stopped at the liquidtight seal formed between surface 21 and the section of insert OD 25 in contact with same. The top of this seal is approximately at the level of shoulder 22; essentially water does not seep below the upper level of such seal.

There is a line-to-line contact fit between the conduit ID and the contiguous section of insert OD 25, however such contact is not liquidtight. Water seeks its own pressure level. Hence water tending to accumulate at the top of the liquidtight seal will reverse its flow direction and then propogate upwardly between the aforesaid line-toline contacting surfaces, the conduit ID and insert OD, until it reaches level P. The head differential H prevents the propagation of water in an upwardly direction above the level P and into the conduit interior. Head differential H also prevents rise of water above level P by means of a capillary or wetting action. The aforesaid liquid tight seal prevents ow of water in a downwardly Idirection into the conduit interior.

Insert 23 also serves to guard against stripping of insulation from cable 14 when snaking same through connector 10. Conduit 15 deforms slightly when set screw 27 is tightened. Normally this causes a slight contraction of the conduit end for example at shoulder 22 thereby introducing a constricted sharp edge into the path of cable 14 as it is being pulled into box 13. The presence of insert 23 precludes stripping of the cable insulation at such time.

The invention also admits a liquid weep hole 30, see FIG. 3, in connector body 11. Water seeping downwardly between surfaces 20 and 28 from the top end of connector 10 will drain out Aof hole 30. The head differential for this embodiment is H.

Connector 10 is the conventional set screw fitting. It does not require any reconstruction or alteration to incorporate the invention thereto. This invention may be incorporated in similar fashion to a crimp-type connector 43, see FIG. 4, wherein the outer shell of the connector is crimped at 44 by a tool in lieu of clamping the conduit by a set screw. The liquid tight connector may be used with the many known types of standard conduit as, for example, thin wall conduit and heavy wall conduit.

FIG. shows an embodiment employing connector 10 with a hollow tubular insert 31 terminating within connector bore section 20. In this device, insert 31 has a flanged end 32 the bottom of which abuts against shoulder 22. The size of the ange OD 33 requires a force press fit with respect to bore section 20 upon assembling insert 31 into connector 10 to create a liquidtight seal along contacting surfaces 20 and 33. The upper section of the insert OD 34 has a uniform diameter. Rain entering from the top end of connector will propagate downwardly between conduit OD 28 and bore section 20 to the top of the liquid-tight seal at 46 and then reverse flow direction and propagate upwardly between the adjacent surfaces of the conduit ID and insert OD 34 to level P. In this embodiment, the lead end of conduit abuts against the upper edge of the insert flange 32. In all other respects, the operation of the raintight connector of FIG. 5 is similar to the embodiment of FIGS. l and 2.

The embodiment of FIG. 6 shows a hollow tubular fitting 36 for connecting a pair of conduits 37, 38. In this device, a hollow tubular insert 39 of flexible material, as described hereinbefore, has a pair of uniform outer diameter sections 40 and a central enlarged uniform diameter section 41. Central section 41 has an OD 42 which is in force press lit with the fitting ID 47 to form a liquidtight seal along the line of contact therebetween. The lead ends of the clamped conduits 37, 38 abut against the respective opposite edges of central section 41. The illustrated embodiment depicts conduit 37 at the top. Consequently, the formed head differential H is that shown in FIGURE 6. In this illustration rain water will not enter at the bottom end of fitting 36. Set screws 27 clamp the conduits 37, 38. In operation this embodiment is substantially similar to that of the prior described figures. The liquidtight seal along OD 42 prevents seepage of moisture and water from entering directly into the interior of conduit 38. Whereas by reason of the head differential H, water propagation between the ID of conduit 37 and the OD of the contiguous section 40 does not rise above level P.

In electrical installations, positive bite electrical ground continuity is made by a set screw clamping `against the conduit. The foregoing embodiments do not preclude this feature. When the conduits are clamped as, for example, by a set screw, such action causes the insert to squeeze against the conduit which assist the action of the raintight seal.

The problem of rainwater or other liquid spray entering into a connector as described hereinbefore is most pronounced when the connector is oriented in a position most favorable to catch rainwater. For a normal outdoor installation, this obtains for the vertically mounted connector, that is to say, when the connector lengthwise axis extends along a vertical line.

The preferred embodiments FIGURES l to 6 contemplate inserts 23, 31 and 39 made of plastic-like material. It is within the scope of the invention to use metallic inserts otherwise identical to the illustarted plastic inserts. The liquidtight seal attachments are formed by force fitting the metallic insert into the connector body as shown hereinbefore.

In the above described embodiments, the liquidtight seals are made by force-press lit attachments. It is within the scope of the invention to obain liquid-tight attachserts otherwise identical :to the illustrated plastic inserts. surface hereinabove described in a force-press lit relationship to a section of conductor bore. For example, in FIG- URES 2 and 3 the force fit attachment is replaced by an adhesive attachment between bore surface 21 and the section of insert surface 25 in contact with same. The adhesive glue may be applied to the lower section of insert OD 25 designed to come in contact with bore ID 21, after which the units are assembled by inserting insert 23 up into the connector bore. In FIG. 5, insert surface 33 is glued to the section of the connector body bore in contact with same; whereas, in FIG. 6 insert surface 42 is glued to the section of the connector body bore contacting same. In these embodiments, the adhesive glue iS applied .to the sections of the bore surfaces designed to contact respective surfaces 33, 42 after which the inserts are assembled into the connector bodies. When the adhesive cures, the `contacting surfaces are attached by a liquidtight seal.

For the purpose of claim definition, the expression conduit chamber means the cylindrical clearance spaced formed between an insert OD and the adjacent body bore surface into which clearance the conduit is inserted for attachment to the connector. For example, in FIG. 2 the conduit chamber is the clearance space between bore surface 20 and the juxtaposed insert OD 25. The inner end of this chamber is shoulder 22. As another example, in FIG. 5, the conduit chamber is the space between bore surface 20 and insert surface 34. Surface 46 is the inner end of the conduit chamber.

While the sleeve disposed within the bore of the connector body was illustrated as being a separate insert member, which is integral with the body when assembled to form the seal, the sleeve `and connector body could be made in one piece, if desired.

What is claimed is:

1. A liquidtight connector for attachment to cable conduit, comprising a connector body having an end and yan open-ended bore extending from said end into the interior of said body, said bore being defined by a wall of said connector body, a tubular sleeve in said bore an-d having an end extending exteriorwise beyond said body end, said sleeve having an outer diameter spaced radially inwardly from said body bore wall for defining a conduit chamber, said conduit being telescopically seated within said chamber for attachment to said connector with the radial outer wall of said conduit being radially inwardly spaced from said |bore wall, said body and sleeve forming a liquidtight seal at the interior end of said chember, water can propagate between the conduit outer wall and said bore wall by reason of entering said connector .at its open end, the axial distance between the end of said sleeve extending beyond -said body and a plane at least through said body end provides `a minimum liquid differential head, said head being sufficient to prevent propagation of water between said conduit and said sleeve beyond the extending end of said sleeve, so that water propagation in opposite directions along the conduit interior is prevented, respectively, by said seal and said differential head.

2. A liquidtight connector for attachment to cable conduit, comprising a connector body having an end and an open-ended bore extending from `said end into the interior of said body, ysaid bore being defined by a wall of said connector body and a tubular member in said bore and having an end extending exteriorwise beyond said body end, said member having a first section of outer diameter spaced radially inwardly from said body bore wall for forming a conduit chamber, said conduit being telescopically seated within said chamber with the radial outer wall of the conduit being radially inwardly spaced from said bore wall, said member having a second section of outer diameter in liquidtight attachment with a section of said body bore wall, water can propagate between the conduit outer wall and said bore wall by reason of entering said connector at its open end, the axial distance between the end of said member extending beyond said body end and a plane at least through said body end provides a minimum liquid differential head, said head being sufficient to prevent propagation of Water between said conduit and said member beyond the extending end of said member, so that water propagation in opposite directions along the conduit interior is prevented, respectively, by said seal and said differential head.

3. A connector as defined in claim 2, wherein said wall defining said bore has sections of enlarged and reduced inner diameters, respectively, axially adjacent and axially spaced from said body end, a shoulder in said bore at the junction of said body sections, said shoulder forming the interior end of said conduit chamber, the second section of said member outer diameter being in a forced press-fit -attachment with said reduced inner diameter bore wall section to form there along the aforesaid liquidtight attachment.

4. A liquidtight connector for attachment to cable conduit, comprising a tubular connector body Ihaving an end and an open-ended bore extending from said end into the interior of said body, said bore being defined by a wall of said connector body, a tubular insert supported in said bore and having an end extending exterior-wise beyond said body end, said insert having an outer diameter .section in a liquidtight, press-fit attachment with a section of said body bore wall, the press-fit sections of said bore wall and insert section forming a liquidtight seal, said insert having another outer dia-meter section spaced radially inwardly from said body bore wall for forming a conduit chamber, said conduit being inserted within said chamber with the radial outer wall of the conduit being radially inwardly spaced from said bore wall, water can propagate between the conduit outer wall and said bore wall by reason of entering said connector at its bore open end, the axial distance between said insert end extending beyond said body and a plane at least through lsaid body end provides a minimum liquid differential head, said head being sufficient to prevent propagation of water between said conduit and said member beyond the extending end of said member, so that water propagation in opposite directions along the conduit interior is prevented, respectively, by said seal and said differential head.

5. A connector as defined in claim 4, wherein said wall defining said bore has sections of enlarged and reduced inner diameters, respectively, axially adjacent and spaced from said body end, a stepped shoulder in said bore at the junction of said bore section, said stepped shoulder defining the interior end of said conduit chamber, the reduced inner diameter section of said bore wall providing the aforesaid sealtight fit with said insert outer diameter.

6. A connector as dened in claim 4, wherein said insert has a flange spaced from its outer end, the outer diameter of said flange is the section of said insert making a sealtight fit with said body bore wall.

7. A connector as defined in claim 4, wherein said insert has an enlarged diameter portion defining the interior end of said conduit chamber, the outer diameter of said enlarged diameter portion is the section of said insert making a sealtight fit with said body bore wall.

,8. A connector as defined in claim 7, said bore wall having ysections of enlarged and reduced inner diameters, respectively, axially adjacent and spaced from said body end, a stepped shoulder in said bore at the junction of said bore wall sections, said insert enlarged diameter portion rbeing in abutment against said bore shoulder.

9. A connector as defined in claim 8, further including means for clamping said conduit within said conduit chamber.

10. A conduit a-s defined in claim 9, wherein said means is a set screw threadedly mounted on said connector body substantially transverse to the longitudinal .axis of said body and communicating with said conduit chamber.

References Cited UNITED STATES PATENTS 1,244,722 10/ 1917 Finne 277-135 1,762,766 6/ 1930 De `Garay 285-398 X 1,800,348 4/1931 Hunter 285-161 2,184,116 12/1939 Eastman 285-256 2,218,835 10/ 1940 Ulrich 285-10-9 2,338,316 1/1944 Buzzell 285-161 2,449,616 9/ 1948 Pennella 285-423 X 2,698,191 12/ 1954 Samiran 285-86 FOREIGN PATENTS 40,656 4/ 1932 France.

`CARL W. TOMLIN, Primary Examiner. DAVE W. AROLA, Assistant Examiner.

Us. C1. xn, 28s-161, 404

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