Fitting for conduit and electrical cable

• US 4,030,742 A
• Filed: 10/10/1975
• Issued: 06/21/1977
• Est. Priority Date: 06/04/1973
• Status: Expired due to Term

• Current Assignee: Gould, Inc. (Transdigm Group Incorporated)
• Original Assignee: Gould, Inc. (Transdigm Group Incorporated)
• Inventors: Mooney, Thomas, Eidelberg, Jonah
• Primary Examiner(s): Callaghan, Thomas F.
• Application Number:
  US05/621,368
• Time in Patent Office: 620 Days
• Field of Search: 285/343, 285/249, 285/248, 285/382.7, 285/341, 285/348, 285/342, 174/65 SS, 174/77 R, 339/103 R, 339/103 B, 339/103 M, 339/94 R
• US Class Current: 285/343
• CPC Class Codes: F16L 5/06 by means of a swivel nut compressing a ring or sleeve
• CPC Class Codes: H02G 3/0641 with means distorted around the conductors

Abstract

A liquid-tight fitting is provided to connect generally non-compressible plastic conduit and electrical cable to a connection of some type. The fitting has a self-adjusting rigid plastic gland, which has a body portion with a relatively thin sleeve extending axially away from the body portion for encircling the conduit or cable. A nut threaded on the body of the fitting compresses the sleeve into sealing engagement with the conduit and fitting and to positively interconnect the conduit and connection to provide strain relief therewith.

Claims

1. A fluid-tight strain relief fitting for connection with an end of a cable having a resilient outer sheath surrounding a plurality of conductors movable therein, comprising a generally tubular body having an internal bore extending into said body and passing therethrough, a bushing telescopically received within said bore and having a through bore for receiving said cable and including a base portion nesting within said body and a sleeve of reduced wall thickness extending beyond said body and terminating at its free end in an inwardly directed peripheral lip, said base portion having a substantially cylindrical portion and an outwardly extending flange at one end thereof adjacent said sleeve and axially spaced from the free end of said base portion, said flange matingly abutting a lip on said body circumferentially about their outer and inner surfaces respectively, a ring coaxially abutting said sleeve free end and at least one of the abutting faces of said sleeve and said ring being tapered, said bushing being made of a rigid plastic material, and means cooperating with said body for longitudinally urging said ring towards said base portion, thereby, circumferentially permanently contracting said sleeve and forcing the free end of said sleeve containing said lip to flow through and beyond said ring and into tight sealing contact with and depressing said resilient sheath and causing annular radial permanent contraction of a portion of said sleeve about said resilient sheath, said contraction displacing sheath material on both sides of said contracted sleeve portion to firmly anchor said fitting to said cable and firmly lock said conductors against movement within said cable and form a fluid tight seal with the cable sheath and body, at least a portion of said sleeve being sandwiched and embraced between said cable and said ring and a portion of the outer face of said sleeve coinciding with the inside face of said ring, when said ring is in its advanced position towards said bushing base portion, the radial dimensions of the sleeve and the base portion being selected so that the sleeve will deform inwardly about the base portion whereby said ring will engage the one end of the base portion and force said flange into sealing engagement with said lip.

2. A fitting as defined in claim 1, wherein said contracting means further includes a nut, and said ring having a generally bevelled portion coacting with the free end of said sleeve and being positioned between said nut and the fitting body, said ring inner diameter being spaced from said cable.

3. A fitting as in claim 2, wherein said ring and said nut having mating bevelled portions circumferentially about their outer and inner surfaces, respectively.

4. A fitting as defined in claim 2 wherein said bushing base portion has a larger outer diameter than said sleeve and has a tubular side wall contiguous to the surface of said inner wall of said body bore, said sleeve being permanently deformed in response to longitudinal movement of said ring and being driven inwardly into engagement with the cable.

5. A fitting as in claim 1 wherein said depression of said sheath by said sleeve being in the form of a channel.

6. A fitting as in claim 1 wherein said flange on said base portion is outwardly flared along an outer peripheral edge and mates with a bevelled upper edge of said body, wherein said longitudinal movement of said ring towards said base portion urges said flared flange of said base portion against the bevelled edge of said body to form a fluid tight seal.