Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
  • H01R13/58—Means for relieving strain on wire connection, e.g. cord grip, for avoiding loosening of connections between wires and terminals within a coupling device terminating a cable
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
  • H01R13/46—Bases; Cases
  • H01R13/516—Means for holding or embracing insulating body, e.g. casing, hoods
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
  • H01R13/56—Means for preventing chafing or fracture of flexible leads at outlet from coupling part

Definitions

• the present invention relates generally to electrical connectors and more specifically to endbells for electrical connectors.
• Electrical connectors are, in certain applications, provided with an endbell or similar element.
• This endbell serves a number of functions. Prime among these functions is tension relief. Occasionally a tensile foi.ce is imposed upon one or more of the conductors passing into the connector. If this force is transmitted to the connector, the interface between the conductor and the connector may be damaged. Specifically, the conductors can pull away from the connector; the connector-conductor mechanical seal can be impaired permitting corrosion resulting in a decrease in electrical integrity; deleterious bending strain can be imposed upon the conductors at the point they join the connector,' etc.
• the use of an endbell provides tension relief which will mitigate or avoid these problems.
• One end of the endbell is fixedly mounted to the connector housing while the other end has the conductors affixed thereto at a position located a spaced distance from the connector-conductor junction.
• This structure serves to transmit forces imposed on the conductors to the endbell and thence from the endbell to the housing of the connector.
• the connector-conductor junction is substantially isolated from the imposition of external forces.
• a second function of the endbell is to provide sealing of the connector-conductor junction. Water and other foreign matter can damage an electrical connection.
• the endbell by extending around this junction, substantially prevents the intrusion of this foreign matter.
• the endbell serves as a shield against shock to the connector-conductor junction. This is especially important in applications where the connector is located such that objects may chaff against it or forceably come in contact with it. Absent such a shield, the connector-conductor junction could be damaged or crushed.
• Existing endbells are generally of two types.
• the first is a solid, one-piece conduit having two openings. The first of these openings engages the connector housing. The conductors pass through the second of those openings.
• a potting agent such as epoxy, is injected to fill the endbell thereby making it rigid, sealing the conductors in the endbell, and bonding the endbell to the connector.
• the second type of existing endbell has two halves, these generally being joined by screws to form a structure similar to that described above, ⁇ .o potting agent need be used with this type of endbell as the interference fit provided by the clamp or screws generates the necessary seal and affixes the endbell to the connector.
• This two piece endbell is disadvantageous in that, being fashioned of multiple pieces, it is unduly expensive and relatively difficult of assembly. Additionally, being fashioned of multiple pieces, such endbells tend to be unduly bulky and less strong than a comparably sized one-piece endbell.
• the present invention is directed to overcoming one or more of the problems set forth above.
• an endbell has a first aperture adapted to receive a connector and a second aperture adapted to receive at least one conductor.
• the endbell is of a unitary construction having a single slit joining the first and second apertures.
• the endbell serves to prevent a force imposed upon the conductors from being transmitted to the conductor-connector electrical junction; to prevent the intrusion of foreign matter; and, to shield the junction from impact and abraiding forces.
• Existing endbells are either one piece and potted to the connector rendering
• the present invention combines the advantageous features of the existing types of endbells.
• the slit and material from which the endbell is formed permits the endbell to be installed on or taken off of the connector without the necessity for disconnecting the conductors from the connector. Additionally, the slit provides the first aperture of the endbell with an adjustable diameter for generating a tight, ready adjustable and controllable interference fit with the connector through use of a clamp positioned around the first aperture. This construction obviates the need for potting.
• Fig. 1 shows an isometric view of an embodiment of the present invention with a portion broken away;
• Fig. 2 shows a view of the endbell of Fig. 1 taken along the axis of the first aperture; * Fig. 3 shows an embodiment of the present invention mounted on a connector; and.
• Fig. 4 shows an embodiment of the endbell particularly suited for applications in which portions of the wires adjacent the connector need not be bent.
• an endbell embodying principles of the present invention is generally indicated by the reference numeral 10.
• the endbell 10 has a first aperture 12 for receiving one end of a connector 14, as shown in Fig. 3.
• the endbell 10 also has a second aperture 16 through which one or more conductors 18 pass.
• the endbell 10 is of a one piece construction and has a slit 20 passing through the surface of the endbell 10. This slit 20 joins the first and second apertures 12,16 and is defined by opposing first and second surfaces 22,24.
• the first aperture 12 has a first aperture perimeter 26 which has a first discontinuity 28 defined by the slit 20.
• the second aperture 16 has a second aperture perimeter 30 which has a second discontinuity 32 defined by the slit 20.
• an injection molding process is used to fabricate the endbell 10.
• Dupont Zytel and other polyamides of adequate flexibility, rigidity and hardness are the preferred materials from which the endbell 10 can be fabricated.
• the proper choice of material and sizing of the endbell 10 is important in that a balance is desirably struck between, on the one hand, rigidity and hardness, to protect the conductor-connector interface (not shown) , and on the other hand, flexibility, to permit the slit 20 to be expanded and reduced.
• Ke have found that for a connector having an outside diameter of about 40 mm, a Zytel endbell 10 having a shell thickness in the range of about .5 to 3 mm, with a preferred value of 1 mm, provides adequate protection to the interface while permitting the slit 20 to be easily expanded by hand for allowing a plurality of conductors 18 to be slipped therethrough.
• An expansion or deformation of the slit 20 to a width or separation equivalent to about 20 to 30% of the diameter of the first aperture 12 will generally permit the entire conductor bundle 18 to be passed through the
• the slit 20 should be expandable to establish a distance between said first and second surfaces 22,24 of between about 10-15 mm to permit an entire conductor harness to be passed therethrough. At a minimum, the slit 20 must expand sufficiently to permit a single conductor 18 to pass therethrough - about 3 mm. In applications for which the intrusion of water or foreign matter is of no concern, the slit 20 can have a relaxed dimension of between 1Q to 40% of the perimeter of the first aperture 12.
• the slit 20, when the endbell 10 is in a relaxed condition, is preferably sized to provide about a 5 mm gap intermediate the first and second surfaces 22,24, as measured about the first aperture perimeter 26.
• This 5 mm gap provides adequate clearance which permits the endbell 10 to be firmly clamped to the connector 14 without interference from abutment of the first and second surfaces 22,24.
• the dimensions of the endbell 10 be controlled to leave a distance of no more than a few millimeters intermediate the first and second surfaces 22,24 in the installed position of the endbell 10 on the connector 14.
• a clamp 34 is positioned around the first aperture 12 and is used to selectively decrease the diameter of the endbell 10.
• a worm-drive type hose clamp is used.
• other clamping means known to those skilled in the art can be utilized.
• the endbell 10 can be provided with a pair of tabs (not shown) , one projecting from each of the first and second surfaces 22,24 and in abutment with the first discontinuity 28.
• a screw (not shown) passing from an aperture (not shown) in one of the tabs into a threaded aperture (not shown) in the other of the tabs may be used to draw the tabs, and hence the first and second surfaces 22,24, together and provide the needed interference fit.
• a pair of spaced apart flanges 36 are used to provide a bounded area in which the clamp 34 can be positioned. This prevents mispositioning of the clamp 34. These flanges 36 also provide additional strength and rigidity to the endbell 10 at a position where it abuts the connector 14.
• the clamp 34 has a hex screw 38 for adjusting the diameter of the clamp 34.
• the use of a hex screw 38 is advantageous in that it permits the use of a torque wrench for tightening and relaxing the clamp
• a strengthening flange 40 surrounds the second aperture 16.
• a cable-strap mount 42 projects from a position abutting the second aperture 16.
• a cable strap 44 passes around the cable strap mount 42 and serves to tightly affix the conductors 18 to the mount 42 in a manner well known to those skilled in the art.
• a connector seat 46 fashioned as an annular internal flange, is positioned within the first aperture 12. This seat 46 permits the endbell 10 to be consistently mounted on the connector 14 a predetermined axial distance from the first aperture perimeter 26 to the face of the connector seat 46. This seat 46 also provides a sealing function and serves to strengthen the endbell 10.
• the endbell 10 described heretofore and shown in Figs. 1-3 is a 90" endbell, best suited for applications in which a conductor harness has little clearance axially outward from the connector 14 to
• the first ' aperture portion of the endbell 10 is essentially identical to that described above.
• the second aperture 16 is, however, substantially coaxial with the first aperture 12.
• Projecting outward from the second aperture 16 is a conductor attachment support 48.
• This support 48 has a smooth, convex conductor support surface 50.
• the conductors 18 are positioned through the second aperture 16 and across this support surface 50.
• a conductor harness clamp 52 which can be similar to the clamp 34 described previously, is used to secure the conductors 18 to the conductor attachment support 48.
• the endbell 10 of the present invention provides all of the functions required of endbells in general. Specifically, it provides strain relief for preventing a force applied to the conductors 18 from being transmitted to the conductor-connector interface; shields the conductor-connector interface from external impacts and chapping; and, provides protection against the intrusion of water, debris, and other foreign material.
• the flexibility of the endbell 10 and slit 20 permits the endbell 10 to be mounted or dismounted without the necessity for disconnecting the connector-conductor interface. This is accomplished by expanding the diameter of the endbell 10 and passing the conductor harness 18 through the slit 20.
• the preferred material from which the endbell 10 is made permits this movement to be easily accomplished by hand
• the process of mounting and removing this endbell 10 is hence vastly more simple and quicker than removal of existing endbells.
• Another advantage is that the endbell 10 of this construction may be slipped down along the conductor harness 18 in situations in which existing endbells may not. Oftentimes certain of the conductors in a conductor harness 18 are "broken out" at a location near the endbell 10. When this is the case, a conventional one piece endbell cannot be slipped back past the point of this breakout and a two-piece endbell must be at least partially disassembled to pass the breakout.
• the endbell 10 of the present invention overcomes this problem in that the broken out conductor may simply and quickly be passed through the slit 20. This, of course, greatly promotes serviceability and avoids waste.
• the 90° endbell 10 is especially advantageous in that it permits the needed 90 bend to be made in the shortest possible distance axial to the connector 14.
• Two piece endbells must have mating halves to provide the necessary rigidity to the assembly. This mandates a substantially greater wall thickness than is necessary for a one piece endbell.
• the present 90 endbell 10 is well suited for applications in which the axial clearance behind a connector is minimal.

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

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ID=22161149

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Cited By (8)

Citations (3)

• 1981
  • 1981-03-23 WO PCT/US1981/000363 patent/WO1982003296A1/en active Application Filing
  • 1981-03-23 DE DE813152777T patent/DE3152777A1/de not_active Withdrawn

Patent Citations (3)

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