Flexible cable conduit joints

Claim 1

A conduit joint assembly for a flexible mechanical transmission cable, comprising in combination: a flexible conduit having an inner liner tube, a lay of helical wires around said liner tube, and an outer plastic sheathing covering said lay of helical wires, said conduit further having a bared end portion formed by said liner tube and said lay of helical wires protruding together beyond the end of said plastic sheathing, an externally screw-threaded union member having an axiallyextending bore receiving within it said bared end portion of said conduit which union member bore is formed with an entry mouth which diverges conically up to the end of said bore at which said bared end portion of said conduit enters it, a nut which is internally screw-threaded for only a part of its length extending up to one end thereof said nut being disposed with the nonscrewthreaded part of its length surrounding an end portion of said plastic sheathing of said conduit and with the screw-threaded part of its length extending into overlapping screwed engagement with said externally screw-threaded union member, said nonscrewthreaded portion of said nut length surrounding said plastic sheathing being formed internally with a conically increasing bore section that diverges in the opposite axial direction to the divergent mouth of said union member bore, said conically increasing bore section of said nut terminating at its larger diameter end nearer said union member in a more abrupt increase in the internal diameter of Said nut thereby forming an internal shoulder within said nut, first contractable collet means disposed in said union member divergent mouth around said bared end portion of said conduit and having a nominally cylindrical internal surface in engagement with said lay of helical wires of said conduit, said first collet means further having a conically enlarging outer surface contiguous with said conically divergent mouth of said union member bore, and second contractable collet means of larger internal diameter and larger maximum external diameter than said first collet means and disposed within said nut in contiguous end-to-end relationship with said first collet means, said second collet means having a nominally cylindrical internal surface in engagement with said plastic sheathing of said conduit, said second collet means further having a conically enlarging outer surface contiguous with said conically increasing bore section of said nut and terminating at its end of larger diameter in a more abrupt increase in the external diameter of said second collet means thereby forming an external shoulder on said second collet means lying between said internal shoulder on said nut and said first collet means and constituting in cooperation with said internal shoulder on said nut a stop abutment to limit relative axial movement of said nut and second collet means in the direction bringing about contraction of said second collet means.