US 4,807,890 AGranted

Sealing combination

AssigneeEsco Elevators, Inc.

InventorsGerald W. Gorman, Everett E. Johnston

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Abstract

An improvement in a sealing combination between a head of a hydraulic cylinder and a plastic covered cable traversing therethrough, including the plastic covered cable connected with a piston interiorly of the cylinder so as to be moved longitudinally responsive to hydraulic pressure applied to the piston traversing interiorly of the cylinder, a gland disposed about and sealingly encompassing the plastic covered cable, a head defining an annular packing box about the plastic covered cable and adapted to receive the gland for holding a seal in place and a wiper ring disposed in the gland and about the plastic covered cable for wiping dirt and the like therefrom before the cable enters the sealing combination; characterized by a split ring of resilient material emplaced in the bottom of the packing box and encompassing the plastic covered cable without sealing engagement therewith; a split backup compression ring of thermoplastic material disposed in the packing box so as to be responsive to the compressive force of the split ring and encompassing the plastic covered cable; and at least one compressed, split pressure balanced seal resilient material disposed in the top of the packing box. The spacer ring has sufficient compressive force to effect sealing with even a single seal even though the seal is split. Specific preferred structures are disclosed for the respective embodiments.

Claims16

Dependent claims

In a sealing combination for sealing intermediate ahead of a hydraulic cylinder and a plastic covered cable that is difficultly disconnectable and reconnectable at either end and traversing therethrough, including:

a. said plastic covered cable having a substantial cylindrical exterior of diameter d1 and being connected with a piston interiorly of the cylinder so as to be moved longitudinally responsive to hydraulic pressure applied to the piston traversing interiorly of the cylinder;
b. a gland disposed about and sealingly encompassing the plastic covered cable;
said gland having a cavity of a diameter d4;
c. a head defining an annular packing box about the plastic covered cable and adapted to receive the gland for holding the seal in place;
and
d. a wiper ring disposed in said gland and about the plastic covered cable for wiping dirt and the like therefrom before the cable enters the sealing combination;
the improvement comprising
e. a split ring of resilient material emplaced in the bottom of said gland cavity and encompassing said plastic covered cable without sealing engagement therewith;
said split ring having a compressive force when pushed against;
f. a split spacer ring of thermoplastic material disposed in the gland cavity and on top of said split ring of resilient material so as to be responsive to said compressive force of said split ring and encompassing the plastic covered cable;
g. only one split pressure balanced seal of resilient material disposed on the top of said split spacer ring and within said gland cavity so as to be responsive to said compressive force of said split ring transmitted by said spacer ring;
said split pressure balanced seal having radially exterior circumferential projections of diameter d3 on an outer leg of the seal and a substantially cylindrical inner leg spaced from said outer leg by a bight portion, said inner leg defining an aperture of diameter d2 that is less than the substantially cylindrical exterior surface diameter d1 of the cable by an amount that is less than the amount the diameter d3 of said lips exceeds the diameter d4 of said gland cavity, all defined as said split pressure balanced seal having an interference fit that is sufficiently greater at its radial exterior with the wall of said packing than the interference fit at its radial interior with the plastic covered cable to prevent gapping and leaking of the formed joint defined by said pressure balanced seal such that the gland can be inserted within the gland cavity to press the pressure balanced seal against the spacer ring when a sufficient force to effect sealing with even a single seal even though said seal is split.

9 more elements

In a sealing combination for sealing intermediate a head of a hydraulic cylinder and a plastic covered cable that is difficulty disconnectable and reconnectable at either end and traversing therethrough, including:

a. said plastic covered cable having a substantially cylindrical exterior of diameter d1 and being connected with a piston interiorly of the cylinder so as to be moved longitudinally responsive to hydraulic pressure applied to the piston traversing interiorly of the cylinder;
b. a gland disposed about and sealingly encompassing the plastic covered cable;
said gland having a cavity of diameter d4;
c. a head defining an annular packing box about the plastic covered cable and adapted to receive the gland for holding a seal in place;
and
d. a wiper ring disposed in said gland about the plastic covered cable for wiping dirt and the like therefrom before the cable enters the sealing combination;
the improvement comprising:
e. split ring of resilient material emplaced in the bottom of said gland cavity and encompassing said plastic covered cable without sealing engagement therewith;
said split ring having a compressive force when pushed against;
f. a split spacer ring of thermoplastic material disposed in the gland cavity and on top of said split ring of resilient material so as to be responsive to said compressive force of said split ring and encompassing the plastic covered cable;
g. at least one split pressure balanced seal of resilient material disposed on the top of said split spacer ring and within said gland cavity so as to be responsive to said compressive force of said split ring transmitted by said spacer ring;
each said split pressure balanced seal having radially exterior circumferential projections of diameter d3 inner leg spaced from said outer leg by a bright portion, said inner leg defining an and a substantially cylindrical interior aperture of diameter d2 that is less than the substantially cylindrical exterior surface diameter d1 of the cable by an amount that is less than the amount of the diameter d3 of said lips exceeds the diameter d4 of said gland cavity, all defined as said split pressure balanced seal having an interference fit that is sufficiently greater at its radial exterior with the wall of said packing than the interference fit at its radial interior with the plastic covered cable to prevent gapping and leaking of the formed joint defined by said split pressure balanced seal such that the gland can be inserted within the gland cavity to press the pressure balanced seal against the spacer ring with sufficient force to effect sealing with even a single seal even though said seal is split.

9 more elements

Dependencies are inferred from the claim text.