US 3792415 A
Apparatus for weatherproofing an electrical cable connecting device, particularly where both an improved cable seal and greater cable flexibility are attained. A cable sealing gland is disposed on a flexible diaphragm to relieve the strain developed in the gland when the cable flexes. Gland resistance to cable flexure is overcome by relieving axial strain through distortion of the diaphragm about an axis perpendicular to the axis of the cable. Separation of the gland from the cable is overcome by relieving lateral strain through distortion of the diaphragm to reorient the axis of the gland in the direction of cable flexure. The diaphragm is disposed on a spacing ring as the end wall of a sealing boot which is otherwise configured to fit conventionally over the cable connecting device.
Description (OCR text may contain errors)
[ Feb. 12, 1974 WEATHERPROOF COVER FOR ELECTRICAL CABLE CONNECTOR 372,361 11/1963 Switzerland 339/60 R  Inventor: Alvin W. Fuller, Shelton, Conn. imary Examiner-Joseph H. McGlynn Assignee Harvey Hubbe Incorporated Attorney, Agent, or FirmWooster, Davis & Cifelli Bridgeport, Conn.
 Filed: Mar. 13, 1972  ABSTRACT PP N 234,261 Apparatus for weatherproofing an electrical cable connecting device, particularly where both an im- 52 US. Cl. 339/60 R, 339/101 Proved cable Seal and greater cable flexibility are [51 Int. H011- 13/52 tained- A Cable Sealing gland is diSPCSed a flgxible  Field of Search 339/59-61, 94 diaphragm to relieve the Strain develOPed the gland 339/] 102 when the cable flexes. Gland resistance to cable flexure is overcome by relieving axial strain through dis-  References Cited tortion of the diaphragm about an axis perpendicular UNITED STATES PATENTS to the axis of the cable. Separation of the gland from the cable is overcome by relieving lateral strain 211271544 8/1938 339/60 R through distortion of the diaphragm to reorient the g axis of the gland in the direction of cable flexure. The 3Tl67374 H965 23 339/60 R diaphragm is disposed on a spacing ring as the end 3 487 353 12/1969 Massit: I: 339/94 R wall of a Sealing boot which is otherwise wnfigured to fit conventionally over the cable connecting device.
FOREIGN PATENTS OR APPLICATIONS 464,685 8/1928 Germany 339/60 R 6 Claims, 4 Drawing Figures M 1 1 ll 42 1 1 r 44 I 1 1 1 1 1 1 1 1 I I 54 I l l l 4 ZZZ 26 WEATHERPROOF COVaERFOR' ELECTRICAL CABLE CONNECTOR BACKGROUND OF THE INVENTION The present invention relates to sealing apparatus for an electrical cable connecting device and more particularly, to such apparatus for providing maximum cable flexibility and a contiguous cable seal over the full arc of cable flexure. Hitherto, various types of form fitting boots have been used to seal the interface between an electrical cable and either the plug or receptacle of a connector. Generally, these boots are made of an elastomeric material and provide a sealing gland which hugs the cable as it passes through an end wall of the boot.
In most boots, the gland separates from the cable before the cable is flexed to its maximum bend radius.
a This separation occurs because the gland is a flat integral part of an end wall which abuts against and is elastically restricted by the rear of the connector device. Therefore, the end wall can not freely distort to relieve strain developed in the gland perpendicularly to the axis of the cable. 1
In some boots, the gland extends along the cable beyond the end wall of the boot. Therefore, as the cable is flexed, the material of the gland accumulates to one side of the cable so as to transfer the flexure point of the cable away from the connector device, which is undesirable.
SUMMARY OF THE INVENTION It is therefore, a general object of the present invention to provide a sealing boot which minimizes and obviates the disadvantages of the prior art.
It is a specific object of the present invention to provide a sealing boot which permits greater cable flexibility.
It is a more specific object of the present invention to provide a sealing boot which provides a cable seal at any flexure position of the cable.
These objects are accomplished in one form accord ing to the present invention by disposing a spacing ring within an otherwise conventional sealing boot. A cable sealinggland is disposed on a flat end wall of the boot. The end wall extends across the spacing ring and is free to flex with the elastic characteristics of a diaphragm. When the boot is applied to a connector device, the spacing ring maintains a gap between the end wall and the connector device to preclude any restrictive influences therebetween.
BRIEF DESCRIPTION OF THE DRAWING The manner in which these and other objects of the invention are achieved will be best understood by reference to the following description, the appended claims, and the attached drawing wherein:
FIG. 1 is a perspective view of an electrical cable connecting device incorporating the weatherproofing boot of this invention;
FIG. 2 is an enlarged side elevational view thereof with portions of the boot and coupling ring cut away to illustrate the suspended disposition of the sealing gland and end wall relative to the electrical cable connecting device;
FIG. 3 is a partial view thereof similar to FIG. 2 and illustrates the disposition maintained by the gland contiguous to the cable when flexure of the cable develops strain in the gland and end wall; and
FIG. 4 is a view similar to FIG. 3 of a cable connecting device incorporating a conventional weatherproofing boot and illustrates both the separation of the gland from the cable and accumulation of the gland in the direction of cable flexure when strain in the gland is not sufficiently relieved.
DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to the drawings and more particularly to FIG. 1, there is illustrated an electrical cable connecting apparatus 10 having a sealing boot 12 into which the concepts of this invention have been incorporated. The boot 12 is fabricated from an elastomeric material and is exteriorly configured to conform with conventional boots. A sealing gland 14 is centrally disposed on an end wall 16 which is disposed across one end of a cylindrical sleeve 18. A cable 20 passes through the gland l4 and end wall 16 to electrically connect with an electrical cable connecting device which, for example, is shown to be a conventional connector body 22. The cable 20 is flexible to arcuately align its axis at varying bend radii.
Grooves 24 are disposed on the cylindrical sleeve 18 to facilitate the grip maintained by the operator during connection of connector body 22 to any conventional connector plug (not shown) with which it is designed to connect, especially where a turning interlocking action has been incorporated into the connector. A coupling ring 26 is carried about the end of the boot 12 opposite to the end at which the gland 14 is disposed to permit locking and sealing of the boot to the connector plug.
The gland 14 is generally cylindricalin configuration and sealingly fits about the cable 20, as illustrated in FIG. 2. To facilitate a sealing fit for a wide range of cable diameters, it is known to structure the gland 14 from a plurality of stacked annular ribs 28 which extend from the end wall 16 in progressively smaller diameters converging upon the cable 20. For cables having a limited range of diameters, the gland 14 could be constructed from one annular rib 28, which would be flush to both sides of the end wall 16 and contained therein.
An annular spacing ring 30.is formed on the interior of the sleeve 18 at one axial end thereof adjacent the end wall 16. The sleeve 18 is configured to sealingly fit around the connector body 22. On its exterior, sleeve 18 has an annular retaining lip 32 and an annular bearing lip 34, between which the coupling ring 26 is axially slidably retained by its annular flange 36. An annular sealing surface 38 is disposed on one side of the bearing lip 34 to seal against a complementary sealing surface on the plug or a second sealing boot (not shown) when the connector body 22 operatively engages the plug. The coupling ring 26 has female threads 40 which mate with male threads disposed on the plug or second sealing boot to generate sealing pressure across the complementary sealing surfaces. The connector body 22 includes a housing 42 comprising a portion to.which both a female 'contact housing portion 44 and a cable clamp 46, including clamping screws 48, are secured by suitable fastening means, such as securing screws (not shown). I
When the boot 12 is utilized to weatherproof an electrical cable connecting device, such as connector body 22, it is assembled thereto by directing one end of the cable 20 through the gland l4 and sleeve 18 until the boot 12 is disposed well back from the end of the cable 20. The electrical connections are then made between the conductors of cable 20 and the contact terminals of connector body 22, after which the cable 20 is directed back through the sleeve 18 and gland 14 as by sliding the boot on the cable until the boot snaps onto and is disposed contiguously and securely over the connector body 22 to its FIG. 2 position, in which conventional complementary portions retain the assembled relationship. In this assembled condition, the spacing ring 30 bears against an end of the connector body 22 to suspend the end wall 16 freely and spaced above the said end of the connector body 22.
In use, the connector body 22 is often oriented in positions which necessitate that the cable 20 be flexed to one side or the other, as illustrated in FIG. 3. This flexure of the cable 20 develops both axial strain and lateral strain in the gland 14. The axial strain is parallel to the arcuate centerline of the cable 20 while the lateral strain is perpendicular thereto. Because the boot 12 is made of elastomeric material and the end wall 16 is sus-' pended freely above the connector body 22, the end wall 16 has the elastic characteristics of a flexible diaphragm. Since the gland 14 is disposed on the end wall 16, any stress or strain developed in the gland 14 must be translated through the end wall 16. Therefore, the flexible nature of the end wall 16 functions to relieve any strain developed in the gland l4 and thereby maintains a contiguous relationship between the gland 14 and the cable 20. In relieving axial strain, the end wall 16 distorts to pivot the gland 14 about an axis perpendicular to the axis of the cable 20. In relieving lateral strain, the end wall 16 distorts to reorient the centerline of the gland 14 in the direction of cable 20 flexure.
A typical prior art boot is illustrated in FIG. 4, which has similar parts to those of the boot 12 illustrated in FIGS. 1 3 and therefore, these parts are identified by the same reference numerals but with a prime added. In this prior art boot 12', as indicated at location A, the contiguous relationship between the gland 14 and the cable 20' is broken after a relatively small amount of cable flexure because only a small amount of the lateral strain developed in the gland 14' is relieved through distortion of the end wall 16. It is also true that cable flexure is limited, as indicated at location B, due to accumulation of the gland 14 to one side of the cable 20 which transfers the flexure point of the cable 20 away from the exterior of the end wall 16'. This is so because none of the axial strain developed in the gland 14 is relieved. through distortion of the end wall 16. Both of these difficulties are encountered due to the end wall 16' being abutted directly against the end of the connector body 22' to thereby restrict the flexure path of the end wall 16'.
Those skilled in the art should readily appreciate that the sealing boot embodied by this invention may be utilized in weatherproofing a cable connecting device without inhibiting cable flexibility. Furthermore, the boot provides a seal around the cable at any flexure position assumed by the cable.
It should be understood that the present disclosure has been made by way of example and that numerous changes in details of construction and the combination or arrangement of parts may be resorted to without departing from the true spirit and scope of the invention and therefore, the present disclosure should be construed as illustrative rather than limiting.
What I claim is:
1. In a weatherproof boot for an electrical cable connecting device including a sealing gland and a flat end wall disposed across one end of a cylindrical sleeve, said gland being disposed on said end wall to contiguously pass the cable along an arcuate axis of varying radius, the improvement comprising:
said end wall having a portion bearing against the cable connecting device and a portion suspended above the cable connecting device as a freely flexing diaphragm, said sealing gland being centrally located on said suspended portion, said bearing portion translating stresses from said suspended portion to the cable connecting device and said suspended portion distorting to relieve strain in said sealing gland when the cable is flexed.
2. The weatherproof boot of claim 1 wherein said bearing portion is a spacing ring, said spacing ring being peripherally disposed in said cylindrical sleeve.
3. The weatherproof boot of claim 1 wherein said sealing gland is annularly configured and is disposed within said suspended portion, lateral strain in said sealing gland perpendicular to the cable axis being relieved by distortion of said suspended portion when the cable is flexed.
4. The weatherproof boot of claim 1 wherein said sealing gland is cylindrically configured and extends from said suspended portion parallel to the cable axis, axial strain in said sealing gland parallel to the cable axis being relieved by distortion of said suspended portion when the cable is flexed.
5. The weatherproof boot of claim 1 wherein said sealing gland is cylindrically configured and extends through said suspended portion parallel to the cable axis, axial strain in said sealing gland parallel to the cable axis and lateral strain in said sealing gland perpendicular to the cable axis both being relieved by distortion of said suspended portion when the cable is flexed.
6. The weatherproof boot of claim 1 wherein said sleeve is configured to contiguously fit around the cable connecting device and includes means for sealing with a second weatherproof boot upon joining the cable connecting device to a mating device, said sealing means being disposed on said sleeve at the opposite longitudinal end from said end wall; and wherein said bearing portion is a spacing ring, said spacing ring being peripherally disposed in said cylindrical sleeve.