DESCRIPTION OF THE PRIOR ART
The prior art is prolific in hinges which are designed to serve the additional function of an electrical connector. Perhaps the most pertinent of these many patents are the following:
352,596 "Hinge Connection for Electrical Instruments" 11-16-1886 603,042 "Hinge Connection for Electrical Measuring Instruments" 9-18-1888 1,744,040 "Electric Connection Hinge" 1-21-30 2,688,733 "Electric Current Carrying Hinge with Spring" 9-7-54 2,778,000 "Conductive Hinge for Refrigerator Door" 1-15-57 3,076,163 "Hinge Pin with Electrical Connector" 1-29-63 3,103,398 "Door Hinge for Electrical Connection" 9-10-63 3,199,059 "Electrical Connector Hinge" 8-3-65 3,355,695 "Hinge for Carrying Electric Circuits" 11-28-67 3,428,738 "Hinge with Conductors Passing Therethrough" 2-18-69 3,659,063 "Hinge with Means for Conducting Electricity" 4-25-72
SUMMARY OF THE INVENTION
The preferred embodiment of the electrical connector hinge of this invention is an intermediate hinge pivot (usually employed as part of a pivot set) which has an external appearance which is substantially identical externally to the conventional intermediate pivot. Accordingly, one is unable to ascertain readily that the intermediate pivot is employed to fulfill the function of an electrical connector.
The novel structure hereafter described, employs a pivot tube which is inserted within bores formed in the knuckles of both the door hinge portion and the jamb hinge portion. This pivot tube is associated with a sleeve bearing so as to provide relative rotation between the two hinge portions and at the same time providing and adequate bearing for the door hinge portion relative the jamb hinge portion. Additionally, the bore of the pivot tube serves as a protective passageway for a helical wound cable which may be a plurality of fine stranded wires which are used for the conductors. In view of the fact that the hinge contains such a conductor, it is necessary to provide means to prevent the hinge portions from being separated after they are joined together. This is attained herein by locking the sleeve bearing on the pivot tube by means of a split retainer ring.
The electrical pivot hinge herein described has the following design features: (1) The external appearance is the same as most standard pivots. (2) The connector cable is coiled to reduce bending and to give long life on repeated flexure. (3) The two halves of the pivot cannot be separated once the unit is assembled, thus minimizing faulty installation or vandalism. (4) The wire assembly can be replaced if it wears out by removing the pivot, and unscrewing the cap and pulling out the wires. (5) Stock pivot parts are used for both the door and jamb portions, bearing and cap, thus minimizing expenditure for new parts. (6) The design is such that fine stranded wire may be used for the conductors, thus relatively high frequencies may be transmitted and there is no electrical noise introduced by operation of the pivots. The use of prior art sliding or brush contacts would produce such an electrical noise. (7) Electrical continuity is maintained at any door position whether the door be opened or closed. (8) The pivot is designed to take the radial load of the door. (9) The pivot has a prelubricated bearing and accordingly does not require additional lubrication throughout its life.
DESCRIPTION OF THE DRAWINGS
In order that all of the structural features for attaining the objects of this invention may be readily understood, reference is herein made to the following drawings wherein:
FIG. 1 is a view of an exterior door which is mounted relative its frame by a pivot hinge set, the intermediate pivot of which is an electrical hinge connector constructed in accordance with the principles of this invention;
FIG. 2 is a rear perspective view of the intermediate pivot of FIG. 1 showing the mounting surfaces of the leaves;
FIG. 3 is an exploded view of the intermediate pivot of the prior figures showing the connector components housed within the pivot knuckles;
FIG. 4 is a side elevation of the intermediate pivot with the knuckle connector portion being in section to show the positioning of the components housed within the assembled jam and door pivot portions; and
FIG. 5 is a simplified plan view showing the general path of the electrical conductor within the intermediate pivot.
Referring now to FIG. 1 of the drawings, door 1 is shown mounted relative building wall 2 by a pivot set which includes top pivot 3, intermediate pivot 4 and bottom pivot 5. As is set forth hereafter, intermediate pivot 4 is an electrical connector hinge incorporating the structural features of this invention. From an electrical aspect, the principal purpose of intermediate pivot 4 is to complete an electrical circuit between conductors 6, located in building wall 2, and an electrical device incorporated within door 1. This device may be, for example, a bolt (not shown) which is electrically energized upon power failure by conductors 7 so as to close a door; or alternatively, this electrical device may be circuit 8 fabricated of a door applied electrical tape which is part of a conventional security system.
From a mechanical aspect, intermediate pivot 4 also performs the usual functions of such a pivot in locating and positioning door 1 relative its frame.
Referring now to FIGS. 2 through 4, pivot 4 comprises pivot jamb portion 9 and pivot door portion 10. Jamb portion 9 includes a jamb mounting leaf 11 and a jamb knuckle 12; and pivot door portion 10 includes a door mounting leaf 13 and a door knuckle 14.
From an external aspect, the appearance of pivot 4 is essentially the same as that of a standard pivot which is not an electrical connector hinge. However, pivot 4 differs (FIG. 2) in that the portions 9 and 10 thereof house an electrical cable 15 which may incorporate one or more individual electrical conductors, as is required for particular installation. Mounting leaves 11 and 13 and knuckles 12 and 14 are formed with internal passageways and bores which house cable 15 and enable this cable to make a complete electrical connection through the hinge. In the usual installation of the pivot, leaves 11 and 13 are mounted in the customary manner upon a jamb and door, respectively. However, leaf 11 is formed with an opening 16 through which cable 15 passes, and leaf 13 is formed with an opening 17 through which cable 15 passes. Both openings 16 and 17 are located on the mounting surfaces or bottoms of their respective leaves and, accordingly, the ends of cable 15 are isolated from external viewing and can pass protectively into conduits located within door 1 and also its jamb and frame.
Each of mounting leaves 11 and 13 is formed with a plurality of countersunk holes 18 which permit the fixing of the leaves to adjacent door and frame surfaces by a plurality of screws (not shown).
Pivot portion 10 is formed with a knuckle 14 (FIGS. 3 and 4). Knuckle 14 has a partial and irregular bore 19 formed therein; and pivot portion 9 is formed with a knuckle 12 which is formed with a through bore 20. Both leaf 13 and knuckle 14 of pivot portion 10 are formed with a communicating passageway 21 which connects cable opening 17 to bore 19. Likewise, leaf 11 and knuckle 12 of hinge portion 9 are formed with a similar passageway 22 which connects cable opening 16 to bore 20.
The general path taken by cable 15 from opening 16 through leaf 11, knuckle 12, knuckle 14, leaf 14 to opening 17 is shown in FIG. 5.
Referring to FIGS. 3 and 4, pivot tube 25 is located within both bores 19 and 20 so as to couple pivot portions 9 and 10 as hereafter outlined. Pivot tube 25 is formed with a centrally disposed bearing flange 26 which separates the tube into an upper section 27 and into a lower section 28. Section 27 is formed with a larger diameter than that of lower section 28. Additionally, section 27 is also formed with a through slot 29 which is located adjacent opening 30 (FIG. 3) so that cable 15 emerges from opening 30 directly into the central bore of pivot tube 25. Pivot tube 25 must be aligned so that opening 30 leads directly into slot 29; otherwise, the opening 30 will be blocked. In the assembly of the connector hinge, pivot tube 25 is press fit into bore 30 until bearing flange 26 rests against shoulder 31. This tight fit maintains slot 29 in alignment with opening 30.
In the assembly of the electrical connector hinge, sintered bronze sleeve bearing 32 is tightly fit within bore 20 of knuckle 12, but the bearing has a loose fit relative lower section 28. Accordingly, relative motion is permitted between sleeve bearing 32 and pivot tube 25. Inasmuch as pivot tube 25 is press fit within bore 19 and sleeve bearing 32 is press fit within bore 20, the relative rotation of hinge portions 9 and 10 produces relative motion in the areas of the adjacent surfaces of sleeve bearing 32 and lower section 28 of pivot tube 25.
Pivot tube section 28 is formed with an annular groove 33 which receives split retainer ring 34 when all of the components are assembled in the manner shown in FIG. 4. The application of split retainer ring 34 locks the two hinge portions 9 and 10 to one another so that they may not be disassociated by an attempt to separate knuckle 12 from knuckle 14.
Cable 15 is coiled in its intermediate portion located within the confines of pivot tube 25 so that the relative movement of the two hinge portions 9 and 10 does not produce undue flexing or bending of the cable. Such flexing, if excessive, will cause premature breaking in the electrical cable. The several helical coils provide sufficient accommodation so that the slight movement of each coil in response to door opening produces negligible flexing of the wire. Accordingly, the structure shown has a more than adequate number of door opening and closing cycles for commerical application.
In order to isolate cable 15 within pivot 10, an inner portion of bore 20 is formed with a helical thread section 35 (FIG. 3). This thread section 35 receives mating threads of cap 36 so that the otherwise bottom opening in knuckle 12 is closed.
Referring now to FIG. 5, additional cable openings are formed in both leaves 11 and 13 so that cable 15 may be appropriately passed through the pivot portions. In particular, leaf 11 is formed with a short passageway 37 which leads directly into passageway 22, and similarly leaf 13 is formed with a short passageway 38 which leads directly into passageway 21. Passages 37 and 38 are used in the initial passage of cable 15 within the pivot portions during factory assembly. Ultimately, in the passing of the cable through passageways 37 and 38, the cable is snaked through both openings 16 and 17 so that the cable emerges through these openings. However, in the initial location of the cable within the pivot portions 9 and 10, the abrupt change of direction occurring at both openings 16 and 17 blocks the cable from being pushed through the hinge portions. However, inasmuch as passageways 37 and 38 lead directly into passageways 22 and 21, resepctively, the cable can be appropriately snaked through the hinge portion passageways. After the cable is removed through both openings 16 and 17, small metallic balls 39 and 40 are press fit into the openings leading into passageways 37 and 38, respectively, so as to close these passageways.
The detailed steps of assembly of electrical pivot 4 are as follows:
1. Initially, pivot tube 25 is forcibly pressed into bore 19 of door portion 10. The milled slot 29 formed in the upper section 27 of pivot tube 25 must be aligned with the conductor opening 30 as previously described.
2. The bearing sleeve 32 is then slipped onto the lower section 28 of pivot tube 25.
3. The retainer ring 34 is installed on pivot tube 25 by locating the ring within groove 33 to retain the bearing sleeve.
4. Jamb portion 9 and door portion 10 are thereafter press fit together by forcing the outside diameter of sleeve bearing 32 into bore 20.
5. Cable 15 is inserted into passageway 38 through passageway 21 through the slot 29 and the central bore of pivot tube 25. The end of the cable projecting from the bottom end of pivot tube 25 is helically wound into a plurality of coils as is required, and the remaining straight portion of the cable is passed through passageway 22 into passageway 37. Thereafter, a small snake is inserted into both openings 16 and 17 to pull the ends of cable 15 out of passageways 37 and 38 so that these cable ends will emerge at openings 16 and 17.
6. Cable 15 is sealed into jamb and door portions 9 and 10 by filling openings 16 and 17 with an epoxy glue where the cable leaves.
7. The assembled pivot 4 is then checked for free turning. During the course of this step, the coiled wire portion must be free to coil and uncoil inside of the pivot tube; otherwise, premature breakage will occur.
8. Cap 36 is installed to seal the helical portion of cable 15.
9. Cable 15 is checked for continuity by test lamp or ohmmeter in a conventional manner.
It should be understood that the particular electrical connector hinge above described is merely illustrative of a preferred embodiment. Modifications can be made without departing from the scope of the invention.