US3544952A - Molded insulator and shell therefor,releasably attachable to an electrical contact,and accompanying flash shield - Google Patents

Description

Dec. 1, 1970 R. E. PIAGET MOLDED INSULATOR AND SHELL THEREFOR RELEASABLY ATTACHABLE TO AN ELECTRICAL CONTACT, "AND ACCOMPANYING FLASH SHIELD Filed Dec. 19, 1968 I N E N TO R. 05567 06416 P4065? Via/21 SJgAM/im United States Patent MOLDED INSULATOR AND SHELL THEREFOR,

RELEASABLY ATTACHABLE TO AN ELEC- TRICAL CONTACT, AND ACCOMPANYING FLASH SHIELD Robert Edgar Piaget, 4432 Homer Ave., Cincinnati, Ohio 45227 Filed Dec. 19, 1968, Ser. No. 785,192 Int. Cl. H01r 7/02 US. Cl. 339-94 8 Claims ABSTRACT OF THE DISCLOSURE The combination of a releasably attachable insulating molded insulator for an electrical conductor with an electrical contact comprising, in one form of the invention, a forceably removable plug mounted in a recess formed within the marginal wall of the sleeve for particular insulating of the contact upon attaching the sleeves thereto, a dog-point screw element having an extension on its outer end engaging a corresponding aperture in a metal ring molded to the inner wall of the insulator and which dogpoint screw element is threadedly mounted in a radially extending cavity aligned with the plug disposed in the recess provided in the opposing Wall of the insulator, whereby with omission of the plug form its recess, the contact is releasably attachable to the insulator before insulating same in such insulator by the plug. In another form of the invention embodied in a receptacle or sleeve coupled with a mounting flange, a screw is provided for disposition in such a recess, said screw extending into a ring molded to the receptacle or sleeve and into the contact thereby attaching the latter to the former, an insulating disc insertable in the recess above the head of the screw, and a flash shield coupled to the insulator for preventing arcing between the electrical contact and the mounting screws in the mounting flange. The shield is mounted about the re ceptacle or sleeve over an opening leading to the recess, thus, also functioning as a seal and insulator at the recess.

BACKGROUND OF THE INVENTION Field of the invention The field of art to which the invention is most likely to pertain is generally located in the class of devices related to electrical connectors. Class 339, Electrical Connectors, United State Patent Ofiice Classification, appears to be the general area of art in which the claimed subject matter of the type involved here has been classified in the past.

Description of the prior art Electrical connectors and their insulating bodies and the like, of the type involved here are disclosed in the following US. Letters Patent: Nos. 1,704,849 and 3,396,360.

SUMMARY This invention relates to electrical connectors and their mating insulators and contacts, and particularly, relates to structure releasably attaching an electrical contact to a molded receptacle body thereabout and to a protective covering referred to as a flash shield for preventing arcing between the electrical contact and screws and/ or nuts pro vided for a mounting flange molded with the insulator body and for covering a recess provided for releasably attaching contact to insulator.

An object of this invention is to provide for a simple yet highly efficient means by which an electrical contact is releasably attached to an insulator body therabouts and by which release, one from the other when one or 3,544,952 Patented Dec. 1, 1970 the other is damaged or for some other reason necessitating replacement of one or the other, is expeditiously obtained.

A still further object of the invention is to provide for an integrated mounting means or flange for an insulator.

Another object of the invention is to provide for protective means for a receptacle or sleeve whereby arcing is prevented or eliminated between an electrical contact and flanged mounting screws on the receptacle sleeve in which the connector is attached or otherwise fitted.

A further object of the invention is to provide a less expensive commercial connector.

A further object of this invention is to provide for a simple yet sturdy and long-lasting connector whereby the above objects are achieved, without the necessity of an otherwise complicated connector to achieve purposes which in the art has shown not to have been done heretofore.

These and other objects and advantages of the invention will become more apparent upon a thorough reading of the following description, the appended claims thereto and the accompanying drawing comprising one sheet.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross-sectional view of an electrical connector embodying the invention.

FIG. 2 is a view taken on line 2-2 of FIG. 1.

FIG. 3 is a perspective view, partly broken away, of another embodiment of the invention.

FIG. 4 is an elevational view of the flash shield and connector shown in FIG. 3.

FIG. 5 is a view taken on line 5-5 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing in which reference characters refer to corresponding numerals recited hereinafter, reference character 10 (FIGS. 1, 2) refers generally to a device embodying the invention. Device 10 comprises a pair of electrical contacts 12, 14 mounted in their respective insulators or sleeves 16, 18, and which are cou pled or joined together in any suitable fashion generally known in the art and trade, an example of such coupling or joining being shown in US. Letters Patent Nos. 2,952,830 and 2,477,818. No further description as to such a coupling connection will be undertaken here, as same is not required for an understanding of the instant invention described herein.

In the formation of insulator or sleeve 18, a recess 20 is molded in its wall 21 (FIG. 2), radially extending between its periphery and a central bore 22 formed therein. A metallic ring 24, preferably of aluminum material, is bonded or otherwise secured, in conventional fashion, to the inner face of wall 21 forming central bore 22 of sleeve 18. Contact 14 includes a body portion 26 slip-fitted in metallic ring 24, upon assembly. Body portion 26 is provided with a diametrically formed bore 28 which is aligned with an aperture 30 of metallic ring 24 which in turn is aligned with recess 20 molded in sleeve 18. A radially disposed enlarged threaded cavity 32 extends from the end of bore 28 opposing the end of bore 28 communicating with aperture 30 and recess 20, and terminates at the peripheral wall of body portion 26.

Before inserting a tightly fitting insulating plug 34 in recess 20, preferably of rubber material, in the assembly of contact 14 to sleeve 18, a means such as a dog-point screw element 36 is threaded into cavity 32 of body portion 26 previous to such assembly, and sufficiently backscrewed thereinto by means of an Allen-type screw wrench, or other type of wrench suited to fit the screw element, inserted through bore 28, so that an extension 38 integrally formed therewith clears metallic ring 24 during such assembly. After body portion 26 is slip-fitted to metallic ring 24 already secured in central bore 22 of sleeve 18, the Allen wrench applied to element 36 rotates the latter radially outwardly so that extension 38 engages a coresponding second aperture 40 in ring 24, thereby preventing relative axial or rotational movement between contact 14 and sleeve 18, thus securely attaching the contact to the sleeve. Thereafter, plug 34 in inserted and mounted in recess 20*. As a result, both an insulating and fluid-tight condition is advantageously achieved at recess 20, i.e., elimination of electrical discharge through recess 20 and prevention of fluid such as water seeping through recess 20 to contact 14.

An annular lip 42 is mounted about recess 20 and is integrally formed of or molded in sleeve 18 during formation thereof. Lip means 42 prevents dislodgment of plug 34 from its functional position in recess 20. Lip 42 provides the advantage of deliberate forceable entry and removal of plug 34 in the assembly and disassembly of device 10. Thus, it is practically impossible for an electrical technician to be exposed to electrical discharge through recess 20 during electrical use of device 10. On the other hand, ready disassembly in the event same is necessary is readily accomplished.

The assembly of device should now be apparent from the above description. Molding of insulator or sleeve 18 is carried out in a conventional fashion of molding such elements, i.e., by making a mold therefor and applying customary molding techniques. After slipping cable 46 through the sleeve 18, it is suitably attached to contact 14, such as by soldering, and with bore 28 and dog-point screw element 36 threaded wholly into cavity 32 of body portion 26, contact 14 is then retracted back into sleeve 18 until bore 28 aligns itself with aperture 30 and recess 20 and cavity 32 with aperture 40 of ring 22. Dog-point screw element 36 is then screwed outwardly so that extension 38 engages aperture 40 in ring 24, thereby providing for a releasably attachable connection between contact 14 and sleeve 18. Plug 34 is thereafter forceably inserted through annular lip 42, thereby completely insulating contact 14 at recess 20. Consequently, in the event one or the other contact or sleeve is damaged or for some other reason required to be removed, rather than to replace an entire device, only the contact or sleeve is necessary to be replaced. Costs and downtime are reduced and no less eflicient or unsafe condition arises which would otherwise demand installment of a different and entirely assembled insulator.

Turning to the embodiment illustrated in FIGS. 3-5, an insulator shell 50 is provided with an integrally formed mounting flange 52, preferably rectangularly shaped in its extremities, molded at a right angle to the axis of shell 50 and mounted along a central portion of its major wall 54. A plurality of holes 56 are included in flange 52, each of which is disposed preferably immediately adjacent a corner of flange 52. Corresponding nuts and screws 58 are utilized in holes 56 for mounting shell 50 upon the rear of a wall panel 60, or the like, of a metallic junction box, with the male portion 62 of shell 50 projecting through an opening 64 provided in panel 60 and towards the front thereof so as to be in position for connection to associated insulator and contact members (not shown). As shown in FIG. 5, screws and nuts 58 securely attach shell 50 to panel 60. Stiffeners 66 (FIG. 3) may be provided in flange 52 and about holes 56 for providing a degree of rigidity against which the tightness of screws and nuts 58 may react, if desired.

Rearwardly of flange 52 along the central portion of major wall 54, a recess 70 (FIG. 4) is radially incorporated within molded shell 50. Recess 70 is positioned in major wall 54 in alignment with a counter-sunk aperture 72 contained in a metallic ring 74 bonded or otherwise secured, preferably flushed as shown in FIGS. 3 and 5, to the inner face of major wall 54, in a similar manner as is ring 24 with sleeve 18. A screw 76 is disposed in aperture 72 via recess 70, with its body threaded into an electrical contact 78 fitted in bore 80 of the inner face of major wall 54 or of ring 74, thereby releasably attaching together contact 78 and shell 50.

Lip means 82 are formed over and about recess 70 so as to retain an insulating disc or plug 84 upon screw 76, thereby providing for an insulating and fluid-tight condition at recess 70 of shell 50 for contact 78, for the same reasons as stated above in regard to plug 34 and recess 20'.

In actual past practice, in diiferent types of insulators and shells for an electrical connector arcing under heavy voltages has in many instances occurred between metallic surfaces, such as, for example, the rear of mounting screws and nuts and some exposed portion of the contact of the electrical connector. For example, as illustrated in FIG. 5, in past usage, a threaded rear 86 of an electrical contact such as 78 is exposed for connection of a copper terminal 87 thereto by means of a washer and nut means 88. Terminal 87 is connected to a house line, and with voltages running into hundreds of volts or higher, arcing could occur between terminal 87, means 88 and means 58. Consequently, to avoid establishing such a dangerous condition, a flash shield 90 is coupled to shell 50 in cooperative relationship with flange 52 whereby arcing or flashing due to such voltage is eliminated. Flash shield 90 comprises a flat molded insulating membrane 92, preferably of rubber material, and a central opening 94 for frictional mounting of the shield about major wall 54. The areal dimensions of membrane 92 are at least co-extensive with those of flange 52, so that upon cooperative relationship with flange 52, the rear of metallic screws and nuts 58 is insulating from rear 86, terminal 87 and means 88, thus, shielding not only screws and nuts 58, but also panel 60 from possible arcing from the area of exposed rear 86. Membrane 92 is of such thickness as to completely cover recess 70, and preferably includes the form of a flanged element 95 of suflicient width (as clearly shown in FIG. 5) to cover recess 70 rather than to include an unnecessary degree of additional material included as part of a uniform depth of material co-extensive with its areal dimensions. Thus, membrane 92 also funations as a seal and insulator over recess 70. This is extremely advantageous when omission of plug or disc 84, due to human failings or otherwise, would expose metallic screw 76 to the exterior of Wall 54.

Pursuant to the requirements of the patent statutes, the principle of this invention has been explained and exemplified in a manner so that it can be readily practiced by those skilled in the art to which it pertains, or with which it is most nearly connected, such exemplification including what is presently considered to represent the best embodiment of the invention. However, it should be clearly understood that the above description and illustrations are not intended to unduly limit the scope of the appended claims, but that therefrom the invention may be practiced otherwise than as specifically described and exemplified herein, by those skilled in the art, and having the benefit of this disclosure.

Therefore, what I claim as patentably novel is:

1. In an insulator and contact assembly for an electrical connector device, such assembly including an insulator, a contact, and a metallic ring bonded to said insulator and slip-fitted about said contact, the improvement comprising a recess radially formed within the wall of the insulator,

insulating plug means disposed in said recess for establishing an electrical insulating and fluid-tight condition,

lip means mounted about said recess for preventing dislodgment of said plug means, and

means contained within the exterior limits of the wall of said insulator below said recess and plug, for attaching said contact to said insulator,

the attachment of said means made operable by omission of said plug from said recess.

2. The improvement of claim 1 in which said attaching means comprises a diametrically formed bore in said contact,

a first aperture in said ring between said bore and recess,

a second aperture in said ring at the end of the bore opposite said first aperture, and

retractable means in said bore and having means for engaging said ring via said second aperture whereby said insulator and contact are releasably attached.

3. The improvement of claim 2 in which said retractable means comprises a threaded cavity and dog-point screw element threaded therein.

4. The improvement of claim 2 in which said engaging means comprises an extension radially extendable for secure engagement to said ring.

5. The improvement of claim 2 in which said rectractable means comprises a threaded cavity, dog-point screw element threaded in said cavity, and an extension mounted on said screw element for radial movement into secure engagement with said ring via said second aperture.

6. The improvement of claim 1 including a flange in- 6 tegrally molded to said insulator for mounting said assembly to a wall panel or the like.

7. The improvement of claim 1 incluing a mounting flange integrally molded to said insulator and a flash shield coupled to said insulator rearwardly of said flange and in cooperative relationship therewith for preventing arcing between an exposed portion of the contact and metallic means supporting said flange in an operable position for use of said assembly.

8. The improvement of claim 7 in which said flash shield covers said recess for additional protection against electrical discharge from said contact through said recess.

References Cited UNITED STATES PATENTS 1,605,033 11/1926 Jensen 339272X 2,414,846 1/ 1947 Aichinger 17459UX ERNEST R. PURSER, Primary Examiner US. Cl. X.R.

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