US3126445A - Pop-in hermetic electric terminal - Google Patents

Description

March 24, 1964 R. u. CLARK POP-IN HERMETIC ELECTRIC TERMINAL Filed March 26, 1962 FIG.

FIG.5

INV EN TOR.

United States Patent M 3,126,445 POP-IN HERMETIC ELECTRIC TERMINAL Richard U. Clark, 4 Orchard Drive, West Acton, Mass. Filed Mar. 26, 1962, Ser. No. 182,486 1 Claim. (Cl. 174153) The present invention has to do with hermetic electric terminals and particularly gasket type terminals of the type employing a resilient sealing insert held under tension by a non-resilient, or pliable member that partially envelopes the said resilient member.

In the past, terminals of the general class just noted have been made to effectively seal a metal electrode coaxial with an insert, and also retaining shell-like members, to effect the insulated passage of the electrode through a hole in a panel or bulkhead.

The above-mentioned terminals are generally partially assembled, fitted into a hole in a panel or the like, capped with a shell-like member and fitted at the shell termination with a pressure-applying member. The whole device is then held together by pressure exerted by means of a clinched eyelet fastening, or a bolt and nut type electrode either of which may exert the pressure necessary to hold the device together.

The outlined terminals have been very satisfactory in many respects but require the expenditure or" time and skill to complete their assembly into the equipment that they serve.

The present terminal is a unitary device requiring only a definite amount of pressure to complete its installation in the device that it will serve.

An object of the present invention is to provide an hermetic electric terminal that can be pressure-fastened into a hole in a panel from one side of the same. Another object is to provide a terminal that can be popped into a hole in a panel or bulkhead, whereupon it supplies a lead'through electrode hermetically sealed therein. A further object of the present invention is to supply a terminal as outlined having a minimum number of component parts. Additional objects are to supply a terminal to operate through a very wide range of temperatures and to provide a terminal that is compact and low in cost.

The present terminal comprises a cup-like member of pliable material such as tetrafluoroethylene, sold under the trademark Teflon, into which is fitted a flared and flanged tubular elastomeric insert, and a pin-like metal electrode, the latter part being axial in respect to the former parts, and having a flange abutting the cup shell.

At the free end of the insert flange a non-retractible push nut is attached to the electrode and pushed against the insert flange causing the flared section of the insert to partially expand the normally open end of the pliable cup like member, but leaving a circumferential groove between the resilient flange and the edge of the cup member.

The pliable cup-like member of the terminal has a longitudinally disposed series of knurled on bars on its outside surface periphery to aid in its facility for being compressed into a hole and then expanding to its original size. It may be tapered or rounded at its semi-closed end.

The terminal as so far defined can thus be compressed, pliable section first, into a hole in a panel of suitable thickness, and when the groove between the insert flange and the cup-like member is encountered the compressed periphery of the latter pops out under pressure of the insert flare section and the terminal becomes firmly seated in the panel. Additional pressure can then be applied at both ends of the terminal if a very tight seal is desired, but by the simple expedient of choosing the optimum panel thickness in respect to the width of the groove 3,126,445 Patented Mar. 24, 1964 between the insert flange and the cup-like member, a very satisfactory seal can be had by simply popping the terminal into place until the cup edge springs out completing the assembly into the panel.

The terminal of the present invention uses what might be described as an inverted T type insert, it being of capital T configuration when sliced through its center longitudinally. An important feature of the design of the present terminal is inherent in what might be termed the cross bar of the T which section terminates at its free end in a cone shaped configuration. This section is also referred to as the flange.

By adopting the configuration outlined above, as viewed when the terminal is assembled, and after the terminal has been assembled into a panel or the like under suitable force or pressure, it will be found that the insert cone terminated flange assumes a doughnut-like shaped exterior. In this last form undesirable radial flow of the insert after terminal installation is prevented due to the flow stress within the flange section reaching the elastic limit of the material.

Under the conditions just outlined and due to the continued stress within the flange section, which section governs the tightness of the terminal assembly in the panel, the terminal assembly will remain firmly seated in the panel over long periods of time and in spite of widely varying environmental conditions. In respect to the cone terminated flange configuration as used and specified above it will be realized that pressure of the push-on nut used to compress same will cause the insert material to flow automatically into the doughnut configuration.

The present application, in so far as the push on nut and cone configuration, to result under pressure in a doughnut type of seal, are concerned, is a continuation in part of my application Serial No. 89,294 (series of 1960) filed February 14, 1961, now issued as Patent No. 3,047,- 653 however the changes in the intermediate section of the insert into the form of a flare from the tubular barrel section into the flange are new and accomplish a new effective way of sealing the terminal into the device it is to be used with.

Turning now to the drawing which is a part of this application there will be seen in FIGURE 1 a complete plan view of my new terminal, while in FIGURE 2 there is shown a cross-sectional view of same. In FIGURE 3 is shown a plan view of the resilient insert and in FIG- URE 4 a bottom view of the assembly of the various parts. In FIGURE 5 the terminal is shown correctly mounted in a hole in a suitable panel, the diameter of the hole being less than that of the terminal.

In FIGURE 1 at 2 is shown the cup-like shell of the terminal, at 3 the terminating end of the electrode with stem at 5 and flange at 4. The remaining termination of the electrode is seen at 6, a positioning groove in the electrode at 7 and a push-on nut at 9 with the prongs 10 fitting in the groove 7. The flange of the insert is shown at 1.

In FIGURE 2 the above parts are repeated the flare start on the insert being also shown at 8, the cone shaped flange terminated on the insert at 11 and the barrel termination at 12.

There is shown in FIGURE 3 at 23 the barrel of the insert, at 16 the axial hole through the insert, at 1 the flange, the flare at 15, and the conical flange termination at 14.

In FIGURE 4 is shown the bottom view of the insert flange at 14, the termination of the electrode at 6 and the push-on nut at 9.

FIGURE 5 shows the terminal mounted in the panel 17 in the hole 18 and the doughnut configuration of the now compressed flange hugging the panel at 20 with the roll over of the flange encasing the push-on nut at 21 and 22, and 19.

The cup-like shell shown as knurled in FIGURE 1 can also be constructed in any manner or form that will allow it to be readily compressed into the mounting hole. It can be made of re-enforced plastic material and have a smooth surface if of compressible material and may be tapered outwardly toward its most open end and have a slight flare to thicken the wall at the rim, which treatment if properly applied will prevent the shell wall from skirting out too much upon being mounted through the panel and give a more uniform bulge to the shell resulting in a satisfactory assembled appearance.

The shell member has been defined as being of a pliable material, and as thus described is meant to be of a material that can be distorted or compressed but that will return to its former state and shape within a few minutes. It is also to be understood that the shell could be of compressible pliable material on the inside with non-yielding ridges or bars on the outside surface.

Having described my invention, I claim:

A pop-in hermetic electric terminal assembly for mounting in a hole in a panel comprising in combination, a resilient tubular insert member having a major diameter tubular section, a minor diameter tubular section, a flared tubular section, said minor diameter section diverging into said major diameter section by means of said flared section, a convex conical termination at each end of said insert member, a pliable compressible cap of non-conducting material, said cap having an axial through-hole, said hole being counterbored at one end of said cap and said counterbore fitting over the minor diameter section of the resilient tubular insert up to the flared section of same, said cap having a concave conical portion within said counterbore to receive the convex conical termination of said minor diameter insert section, an electrode pin having a stem section, a flange adjacent one end of said stem and a peripheral positioning groove on said stem adjacent the other end, the said electrode pin being positioned axially within said insert and said cap and the flange on said pin located so as to bear against said cap, the said groove on said stem extending beyond the conical termination of the major diameter insert section, a push-on nut, said nut riding within said groove in said electrode stern and abutting the said major diameter and termination of said resilient insert, the said terminal assembly being held securely within the hole in the previously mentioned panel upon the forced insertion of the compressible cap therethrough.

References Cited in the file of this patent UNITED STATES PATENTS 2,235,429 Henry et al Mar. 18, 1941 2,542,144 Kearns Feb. 20, 1951 2,678,346 Garraway May 11,1954 2,868,868 Corey Ian. 13, 1959 2,984,698 Strauss May 16, 1961 3,047,653 Clark July 31, 1962 FOREIGN PATENTS 559,422 Canada June 24, 1958

Images