US3266007A - High voltage terminal block - Google Patents

Description

1966 F. R SULLIVAN 3,266,007

HIGH VOLTAGE TERMINAL BLOCK Filed May 18, 1964 IN VENTOI? FREDERICK 72. SUZL/V/M United States Patent 3,266,007 HIGH VOLTAGE TERMINAL BLOCK Frederick R. Sullivan, Auburn, N.H., assiguor to Sanders Associates, Inc, Nashua, Nl-L, a corporation of Delaware Filed May 18, 1964, Ser. No. 368,102 9 (Jlaims. (Cl. 339-128) to guard against the above noted problems was to pot the entire terminal area with some suitable potting compound. While this provided the needed protection against arcing and corona effects, these potted terminals presented numerous deficiencies in that they required the complete destruction of the terminal area in order that the electrical leads connected therein be removed for purposes of repair or testing. The need for special solvents to dissolve the potting compound also presented another problem.

There have been in the prior art attempts to solve this problem. A number of contributions typical of one effort is the high voltage connector to DeTar, Patent No. 2,897,-

471, which makes provision to assure arc-free operation at higher altitudes. The DeTar patent, While providing one approach to a solution of the problem, does not present an electrical connection which is totally free of the problems noted above, the DeTar patent being complex in a number of elements and .the need for a multitude of C rings to provide adequate sealing of the units connected.

A patent to Stevens, No. 2,677,115, represents another prior art approach, but this patent also presents an electrical connection which does not have the isolation which will be present in the invention to be described hereafter.

Important to the invention to be described is the recognition that there must be, from the point of electrical interconnection between leads sought to be connected, a minimum length of mating connector interface needed to ultimately assure the electrical connection from having present therein sufiicient air dielectric within the mating portion of the connector which might allow the ionization thereof and .a concomitant breakdown of this air dielectric with related arcing and corona deficiencies.

The invention noted above avoids all of the problems present in the prior art and does so with a minimum of parts but with a maximum of electrical isolation and does so in the minimum of space with a versatility of electrical lead wire input and output heretofore not present in the prior art.

It is therefore an object of this invention to provide a high voltage terminal that has no high altitude arcing and corona effects and is readily demountable.

Another object of this invention is to provide a high voltage terminal block that can support a plurality of electrical leads of varying outside dimensions.

Another object of this invention is to provide a high voltage terminal block that can have a plurality of electrical leads entering and leaving the block at dilferent angles.

Another object of this invention is the provision of a high voltage terminal block that is free from air contamination at the point of electrical interconnection.

Another object of this invention is to provide a high voltage terminal block that may be readily assembled or Patented August 9, 1966 disassembled without damage to any portion of the terminal block arrangement.

Another object of this invention resides in the provision of a high voltage terminal connector that avoids air contamination by utilizing an interference fit socket arrangement that resists inadvertent separation but is readily interconnected.

Other and further objects of this invention Will be apparent from the following description of preferred embodiments thereof taken inconnection with the accompanying drawing.

In the accompanying drawing:

FIG. 1 is a three dimensional illustration depicting several aspects of one embodiment of the invention;

FIG. 2 is a cross sectional view of a second embodiment of the invention; and

FIG. 3 is another configuration of the invention embodied in FIG. 2.

Reference is now made to FIG. 1 in which there is illustrated one embodiment of the subject invention. The high voltage terminal arrangement is made up of a high voltage terminal block 11 which has formed therein a number of slotted openings or channels 12 and 13. Mounted in the center of these channels are terminal posts .14, 16 and 17, each of the terminal posts having therein threaded openings 18 and 19 on the upper surface. These terminal posts 14, 1'6 and 17 may be of an insulating material of the same composition of the high voltage terminal block 11. Bakelite is one such commercially available material that is suitable for a high voltage terminal block arrangement of the type depicted herein. When very high strength is needed, the block 11 may be made of metal such as brass or steel and the terminal posts are constructed of an insulating material.

In this particular embodiment the terminal post 17 is of a conductive material which passes downwardly through the terminal block 11 for a subsequent electrical interconnection to an electrical lead wire 38 which is connected to the post in a manner not shown. In order that the electrical connection of the lead wire 38 be [free from arcing the bottom of the block 1J1, it would require the presence of a pressurized housing (not shown) secured to the block 11.

At the central area of the slotted openings of channels 12 and 13 are arcute central regions 21 and 22 which are to receive a lower preformed resilient insert 23 and an upper preformed resilient insert 24. These resilient inserts may be fabricated from a number of materials, two of which are rubber or a silicone type rubber which are easily formed or molded and provide the resilient surrounding medium in which electrical lead wires 28 and 29 will ultimately reside when the entire device is assembled. Each of the preformed resilient inserts 23 and 24 have in the faces thereof electrical lead grooves 2 6 and 27. The radii of these electrical lead grooves are determined by the size of the outside diameter of the electrical lead wire being used and in those situations in which the wire is very small, the grooves in turn are' molded of a smaller radii to complement the wire to be handled.

Depicted in FIG. 1 directly above the slotted opening or channel 12 there is shown in an exploded perspective the preformed resilient inserts 23 and 24 and in between these two inserts are the electrical lead wires 28 and 29 having their electrical lead eyelets 31 and 32 in register with a terminal post opening 25 in the lower resilient insert 23.

A screw 33, when the device is assembled, passes through the eyelets 31 and 32 and then through the terminal post opening 25 into the threaded opening 18 of the terminal post 14. Once the lower performed resilient insert 23 is placed down with the channel 12 and the electrical connection as described above has been made, the lower insert 23 may be coated with a silicone lubricant prior to the placing of the upper preformed resilient insert 24 down upon the lower insert 23. When this upper insert 24 has been placed in position, it is then placed under pressure by a top plate 51 which is held in place by screws 52, 53, 54 and 56 and in so being held in place, the pressure exerted upon the upper preformed resilient insert is suflicie-nt to cause the silicone lubricant, described above but not shown in the drawing, to be forced outwardly along the grooves 26 and 27 and the wires 28 and 29. The above arrangement along with any air trapped therein establish the ultimate in a high voltage, high altitude terminal junction which is capable of resisting the corona and arcing effects inherently present in terminal blocks exposed to altitudes in excess of 50,000 feet and voltages in a magnitude of -20,000 volts.

As can be seen, the terminal block 11 is susceptible of a number of variable arrangements; that is to say, the

slotted opening 13 may have a portion thereof extending at an angle away fro-m the terminal post 16 thereby permitting two wires to be interconnected so that they are joined at an angle that is less than 180. The resilient inserts 23 and 24 which fit in slotted opening 12 illustrate electrical lead interconnection in the 180 position.

To the right of the slotted opening or channel 12, there is another example of how two parallel electric lead wires may enter the high voltage block 11 between two resilient inserts 30 and 4 1 and form an electrical connection at screw 37 which in turn is connected to electrical lead wire 38 which provides a three-way junction in an isolated region of the terminal block 11.

In position to the far left of FIG. 1 is shown an electrical lead wire 10 in an assembled condition with preformed inserts 39 and 40 in mating relationship.

Reference is now made to FIGS. 2 and 3 where similar numerals depict similar elements in the two embodiments set forth in these figures.

Referring specifically now to FIG. 2 there is shown a female preformed element 61 which may be cast of a rigid insulating material of sufiicient dielectric strength to meet the high voltage needs to be experienced by the electrical interconnection to be described more fully hereafter. The female preformed element 61 has an opening 62 at one end. At the base of the preformed element 61 there is molded therein a shouldered contact member 63 which has a contact prong 64 which will mate ultimately with a slotted portion 74 to be described hereafter.

Securely soldered within the preformed element 61 is an electrical lead wire 66. The opening 62 has a truncated tapered contour 67 which has therein concave impressions 6S and 69. The contour of the opening is important to the invention for it has been discovered that when high altitude operations are coupled with high voltages, there is a need for a maximizing of the total interface distance from, for example, contact prong 64 and the exterior of the opening 62. The presence of only one such contour or impression such as 69 would be insufficient to meet the needs of high voltage operations.

Directly above the opening 62 there is depicted a mating male element 71. It is imperative to the successful operation of this invention that one of the elements 61 or 71 must be of a resilient material. In the illustration convered by FIG. 2, the mating male element 71 is of such a resilient material. Rubber or silicone rubber are adequate materials to meet the needs of high voltage operations. The use of silicone grease at the interface also enhances the reliability of this arrangement.

Secured within the male element 71 is a shouldered element 73. This shouldered element 73 has a slotted portion 74, the slotted portion '74 having a bore opening therein, the diameter of which is slightly smaller than the outside diameter of the contact prong 64 thereby permitting the male element 71, when fitted within the preformed element 61, to expand slightly to form an interference fit with the prong 64. Accordingly, this invention contemplates the possible usage of a resilient material for the female element 61 and a rigid material for the male element 71. Of course, this would require that the slotted portion 74 and shouldered element 73 be located within the element 61 because it is essential that the slotted portion 74 be mounted within a resilient material that will afford the needed expansion to provide the interference fit noted above.

Reference is now made to FIG. 3 in which there is shown a second embodiment of the invention illustrated in FIG. 2. This embodiment shows a right angle connection of electrical lead wires 66 and 72. This illustration is also highly illustrative of one important aspect of this invention in that it shows the mating imaile element 71 fitted in position and also shows an interface 75. As can be appreciated in this figure, the distance from the electrical contact prong 64 along the interface 75 is maximized by the presence of the concave impressions 68 and 69 along which any air that might be trapped would be located. For it is the ionization of air along the interface of most electrical connections that provides the undesirable arcing and corona eifects. It can be seen that this arrangement provides a maximum of surface interface while providing a secured electrical connection enhanced by the convoluted surface of the mating elements 71 and 61.

While there has been hereinbefore described what are at present considered preferred embodiments of the invention, it will be apparent that many and various changes and modifications may be made with respect to the embodiment illustrated, without departing from the spirit of the invention. It will be understood that all changes and modifications as fall fairly within the scope of the present invention, as defined in the appended claims, are to be considered as part of the present invention.

What is claimed is:

1. A high voltage terminal block capable of high altituide usage without arcing or corona disabilities comprised of:

(A) a terminal body having at least one transverse channel therelacross,

(B) a terminal post disposed in said channel to carry a set of electrical high voltage lead wires,

(C) fastening means to secure said electrical leads to said tenmintal post,

(D) a plurality of shaped resilient preformed inserts mounted in mating relationship in said channel,

(E) a first one of said shaped resilient inserts mounted beneath said electrical leads and extending along the bottom of said channel,

(F) a second resilient preformed insert mounted above .and in mating contact with said electrical leads and said preformed insert to thereby totally encapsulate said electrical leads and said terminal post and pre vent the possibility of possible high voltage arcing and corona effects to adjacent objects, and

(G) a top plate securely mounted on said terminal body and in contact with said second preformed insert to thereby assure the electrical integrity of said electrical lead wires. 7

2. The combination set forth in claim 1 wherein said top plate and said second prefonmed insert are readily removable to thereby facilitate the inspection and removal of said electrical leads without removing the high voltage terminal block capability to be reused again.

3. The combination set forth in claim 1 wherein there is an electrically inert substance between said firs-t and said second resilient preformed inserts.

4. The combination set forth in claim 3 wherein said substance is a lubricant.

5. The combination set forth in claim 1 wherein said channel has a path that has an angled position starting at said terminal post to thereby permit said electrical leaid Wires to be joined at .some predetermined angle.

6. The combination set forth in claim 1 wherein said channel terminates at a point just past said terminal post and said electrical lead wires are mounted in a parallel arrangement to said post.

7. The combination set forth in claim 1 wherein said tenminal post is electrically conductive and passes downwardly through said terminal blocks body to thereby provide an externally located terminal for electrical connection to another component.

8. The combination set forth in claim 1 wherein said terminal body is made of a plastic insulating material.

9. The combination set forth in claim 1 wherein said terminal body is made of a high strength metal.

References Cited by the Examiner UNITED STATES PATENTS 2,275,762 3/1942 Horton 339-60 2,766,436 10/1956 Luebking 339-498 2,907,973 10/ 1959 Stevens 33959 2,924,808 2/1960 Hewes et a1 339-198 PATRICK A. CLIFFORD, Primary Examiner. J. H. MCGLYNN, Assistant Examiner.

Claims (1)

1. A HIGH VOLTAGE TERMINAL BLOCK CAPABLE OF HIGH ALTITUDE USAGE WITHOUT ARCING OR CORONA DISABILITIES COMPRISED OF: (A) A TERMINAL BODY HAVING AT LEAST ONE TRANSVERSE CHANNEL THEREACROSS, (B) A TERMINAL POST DISPOSED IN SAID CHANNEL TO CARRY A SET OF ELECTRICAL HIGH VOLTAGE LEAD WIRES. (C) FASTENING MEANS TO SECURE SAID ELECTRICAL LEADS TO SAID TERMINAL POST, (D) A PLURALITY OF SHAPED RESILIENT PREFORMED INSERTS MOUNTED IN MATING RELATIONSHIP IN SAID CHANNEL, (E) A FIRST ONE OF SAID SHAPED RESILIENT INSERTS MOUNTED BENEATH SAID ELECTRICAL LEADS AND EXTENDING ALONG THE BOTTOM OF SAID CHANNEL, (F) A SECOND RESILIENT PREFORMED INSERT MOUNTED ABOVE AND IN MATING CONTACT WITH SAID ELECTRICAL LEADS AND SAID PREFORMED INSERT TO THEREBY TOTALLY ENCAPSULATE SAID ELECTRICAL LEADS AND SAID TERMINAL POST AND PREVENT THE POSSIBILITY OF POSSIBLE HIGH VOLTAGE ARCING AND CORONA EFFECTS TO ADJACENT OBJECTS, AND (G) A TOP PLATE SECURELY MOUNTED ON SAID TERMINAL BODY AND IN CONTACT WITH SAID SECOND PREFORMED INSERT TO THEREBY ASSURE THE ELECTRICAL INTEGRITY OF SAID ELECTRICAL LEAD WIRES.

Images