US3321168A

US3321168A - Internal base plate for instrument transformers

Info

Publication number: US3321168A
Application number: US471161A
Authority: US
Inventors: Entremont Franklin R D
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1965-07-12
Filing date: 1965-07-12
Publication date: 1967-05-23
Anticipated expiration: 1984-05-23

Description

May 23, 1967 F. R. DENTREMONT INTERNAL BASE PLATE FOR INSTRUMENT TRANSFORMERS Filed July 12, 1965 United States Patent Ofi 3,321,168 Patented May 23, 1967 s 321 168 INTERNAL BASE PiATE FOR INSTRUMENT TRANSFORMERS Franklin R. DEntremont, Dover, N.H., assignor to Gen- This invention relates to instrument transformers and more particularly to an internal base plate for an instrument transformer.

In recent years it has become a common practice in the instrument transformer field to completely enclose the various parts of instrument transformers in a molded plastic body. The plastic body provides the insulation between the various parts of the transformer and also forms the outer casing or housing for the transformer. An example of such transformer is found in Patent No. 2,618,689.

In these molded transformers, various problems have been noted in attempting to mount the transformer for use. One mounting means which has been used includes a pair of metallic strap members which encircle the transformer. These strap members are secured to a base plate or a mounting plate by means of bolts or the like. These types of mountings are generally considered undesirable due to the relatively high labor cost required to assemble the mounting means to the transformer. Another solution which has been tried is to mold the base plate into the base of the transformer, embedding it in the plastic body member. Various of these base plates have been unsuccessful in that only a very thin layer of plastic material is available to hold the base plate to the body member. When the mounted transformer is subjected to vibration or mechanical shock, the transformer has tended to separate from the base plate.

Therefore, it is one object of this invention to provide a novel base plate for instrument transformers.

A further object of this invention is to provide an internal base plate which may be molded in the body of an instrument transformer.

A still further object of this invention is to provide a novel internal base plate for an instrument transformer which will be securely locked in the molded body thereof.

In carrying out this invention in one form, a base plate for an instrument transformer is provided in the form of a rectangular metallic plate. The metallic plate has a pair of upstanding flanges on opposite sides of the plate, each flange having a plurality of holes therethrough.

When the base plate is molded in the plastic body of a transformer, the plastic material flows through the plurality of holes, and when cured, securely attaches or locks the base plate to the plastic body. A plurality of bosses are provided extending from the metallic plate in a direction opposite the upstanding flanges. These bosses are provided with tapped holes for mounting the transformer to any desired mounting bracket.

The invention which is sought to be protected will be particularly pointed out and distinctly claimed in the claims appended hereto. However, it is believed that this invention and the manner in which its various objects and advantages are obtained, as well as other objects and advantages thereof, will be more clearly understood from the following detailed description of a preferred embodiment thereof, particularly when considered in the light of the accompanying drawing, in which:

FIGURE 1 is an end view of an instrument transformer showing one form of base plate according to this invention;

FIGURE 2 is an enlarged sectional view of a portion of a transformer and base plate showing further features of this invention in greater detail;

FIGURE 3 is a perspective view of one form of base plate according to this invention; and

FIGURE 4 is a sectional view taken on the line 4-4 of FIG. 3.

Reference will now be made to the drawing in which like numerals are used to indicate like parts, throughout the various views thereof. In FIG. 1 there is shown an end view of an instrument transformer 10 which comprises a core and coil unit 12, the core and coil unit 12 being contained or embedded in a molded plastic body 14. As shown, a window opening 18 is provided in the core and coil unit 12 and the plastic material is molded about the core and coil unit to provide a window opening 20 in the body 14. A primary bar member 22 may be mounted in window opening 20 in a manner well understood. Also, the secondary terminals 24 and 26 are provided on top of the body 14, as shown. In accordance with this invention a base plate 28 is provided, molded in the plastic body 14 as shown. Bosses 30 are provided on base plate 28 and may be tapped to receive bolts 32. As shown, bolts 32 are used to attach the instrument transformer 10 to a mounting plate 34.

A preferred form of base plate 28 isbest shown in FIGS. 3, and 4 of the drawing. As there shown, the base plate 28 is preferably in the form of a rectangular metallic plate having a central portion 36 and

upstanding flanges

38 and 40 on opposite ends thereof. Each of

flanges

38 and 40 is provided with a plurality of holes 42 extending through the

flanges

38 and 40, as is clearly shown in the drawing. A plurality of bosses 30 are formed on the bottom of the central portion 36 of base plate 28. These bosses extend from base plate 28 in a direction opposite to the

upstanding flanges

38 and 40. Bosses 30 have tapped holes 44 therein for securing the base plate 28, and therefore, the transformer 10, to any desired mounting means. In the preferred form of base plate according to this invention the central portion 36 has a curved channel 46 with an opening 48 therein. The opening 48 allows a portion of the core and coil unit of the instrument transformer to extend therethrough. This allows the base plate 28 to be embedded in the plastic body 14 without unnecessarily increasing the thickness of the plastic material below the core and coil unit 12. Of course, the plastic material of body 14 will extend between the core and coil unit 12 and the edges of opening 48 in the base plate 28 providing the desired insulation between the core and coil unit 12 and the base plate-28.

As will be apparent from the above description, the base plate 28 is embedded in the plastic body 14 with the

upturned flanges

38 and 40 extending in to the body 14. The base plate 28 and the core and coil unit 12 will be mounted in the desired relative position in a mold, and a plastic material for the body 14 will be poured into such mold. This plastic material will flow around the

upturned flanges

38 and 40 and through holes 42. As will be understood, threaded plugs will be provided in tapped holes 44 during molding to prevent the plastic material flowing into these holes. As will be apparent, when the plastic material is cured, integral locking portions will be provided extending through the holes 42. This is more clearly shown in FIG. 2 of the drawing.

As can be seen in FIG. 2, the plastic material of body '14 extends through the hole 42 in the flange 40 and is integral with the plastic material on both sides of the flange 40. Obviously, this same integral locking will be obtained through each of holes 42 on both of

flanges

38 and 40. The bosses 30 are generally provided flush with the bottom of the molded body 14 in the manner shown in FIG. 2. Thus a mounting means, such as mounting member 34, may be readily attached to the base plate 3 28 by the bolts 32. This of course will firmly attach the transformer 10 to the mounting means.

While there has been shown and described the present preferred embodiment of the internal base plate of this invention, it will be obvious to those skilled in the art that various changes may be made in the structural details thereof. openings could be provided in the upturned flanges. The opening 48 in the base plate could be eliminated, if desired, and a greater thickness of material provided on the lower portion of the transformer. Obviously, these and other changes may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed as new and which it is desired to secure by Letters Patent of the United States is:

1. A base plate for an instrument transformer comprising: a substantially rectangular metallic plate member, a pair of upturned flanges on opposite sides of said plate member, said upturned flanges provided with a plu- -rality of holes therethrough, and a plurality of bosses on said plate member, said bosses extending from said plate member in a direction opposite to said upturned flanges, said bosses having tapped holes therein.

2. A base plate as claimed in claim 1 in which the central portion of the metallic plate member is provided with an opening the-rethrough for the entry of the core and coil unit of an instrument transformer.

For example, a more or less number of 3. An instrument transformer having an internal base plate, comprising in combination, a molded plastic body for said transformer, a substantially rectangular metal-lic plate member molded into said molded body, said metallic plate having a pair of upturned flanges on opposite sides of said plate, said flanges provided with a plurality of holes therethrough, the plastic material of said molded body extending through said holes for securing said metallic plate in said molded body and a plurality of bosses on said plate, extending from said plate in'a direction opposite said flanges, said bosses being provided with tapped holes for mounting to a mounting bracket.

References Cited by the Examiner UNITED STATES PATENTS 1,877,064 9/ 1932 Schultz 248350 2,618,689 11/1952 Cook 336 2,930,011 '3/ 1960 Wigert et al. 33696 3,024,434 '3/ 1962 Carson 33696 3,092,364 6/1963 Sa-rafinos 248-350 3,202,947 8/ 1965 Budovac 326-96 JOHN PETO, Primary Examiner.

CLAUDE A. LEROY, Examiner.

I. F. FOSS, Assistant Examiner.

Claims

1. A BASE PLATE FOR AN INSTRUMENT TRANSFORMER COMPRISING: A SUBSTANTIALLY RECTANGULAR METALLIC PLATE MEMBER, A PAIR OF UPTURNED FLANGES ON OPPOSITE SIDES OF SAID PLATE MEMBER, SAID UPTURNED FLANGES PROVIDED WITH A PLURALITY OF HOLES THERETHROUGH, AND A PLURALITY OF BOSSES ON SAID PLATE MEMBER, SAID BOSSES EXTENDING FROM SAID PLATE MEMBER IN A DIRECTION OPPOSITE TO SAID UPTURNED FLANGES, SAID BOSSES HAVING TAPPED HOLES THEREIN.