US2235180A - Stator mounting for variable condensers - Google Patents

Description

March 18, 1941. J TEAF 2,235,180

STATOR MOUNTING FOR VARIABLE CONDENSERS Filed 001:. 6, 1958 INVENTOR 70 672 A Zy BY A r fA O ifN EY i Patented Mar. 18, 1941 UNITED STATES PATENT OFFICE STATOR MOUNTING FOR VARIABLE CONDENSERS Jersey Application October 6, 1938, Serial No. 233,591 5 Claims. (c1. its-41.5)

This invention relates to means for insulatingly mounting an electrical apparatus in a frame or support member specifically, T. have "m invention as opplied to the mounting of the tor unit of s "able condenser in e frame the rotor sud. stator Heretoiore it has been proposed, in some cases, to mount the insulators carrying o, condenser stator in e. frame providing openings in the frame end inserting the ends or" the insulators therein and then forcing the metal of the frame against the sides of the insulator. Since condenser'iremes are now usually made of steel, has a. high elastic limit, there is e. tendency for the metal to spring back a certain amount away from the insulator, thereby leaving it loose in its opening. Another form of fastening such insulators to the frame has consisted of staking metal tines over the insulators, but since the staked portions of the metal engage a relatively small area. on the insulator, any extra. blow or force applied to overcome the spring-back effect is apt to crush or crack the insulator.

After considerable study and many tests, I have found a way of overcoming this difilculty or trouble, and this is the principal object of my invention; that is to say, the provision of ways and means for attaching the insulator directly to a frame or support member without the use of screws, rivets and the like, and without injuring the insulator, and providing a secure attachment between the insulator and the frame or support member.

I have found that in prior art staking methods the stroke of the press or ram is critical, as too little pressure results in loose parts and too much pressure invariably shatters or cracks the insulater. My invention overcomes these objections and at the same time the tools used are very much simpler than those required in the said prior art staking operations. Furthermore, with my method of assembly, the life of the tools is greatly lengthened. Hence, the whole assembly is simpler, cheaper and more effective than those to which reference has been made.

My invention will be best understood by reference to the annexed drawing, wherein:

Figure 1 shows a two-gang condenser, the rotor and stator units being shown merely in outline.

Figure 2 is a bottom view of Figure 1.

Figures 3 and 4 are end and side views of one form or a. slug device which is used in the process.

Figure 5 shows the apparatus tor and illustrates certain steps to be taken in the assembly For or it, while the stator is supported by the insulatlog strips ii and A description of the mounting of one stator will apply to both or any number of stators which might be mounted in a frame to accommodate them. The base portion l of the frame is provided with openings materially wider than the thickness of the insulators 9 and 10. To assemble the insulators 9 and Hi to the frame, the frame is placed in a die 13 with the base portion I rest-'- lng on the top of the die. The. dieihas recesses to recelve the ends of thelnsulators 9 and Hi to the opposite ends of which have first been attached terminal strips l4 and I5 by meansof bent-over lugs 22 which rest in notches in the sides of the 4 Q 9 one, so

insulators, and have their ends bent over the back side of the insulators.

With the insulators 9 and 10, having their terminals H and I5 attached thereto, inserted in place in the die IS, the frame is placed on the die l3 in inverted position as shown in Figure 5. Then the slugs l6, shown in Figures 3 and 4, are placed in the space between the side of the insulators and the well of the openings in the frame I, the diameter or width of the slugs 16 being such that they maybe readily put into place. Then a punch l'l, having projections l8 and 19 positioned to'engage the slugs l8, is brought down onto the slugs which are of malleable or deformable metal such as aluminum, soft zinc, etc, having a relatively low elastic limit, and the slugs which rest against the top of the die H are squeezed by the punch members so that the metal of the slug is expanded to fill substantially the entire space between the insulators 9 and Ill and the wall of the opening in the frame I, it being understood that the slugs are large enough in diameter to provide the necessary metal for filling this said opening so as to make a smooth and workmanllke looking job after the squeezing operation has taken place. By this method or assembly, the slug is caused to engage the insulator over its entire length in the opening and over the full thickness of the wall of the frame, and squeezes the insulator tightly into fixed position without any danger of shattering or cracking it, thereby making a more secure fastening than any other method of which I am aware.

After the insulators have been fastened to the frame in the manner indicated, the separate stator unit or units may then be placed in the frame and their tie bars 28 are then attached to the :dnger portions 28 of the terminal strips id and 55 of the respective insulators. The method of attachment is that of soldering such as disclosed in Cramei' Patent 2,687,902; issued July 27, 1937.

From what has been said it will be seen that the stator unit per se merely comprises its plates attached to its tie bars 26 in spaced relation, while the insulators with their terminal plates attached are fastened to the frame, forming a separate unit therewith.

While I have shown only one type of slug memher in Figures 3 and the exact shape of the slug may be varied over a considerable range without departing irons the spirit of any invention or the scope of the appended claims.

What 3 claim is:

l. A stator mounting for a variable condenser including a frame having openings, a group of plates held together by tlebars forming a complete stator, insulating strips having one end thereof located in said openings, deformable metal slugs wedged in said openings between an insulator end and a wall of the opening in which it is located, forcing the insulator end against an opposite wall of the opening, the slug, after being wedged into place, substantially filling the remainder of the opening not occupied by the insulatonthe insulator extending away from the frame and having a terminal plate at its free end, and means on the plate extending adjacent a stator tiebar for attachment thereto after the so stator is positioned in the frame.

2./A stator mounting for a variable condenser Y ly anchor them in said base openings, the Zree.

ends of said insulating members extending toward the stator tiebars and having means for completing an attachment to said bars.

3. In a variable condenser having a rotor, a stator and a frame; means :cr mounting the stator in the frame including a pair of opposite- 1y disposed insulators initially fastened to the frame, the fastening comprising openings in the frame to receive the ends of said insulator and deformable metallic strips forced into the open= ings against the wall thereof and the insulator end therein, the free end of the insulators hav= ing means extending toward the stator for cornpleting an attachment thereto.

4. In an electrical apparatus having a frame for carrying parts of the apparatus, an insulating support, for certain of said parts, fastened to the frame, said fastening including an opening in the frame to receive the insulating support, and a deformable metallic slug forced into the opening against the wall thereof and the insulating support which extends from the frame.

5. In a variable condenser having fixed and movable electrodes, the combination of a metallic frame having openings therein and insulating pieces for supporting the fixed electrodes of the condenser, portions of said insulating pieces extending into said openings, and malleable slugs positioned in and distorted in said openings against said portions of said insulating pieces for fastening them securely in said openings.

JQHN H. TEAF.

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