US2172200A - Contact terminal for rectifier plates - Google Patents

Description

Sept. 5, 1939. c. c. 'HE'IN 2 2,172,200

CONTACT TERMINAL FOR RECTIFIER PLATES Filed June 8, 1938 5prayedMeI%//3 /7/6 23 la per-041226 VIIIII' ci'l."......l

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ATTORN Patented Sept. 5, 1939 My invention relates to especially contact rectifiers An object of my fective contact terminals rectifier plates whic CONTACT TERMNAL FOR PLATES Carl C. Hein, Forest Hi1 Manufacturing Company iughouse Electric & East Pittsburgh, Pa., sylvania RECTIFIER ls, Pa., assignor to Westa' corporation of Penn- Application June 8, 1938, Serial No. 212,442

4 Claims.

contact rectifiers and of large size.

inventionis to provide effor large-size contact.

h will not interfere to any extent with the cooling of the rectifier.

Other objects and will be apparent fro and drawing, in which:

advantages of the invention m Figure-1 is a top plan view of a preferred embodiment of my invention;

Fig. 2 is a side elevationalfview of the device of Fig. 1;

Fig. 3 is an enlarged cross sectional view taken 15 on the line 1n m of Fig. 1;

Fig. 4 is an enlarged cross sectional view taken on the line IVIV o Fig. 5 is a top plan view;

6 is a cross sectional view of the one end the contact terminal;

.Figs. 7 and 8 are a top plan view and a cross sectional view of the horseshoe washer disclosed in cross section in Fig. 3;

Figs. 9 and' 10 are 25 sectional view of the c ntact a semb y the top metal; eyelet utilized in the and sectional view of the insulating eyelet utilized'irf the contact assembly.

My invention parti cularly concerns making improved contact terminals to contact rectifiers having large rectifying rectifiers, especially of the copper been adapted for various uses amounts of current electroplating and welding. For heavy current demands, numerous areas. These contact for various these uses of stacks of large copper plates are utilized and these plates are constantly cooled by fans when in operation. The

0 individual plates have a large area generally from 30 to 50 square inches on each side of the plate for the rectifying area. larly concerns making a the surface of such My invention particua plate without interfering with the cooling of the plate to any extent. In

Figs. 1 and 2, I have .disciosed a large area copper plate I having a copper oxide rectifying layer It and [2 on each side thereof. I preferably coat the oxide layer with a solution of i0 graphite in water and then spray a metal over the surface to form the graphite solution be used alone, but I a contact layer 13,- Either or the sprayed metal may prefer the combination of v the two layers as being more satisfactory. The

5 sprayed metal coati ng l3 may be of any low the following description plan view and cross oxide type, have large area contact tomelting alloy such as one composed of 37 by weightof tin.

At each end of the plate, but preferably symmetrically disposed Within the plate, I provide two openings l4 and I5. An insulating eyelet, preferably of fish paper It, particularly disclosed in Figs. 11 and 12, is inserted in the hole It and its flanges bent around the edges of the hole to completely cover the exposed copper part I 0 of the plate. A long thin strip I1, preferably copper, has one end l8 havwhose shape is more ing an opening therethrough of the same size as the hole It. This strip is placed on the top surface'with its opening coinciding with the opening l4, and a similar strip I1 is placed on the underside of the rectifier plate. The other end IQ of the'strip terminates in the tap that is covered with insulation 2| and this extends to the inner edge of the hole IS in the plate. The under strip likewise terminates in an insulat ing covered tab. This terminal strip is of relatively thin material both for the saving in cost of material and for the reduction of thickness so as to reduce the cross sectional area of the rectifier presented to the fan or blower used for ventilation. The terminal strip can also be flexed slightly to exert a slight pressure against the 'fspra'yedcoating." The contact area can be relatively large and made to eliminate much of the 'point contact in devices of the prior art. The contact strip can be crimped at the edges or center if any strengthening is desired. At the end having the opening IS, a horseshoe washer 22, as disclosed in Figs, 7 and 8, is placed around the top and bottom of the hole l 5 in order to hold the .insulation covered tabs 20 in place -A metal eyelet 23 is then placed in the opening l4, and the bottom .edges 24 are peened over to securely bind-the terminal strips IT to the plates at this end. A similar metal eyelet 25 is placed in the opening I5 at the other end of the plate and its bottom edge 16 is'peened over to securelg bind the terminal strips [1 and the horseshoe washer 22 to the contact rectifier. These metal eyelets are disclosed in their preferred shape in Figs. 9. and- 10.

It will be noted from an examination of Figs. 1

nal strip H by the insulation and also by the absence of the oxide adjacent the opening 55 and makes contact with the copper it which is ex-' posed in the central portion of the opening it. The eyelet 25 accordingly acts asthe positive contact to the rectifier and the circuit terminal may be secured thereto.

While I have disclosed the invention as applied to a copper oxide rectifier, the invention may be applied to contact rectifiers. of other materials. Theparticular advantages of the contact terminals is a large reduction in cost due to the specific design utilizing design is symmetrical both in regard to the mounting holes symmetrically placed and being within the area of the plate with a resulting reduction in overall volume. The narrow cross sectionalarea of the assembled plate will permit closer spacing of the plates with the further decrease in the volume occupied by a specific number of plates. The terminal strip is securely fastened to the plate and provides a constancy of contact resistance. If desired, protective coatings can be applied to the entire surface and edges.

While I have disclosed a preferred embodiment of my invention, it is apparent that many media flcations may be arrangement and location of the various elements. Accordingly, I desire only such limitati ons to be imposed upon the following claims as is necessitated by the prior art.

4 I claim as my invention:

1. A contact rectifier comprising a metal plate,

a layer making a rectifying contact with said metal plate on the surface thereof, said plate very little material. The

made in the particular shape,

} awaaoo 'I'he'metal eyelet 25 is insulated. from the termihaving two spaced openings therethrough, a contact strip extending from one opening to the other, insulation about the metal plate at one opening and insulation about the strip at the other opening and fastening contact means I through said openings, binding said strip, plate and layer.

2. A contact rectiflercomprlsing a. plate. a

the surface of said platecopper omde layer on said. plate having two openings therethrough, a contact strip extending from one opening to the other, insulation about the copper plate atone opening, insulation about the strip at the other opening and fastening contact means through said openings binding said strip, plate and layer.

3. A contact rectifier comprising a metal plate, a layer making a' rectifying contact withv said metal plate on having two spaced openings therethrough, a. contact strip extending from one opening to the other, insulation about the metal plate at one opening, insulation about the strip at the other opening, and an eyelet through each opening binding saidstrip, plate and layer together.

i. A contact to a contact rectifier cl! 9. metal and a layer thereon comprising a flat strip of metal making a broad surface contact to said layer, said rectifier having an opening therethrough, the layer-being absent from around said opening, said strip extending to said opening and having its end adjacent thereto covered with insulation, ahorseshoe washer making contact with the metal around said opening and holding the end of the strip in place and an eyelet through washer and rn'etal together.

. CARL 0. m.

said'opening binding said strip the surface thereof, said plate

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