Patents On Glass Insulators
by Jack H. Tod, NIA #13
Reprinted from "INSULATORS - Crown Jewels of the Wire", December 1981, page 3
I used the book "Electrical
Porcelain" as a vehicle to publish essentially my entire patent file,
nearly 700 of the most important 1880-1962 insulator patents from the several
thousand I recorded in my patent search work in the early 1970's. The listing
includes a number of previously unknown or unpublished patents on specific glass
insulators, but as yet no glass researchers or writers have picked up the ball
by publicizing these interesting patents.
On a
"speak-now/thereafter-shut-up" basis, I'm re-listing below the most
important of these patents, and I'll leave it up to writers on glass insulators
to look up the patents, report on them and list them in the glass books. Until
this is done, we will continue to have "what-is-it" questions on items
when the questions were already answered in a book published in 1977.
The list
below omits commonly known patents already shown in Milholland's book unless
I've noted a correction or amplification of the data. I've indicated the
comparable style in porcelain if one exists, plus closely allied patents where
specimens exist in porcelain only. (D = Design patent)
Pat. No.
|
date - inventor
- description & notes
|
289,449
|
12-14-83 N. Rousseau. Specifically the CD-199
transposition -- the U-197 in porcelain.
|
316,812
|
4-28-85 J. O'Brien. This date
is embossed on CD-119 specimens, but the following patent of 1886 seems to be the
correct one involved.
|
347,635
|
8-17-86 J. O'Brien. (see above)
|
D. 22,684
|
8-8-93
L. Gray. Specifically the top-groove pin type, specimen of which was shown on
page 34 of the Dec. 1974 issue of Cross Arms magazine.
|
504,059
|
8-29-93 G.
Blackburn. A bail wire system for self-tying, illustrated in O.G. as a cleat,
but exists In a glass pin type, as written up in the May 1981 issue of Crown
jewels magazine.
|
557,881
|
4-7-96 H. Rappleye. A bail wire tying system requiring
a double-groove insulator, specimens of which exist in glass pin types embossed
with a reference to this patent.
|
605,256
|
6-7-98 R. Mershon. The glass CD-288,
but also specifically the U-938 porcelain, a rarity. Also long skirted U-945
porcelain and which references MERSHON in the marking.
|
D. 31,798
|
11-7-99
F. Withycombe. Diagonal/spiral cushion ing ridges on glass insulator exterior.
Letters patents listed by Milholland, but not this and the following Design
patent.
|
D. 31,799
|
11-7-99 (as above)., vertical cushioning ridges an the skirt
and crown surfaces.
|
664,432
726,846
|
12-25-00 E. Renault, Waldo, Fla.
5-5-03 J.
Bell, Peckville, Pa Certainly one of these two patents fits CD-207, and I'll
leave it to glass researchers as to which one it is.
|
700,463
|
5-20-02 W.
Walther. Strengthening ribs, skirt to petticoat. See CD-301 and CD-321.
|
744,631
|
11-17-03 E. Schoethaler. Specifically CD-139!
|
882,803
|
3-24-08 L. Storror. CD-211
|
1,194,957
|
8-15-16 H. Cochrane, Butte, Montana The CD-311 stacker (assembly).
|
1,703,853
|
2-26-29 R. Gould (Postal Tel. Co.). The CD-182 dry-spot, and the
identical U-174 Porcelain. Original basis for this patent was the somewhat
skinnier version, U-173 porcelain.
|
1,620,804
|
3-15-27 S. Cutter. Glass CD-1001.
Later Patent 1,721,657 (7-23-29) adds side strengthening ribs - - the common
porcelain version of Cutter.
|
1,760,983
|
6-3-30 C. Gordon & J. Lowe (A T &
T Co). Two- piece tramp, top piece petticoated, probably basis for the
CD-194/195 design.
|
2,099,540
|
11-16-37 D. Smith (W U Tel Go). Metal skirt to
protect against thrown missiles, on CD-154 style. Specimen reported to exist.
|
2,165,773
|
7-11-39 (filed 7-8-32) H Wheeler (W U Tel Co). Specifically the
CD-142/142.4 designs, this one with a glass insert such as on CD-142.4 but which
screws up into the internal threads instead of being cemented in as on
specimens.
|
2,266,400
|
12-16-41 F. Reed. Specifically the design of CD-216 (or
possibly CD-219).
|
2,455,227
|
11-30-48 R. Case. Midspan bracket, 2 rotatable
CD-1049 spools, for transpositions.
|
2,455,228
|
ditto, but midspan 4-spool bracket
casting. Patents 2,455,229 & 2,655,553 (1953) similar.
|
2,734,098
|
2-7-56
Bonnessen (A T & T Go). Specifically the CD-203.2 transposition. Skirt of
elastic mat erial held by center groove affords a rainshed between the two
conductors.
|
|
