Insulator Historical Timeline! 1890-1899

Key events are noted by approximate date.  Hyperlinks will provide additional information.  Please feedback additional key dates or note any needed corrections.  Dates considered particularly significant are highlighted in red.

• May 6, 1890:  Joseph F. Buzby of Roger's Ford, PA    patent for a unique no-tie insulator incorporating a slot to hold the conductor.  This patent was implemented in the rare CD 141.8 glass insulator. (US Patent 427,296) -- [Full Patent Text]
• June 17, 1890:  Samuel Oakmen patent for the ears found on cable insulators - CD 258, CD 259, and CD 260 match closely the patent drawings.  (US Patent 430,296) -- [Full Patent Text]
• August 6, 1890 - William Kemmler is executed at Auburn Prison, NY in the first use of the electric chair.
• August 19, 1890:  Samuel Oakman for a skirt projection to act as a water stop as well as threading the inside of the inner skirt to increase the leakage distance.  This was implemented in CD 258, CD 259, and CD 260.  (US Patent 434,879) -- [Full Patent Text]
• December 23, 1890:  Foree Bain patent for grooves inside and outside the insulator surface for the dual purpose of increasing leakage distance.   This has been implemented on CD 144.  This patent was assigned to the Hemingray Glass Company on February 28th, 1901. (US Patent 443,187) -- [Full Patent Text]
• February 1891:  Pass and Seymour of Syracuse, NY starts making threaded porcelain "wet process" insulators.  The only known existing style they made is U-146, although they also catalogued U-141.  Sometime in 1895 or 1896 they stopped making pintype insulators.
• March 24, 1891:  George H. Graham and Thomas Gannane, both of Illinois, patented an unusual insulator and wire clamping device.  No known insulators have been discovered matching this patent. (US Patent 448,956) -- [Full Patent Text]
• May 12, 1891:  Samuel Oakman patent for an insulator with a hole to hold the tie wire.  This patent was implemented in the Columbia style insulators CD 262, CD 263, and CD 264.  (US Patent 451,950) -- [Full Patent Text]
• January 16, 1892: James M. Brookfield died at the age of 72.  James M. Brookfield along with is son William A. Brookfield founded the Bushwick Glass Works in 1864 which were later changed to the Brookfield Glass Company,
• June 14, 1892: James Pass and Albert Seymour of Syracuse, NY patent for a porcelain insulator with the inner section filled with cement material impregnated with paraffin.  No specimen of this insulator has been found, but it has been assigned U-141.  (US Patent 476,813) -- [Full Patent Text]
• October 11, 1892:  Fred M. Locke patent for a special four groove pin and metal rain shed which would allow an insulator to be mounted under the crossarm.  The insulator pictured appears to be very close to the "Edison" style CD 285.  (US Patent 484,209) -- [Full Patent Text]
• December 14, 1892:  The Muncie Daily Times reports The Standard Glass Insulator Company was organized recently at Portland, Mass. for the purpose of manufacturing glass.
• January 14, 1893: "The Commoner & Glassworker" reports King City Glass Works in operation in Fairmount, IN employing four men on battery jars and two presses making electric supplies.
• May 2, 1893: Ralph G. Hemingray patented drip points.  The intent was to provide a point for moisture to accumulate and more quickly drip off the insulator keeping it dryer.  This date is considered significant as drip points were so widely implemented.  (US Patent 496,652) -- [Full Patent Text]
• August 8, 1893:  Laurence B. Gray design patent for a unique cable insulator.  This patent was implemented in the Standard Glass Insulator Co. CD 268.5.  (US Design Patent 22,684) -- [Full Patent text]
• August 29, 1893:  George W. Blackburn of Palmyra, NJ patented an insulator design using a bail clamp to hold the conductor wire.  This patent was implemented in CD 141.6 (US Patent 504,059) -- [Full Patent Text]
• September 30, 1893:  "The Commoner & Glassworker" reports the King City Glass Works factory being operated by a non-union crew making insulators run by Charles Tigner.
• February 6, 1894:  Lawrence B. Gray patent for a insulating pin sleeve to increase the insulation value of an insulator for power transmission.  The insulator illustrated with the sleeve appears to be a CD 138.2.  (US Patent 514,221) -- [Full Patent Text]
• May 5, 1894: John Fuller, George Fuller, and William Langdon British patent for a triple skirt insulator to increase the leakage distance from the wire to the pin. (UK Patent 6669 - 1894) -- [Full Patent Text]
• May 22, 1894:  Fred Locke patents external petticoats to increase leakage distance between two conductors on a one piece transposition.  Used on CD 204 and CD 202. (US Patent 520,367) -- [Full Patent Text]
• August 14, 1894:  George H. Winslow of Pittsburgh Pennsylvania patent for a unique series of oil cup insulators for high voltage use.  This patent appears to have been implemented in several rare insulator styles including  CD 180, CD 180.1 and CD 244.  (US Patent 524,659) -- [Full Patent Text] -- (Additional Patent Image).
• September 25, 1894:  David N. Osyor patent for a pin and insulator combination that was assigned to the Jeffery Mfg. Co.  This was implemented in the CD 185 Mine insulator and porcelain U-89 through U-98B.  (US Patent 526,498) -- [Full Patent Text]
• 1895: The first underground trolley system in the United States is constructed in Boston, MA.  This system used relatively low voltage DC which required very large copper cables.  The CD 140 "Jumbo" was designed for this line.
• January 22, 1895:  Seraphin Kribs of Brooklyn, NY patent for an insulator press.  This patent was assigned to William Brookfield. (US Patent 532,973) -- (Additional Patent Image) -- [Full Patent Text]
• August 20, 1895:  Clinton Sproat and Edward N. Tarr patent for a two piece no-tie insulator design.  This patent was implemented in CD 207.2 which only 1/2 has been found.  (US Patent 544,778) -- [Full Patent Text]
• September 3, 1895:  Danial Rothenberger patent for a unique cable style insulator with a hole through the crown perpendicular to the tie wire.  This patent was implemented in the rare Brookfield CD 268.  (US Patent 545,819) -- [Full Patent Text]
• December 21, 1895:  "The Commoner & Glassworker" reports that the Baltimore Glass Mfg. Co. is the name of the aggregation of capitalist that have purchased and will operate the old Maryland glass works at Baltimore.
• February 12, 1896: "China Glass & Lamps" reports the new glass works being erected at Westport, Md., by the Baltimore Glass Mfg. Co., is nearing completion.  Later reports show production started by the end of March making Screw cap ware, fruit jars and electrical supplies. -- Their insulators are marked B.G.M.Co. and are mostly found in purple glass.
• April 7, 1896:  Hannibal W. Rappleye patent for a bail-clamp tie arrangement to hold the conductor.  This patent was implemented by Brookfield in the rare CD 134.6 (US Patent 557,881) -- [Full Patent Text]
• November 15, 1896:  Power transmission was started between Niagara Falls and Buffalo, NY by the Cataract Construction Company.  A decision was made to use alternating current (AC) for power generation and transmission based on Nikola Tesla's alternating current (AC) transmission system developed and implemented by George Westinghouse.  The line was about 22 miles long and was a 11,000Volt three phase AC system.  The other alternatives that were seriously considered were DC power transmission and piping compressed air (Pneumatic transmission).
• November 24, 1896:  Fred M. Locke patent for a power insulator shell that was much wider than it was high.  This matches with the top shell of most multipart insulators.  (US Design Patent 26,323) -- [Full Patent Text]
• December 15, 1896:  Fred M. Locke patent for a combination porcelain and glass multipart insulator to take advantage of the best properties of both materials.  (US Patent 573,092) -- [Full Patent Text]
• December 15, 1896:  James J. O'Neill patent for a wall insulator designed to be attached to brick wall surfaces.  No known specimens of this insulator have been found.  (US Patent 573,101) -- [Full Patent Text]
• April 26, 1897:  "The North Adams Transcript" reports Samuel J. Oakman  will begin operations in a couple of months for a glass plant near Cheshire, MA. The new firm is to be known as the Oakman Manufacturing company and they will manufacture carboys, demijohns and insulators.
• June 2, 1897: The "Electrical Review" reports the National Insulator Company has been incorporated to manufacture insulators for telegraph and telephone companies in Gainesville, FL.
• September 3, 1897: "The North Adams Transcript" reports the Oakman Glass Manufacturing company started Wednesday making carboys and insulators.
• September 28, 1897:  Fred Locke patent for a power insulator with an oblong shape and side troughs to direct water away from splashing on the crossarm.  This patent was implemented in the U-937 insulators that Locke had Imperial Porcelain make for use on the Niagara to Buffalo power line.  (US Patent 590,806) -- [Full Patent Text]
• September 28, 1897:  Fred B. Grimm and John H. Nessler patent for a no tie style insulator with a slotted top.  No known specimens of this insulator have been found.  (US Patent 590,832)
• 1898: Ralph G. Hemingray becomes President; Robert C. Hemingray, Vice-President; and Daniel C. Hemingray, Secretary-Treasurer, of the Hemingray Glass Company following the illness and retirement of their father, Robert Hemingray.  Link for more information.
• March 8, 1898:  John W. Boch patent for a three piece porcelain power insulator where the three shells were fused together with extra glaze.  This was implemented in the Classic Thomas styles U-928 and U-928A.  (US Patent 600,475) -- [Full Patent Text]
• March 10, 1897:  "China Glass & Lamps" reports a petition was filed to have a receiver appointed for the Baltimore Glass Mfg. Co. as they are unable to continue operations because of insufficient capital
• March 22, 1898: John W. Boch patent for an extended skirt to actually extend into the cross-arm to reduce leakage and protect the pin.  Although no pieces are known with this attribute, this may have influenced the design of U-944.  (US Patent 601,195) -- [Full Patent Text].
• March 24, 1898: "The Electrical Engineer" reports the Boch high potential petticoat insulator by the R. Thomas & Sons Company made in three shells glaze-filled to improve the insulation qualities. 
• April 2, 1898: "The Commoner & Glassworker" reports Robert Good, Jr. will operate the Valverde Glass Works which is on the outskirts of Denver.
• June 7, 1898:  Fred M. Locke patent for a multipart insulator with a long extended inner-most skirt.  Oddly enough this patent is quite similar to the Mershon patent of the same date!  (US Patent 605,109) -- [Full Patent Text]
• June 7, 1898:  Ralph D. Mershon of Colorado patent covering a power insulator design with a far extended inner petticoat and ridges on the top skirt to direct water off the insulator.  This patent was implemented in CD 288 and CD 298 as well as U-938, U-944 and U-945.  (US Patent 605,256) -- [Full Patent Text]
• September 3, 1898: A British patent by Daniel Sinclair and William Aitken both of Oxford Court, London patent for a two part dry spot insulator implemented in U-1925,U-1929, and U-1929A. (UK Patent 25,816 of 1897) -- [Full Patent Text]
• December 8, 1898: "China Glass & Lamps" reports that John Gayner, Edward J. Gayner, and J. William Gayner have filed in the County Clerk's office papers of incorporation of the Gayner Glass Works at Salem, NJ.
• March 21, 1899:  Morton Harloe and Wilton S. Bloes patent for a insulator and bracket combination that used three projections to lock in the wire.  The patent also shows an additional tie wire.  (US Patent 621,661) -- [Full Patent Text]
• April 25, 1899:  Vernon G. Converse of Pittsburg, PA design patent for a power insulator assigned to the Hemingray Glass Co.   This was implemented in CD 282 and 283 and later copied by U-372.  (US Design Patent 30,637) -- [Full Patent Text]
• September 19, 1899:  Frederick H. Withycombe of Montreal, Canada patent  for a various ridge designs on the outside of an insulator to provide a "cushion" to damage from projectiles (ie: thrown rocks).  This first patent illustrates horizontal ridges.  He released four very similar Letters Patents and two design patents for virtually the same ideas.    Horizontal ridges are found on a number of Canadian CD 143's.  (US Patent 633,173) -- [Full Patent Text]
• September 19, 1899:  A Second related patent by Frederick H. Withycombe.  This patent illustrates spiral ridges which are found on a number of Canadian CD 143's. (US Patent 633,174) -- [Full Patent Text]
• September 19, 1899:  A Third related patent by Frederick H. Withycombe.  This patent shows patterned bumps.  No known insulator has been found with this feature. (US Patent 633,175) -- [Full Patent Text]
• September 19, 1899:  A Second related patent by Frederick H. Withycombe.  This patent shows patterned indentations.  No known insulator has been found with this feature. (US Patent 633,176) -- [Full Patent Text]
• October 10, 1899:  Carroll N. Beal of San Francisco, CA patent for a power insulator that mounts below the cross arm.  This patent was implemented in the super rare CD 309 that was most likely made by Hemingray.  (US Patent 634,568) -- [Full Patent Text]
• November 7, 1899:  Frederick H. Withycombe of Montreal, Canada patent that is similar to his previous letters patents but with added additional patterns.  This patent illustrates diagonal ridges.  No known insulator has been found with this feature.  (US Design Patent 31,798) -- [Full Patent Text]
• November 7, 1899:  Another Frederick H. Withycombe of Montreal, Canada patent.  This time for horizontal ridges.  This patent was implemented in CD 143 and CD 121.  (US Design Patent 31,799) -- [Full Patent Text]

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