Westinghouse had patents assigned to them for lamp sockets as early as February of 1886.

These patents were short lived as they were working towards a good socket and bulb combination to adopt as their standard. This was completed with what is known as the "Pope, Byllesby & Lange Patent" (no. 366,606) which was applied for on November 18th 1886 and approved on July 12th 1887. The next (design improvement) socket is known as the "Lang Patent" (no. 434,153) which was applied for on October 31st 1888 and approved on August 12th 1890.

There are no other Westinghouse SOCKET patents after this 1890 date with the exception of one other socket which is called the "Stopper Socket". The Stopper Socket was a special case. When Westinghouse won the bid to provide lighting to the 1893 Chicago Worlds Fair, a new socket that did not infringe on Edison patents needed to be manufactured, which was the Stopper Socket.

While it is clear that Westinghouse did not continue to manufacture and sell lamp sockets after 1890, it is also a fact that Sawyer-Man which was owned by Westinghouse did continue to sell these sockets in 1890 and well after.



An ad from Electrical World May 21 1892 shown on the right and the ad below that shows Sawyer-Man selling sockets in the Nov 21 1891 Electrical World.

There were also other manufacturers that offered or started offering Westinghouse based sockets in and after 1890 as shown below.

After 1890 Westinghouse found it "expedient" to stop manufacturing sockets and began to purchase their needs elsewhere.

Bryant Electric Company purchased a considerable amount of stock and material that was on hand at the Westinghouse factory. Bryant also acquired rights under several patents on sockets invented by Westinghouse engineers. At this time Bryant only offered one Thomson-Houston socket. It is assumed that Bryant assembled these parts and sold them during this early period until they began manufacturing their own patented Westinghouse sockets in March of 1891. Bryant also purchased Empire China Works in 1890 which they used to manufacture their own porcelain for their sockets. In the 1890 ad shown below we see Empire China advertising a porcelain insulator. In the 1891 ad shown below, cut out parts for switches. Also noteworthy is the fact that Bryant bought out the Perkins Switch company before Westinghouse bought out Bryant on April 10, 1901.

Empire China Works - 1890 Electrical World Ad	Empire China Works - 1891 Electrical World Ad

Other Pre 1892 Westinghouse Base Socket Manufacturers

Because of the fact that Westinghouse stopped making sockets, there are not as many variants and it is much easier to identify them.

Many collectors get confused when it comes to identify a "Westinghouse" socket. The common error is that because it has the Westinghouse prongs, that it is a Westinghouse socket. This is like saying that any socket with Edison threads was made by Edison, or any T-H based socket was made by Thomson-Houston. There are many different types of socket bases that fit different types of bulbs. Just because a socket has the Westinghouse base design, it does not mean that it was made by Westinghouse. There were many unmarked sockets prior to the ruling in 1899, also many shell designs were shared during these years, so the only way to really tell a true Westinghouse socket (made by the Westinghouse company) is to compare the inside of the socket to the actual Westinghouse patents for the sockets. In this case there are two of them: the Pope, Byllesby & Lange and the Lang patent.

For quick and easy identification, look for a Westinghouse socket with mica. Since Westinghouse sockets also pre date the use of porcelain in sockets, look for the vulcanized fiber (all examples that I have seen of Westinghouse sockets have been brown vulcanized fiber). You can also compare this switch with the Lange patent.


The best place to start would be the switch contact. Notice that there is a spring brass contact ring at the top that the key bar pushes up against when turned into the ON position. Also notice the indent on the key bar and the projection on the bottom part of the spring brass that holds the key switch in place when it is turned on.
The patent also describes this on page no. 2:30-35 "For this purpose the piece is constructed with a transverse slot k4 of greater width than the width of the pin k5. The ends of the movable piece k are preferably indented, as shown, so that a projection h' upon their plate H' will enter it and hold it in the proper position when the circuit is closed".

The 1888 Lange Porcelain Socket Switch