Antique Light Sockets - Research - Sales

| Back to main

Next to Brush |

July 6th 2009 - A start on a rewrite of the Bergmann section
When complete, this new Bergmann section will cover all known Edison, Bergmann and Edison General Electric Co. sockets.
It will also include the complete lineup of sockets for the early part (1892-1894) of the General Electric Co..

BERGMANN & CO.
1881 to 1889 (more info about Bergmann)

How To ID A Bergmann & Co. Socket

The Ornate Stamped Brass Key Design

The Twist Screw Cap Design

The Method Used To Attach The Cap

By The Bergmann Mark On The Shell

The Fiber Collar/Ring

The Unique Bergmann Designs

Many of the Bergmann & Co. designs were also used by the "Edison Electric Company" after they merged with Bergmann in 1889.

These are commonly called "Edison-Bergmann" sockets. The "Edison General Electric Co." continued using these designs until 1892 at which time they became the "General Electric Co.". Note that CGE (Canada General Electric) may have still used one or more of the Bergmann designs for a short time longer, which would be marked with the Canada General Electric Company markings.

You can tell the difference in these later sockets by new post 1899 patent dates stamped on the shell, as well as the new "Edison General Electric Co." mark which replaces the "Bergmann & Co." marking that was on the older pre-1899 sockets.

EGE Sockets that include the 1890 patent date, or Bergmann sockets with a replaced EGE socket, are easy to spot having the new 1890 Edison thread slit design which is shown to your right.

The older Bergmann sockets from 1883 show a transition period of rectangular to round head screws, shell design and patents missing from the shells.

1883 Bergmann Moving Tongue	Early Patent Design	Later Design

Short Ornate Shell Design	Tall Smooth RIB Design	Cap Designs

Bergmann & Co. Acorn Socket (First Generation)

The First Known Acorn Socket - This socket is easy to ID because there is no shade ring Rib. While the patent shows up in the 1883 Bergmann catalog as Dec. 27th 1881(251,554 and/or 251,596), and May 2nd 1882 (257,277), these patents were not for the Acorn shell. The 1882 patent was for a center contact already used on other sockets; and the patent date for 1881 brings up two patents non related to the Acorn design itself. Bergmann pointed out that these two patent dates cover enough of the design to avoid patent infringement. The real Acorn shell patent was applied for on October 9th 1882 and was approved after the printing of the catalog on Feb. 12th 1884.

First Generation

Bergmann & Co. Acorn Socket (Second & Third Generation)

This was the second generation of the Acorn shell. Unlike the version shown above, this version came with a Rib to secure a shade fitter. The early version shown below came with an ornate Rib and white/gray colored fiber.

Second Generation

White Fiber

Ornate Rib

Third Generation

Red Fiber

Smooth Rib

Note: The examples shown for the third Generation Bergmann acorn socket come from the Allerhand Collection.

Bergmann & Co. Moving Tongue Socket

The moving tongue socket was made so that when not in use and switched in the OFF position, the electrical tongue did not make contact with the bulb base. When the key is turned into the ON position, the tongue moves up and into the center of the switch which then makes the electrical contact with the bulb base center contact. This design was also

used by the Edison Electric Company after they merged with Bergmann in 1889. These are commonly called the "Edison-Bergmann" moving tongue socket. You can tell the difference in these later sockets by the new patent date of 1890 stamped on the shell as well as the new "Edison General Electric Co." mark which replaces the "Bergmann & Co." marking that was on the older sockets. The 1890 patent date that was added to the EGE socket was for a new design of two slits on the Edison thread (which was added to help secure the bulb base). This new design is now known to cause problems with some of the collectors of these 100 year old sockets. Two things to watch out for would be cracking below the bottom parts of the slits and broken or cracked fiber rings, which is common on these sockets once the base is cracked. A perfect EGE socket slit is shown above to your right, and a cracked one on your left.

The 1884 Patent Moving Tongue Socket	The Moving Tongue Socket Taken Apart

The Moving Tongue In The ON Position	The Moving Tongue In The OFF Position

Note that the socket pictured above is the Edison / Bergmann porcelain EGE version.
Bergmann & Co. Push Pull Socket

The Push-Pull switch is another socket that was also used by EGE after merging with Bergmann & Co. in 1889. The same changes take place with the patent date and the Edison threaded socket base (please read and see the pictures above). It is unknown if there was a patent for this switch, or where or how to locate it. Since there are examples of this switch in both Bergmann and EGE shells AND all of the patents on the shells are accounted for (except the Canada patent), we are at a bit of a loss for more information about this item. If you can shed some light, please feel free to contact us. As shown below on your right, the socket was being sold by Edison General Electric in 1892 as seen in the Chicago Electrical Supply Co. catalog.

The Push-Pull In The ON Position	The Push Pull Socket Taken Apart
		1892 - Electrical Supply Catalog A Patent Has Not Yet Been Found For This Socket If You find It Please Forward It On
The Push-Pull In The OFF Position	The Push Pull Switch


Bergmann & Co. 1888 Rotary Switch Socket

This rotary switch design was used in Bergmann switches right before they merged into Edison General Electric. This switch is a little more rare in that the preferred switch was the moving tongue. This design was first used in Bergmann's lamp/light switches. The example shown below was likely before the patent for the switch was approved, seeing that the shell is not marked with the 1888 patent date.

The 1888 Bergmann Rotary Switch	The 1888 Rotary Switch Taken Apart

The 1888 Rotary Switch In An 1885 Shell	Rotary Switch Contact