Museum of Plugs and Sockets logo, small Daki-Buchse and T.E.G prise,
to branche off current from cords
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Daki - Buchse
Prise universelle de courant T.E.G.
Image of Daki connector
Prise de courant T.E.G.

German Daki and French T.E.G. connectors offered the possibility to branche off current from twisted cords. Both connector types use sharp needes to penetrate cord insulation and making contact with the copper wire. Two Daki connectors are necessary to tap a twisted cord. The T.E.G. connector has two separate needles.
A box with two Daki-Buchsen has been donated by Reiner Hahn. The prise universelle de courant "T.E.G." is not a museum item. Click T.E.G. image for details.


Components of Daki Buchse
Daki-Buchse. detail of cord puncture
Daki-Buchsen with twisted modern cord
Daki-Buchse with woven cord

1 A Bakelite Daki connector (Buchse) consists of two parts:
(i) a 28.2 mm long tube with two 7.6 mm deep gaps opposite of each other. The inner part of  the tube has a copper, 4.5 mm long, sharp needle. The needle is connected to a contact for a 4.0 mm plug pin (see image 3).
(ii) a hollow screw head.   {RH}
2 Magnification of the connector top half. A modern wire is used to illustrate the method of branching off current. 
Left: a short piece of wire (conducting copper filaments and intact insulation) fits exactly in the 2.0 mm wide gap. 
Right: screwing down the Bakelite head presses the wire down. The sharp copper pin punctures the wire insulation and makes contact with the copper filaments.
3 Connectors are connected to each of the twisted wires (same type as shown in image 2). A standard (6A) plug with 4.0 mm pins and attached cord connects the pair of Daki connectors to an appliance. To show pin connection clearly the plug is not fully inserted in the Daki connectors, but connector length is sufficient for full insertion. Plugs are not a part of Daki-Buchse packages.

A Daki connector can be used only with a single wire. Twisted cords were used in the past, among others for hanging lamps (see image shown in manual below). Modern cords with two wires surrounded by an additional overall insulation can't be used.
4 The Daki manual mentions two types of applications: extra low voltage (telephones, cars, radio etc.), and 110 / 220 Volt appliances (ligthing, irons etc.). The second category of applications asks for considerable thicker cords than shown in images 2 and 3.
Image 4 shows that an attempt to branch off an old 220V twisted cord failed. Thinner (110V ?) cords may have existed.

Daki-Buchse with additional brached off wire
Daki connectors offer also the possibility to use the screw head for the branched off wire (yellow wire in image left). The wire has to be inserted a bit further than full length of the head. The head must screwed further down than shown in image 2 to be sure that the needle appears at the other side of the power wire (red) to make sufficient contact with the wire in the screw head.

In principle the method works, but a stable fixation of the branched off wire in the hollow screw head is difficult. The procedure shown in images 2 and 3 is a more reliable method.
The manual suggests that the Daki connectors can be used safely to connect an iron. Possible, but not advisable. Extra low voltage applications are more safe. Daki connectors do not have a VDE certification.

Daki-Bochsen manual

Sensational novelty!     Daki connectors as pantographs     D.R.G.M.*

The Daki connector is used for all braided electrical cords for telephones, cars, radios, etc.; is very easy to attach without damaging the insulation of the wires. Without tools, without insulating tape and usable without any risk, as described below.

Create some space between the power wires and insert one of the wires into the gap of the connector. Do the same with the second wire using the second connector. Put both connectors so close together that any standard plug can be used.

If you need a second connection at the same point, put another wire through the hole in the head screw, it must protrude approx. 1 mm, then the head screw is screwed tightly into the connector, to clamp the second connection wire also, use the other screw head for a second connection of the other wire.

In this way, any desired connection is poossible, such as garlands, irons, electric lamps, telephones, garage and shop window lighting, etc.

Sole manufacturer: Max Schulz, Daki-products      Berlin-Lichterfelde-Ost, Giesendorfer Straße 15
* Deutsches Reich Gebraugsmuster (German Reich Registered Design; see link for details)

T.E.G. text
The universal socket "T.E.G." for flexible cords  Patented S.G.D.G* recommended to all:
Use it !  It will give you complete satistaction !

E. Gaillemin manufacturer   24 Rue de la République  Saint-Mandé (Seine)

* S.G.D.G = Sans Garantie Du Gouvernement (patent without government guarantees; see link )


T.E.G. socket, basic image

a. cover

b. socket base

c. socket needle

d. mains twisted cord

e. screw to attach cord (f) to needle

f. branched off cord

g. plate for wall mounting cover (a)

h. adapter for lamp socket

i. bolt to fasten adapter to base (b)

k. lamp socket (optional)

Images are based on T.E.G. manual

T.E.G. socket, additional parts

The Prise universelle de courant "T.E.G." was presented at the Concours Lépine 1920 (trade fair for inventors to show new designs) and has been awarded with a silver medal. Whether the invention was a commercial success is unclear, but it could have inspired Max Schulz to design his Daki-Buchse. The significance of the abbreviation T.E.G. has not been found.

5 The basic T.E.G. module consists of two parts: (1) socket with two needles to punch flexible, twisted power wires. Needles are connected to contacts to fasten the branched off cord, and (2) a cover with insulation inside to shield the needles.
6 Two additional parts could be ordered: (1) a plate for wall mounting the basic module, and (2) a lamp adapter to fasten on the socket. The lamp socket is not a part of the T.E.G. package.


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