2. THE BUILD-UP OF THE TELEPHONE
The Ericofon comprises 3 main parts:
1. Housing (Case) with transmitter and receiver insets
2. Chassis (Base Assembly) with dial and Transmission circuit
3. Coiled cord with wall terminal box
The case (housing) is made of a thermoplastic material and is available
in 9 colours. The base assembly comprises among other things a die-
cast metal frame on which the dial and the transmission components
are mounted. The cord is a combination straight and coiled cord.
Several connecting devices are available.
The four captive screws (see fig 3) which secure the base assembly to
the housing are loosened. The housing can then be lifted off and the
base assembly exposed, photos 4, 5 and 7. This method is always the
same for all versions of the Ericofon.
To disengage the housing completely, the receiver conductor wires must
be loosened. The wires are connected to captive screws on the contact
springset. Figures 5 and 6 show an Ericofon with earth button. Its
function is to close the La and Lb branches to earth, a procedure that is
sometimes necessary with certain types of exchanges. The earth button
is removed from the housing by unscrewing the threaded nipple, fig. 6.
The manual Ericofon (photo 7), which has no dial, has a much simpler
mechanism than the other versions.
Fig. 8 shows the inside of the housing without the receive However, the
connections come down inside the housing. The figure shows the
transmitter and its locking ring (retainer clip), circuit and wiring
diagram and finally the rear metal frame.
Next, the four captive screws are removed and the rubber pedestal
round the number plate is eased off. The red cradle switch (stand-
switch plunger) is then removed by shifting (displacing) a clip in the
direction of the arrow (see fig. 9) thereby releasing the cradle switch and
its spring.
Fig. 10 shows the released cradle switch and its spring and the next
step - removal of the centre nut. This nut secures the figure disc, the
finger wheel and the spring housing, see fig. 11 and 12. Lift out the
spring housing with care so that the spring remains intact inside the
housing. If the spring should jump out, don't touch it with your bare
fingers. Use gloves to replace it so that its protective coating of oil is not
disturbed and the spring is, as a result, not attacked by rust.
Spring housing with spring, see fig. 13.
4
Dismantling an Ericofon
