Description; Design; Functional Description - strapex SMA 20 Betriebsanleitung

Strapex SMA 20
5

5.1 DESIGN

The machine consists of the following main assem-
blies (see Fig. 2):
a Drive unit
b Tensioning unit
c Sealing unit
d Machine frame
e Electric part

5.2 FUNCTIONAL DESCRIPTION

a) Drive unit
The drive unit consists of an electric motor which actu-
ates the worm drive and the tensioning belt by means
of a drive belt. The tensioning belt and the worm drive
are isolated from the drive by means of electromagne-
tic clutches.
b) Tensioning unit
The tensioning unit comprises two electro-magnetic
clutches Y2 and Y3, the drive shafts, the ribbed disc-
wheels and the tensioning belt.
The plastic strap is fed, retracted and tensioned by
means of the tensioning belt.
A sprung slide fl ap takes up surplus strap if a malfunc-
tion (e.g. in the feeding) occurs.
c) Sealing unit
The sealing unit is controlled by means of four cams
and their associated tappets. Three clamps which are
used for the holding, cutting and heat-sealing of the
strap are moved by means of the tappets. In addition,
two proximity switches B1 and B2 are activated by
means of the cams.
The heating element is swivelled to the straps, by
means of a further cam, in order to heat them.
The proximity switch B4 is located on the heat-sealing
unit above. The fan serves to draw off the smoke
which is generated during the heat-sealing process.
d) Machine frame
The machine frame is the mobile carrier of all other
sub-assemblies. The machine height can be altered
on the machine height.
The table top can be opened for maintenance work. If
this is done the entire engine circuit is disabled. In its
open position the table top is mechanically protected
by means of a shear hinge.
The drum for mounting of the strap coil is mounted be-
low in the machine frame. A plate showing the method
of threading the strap is also located on the machine
frame.
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DESCRIPTION

c
e
Fig. 2
e) Electric part
The electric part contains all the operational elements
and the electrical components:
– Main control unit
– Control panel circuit board
– Welding transformer
– Capacitor
– Micro fuses
– Safety switch (table top)
For overhaul work the electric part can be folded up
after the loosening of two screws.
a
b
d
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