Hohner ECONOMY 25/40, Operating Instructions Manual

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Operation
Hohner Maschinenbau GmbH ECONOMY 25/40 02/2016 29
4.5 Exchanging the upper and lower knife
The upper and lower knives are subject to the heaviest stress and therefore wear
most quickly. The quality of the stitching depends to a large extent on the condi-
tion of these knives.
Blunt knives pinch the wire off obliquely and form burrs. This results in poor sta-
ple penetration and, in the case of pad stitching, the staples do not penetrate the
paper parallely, but run untrue in the paper.
- Fig. 4.5 -
- Remove finger guard -20-and former -21-.
- Turn the machine by hand, until the knives open.
- Unscrew cover -26-, remove knife holder with pressure slide -14- and unscrew fastening
screws -28- on upper knife -29- and fastening screws -30- on lower knife -31-.
Fitting the new knife is executed in the reverse order, ensuring correct seating of upper and lower
knives (cutting edges must converge exactly parallel).
- Mount the finger guard in the correct position and note the markings (see 3.2).
Before switching on the machine, make sure that all protective devices are fit-
ted to the machine and all tools have been removed from the machine!
Quick stroke movements of the stitching heads!
Danger of crushing!
 Before carrying out maintenance or repairs, take care that the power supply is switched off
and prevented from being switched on again accidentally.
 Never operate the system without properly mounted finger guard.
TIP