Instruction manual

Rotary Microtome HM 355 S
MICROM International GmbH
Robert-Bosch-Str. 49
D- 69190 Walldorf
PART 3 THEORY OF OPERATION
3-1 CUTTING MOVEMENT AND
RETRACTION
The rotary movement of the handwheel of the
HM 355 S results in the vertical movement of the
specimen clamp. This rotary movement is carried
out either manually or by means of the motorized
cutting drive.
Sectioning is carried out by knives or blades, which
must be adjusted and fixed on the knife carrier.
With the downward movement of the specimen,
sectioning is carried out (cutting movement).
The upward return travel of the specimen is carried
out by turning the handwheel further in a clockwise
direction. During this return travel, the specimen is
drawn back automatically to protect knife and
specimen. If required, the function <retraction> can
be turned off.
The selected section thickness is delivered at the
upper reversal point of the return travel.
The number of the sections made can be shown on
the section counter on the display. After each
downward movement of the specimen holder, the
number on the section counter increases by 1. The
sum of the sections carried out can also be seen on
the display. For this, trimming values and sectioning
values are added up. Section counter and sum of
section thicknesses can be reset to zero at any time
by means of the RESET-button.
Moreover, the remaining travel to the front end
position can also be shown on the display. The
remaining travel, which is still available for
sectioning, is shown in microns. If the specimen
holder is in the back end position, the display shows
28 000 µm. This number decreases, the further the
specimen holder is moved towards the front. (See
2-7, indication of cutting processes).
3-2 SPECIMEN COARSE FEED
AND TRIMMING FUNCTION
After changing the specimen or moving the knife or
knife carrier, it is necessary to adjust the specimen
to the knife edge again. This can easily be done by
means of the specimen coarse feed and the defined
trimming values. After the specimen and the knife
are adjusted, further gradual feed for trimming can
be carried out by pressing the button for trimming,
which is available as pulse or permanent function.
If the <pulse function> is chosen, the specimen
holder moves forwards by the pre-selected
trimming value whenever pressing the button for
trimming. If the <permanent function> is chosen,
the feed is carried out in the upper reversal point at
each handwheel rotation.
3-3 OPERATING PANEL
AND FOOT PEDAL
The operating controls of the panel are well
arranged for safe and easy use. The operating
panel can be removed from the instrument at any
time and used as a separate unit. In addition, the
cutting movement can be started and stopped by
means of the foot pedal.
3-4 SPECIMEN CLAMPING
SYSTEM AND SPECIMEN
ORIENTATION
According to the form and size of the specimens,
different specimen clamping systems are available
to carry the specimen.
It is very easy to align the specimen to the knife,
using the orienting adapter.