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Friedrich Leutert GmbH & Co. KG
Engine Indicator S1 - Operating instructions
Drive of Recording Drum
Many engines, particularly the high speed ones for which the bar
spring indicator has specifically been designed, do not have indicating
rods since for high speeds it would be very difficult to catch the cord.
Therefore, in practice diagrams are often drawn by hand.
The drum drive makes it possible to take perfect diagrams also on high
speed engines. The drum drive essentially consists of a crank gear with
connecting rod and piston; it is a reduced copy of the motor. The piston
which drives the indicator drum by a steel band, runs synchronously
with the crank shaft of the engine to be tested. Coupling to the engine
is effected either directly or by toothed gear or chain wheels.
For details refer to special leaflet.
Handling and Care of the Indicator
Always remember, the Leutert bar spring indicator is a high precision
instrument that should always be treated accordingly if it is to meet
the requirements. Never use sharp polishing material, such as emery
paper, polishing paste etc. to clean dirty pistons and cylinders, as the
piston clearance would soon exceed the admissible play in the cylinder.
The best means to avoid clogging and oil crusts is a careful cleaning
with a soft cloth and new oiling of piston with SHC-Mobil-Oil after
each application of the indicator (oil bottle in box). After removal of the
protecting cover, the links of the recording mechanism should also be
oiled now and then with a drop of the same oil. The same applies for
the drum bearings by squirting oil into the bore of the drum shaft after
unscrewing oil nut (30).
Being very precise measuring springs, the bar springs are to be treated
carefully and put back into the recess in the box immediately after use.
Blows will alter the scale of the spring. The receiving cone of the springs
should always be slightly greased.
Technical Advice for Taking Diagrams
Prior to taking diagrams check whether the indicator is in perfect
condition, whether the proper spring according to the expected pressure
is applied and whether the ring of the upperpart is tightened firmly.
Furthermore, check whether the drum drive operates properly and
whether the drum swings freely without knocking against drum stop.
The diagram paper should fit tightly around the drum without wrinkling,
for loose paper is torn by the pencil.
