InstructionsForOperatingNo820Microtome
Inside Cover  DIR. 28-646   

DIR 28-646							Made In U.S.A.
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After removing the paper that is packed into the instrument to protect it from damage in transit, also the wooden block between the feed screw nut tip P and the inclined plane SP, carefully wipe the inclined plane to be sure it is free from dust or grit and apply to it a thin coating of clean light neutral grease.   

Close the cover and set the feed button FB  so that the line indicating the desired thickness of section in micron(s) comes exactly oppisite the fixed index line.

Remove the catch F from the hand wheel W and the instrument is ready to operate.  This catch should always be used to lock the hand wheel when the speciment is beng trimmed in place.  It prevents the specimen from being pushed down and from bringing the opeators fingers in contact with the knife edge.  A much safer procedure, however, is to remove the knife when working with the specimen.

When the limit of the feed has been reached, the block M pushes against the pin N and disengages the feeding mechanism.  When this occurs, the block shold be brough back to the beginning of its range by turning the handle E.  Care must be exercised not to turrn this handle in the direction to produce forward motion beyond the limit of the feed, as the feeding screw may thereby be damaged.

When the mechansim has beed automatically shut off, it may be again engaged, after the feed block has been turned back, by simply lifting up the lever L,  (marked PULL UP) till the pin snaps back into place.

There is the posibiltiy that from considerable use the friction of the feed screw FS and its ratchet wheel RW will be lessened.  This will be noticed by the sections sometimes coming thicker than that for which the instrument is set.  This lessened friction can be detected by the ease with which the feed screw crank E can be turned.  To increase the friction, tighten the friction collar FC against the bracket.  If this is not sufficient, friction can also be obtrained by slightly screwing in the square head friction screw FN, shown between the hand wheel and the case, and inside screw with slotted head FN.  No more than one turn of the friction nut should be made at one time. 

Only small quantities of the best grade of thin oil should be used on bearing surfaces (except the inclined plade as nentioned above.)  A ca of this oil is supplied with each instrument.  

CARE SHOULD BE TAKED that all the clamping screws on the knife holder as well as the eccentric clamping device are well tightened to prevent movemnet ot the knife while sectioning