Patent ID: 8051760

Claim:
A microtome for producing thin sections for microscopy, having a sectioning knife held on a knife receptacle; a specimen holder for receiving a specimen of which thin sections are to be produced; a first motor unit for relative displacement of the sectioning knife with respect to the specimen holder; a second motor unit for a relative oscillating motion between the sectioning knife and specimen holder in order to produce the thin sections; a control system for applying control to the first motor unit and to the second motor unit; and an operating unit, said operating unit comprising: a first operating element upon the actuation of which a first operating state of the first motor unit can be established, wherein a relative displacement between the sectioning knife and specimen holder at an elevated first displacement speed takes place; and a second operating element upon the actuation of which a second operating state of the first motor unit can be established, wherein a relative displacement at a predetermined advance rate takes place, wherein the first operating element is embodied as a rotating ring that, after a manual rotation, upon release automatically returns into a zero position wherein the displacement speed is equal to zero, the magnitude of the first displacement speed being adjustable, upon a deflection of the rotating ring through a rotation angle, as a function of said rotation angle; and the second operating element is embodied as a rotary knob, concentrically within the rotating ring, having detent positions, the advance rate being adjustable as a function of the rotation angle of the rotary knob.