Automatic initial-cutting device for microtomes, particularly ultramicrotomes

• US 5,226,335 A
• Filed: 04/10/1991
• Issued: 07/13/1993
• Est. Priority Date: 04/11/1990
• Status: Expired due to Fees

• Current Assignee: Armin Kunz, Hellmuth Sitte, Helmut Hassig, Klaus Neumann
• Original Assignee: Armin Kunz, Hellmuth Sitte, Helmut Hassig, Klaus Neumann
• Inventors: Neumann, Klaus, Kunz, Armin, Sitte, Hellmuth, Hassig, Helmut
• Primary Examiner(s): PHAN, HIEN HUY
• Application Number:
  US07/682,954
• Time in Patent Office: 825 Days
• Field of Search: 83/13, 83/76, 83/74, 83/703, 83/915.5, 83/76.7, 83/72
• US Class Current: 83/74
• CPC Class Codes: G01N 1/06 providing a thin slice, e.g. microtome
• CPC Class Codes: G01N 2001/066 electric
• CPC Class Codes: Y10T 83/141 With means to monitor and control operation [e.g., self-regulating means]
• CPC Class Codes: Y10T 83/148 Including means to correct the sensed operation
• CPC Class Codes: Y10T 83/6492 Plural passes of diminishing work piece through tool station

Abstract

A device automatically applies an object (7) to a cutting edge (11) of a knife 10), and automatically makes an initial cut in the object (7), in microtomes, especially ultramicrotomes. Force sensors (27,28), length sensors (29) or other sensors, an elecrotronic control unit (25) and an encoder (22) coupled to a drive device register forces (k,-k) connected with the separation of sections by the knife edge (11) or variations in the system triggered by these forces. Subsequently, via the electronic control unit (25), a transition from a rapid speed or rate of feed to a lower cutting speed or a lesser rate of feed for making an initial cut is automatically performed. A visual and/or acoustic signal informs the user of this change. Signals (S₁, S₂) from the sensors (27-29) serve for automatic adjustment of the position of two switch-over points (U₁, U₂) from the rapid return speed (V_R) to the slower cutting movement (V_S) or from this slower cutting movement to the more rapid return movement (V_R). In a further development, by electronic comparison of the force/time patterns or length/time patterns, the end of the initial cutting process is established and used for a fresh automatic variation in cutting speed (V_S) and rate of feed.

Claims

1. An automatic initial cutting device in a microtome, comprising:

a knife having an edge for cutting an object;

holding means for holding the object to be cut by said knife;

a driving means operably connected to one of said knife and said holding means for relative movement therebetween at a travelling speed for cutting the object;

feed means for producing a relative feed movement between said knife edge and said holding means such that the object can be sectioned by said knife edge, said feed means comprising a servomotor;

sensing means, comprising at least one sensor, for sensing a condition resulting from forces generated by said knife edge cutting a section of the object and generating a signal corresponding to the condition sensed; and

an electronic control means for receiving said signal from said sensing means and controlling at least one of said driving means and servomotor of said feed means as a function of the condition resulting from the forces generated by said knife edge cutting a section of the object, wherein said electronic control means controls said driving means to generate a first relatively rapid and constant travelling speed between said knife and said holding means, automatically switches over from the first travelling speed to a second, reduced cutting speed outside of said cutting zone, said cutting zone being defined as a function of said signal from said sensing means.

2. The automatic initial cutting device in a microtome of claim 1, wherein said electronic control means switches over to said return speed from said reduced cutting speed based on said signal from said sensing means indicating an end of cutting between said knife edge and an object held by said holding means.

3. An automatic initial cutting device in a microtome, comprising:

a knife having an edge for cutting an object;

holding means for holding the object to be cut by said knife;

a driving means operably connected to one of said knife and said holding means for relative movement therebetween at a travelling speed for cutting the object;

feed means for producing a relative feed movement between said knife edge and said holding means such that the object can be sectioned by said knife edge, said feed means comprising a servomotor;

sensing means, comprising at least one sensor, for sensing a condition resulting from forces generated by said knife edge cutting a section of the object and generating a signal corresponding to the condition sensed;

an electronic control means for receiving said signal from said sensing means and controlling at least one of said driving means and servomotor of said feed means as a function of the condition resulting from the forces generated by said knife edge cutting a section of the object; and

a recording device connected to said electronic control means for recording the relative position of said knife edge and an object held by said holding means and indicating the relative position to said electronic control means, wherein said electronic means controls said driving means as a function of said signal from said sensing means when the object held by said holding means contacts said knife edge and the indication from said recording device to switch from a rapid relative speed between said knife and the object held by said holding means to a slower cutting speed at a position before contract between said knife edge and the object such that vibrations arising from switching over from the rapid relative speed to the slower cutting speed have abated before contact between said knife edge and the object takes place.

4. An automatic initial cutting device in a microtome, comprising:

a knife having an edge for cutting an object;

holding means for holding the object to be cut by said knife;

a driving means operably connected to one of said knife and said holding means for relative movement therebetween at a travelling speed for cutting the object;

feed means for producing a relative feed movement between said knife edge and said holding means such that the object can be sectioned by said knife edge, said feed means comprising a servomotor;

sensing means, comprising at least one sensor, for sensing a condition resulting from forces generated by said knife edge cutting a section of the object and generating a signal corresponding to the condition sensed; and

an electronic control means for receiving said signal from said sensing means and controlling at least one of said driving means and servomotor of said feed means as a function of the condition resulting from the forces generated by said knife edge cutting a section of the object, wherein said electronic control means controls said driving means and said feed means such that said knife edge can repeatedly cut sections from an object held by said holding means, said electronic control means comparing said signals from said sensing means for successive sections cut from the object and switching at least one of said driving means and said feed means to a low cutting speed, or low rate of feed or cutting thickness, respectively, when substantially identical said signals result from two consecutive sections cut from the object.

5. The automatic initial cutting device in a microtome of claim 4, and further comprising means for manually correcting the values of the low cutting speed and low rate of feed or cutting thickness set by said electronic control means within predetermined limits.

6. An automatic initial cutting device in a microtome, comprising:

a knife having an edge for cutting an object;

holding means for holding the object to be cut by said knife;

a driving means operably connected to one of said knife and said holding means for relative movement therebetween at a travelling speed for cutting the object;

feed means for producing a relative feed movement between said knife edge and said holding means such that the object can be sectioned by said knife edge, said feed means comprising a servomotor;

sensing means, comprising at least one sensor, for sensing a condition resulting from forces generated by said knife edge cutting a section of the object and generating a signal corresponding to the condition sensed;

an electronic control means for receiving said signal from said sensing means and controlling at least one of said driving means and servomotor of said feed means as a function of the condition resulting from the forces generated by said knife edge cutting a section of the object;

a display means for displaying to a user at least one of the minimum and maximum forces resulting from said knife edge cutting a section of the object, said display means displaying the forces from the most recent cutting of a section of the object, and the forces being determined from said signal of said sensing means; and

signalling means for signalling a user when one of the minimum and maximum forces falls below or exceeds a predetermined value.