Slicing machine having a knife monitoring device

Patent metadata

Field	Value
Publication number	US-12397463-B2
Application number	US-202318159095-A
Country	US
Kind code	B2
Filing date	Jan 25, 2023
Priority date	Feb 27, 2017
Publication date	Aug 26, 2025
Grant date	Aug 26, 2025

Abstract

A method monitors a slicing machine, which has a circular knife driven by an electric knife motor. The method includes: sensing a knife motor current or a temporal profile of the knife motor current from the electric knife motor; determining measurement data based on the knife motor current or the temporal profile of the knife motor current; and determining a current cutting characteristic value based on the measurement data. The measurement data includes a load-dependent or load-independent current component. The cutting characteristic value includes a soiling, wear, or knife sharpness characteristic value, the soiling and wear characteristic values being derived from the load-independent current component, and the knife sharpness characteristic value being derived from the load-dependent current component.

First claim

The invention claimed is:

1. A method for monitoring an electrically operated slicing machine for cutting off slices from an item to be cut, the slicing machine comprising: a cutting device, the cutting device comprising a rotating circular knife driven by an electric knife motor; and a carriage, movable in parallel to the circular knife, for receiving and moving the item to be cut, the method comprising:
sensing a knife motor current over time to obtain a temporal profile of the knife motor current from the electric knife motor;
determining measurement data based on the temporal profile of the knife motor current; and
determining a current cutting characteristic value based on the measurement data, the measurement data comprising:
a load-dependent area comprising a sum or integral of a load-dependent current component of the temporal profile; and
a load-independent area comprising a sum or integral of a load-independent current component of the temporal profile,

wherein the current cutting characteristic value comprises:
a soiling characteristic value derived from the load-independent area, and at least one of:
a wear characteristic value derived from the load-independent area of the measurement data, or
a knife sharpness characteristic value derived from the load-dependent area, and

wherein the method further comprises outputting an indication signal indicating that the slicing machine is soiled based on the soiling characteristic value.

2. The method according to claim 1 , the method further comprising determining the current cutting characteristic value at predefined time intervals, the predefined time intervals being:
as a result of predefined events, or
after reaching a predefined cutting power limit.

3. The method according to claim 2 , the method further comprising, at a beginning of each start-up of the slicing machine, a no-load current of the knife motor is measured and then the load-independent current component of the temporal profile is determined therewith,
wherein the predefined time intervals are as the result of the predefined events, the predefined events comprising the start-up of the slicing machine.

4. The method according to claim 1 ,
wherein the measurement data comprises a currently measured value of the knife motor current and the temporal profile of the knife motor current,
wherein the cutting characteristic value is determined based upon an intermediate result derived from the currently measured value of the knife motor current and the temporal profile of the knife motor current.

5. The method according to claim 4 , wherein the intermediate result is determined as an integral value of a net current of the knife motor starting from a completion of a previously run knife grinding program to the currently measured value of the knife motor current.

6. The method according to claim 1 , wherein a target/actual comparison to a predefined limit value and/or to a dynamically determined limit value takes place with a measurement datum and/or with an intermediate result.

7. The method according to claim 6 , wherein the indication signal is output via a signal output unit upon a value of the soiling characteristic value reaching, exceeding, or falling below the predefined limit value or the dynamically determined limit value.

8. The method according to claim 6 , wherein a knife grinding program for sharpening the circular knife is automatically started upon the cutting characteristic value reaching, exceeding, or falling below the predefined limit value or the dynamically determined limit value.

9. The method according to claim 8 , wherein the dynamically determined limit value is determined at the start of the knife grinding program from the current cutting characteristic value.

10. The method according to claim 8 , wherein the knife motor is operated at a predetermined grinding speed at the start of the knife grinding program.

11. The method according to claim 8 , the method further comprising:
in a first step, operating the knife motor at a predetermined speed at a start of the knife grinding program, measuring the knife motor current while operating the knife motor at the predetermined speed in the first step, and determining a characteristic of the circular knife from the measured knife motor current measured in the first step; and
in a second step, operating the knife motor at a predetermined grinding speed, the predetermined grinding speed depending on the characteristic determined in the first step, and grinding the circular knife.

12. The method according to claim 1 , the method further comprising:
detecting, monitoring, or controlling a deburring process of the circular knife based on the knife motor current or the temporal profile, or
outputting a deburring indication signal, which indicates an outstanding or a completed deburring process, based on the knife motor current or the temporal profile.

13. The method according to claim 1 , the method further comprising detecting, monitoring, or controlling an operation of the slicing machine based on the temporal profile.

14. The method according to claim 1 , wherein the soiling characteristic value is derived from the load-independent current component of the measurement data, the soiling characteristic value indicating a measure of a soiling of the slicing machine corresponding to particles slowing down the circular knife.

15. The method of claim 1 , wherein the cutting characteristic value comprises the wear characteristic value being derived from the load-independent current component of the measurement data, the wear characteristic value indicating whether and to what extent parts of the slicing machine are worn.

16. The method of claim 1 , wherein the cutting characteristic value comprises the soiling characteristic value and the knife sharpness characteristic value, the knife sharpness characteristic value indicating a current degree of sharpness of the circular knife.

17. The method of claim 1 , wherein the determining of the current cutting characteristic value based on the measurement data comprises:
deriving the soiling characteristic value and the wear characteristic value from the load-independent current area of the measurement data; and
deriving the knife sharpness characteristic value from the load-dependent current area of the measurement data.

18. The method of claim 1 , wherein the knife motor current corresponds to a consumption of current by the knife motor while cutting, wherein the load-independent current component corresponds to the current consumption by the knife motor while idling, and wherein the load-dependent current component comprises a difference between the knife motor current and the load-independent current component.

19. The method of claim 1 , wherein the temporal profile begins after a completion of a previously run knife grinding program.

20. An electrically operated slicing machine for cutting off slices from an item, the slicing machine comprising:
a cutting device, the cutting device comprising a rotating circular knife configured to be driven by an electric knife motor;
a carriage, movable in parallel to the circular knife, and configured to receive and move the item to be cut;
a knife monitor configured to monitor a state of the circular knife; and
a controller,
wherein the knife monitor is further configured to sense a knife motor current over time to obtain a temporal profile of the knife motor current,
wherein the controller is configured to:
determine measuremen

Assignees

• Bizerba Se & Co Kg

Inventors

• Steinhilber Ralf
• Bodmer Markus

Classifications

• B23Q17/0961

  by measuring power, current or torque of a motor · CPC title

• B26D2210/02

  for cutting food products, e.g. food slicers · CPC title

• B26D7/0616

  by carriages, e.g. for slicing machines · CPC title

• B26D5/00

  Arrangements for operating and controlling machines or devices for cutting, cutting-out, stamping-out, punching, perforating, or severing by means other than cutting · CPC title

• B26D1/15

  with vertical cutting member · CPC title