Food slicer and associated carriage tracking system

Abstract

A food slicer includes: a base; a knife mounted to rotate relative to the base; a carriage mounted to the base for reciprocating movement back and forth past the cutting edge of the knife; and a driving device connected to the bracket to move the bracket. The distance sensing system is arranged to detect the distance of the movable portion from the defined position, where the movable portion is part of the drive or part of the carriage in order to detect and track the position of the carriage.

Description

Technical Field

[0001] The present application generally relates to a food slicer commonly used for slicing large-volume foods, and more particularly to a carriage tracking system in such a food slicer. Background Art

[0002] A typical reciprocating food slicer has a rotatable circular or disk-shaped slicing blade, an adjustable gauge plate for determining the slice thickness, and a carriage for supporting the food as it moves back and forth past the cutting edge of the blade during slicing. An automatic drive system for the carriage includes a drive motor typically connected thereto via a belt and a conveying device connected to the belt to drive the carriage back and forth during an automatic slicing operation performed by a controller of the slicer.

[0003] In the automatic drive system of a slicer, a feedback loop from the motor (such as a brushless DC motor) to the motor controller is typically required. The motor controller essentially needs to be able to determine the motor position accurately to some extent. This is typically achieved by an encoder attached to the motor. The encoder allows the relative position of the motor shaft to be determined with a high degree of accuracy when the motor controller is powered on.

[0004] For many existing slicers, once the machine is powered off, the controller cannot be set to monitor any motor movement. This creates a problem when the slicer is powered on. If there is a specific profile that the motor controller will use to control the motor to move the carriage, the motor controller must know the position where the motor / conveying device is located (i.e., the position where the carriage is located). If the conveying device / carriage was at the front of the machine when power was off, but has moved to the rear of the machine after power off, in this scenario, the motor controller will not recognize that the conveying device / carriage is at the rear of the machine, and if this problem is not solved, the motor controller will send the conveying device / carriage into the rear wall. To avoid this situation from occurring, there are several solutions on current slicers: physical limit switches signal the controller that the conveying device is at or near the end of its travel; proximity magnetic switches can be used to force enablement before starting the machine (to start the machine, you must first move the conveying device, thereby actuating this switch, and then the motor controller will know the position of the conveying device along its travel); or the motor controller can very slowly and automatically feed the motor in one direction until it slightly touches the end of the travel. The end of the travel can be determined by detecting the motor current difference.

[0005] Slowly lowering the carriage down to the rear wall takes extra time and is somewhat unintuitive for the operator. Forcing the operator to position the conveying device in a specific location may also be somewhat unintuitive. The limit switch option is viable, but this option has some limitations when it comes to the faster speed and accuracy of this method at the production level (without some in-line adjustments during assembly).

[0006] Accordingly, it is desirable to provide a slicer that has a system capable of better identifying and tracking the position of the carriage. Summary of the Invention

[0007] In one aspect, a food slicer includes: a base; a knife mounted to rotate relative to the base; a carriage mounted to the base for reciprocating movement past the cutting edge of the knife; and a drive device connected to the carriage to move the carriage. A distance sensing system is arranged to detect the distance of a movable part from a defined position, where the movable part is part of the drive device or part of the carriage, so as to detect and track the position of the carriage.

[0008] In another aspect, a food slicer includes: a base; a knife mounted to rotate relative to the base; a carriage mounted to the base for reciprocating movement past the cutting edge of the knife; and a drive device connected to the carriage to move the carriage. A time-of-flight sensor is arranged to detect the actual distance of a movable part from a defined position, where the movement of the movable part directly corresponds to the movement of the carriage.

[0009] In another aspect, a food slicer includes: a base; a knife mounted to rotate relative to the base; a carriage mounted to the base for reciprocating movement past the cutting edge of the knife; and a drive device connected to the carriage to move the carriage, the drive device including a motor and an encoder associated with the motor. An energy harvesting device is configured to supply power to the encoder when the food slicer is not powered. Brief Description of the Drawings

[0010] Figure 1 and Figure 2 shows a food slicer;

[0011] Figure 3 shows a food slicer in which the body is removed to expose internal components;

[0012] Figure 4 and Figure 5 shows a view of a belt drive assembly;

[0013] Figure 6 shows a schematic diagram of the distance sensing system of the slicer;

[0014] Figures 7 to 8 Illustrates an exemplary configuration and positioning of a time-of-flight sensor. Detailed Description

[0015] Reference Figures 1 to 5 , the food slicer 10 includes a housing or base 12 and a motor-driven circular slicing blade 14, which is mounted to the housing to rotate about an axis 16. Figure 2 Depicts a right side view of the slicer. Figure 2 The left side (where the controls are located) is generally referred to as the front side of the slicer (i.e., the position where the operator stands to perform slicing), Figure 2 and the right side is generally referred to as the rear side of the slicer. The food can be supported on a motor-driven food carriage 20, which moves the food to be sliced past the cutting edge 14a of the rotating slicing blade 14. The food carriage 20 reciprocates along a linear path from left to right, such that the lower end of a large volume of food slides along the surface of the gauge plate 22, is cut by the knife 14, and then slides along the knife cover plate 24. The gauge plate system includes a rotatable knob 40, which is mechanically connected to adjust the position of the gauge plate for slice thickness control. Figure 2

[0016] The food carriage 20 includes a tray mounted on a tray arm 26, which orients the tray of the food carriage at an appropriate angle (usually perpendicular) to the plane of the knife cutting edge. The arm of the food carriage or the portion on which the arm is mounted reciprocates in a slot 28 in the lower portion of the housing 12. The carriage 20 can be moved manually (e.g., by a handle) and / or the carriage 20 can also be automatically driven. Here, an internal motor 30 drives a belt 32, which is internally connected to a tubular conveying member 34, which is connected to the arm 26, and the tubular conveying member 34 spans across a slide bar 36. In particular, the motor 30 moves an output belt 38 to rotate a gear 42, which in turn includes a drive pulley 44 that engages the belt 32, and the belt 32 also extends around an idler pulley 46 spaced from the drive pulley. The conveying portion 34 is coupled to the belt 32 by a belt connector 50 to move with the belt, which belt connector is a clamping connector on the belt.

[0017] Figure 6 Reference Figure 6, which shows a schematic diagram of the distance sensing system 60 of the slicer and includes a distance sensor 62 that is positioned to detect the position of a portion 34a of the conveying device 34 relative to a defined position (i.e., the position of the sensor 62 itself). In one embodiment, the sensor 62 is a time-of-flight (ToF) sensor. The sensor 62 can be used to track and update the positioning by communicating with the slicer controller 64. The sensor 62 can also be used by the controller 64 to count and record the carriage travel. The ToF sensor is a range imaging system that measures the distance between the sensor and a detectable object / portion based on the time of flight, which is the round-trip time of an artificial light signal that can be provided by a laser or an LED or other light source acting as the sensor transmitter, and the artificial light signal travels to the object / portion and is reflected back to the sensor to be detected by the detector of the sensor. As used herein, the term controller is intended to broadly cover any circuit (e.g., solid state, application specific integrated circuit (ASIC), electronic circuit, combinational logic circuit, field programmable gate array (FPGA)) that performs the control function of a machine or any component thereof, a processor (e.g., shared, dedicated, or group, including hardware or software that executes code), software, firmware, and / or other components, or a combination of some or all of the above. The controller 64 can operate as part of the distance sensing system 60 and part of the drive device (e.g., in the case where the controller 64 is configured to operate the motor 30).

[0018] In one embodiment, the ToF sensor 62 is capable of detecting and monitoring the conveying device 34 over the entire conveying travel length L. In this embodiment, the requirement for homing is reduced because the controller 64 will determine the position of the conveying device and thus determine the position of the carriage at any time. However, in such an embodiment, the homing process can still be implemented, and according to Figure 6 , arranging the sensor 62 at the rear portion of the slicer towards the end of the slicing travel may still be advantageous for providing the highest position resolution towards the end of the slicing travel.

[0019] In another embodiment, the ToF sensor 62 cannot detect or "see" the conveying device 34 over the entire conveying stroke length. In this design, the ToF sensor 62 is restricted to a specific range and cannot resolve the conveying position over the entire conveying stroke length. In such an embodiment, the ToF sensor will be myopic and have a higher resolution / accuracy than the case where it can detect the entire stroke length. In such an embodiment, the ToF sensor 62 should be arranged at the rear part of the slicer such that when the position of the carriage exceeds the slicing knife, after the machine (at the cutting end or the rear end of the machine, opposite the in-situ end or the front end of the machine) has cut the slice, the ToF sensor will only be able to see the conveying device. In this embodiment, the controller 64 can still use the sensor output to count the strokes. However, a "homing process" can also be implemented because the sensor cannot resolve the conveying device position over the entire conveying stroke length.

[0020] In an embodiment, to "home" the conveying position, the following process is performed by the controller:

[0021] (1) Check whether the ToF sensor can see the conveying device.

[0022] (2) If "yes", then measure the distance to the conveying device and use this data to "home" and update the actual conveying position (within the motor controller).

[0023] (3) If "no", then start the motor with a predefined stroke profile that is normally used for slicing (this is different from the standard "homing process" of very slowly feeding the conveying device down). Since the maximum range of the ToF is known, the position of the conveying device is known to be within a certain range (if the ToF sensor can only see 10 cm and the ToF sensor reads "maximum range" or "10 cm", the controller is configured to initially assume that the conveying device is anywhere from 10 cm to the opposite end of the stroke). Once the motor starts the normal slicing stroke, it is assumed that the conveying device starts at the front end of the stroke (even if the conveying device is actually somewhere between 10 cm and the front end of the stroke). At a predefined time interval, the controller checks to see if the ToF sensor has started sensing the conveying device. Once the ToF sensor has started sensing or detecting the conveying device, the controller updates the actual conveying device position. In an embodiment, the update is continuous, not just instantaneous. Continuous update until the end of the stroke will ensure a high degree of accuracy.

[0024] This design utilizes the ToF sensor to "capture" the conveying device or the carriage and determine its position through a dynamic homing process (also known as dynamic zeroing), which does not require the conveying device or the carriage to reach either end of its full stroke to determine the actual position.

[0025] In another embodiment, the ToF sensor 62 (if the conveying device is monitored over its entire travel length) can be used in place of the associated encoder on the motor. If the ToF sensor 62 can resolve the actual conveying device position with sufficient accuracy, there is no need for a feedback loop that feeds the rotation of the associated motor back to the controller.

[0026] Advantages of the system described above include one or more of the following: (i) elimination of additional sensors for counting travel; (ii) elimination of the possibility of redundant components (motor rotation encoders); and (iii) increased operator intuition because the machine will not need the conveying device / carriage to be in the original position at the front of the machine before allowing the machine to start, or the machine will not need to run a homing process before starting a slicing travel profile.

[0027] Reference Figures 7 to 8 , in one embodiment, the conveying device 34 includes an integral support 34b that extends through the slot 28, to which the arms of the food carriage are mounted. The support 34b includes a bracket 34c to which the support rollers 35 are mounted, and the rollers 35 are supported along the upper surface of the track 37. The sensor 62 is mounted at the rear end of the track 37 and is oriented to detect the position of the bracket 34c.

[0028] In an alternative solution, a distance sensor is not used. In this solution, the controller 64 monitors the position only using the associated encoder / sensor, but includes a system that monitors the encoder / sensor even when the machine is powered off. This will allow the controller 64 to maintain an updated position of the conveying device and thus an updated position of the carriage, even when the machine is not powered. Thus, in the case where the machine is powered off, the conveying device is moved, and the machine is powered on again, the machine will have an updated and accurate measurement of the conveying device position in memory. To temporarily power the encoder / sensor and move this data to a storage device, energy can be harvested from the unpowered machine. For example, this energy harvesting is feasible by using electromagnetic induction or the Wiegand effect. Manual movement of the carriage in turn causes rotation of the motor 30, generating an electromagnetic field from which energy can be harvested using a Wiegand sensor 75 ( Figure 5 ).

[0029] It should be clearly understood that the above description is for illustrative and exemplary purposes only and not for purposes of limitation. Variations can be made. For example, while Figure 6The system in [description] detects the distance of a part 34a of the conveyor 34, but the sensor can detect other movable parts. In particular, the movable part detected can be any one of the following: (i) a part 32a of the belt 32 according to the sensor position 62' (if the position of the conveyor on the belt is known); a part 34a of the conveyor 34 or a part of the arm or arm support of the carriage (preferably, the part of the arm / arm support inside the housing of the slicer) according to the sensor position 62"; or (ii) a component (e.g., a component designed to enhance reflection) connected to a part of the belt, a part of the conveyor, or a part of the arm. The movement of any one of these options directly corresponds to the movement of the carriage (e.g., a 1-mm linear movement of the monitored part corresponds to a 1-mm movement of the carriage). Other variations are possible.

Claims

1. A food slicer, comprising: A base; A knife, the knife being mounted to rotate relative to the base; A carriage, the carriage being mounted to the base for reciprocating movement past the cutting edge of the knife; A drive device, the drive device being connected to the carriage to move the carriage; A distance sensing system, the distance sensing system being arranged to detect the actual distance of a movable part from a defined position, wherein the movable part is part of the drive device or part of the carriage.

2. The food slicer according to claim 1, wherein The distance sensing system includes a sensor and a controller, the controller being configured to detect and track the position of the carriage and control the operation of the motor of the drive device.

3. The food slicer according to claim 1, wherein The distance sensing system includes a time-of-flight sensor, the time-of-flight sensor having a transmitter oriented to emit an optical signal towards the movable part and having a detector for detecting the optical signal reflected from the movable part back to the time-of-flight sensor.

4. The food slicer according to claim 3, wherein, The drive device includes a movable belt and a conveying device connected to move with the belt, wherein the carriage includes an arm connected to the conveying device to move with the conveying device, wherein the movable part is (i) part of the belt, part of the conveying device or part of the arm, or (ii) a component connected to part of the belt, part of the conveying device or part of the arm.

5. The food slicer according to claim 3, wherein, The drive device includes a motor and an associated controller for controlling the motor, and the time-of-flight sensor provides time-of-flight information or distance information to the controller.

6. The food slicer according to claim 3, wherein, The movable part has a travel length corresponding to the travel length of the carriage, and the time-of-flight sensor is configured to detect the distance of the movable part from the defined position at all positions of the movable part along the travel length.

7. The food slicer according to claim 3, wherein, The movable part has a travel length corresponding to the travel length of the carriage, and the time-of-flight sensor is configured to detect the distance of the movable part from the defined position only when the movable part is within a set range of the defined position, wherein the set range is less than the travel length.

8. The food slicer according to claim 7, wherein, The defined position is at or near the end of the travel length, at the end of the travel length where the position of the carriage extends beyond the knife towards the rear of the slicer, wherein the set range is defined by a rear portion of the travel length.

9. The food slicer according to claim 1, wherein, The defined position is at or near the end of the travel length, at the end of the travel length where the position of the carriage extends beyond the knife towards the rear of the slicer.

10. A food slicer, comprising: A base; A knife, the knife being mounted to rotate relative to the base; A carriage, the carriage being mounted to the base for reciprocating movement past the cutting edge of the knife; A drive device, the drive device being connected to the carriage to move the carriage; A time-of-flight sensor, the time-of-flight sensor being arranged to detect an actual distance of a movable part from a defined position, wherein movement of the movable part directly corresponds to movement of the carriage.

11. The food slicer according to claim 10, further comprising a controller configured to receive distance information or time-of-flight information from the time-of-flight sensor, the controller being configured to detect and track a position of the carriage and to control an operation of a motor of the drive means.

12. The food slicer according to claim 11, wherein, When the food slicer is powered on, the controller is configured to perform a dynamic homing process to determine an actual position of the movable part before the carriage reaches either end of its full stroke length.

13. The food slicer according to claim 10, wherein, The time-of-flight sensor is mounted inside the base, towards the rear end of the slicer.

14. The food slicer according to claim 13, wherein, The time-of-flight sensor is mounted on or near a rail, wherein the drive means includes a movable belt and a conveying means connected to move with the belt, wherein the conveying means includes a support member extending from the conveying means and including a roller supported on the rail, and the movable part is the support member or a component mounted to the support member.

15. A food slicer, comprising: A base; A knife, the knife being mounted to rotate relative to the base; A carriage, the carriage being mounted to the base for reciprocating movement past a cutting edge of the knife; A drive means, the drive means being connected to the carriage to move the carriage, the drive means including a motor and an encoder associated with the motor; An energy harvesting device for supplying power to the encoder when the food slicer is not powered.

Images