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Title:
GRIPPING TOOL
Document Type and Number:
WIPO Patent Application WO/2021/233888
Kind Code:
A1
Abstract:
This invention relates to a pick-and-place handling device, more specifically to a gripping tool, for manipulating, engaging, clamping, taking up and/or releasing soft or otherwise difficult-to-handle articles, in particular meat products, and to a corresponding method for automatic gripping, moving, manipulating and releasing such articles.

Inventors:
BOVIN, Andreas Nikolai Kyed (DK)
Application Number:
PCT/EP2021/063095
Publication Date:
November 25, 2021
Filing Date:
May 18, 2021
Export Citation:
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Assignee:
TEKNOLOGISK INSTITUT (DK)
International Classes:
B25J15/12
Download PDF:
Claims:
CLAIMS

1. A gripping tool (1), adapted to grip, hold, manipulate, and/or release a soft or otherwise difficult-to-handle workpiece (15), which gripping tool is characterised by comprising the following elements: a. two or more drums/cylinders or wheels/rollers (2), each drum/cylinder and wheel/roller mounted at one end of one of two or more the distance arms (3), connected to a gripper base (4), which two or more wheels in collaboration, are capable of controlling a friction belt (5), which moves along (part of) the surface of the two or more drums/wheels; b. two or more distance arms (3), each arm in one of its ends connected to the gripper base (4) via a rotary joint (3A), and in the other end connected to an axis (2A) of the drum/wheel (2) in question, and which two or more arms (3) are interconnected by one or more spring mechanisms (9) that may form part of (internally to) the rotary joint (3A), or may be mounted outside (externally to) the rotary joint (3A); c. a gripper base (4), acting as base for the friction belt (5) via a belt roll-up mechanism (6), an actuator (7), and a fastening element (8); d. a friction belt (5), in each end attached to the roll-up mechanism (6), and in its middle attached to an actuator string/rod/wire (7A); e. an actuator (7), connected to, and capable of activating the actuator string/rod/wire (7A), which string (7A) in its other end is connected to the friction belt (5) at an actuator mounting point (10) located in between the two or more drums/wheels (2); and f. a fastening element (8), connected to the gripper base (4), for mounting the gripping tool (1) on an industrial robot (13).

2. The gripping tool of claim 1, wherein the two or more drums/cylinders (2) are made from a durable material having a smooth surface.

3. The gripping tool of claim 1, which tool comprises two or more wheels/rollers (2) capable of rotating around the axis (2A) of the wheel.

4. The gripping tool of claim 3, wherein the two or more wheels/rollers (2), capable of rotating around the axis (2A) of the wheel, are passively rotating about each of their axis (2A).

5. The gripping tool of claim 3, wherein the two or more wheels/rollers (2), capable of rotating around the axis (2A) of the wheel, are actively driven by an internally or externally mounted servo motor (12).

6. The gripping tool of claim 1, wherein the two or more distance arms (3) are interconnected by one or more spring mechanisms (9) that are mounted within (internally to) the rotary joint (3A).

7. The gripping tool of claim 1, wherein the two or more distance arms (3) are interconnected by one or more spring mechanisms (9) that are mounted outside (externally to) the rotary joint (3A).

8. A system (16) for gripping, holding, manipulating, and/or releasing a soft or otherwise difficult-to-handle workpiece, which system is characterised by comprising the following elements:

• a gripping tool (1), operatively mounted on an industrial robot (13);

• an industrial robot (13), in function with a processing means (14); and

• a processing means (14) in function with the industrial robot (13) which system is characterised in that the gripping tool (1) is the gripping tool of claim 1.

9. A method for gripping, holding, and/or releasing a soft or otherwise difficult- to-handle workpiece, which method is characterised by comprising the following steps: i. providing the workpiece (15) to be manipulated and bringing it within working distance of an industrial robot (13), holding a robotic arm mounted with a gripping tool (1); ii. directing the gripping tool (1) towards the workpiece (15) so that the workpiece become located within a pinch zone (11); iii. causing the two or more drums/cylinders or wheels/rollers (2) to work on, and finally grip and hold the workpiece (15); iv. bringing the gripped workpiece (15) to a set delivery position; and v. delivering the product; which method is characterised in that the gripping tool (1) of step i is the gripping tool of claim 1.

Description:
GRIPPING TOOL

TECHNICAL FIELD

This invention relates to a pick-and-place handling device, more specifically to a gripping tool, for manipulating, engaging, clamping, taking up and/or releasing soft or otherwise difficult-to-handle articles, in particular meat products, and to a corresponding method for automatic gripping, moving, manipulating and releasing such articles.

BACKGROUND ART

Pick-and-place devices are gaining importance in industrial product handling lines, e.g., packing lines, where many formerly manually performed handling tasks are becoming substituted for automatic processing of various articles.

When dealing with non-rigid objects, i.e., soft, or otherwise difficult-to-handle articles, e.g., various meat products, automatic processing faces particular challenges, and several technical solutions have been suggested in this field.

W02007093774 describes a pick and place device for picking up and re-positioning an article carried by a support surface.

W02008150164 describes a gripper for handling delicate products, for instance fruit or vegetables.

W02009026925 describes a gripping device for use with a robot, for gripping, e.g., food articles.

WO2018122323 describes a gripping device for use with a robot, for picking up and repositioning an item carried by a support surface.

WO2019137585 describes a gripper for handling a piece of cloth.

US2017282379 describes a robot gripping device having finger parts.

However, the pick-and-place handling device described herein has not been disclosed.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a pick-and-place device useful for handling soft and/or otherwise difficult-to-handle articles, e.g., food products, and in particular meat products.

The gripping tool of the invention is for use in automatic processes and is suited for being mounted on an industrial robot or similar manipulator, and thus is capable of facilitating heavy and repetitive work. The gripping tool of the invention has proven to work quickly and flexibly and is made from materials, and is of a design, that make it easy to clean.

In its first aspect, the invention provides a gripping tool, adapted to grip, hold, manipulate, and/or release a soft or otherwise difficult-to-handle workpiece.

In its second aspect, the invention provides a system for gripping, holding, manipulating, and/or releasing a soft or otherwise difficult-to-handle workpiece.

In a further aspect, the invention relates to a method for gripping, holding, manipulating, and/or releasing a soft or otherwise difficult-to-handle workpiece.

Other objects of the invention will be apparent to the person skilled in the art from reading the following detailed description and accompanying drawings.

Any combination of two or more of the embodiments described herein is considered within the scope of the present invention.

BRIEF DESCRIPTION OF THE FIGURES

The present invention is further illustrated by reference to the accompanying drawing, in which:

Fig. 1 shows an example of a gripping tool (1) of the invention; and

Fig. 2 shows the essential elements of the system (16) of the invention.

DETAILED DISCLOSURE OF THE INVENTION

The gripping tool

In its first aspect, the present invention provides a gripping tool (1), adapted to grip, hold, manipulate, and/or release a soft or otherwise difficult-to-handle workpiece (15).

The gripping tool of the invention may be characterised by comprising the following elements: a. two or more drums/cylinders or wheels/rollers (2), each drum/cylinder and wheel/roller mounted at one end of one of two or more the distance arms (3), connected to a gripper base (4), which two or more wheels in collaboration, are capable of controlling a friction belt (5), which moves along (part of) the surface of the two or more drums/wheels; b. two or more distance arms (3), each arm in one of its ends connected to the gripper base (4) via a rotary joint (3A), and in the other end connected to an axis (2A) of the drum/wheel (2) in question, and which two or more arms (3) are interconnected by one or more spring mechanisms (9) that may form part of (internally to) the rotary joint (3A), or may be mounted outside (externally to) the rotary joint (3A); c. a gripper base (4), acting as base for the friction belt (5) via a belt roll-up mechanism (6), an actuator (7), and a fastening element (8); d. a friction belt (5), in each end attached to the roll-up mechanism (6), and in its middle attached to an actuator string/rod/wire (7A); e. an actuator (7), connected to, and capable of activating the actuator string/rod/wire (7A), which string (7A) in its other end is connected to the friction belt (5) at an actuator mounting point (10) located in between the two or more drums/wheels (2); and f. a fastening element (8), connected to the gripper base (4), for mounting the gripping tool (1) on an industrial robot (13).

It is not a pre-requisite for the tool to work that the friction belt (5) moves along two rotating wheels. If the surface of this element (2) is sufficiently smooth, the friction belt may be able to work freely around the drum/ cylinder.

In this case, the drum/cylinder (2) may, e.g., be made from a durable material having a smooth surface, e.g., steel, plastic, ceramics, glass, or a coated material.

In the alternative, the gripping tool of the invention comprises two or more wheels/rollers (2) capable of rotating around the axis (2A) of the wheel.

In one embodiment, the two or more wheels/rollers (2), capable of rotating around the axis (2A) of the wheel, are passively rotating about each of their axis (2A).

In another embodiment, the two or more wheels/rollers (2), capable of rotating around the axis (2A) of the wheel, are actively driven by a servo motor (12). This motor may in particular be mounted internally within the wheel/ roller (2), or it may be mounted externally to the wheel/ roller (2).

It is a feature of the gripping tool (1) of the invention, that the two or more drums/cylinders or wheels/rollers (2), are stretched away from the gripper base by two or more distance arms (3). The actual form and material of these arms is not critical, as long as the arms are strong enough to push away the drums/wheel (2) during operation.

In one embodiment, when the two or more wheels/rollers (2) are capable of rotating around the axis (2A) of the wheel, the two or more distance arms (3) must provide the opportunity for the wheel/ rollers to rotate, and thus shall be rotatably connected to the axis (2A) of the wheel/roller.

Next, in order for the two or more drums/cylinders or wheels/rollers (2) to work on and hold the workpiece (15), the two or more distance arms (3) shall allow the drums/wheels (2) to squeeze and pinch the workpiece (15) located within the pinch zone (11). To create this effect, the two or more distance arms (3) shall be interconnected by one or more spring mechanisms (9).

Spring mechanisms are commercially available and comes in various forms. As defined herein, spring mechanisms include, e.g., conventional helical/coil springs, torsion springs, volute springs, gas springs, rubber springs, pneumatic mechanisms, hydraulic mechanisms, etc.

This spring mechanisms (9) may be mounted within (internally to) the rotary joint

(3A).

In another embodiment, this spring mechanisms (9) may be mounted outside (externally to) the rotary joint (3A).

The gripper base (4) of the invention represents an element of any practical design, that connects the various parts of the gripping device, i.a. as base for the friction belt (5) via its belt roll-up mechanism (6), the actuator (7), and the fastening element (8).

To be effective in picking up the workpiece (15) from its support, the belt (5) of the invention must be designed so that a friction of a certain strength is achieved, e.g., by applying a pattern to the belt such as ribs or buds.

The belt for use according to the invention may, e.g., be made from a friction coated material, steel, metal rubber, plastic, textile, and/or leather, or a mixture hereof. Also, to stretch the friction belt it may be in operation with a roll-up mechanism (6) located in one or in both ends of the friction belt (5). This roll-up mechanism makes belt length available in order for the gripper to embrace and pick up objects of different sizes.

This roll-up mechanism (6) may be designed using a simple spring mechanism, or by applying a lamella belt, i.e. a belt that can change its length in response to different influences from the outside.

In another embodiment, roll-up mechanism (6) is designed using a cylinder roller/drum container. This design may include a controllable scroll mechanism, allowing feeding of the belt from one side and receival of the belt in the other side. This design allows the object to roll around its own axis while placed in the pinch zone (11), which principle is known as "With-In Hand Manipulation" (WIHM).In order to create a pinch zone (11) of a large volume, the friction belt (5) shall be operatively connected to the actuator mechanism (7), in practice through the actuator string/rod/wire (7A), attached to the belt at an actuator mounting point (10) located in between the two or more drums/wheels (2).

The actuator (7) for use according to the invention may be any commercially available actuator mechanism that can be operatively connected to a processing means (14). This actuator may be an air powered cylinder, an electrically operated mechanism, or similar device.

The actuator (7) therefore is capable of activating the actuator string/rod/wire (7A), which string (7A) in its other end is connected to the friction belt (5) at the actuator mounting point (10) located in between the two or more drums/wheels (2).

Finally, as the gripping tool of the invention is intended for implementation in automatic processes, this tool should comprise a fastening element (8) for mounting the gripping tool (1) on an industrial robot (13). The system

In another aspect the invention provides a system (16) for gripping, holding, and/or releasing a soft or otherwise difficult-to-handle workpiece.

The system of the invention may be characterised by comprising the following elements: i. a gripping tool (1), operatively mounted on an industrial robot (13); ii. an industrial robot (13), in function with a processing means (14); and iii. a processing means (14) in function with the industrial robot (13); which system is characterised in that the gripping tool (1) of step i is the gripping tool of the invention.

In the system of the invention, the gripping tool (1) may in particular be mounted on a robotic arm of the industrial robot (9), whereby a certain working distance/working zone may be defined, depending on the size/length of the robotic arm.

The industrial robot

The industrial robot (13) for use according to the invention shall be controlled by a processor (14) used according to the invention, and the robot (13) shall be equipped with the gripping tool (1) of the invention.

The robot (13) for use according to the invention may be any commercially available industrial robot. Industrial robots may be classified based on their coordinate systems, i.e. based on reachable coordinates of a point on the end-effector, and include Cartesian robots (when arms of a robot move in the XYZ rectangular coordinate system), Cylindrical robots (when arms of a robot move in one angular and two linear directions), Spherical robots (the arms move in two angular and one linear direction), SCARA robots (Selective Compliance Arm for Robotic Assembly; have two parallel revolute joints providing compliance in a selected plane), and Articulated robots (also known as the anthropomorphic robot, the robot arm has 3 revolute joints).

The processing means

The processing means (14) for use according to the invention may be any commercially available processor/PC being in function with, capable of receiving and processing of data obtained from, the industrial robot (13).

The method

In further aspect, the invention to provides a method for gripping, holding, and/or releasing a soft or otherwise difficult-to-handle workpiece. The method of the invention may be characterised by comprising the subsequent steps of: i. providing the workpiece (15) to be manipulated and bringing it within working distance of an industrial robot (13), holding a robotic arm mounted with a gripping tool (1); ii. directing the gripping tool (1) towards the workpiece (15) so that the workpiece become located within a pinch zone (11); iii. causing the two or more drums/cylinders or wheels/rollers (2) to work on, and finally grip and hold the workpiece (15); iv. bringing the gripped workpiece (15) to a set delivery position; and v. delivering the product; which method is characterised in that the gripping tool (1) of step i is the gripping tool of the invention.

In Step 1, the workpiece (15) to be manipulated may be provided, arriving, and lying on a conveyor belt.

In Step iii, the drums/wheels (2) may work on the workpiece (15), located within the pinch zone (11), by being pressed (gently) towards the workpiece causing the distance arms (3) to open and expand the pinch zone (11). When grabbed, the workpiece (15) may be manipulated, and, e.g., be slightly rotated within the pinch zone, before the workpiece is being moved towards the delivery position.

Examples of soft or otherwise difficult-to-handle products include, e.g., fish filets, filets from poultry, and other, usually smaller, pieces of meat.

DETAILED DESCRIPTION OF THE FIGURES

The present invention is further illustrated by reference to the accompanying drawing, in which:

Fig. 1 shows an example of a gripping tool (1) of the invention, which gripping tool comprises the following elements: Two wheels/rollers (2), each wheel having an axis of rotation (2A); Two distance arms (3) to keep the wheels/rollers stretched from the gripper base; The gripper base (4) that gathers and maintains the individual parts together; The friction belt (5); The belt roll-up mechanism (6), designed to keep the friction belt stretched during operation; The actuator (7) operating the friction belt through the actuator string/rod/wire (7A), thus helping to create a pinch zone (11), in which zone the workpiece (15) is manipulated; The fastening element/connection unit (8), which constitutes the link to the industrial robot (13); The distance arm spring mechanism (9), helping to secure a tight grip on the workpiece (15); The actuator mounting point (10) at which point the actuator engages the friction belt and helps creating the pinch zone (11), where the two wheels can enclose the workpiece; An example of a servo motor (12), which motor, if installed, may help manipulating the workpiece; The workpiece/product/article (15); and Fig. 2 shows the essential elements of the system (16) of the invention: A gripping tool (1) of the invention; an industrial robot/manipulator (13); and a processing means/processor (14).

List of reference signs

1. The gripping tool

2. Wheel/roller

2A. Axis of rotation of the wheel

3. Distance arm

3A. Rotary joint of the distance arms

4. Gripper base

5. Friction belt

6. Belt roll-up mechanism

7. Actuator

7A. Actuator string/rod/wire

8. Fastening element/connection unit

9. Distance arm spring mechanism

10. Actuator mounting point

11. Pinch zone

12. Servo motor

13. Industrial robot/manipulator

14. Processing means/processor

15. Workpiece/product/article/object