EP-4735337-A1 - SAFETY LABELLING SYSTEM AND METHOD FOR OPERATING A SAFETY LABELLING SYSTEM

Abstract

A safety labelling system (S) comprising a lifting device (1) for positioning a labelling unit (2) in a vertical direction (Z) in relation to a flow of objects (3). The lifting device (1) comprises an upper section (1a) and a lower section (1b), wherein the upper section (1a) is movably arranged relative to the lower section (1b) by means of a balancing displacement unit (U). The labelling unit (2) is attached to the upper section (1a). The balancing displacement unit (U) comprises a cylinder barrel (5), a piston (6) movably arranged in the cylinder barrel (5), a piston rod (7), and a cylinder nut (8). The piston rod (7) and the cylinder nut (8) are rotatably engaged with each other, wherein the piston rod (7) at an inner end (7a) is connected to the piston (6) and the cylinder nut (8) is connected to the cylinder barrel (5). An actuator (M) is configured for rotatably displacing the piston rod (7) or the cylinder nut (8) resulting in linear displacement of the labelling unit (2) in the vertical direction (Z). The balancing displacement unit (U) further comprises a load balancing pressure chamber (9) arranged in the cylinder barrel (5) in connection to the piston (6), configured for counterbalancing a gravitational force (FG) exerted on the piston rod (7) by means of fluid pressure (P).

Inventors

• ESSMAN MELIN, Jonatan

Assignees

• Evolabel AB

Dates

Publication Date

20260506

Application Date

20240612

Claims (19)

1. 1. A safety labelling system (S) comprising a lifting device (1) and a labelling unit (2), wherein the lifting device (1) is configured for positioning the labelling unit (2) in a vertical direction (Z) in relation to a flow of objects (3), wherein the labelling unit (2) is arranged for printing labels (4) and/or applying labels (4) to the objects (3), wherein the lifting device (1) comprises an upper section (1a) and a lower section (1 b), wherein the upper section (1a) is movably arranged relative to the lower section (1b) by means of a balancing displacement unit (II) arranged between the upper section (1a) and the lower section (1b), wherein the labelling unit (2) is attached to the upper section (1a), wherein the balancing displacement unit (II) comprises a cylinder barrel (5), a piston (6) movably arranged in the cylinder barrel (5), a piston rod (7), and a cylinder nut (8), wherein the piston rod (7) and the cylinder nut (8) are rotatably engaged with each other, wherein the piston rod (7) at an inner end (7a) is connected to the piston (6) and the cylinder nut (8) is connected to the cylinder barrel (5), wherein an actuator (M) is configured for rotatably displacing the piston rod (7) or the cylinder nut (8) resulting in linear displacement of the piston rod (7) and the piston (6) relative to the cylinder barrel (5) for moving the upper section (1a) with the labelling unit (2) in the vertical direction (Z), wherein the balancing displacement unit (II) further comprises a load balancing pressure chamber (9) arranged in the cylinder barrel (5) in connection to the piston (6), wherein the load balancing pressure chamber (9) is configured for counterbalancing a gravitational force (FG) exerted on the piston rod (7) from the safety labelling system (S) by applying a counterbalancing force (Fc) onto the piston (6) by means of fluid pressure (P) in the load balancing pressure chamber (9).
2. 2. The safety labelling system (S) according to claim 1 , wherein the inner end (7a) of the piston rod (7) is rotatably connected to the piston (6) via a piston bearing unit (13), wherein the cylinder nut (8) is non- rotatably connected to the cylinder barrel (5), wherein the actuator (M) is connected to the piston rod (7) and configured for rotating the piston rod (7) around a rotational axis (X) upon actuation for displacement of the upper section (1a) with the labelling unit (2) in the vertical direction (Z).
3. 3. The safety labelling system (S) according to claim 1 , wherein the inner end (7a) of the piston rod (7) is non-rotatably connected to the piston (6), wherein the cylinder nut (8) is rotatably connected to the cylinder barrel (5) via a nut bearing unit (14), wherein the actuator (M) is connected to the cylinder nut (8) and configured for rotating the cylinder nut (8) around a rotational axis (X) upon actuation for displacement of the upper section (la) with the labelling unit (2) in the vertical direction (Z).
4. 4. The safety labelling system (S) according to any preceding claim, wherein the balancing displacement unit (II) is arranged inside the upper section (1a) and the lower section (1 b).
5. 5. The safety labelling system (S) according to any preceding claim, wherein the upper section (1a) and the lower section (1b) are telescopically arranged relative to each other.
6. 6. The safety labelling system (S) according to any preceding claim, wherein an outer end (7b) of the piston rod (7) is connected to the upper section (1a), and wherein the cylinder barrel (5) is connected to the lower section (l b).
7. 7. The safety labelling system (S) according to claim 6, wherein the upper section (1a) comprises an upper support bracket (10a) and the lower section (1b) comprises a lower support bracket (10b), wherein the outer end (7b) of the piston rod (7) is connected to the upper support bracket (10a) and the cylinder barrel (5) is connected to the lower support bracket (10b).
8. 8. The safety labelling system (S) according to any preceding claim, wherein the piston rod (7) is configured as a ball screw and the cylinder nut (8) is configured as a ball nut, or wherein the piston rod (7) is configured as a threaded screw and the cylinder nut (8) is configured as a threaded nut.
9. 9. The safety labelling system (S) according to any preceding claim, wherein the actuator (M) is arranged to control the position of the labelling unit (2) in the vertical direction (Z) in relation to the flow of objects (3) through displacing the upper section (1a) in an upwards direction (Du) and/or a downwards direction (DD) to a labelling position (PLAB) of the labelling unit (2), wherein in the labelling position (PLAB) the labels (4) are printed and/or applied to the objects (3).
10. 10. The safety labelling system (S) according to any preceding claim, wherein the load balancing pressure chamber (9) is configured as a pneumatic cylinder chamber, wherein the load balancing pressure chamber (9) is pressurized by means of compressed air (A) from an air pressure source (11) for establishing the counterbalancing force (Fc) onto the piston (6) for counterbalancing the gravitational force (FG) exerted on the piston rod (7).
11. 11 . The safety labelling system (S) according to any preceding claim, wherein the actuator (M) is arranged inside the upper section (1a) and/or the lower section (1 b).
12. 12. The safety labelling system (S) according to any preceding claim, wherein the actuator (M) is a stepper motor adapted for rotatably positioning the piston rod (7) or the cylinder nut (8) with high precision.
13. 13. The safety labelling system (S) according to any preceding claim, wherein the safety labelling system (S) is provided with a safety brake arrangement (12) configured to prevent the upper section (1a) from unwanted displacement from the gravitational force (FG) exerted on the piston rod (7) if a malfunction of the balancing displacement unit (II) occurs.
14. 14. A method for operating a safety labelling system (S), wherein the safety labelling system comprises a lifting device (1) and a labelling unit (2), wherein the lifting device (1) is positioning the labelling unit (2) in a vertical direction (Z) in relation to a flow of objects (3), wherein the labelling unit (2) is printing labels (4) and/or applying labels (4) to the objects (3), wherein the lifting device (1) comprises an upper section (1a) and a lower section (1 b), wherein the upper section (1a) is movably arranged relative to the lower section (1b) by means of a balancing displacement unit (II) arranged between the upper section (1a) and the lower section (1 b), wherein the labelling unit (2) is attached to the upper section (1a), wherein the balancing displacement unit (II) comprises a cylinder barrel (5), a piston (6) movably arranged in the cylinder barrel (5), a piston rod (7), and a cylinder nut (8), wherein the piston rod (7) and the cylinder nut (8) are rotatably engaged with each other, wherein the piston rod (7) at an inner end (7a) is connected to the piston (6) and the cylinder nut (8) is connected to the cylinder barrel (5), wherein the balancing displacement unit (II) further comprises a load balancing pressure chamber (9) arranged in the cylinder barrel (5) in connection to the piston (6), wherein the method comprises the steps: rotatably displacing the piston rod (7) or the cylinder nut (8) by means of an actuator (M), wherein the rotational displacement of the piston rod (7) or the cylinder nut (8) is resulting in linear displacement of the piston rod (7) and the piston (6) relative to the cylinder barrel (5) for moving the upper section (1a) with the labelling unit (2) in the vertical direction (Z); counterbalancing a gravitational force (FG) exerted on the piston rod (7) from the safety labelling system (S) by applying a counterbalancing force (Fc) onto the piston (6) by means of fluid pressure (P) in the load balancing pressure chamber (9).
15. 15. The method according to claim 14, wherein the inner end (7a) of the piston rod (7) is rotatably connected to the piston (6) via a piston bearing unit (13), wherein the cylinder nut (8) is non- rotatably connected to the cylinder barrel (5), wherein the actuator (M) is connected to the piston rod (7), wherein the method further comprises the step: rotating the piston rod (7) around a rotational axis (X) by the actuator (M) for displacing the upper section (1a) with the labelling unit (2) in the vertical direction (Z).
16. 16. The method according to claim 14, wherein the inner end (7a) of the piston rod (7) is non-rotatably connected to the piston (6), wherein the cylinder nut (8) is rotatably connected to the cylinder barrel (5) via a nut bearing unit (14), wherein the actuator (M) is connected to the cylinder nut (8), wherein the method further comprises the step: rotating the cylinder nut (8) around a rotational axis (X) by the actuator (M) for displacing the upper section (1a) with the labelling unit (2) in the vertical direction (Z).
17. 17. The method according to any of claims 14 to 16, wherein the method further comprises the step: controlling the position of the labelling unit (2) in the vertical direction (Z) in relation to the flow of objects (3) by means of the actuator (M), by displacing the upper section (1a) in an upwards direction (Du) and/or a downwards direction (DD) to a labelling position (PLAB) of the labelling unit (2), wherein in the labelling position (PLAB) the labels (4) are printed and/or applied to the objects (3).
18. 18. The method according to any of claims 14 to 17, wherein the load balancing pressure chamber (9) is configured as a pneumatic cylinder chamber, wherein the method further comprises the step: pressurizing the load balancing pressure chamber (9) by means of compressed air (A) from an air pressure source (11) for establishing the counterbalancing force (Fc) onto the piston (6) for counterbalancing the gravitational force (FG) exerted on the piston rod (7).
19. 19. The method according to any of claims 14 to 18, wherein the safety labelling system (S) is provided with a safety brake arrangement (12), wherein the method further comprises the step: preventing the upper section (1a) from unwanted displacement from the gravitational force (FG) exerted on the piston rod (7) if a malfunction of the balancing displacement unit (II) occurs by means of the safety brake arrangement.

Description

SAFETY LABELLING SYSTEM AND METHOD FOR OPERATING A SAFETY LABELLING SYSTEM TECHNICAL FIELD The present disclosure relates to a safety labelling system comprising a lifting device and a labelling unit. The lifting device is positioning the labelling unit in a vertical direction in relation to a flow of objects, and the labelling unit is arranged for printing labels and/or applying labels to the objects. The disclosure further relates to a method for operating a safety labelling system. BACKGROUND Lifting devices are commonly used in labelling applications, where a labelling unit is positioned in a vertical direction in relation to objects that are labelled. The objects that are labelled sometimes have different dimensions and labelling positions and therefore the labelling unit needs to be repositioned to a correct labelling position for the objects to be labelled. The labelling units are often attached to a movable stand that is used for repositioning the labelling unit. Known movable stands are often complex in construction and are repositioning the labelling unit with low speeds. It is also difficult to position the labelling unit with high precision since drive units used need to move heavy loads in short time periods, and therefore are dimensioned with high power to manage high loads. When repositioning the labelling unit there is a risk that the moving labelling unit or a part of the movable stand is interfering with persons or is damaging objects if not handled in a correct way, which also could be the case if a malfunction of the movable stand occurs. To avoid accidents, the lifting device with the labelling unit is therefore often placed in fenced areas, which is a costly solution that takes up large floor areas. There is thus a need for an improved lifting device with a compact, safe, and simple construction, where the labelling unit can be repositioned with high speed and with high precision. Since the lifting device is robust in construction, carrying high loads, and is repositioned with high speed, there is a need to construct the lifting device to prevent accidents and damage to objects when the labelling unit is repositioned, or when the labelling unit is displaced in an unwanted manner. SUMMARY An object of the present disclosure is to provide a safety labelling system and method for operating a safety labelling system, where the previously mentioned problems are avoided. This object is at least partly achieved by the features of the independent claims. The dependent claims contain further developments of the safety labelling system and method for operating a safety labelling system. The disclosure concerns a safety labelling system comprising a lifting device and a labelling unit. The lifting device is configured for positioning the labelling unit in a vertical direction in relation to a flow of objects. The labelling unit is arranged for printing labels and/or applying labels to the objects. The lifting device comprises an upper section and a lower section, where the upper section is movably arranged relative to the lower section by means of a balancing displacement unit arranged between the upper section and the lower section. The labelling unit is attached to the upper section. The balancing displacement unit comprises a cylinder barrel, a piston movably arranged in the cylinder barrel, a piston rod, and a cylinder nut. The piston rod and the cylinder nut are rotatably engaged with each other. The piston rod is at an inner end connected to the piston and the cylinder nut is connected to the cylinder barrel. An actuator is configured for rotatably displacing the piston rod or the cylinder nut resulting in linear displacement of the piston rod and the piston relative to the cylinder barrel for moving the upper section with the labelling unit in the vertical direction. The balancing displacement unit further comprises a load balancing pressure chamber arranged in the cylinder barrel in connection to the piston. The load balancing pressure chamber is configured for counterbalancing a gravitational force exerted on the piston rod from the safety labelling system by applying a counterbalancing force onto the piston by means of fluid pressure in the load balancing pressure chamber. Advantages with these features are that through the counterbalancing of the piston rod, the safety labelling system comprising the lifting device and the labelling unit can be constructed in a safe manner with low forces acting on the actuator and the surrounding environment. Through the counterbalancing action, the load exerted on the actuator is low, and the labelling unit can be moved with high speed and positioned with high precision since the actuator is not used for moving heavy loads. The load balancing pressure chamber is counterbalancing the gravitational force exerted on the piston rod from the safety labelling system by applying the counterbalancing force onto the piston by means of fluid pressure in th