MOUNTING DEVICE FOR RECEIVING A HOLLOW CYLINDRICAL OBJECT AND PRINTING SYSTEM

Abstract

A mounting device for holding a hollow cylindrical object, particularly a screw cap, in a printing system, comprises a support member, and a mandrel for receiving a hollow cylindrical object arranged at the support member, and a heating device for heating the hollow cylindrical object mounted at the mandrel. A printing system for printing on hollow cylindrical objects, preferably screw caps, comprises at least one mounting device, and at least one printhead configured to print on surfaces of cylindrical objects, preferably screw caps.

Claims

1. A mounting device for holding a hollow cylindrical object, particularly a screw cap, in a printing system, comprising: a support member, and a mandrel for receiving a hollow cylindrical object arranged at the support member, characterized by a heating device for heating the hollow cylindrical object mounted at the mandrel.

2. The mounting device according to claim 1, wherein the heating device is configured to heat the hollow cylindrical object from an outer side of the hollow cylindrical object, and/or wherein the heating device is configured to heat the hollow cylindrical object from an inner side of the hollow cylindrical object.

3. The mounting device according to claim 1, wherein the heating device comprises an internal heating unit.

4. The mounting device according to claim 3, wherein the internal heating unit comprises a heat source, preferably a heating wire, more preferably a plurality of heating wires.

5. The mounting device according to claim 3, wherein the heating unit is arranged to heat an outer surface of the mandrel and/or the heating unit is arranged to heat a fluid, preferably air, being directed to the mandrel.

6. The mounting device according to claim 1, wherein the heating device comprises a wireless induction unit for wireless induction heating of the hollow cylindrical object, and/or the heating device comprises an infrared heating unit for emitting infrared radiation.

7. The mounting device according to claim 1, wherein heating device comprises a fluid supply conduit for supplying a flow of heating fluid to the mandrel.

8. The mounting device according claim 7, wherein the mandrel comprises a heating fluid passage for directing the flow of fluid towards an inner surface of the hollow cylindrical object.

9. The mounting device according to claim 8, wherein the mandrel comprises a mounting sleeve comprising the form of a hollow cylinder, wherein preferably, the heating fluid passage is arranged inside the mounting sleeve, wherein preferably, the mounting sleeve comprises one or more openings being in fluid communication with the heating fluid passage.

10. The mounting device according to claim 9, wherein one or more spacers are arranged on an outer surface of the mounting sleeve for providing a gap between the outer surface of the mounting sleeve and an inner surface of the hollow cylindrical object, wherein preferably the one or more spacers are arranged on an outer lateral surface of the mounting sleeve and/or on an outer end face of the mounting sleeve.

11. The mounting device according to claim 9, wherein the mounting sleeve extends along a longitudinal axis and comprises an expansion region, wherein the mandrel further comprises a core arranged inside the mounting sleeve, wherein the core is movable in relation to the mounting sleeve, wherein the core is configured to be positioned in a first position of the core relative to the mounting sleeve in which the expansion region is in a not expanded state, and configured to be positioned in a second position of the core relative to the mounting sleeve in which the core exerts a radial force onto the expansion region such that the expansion region is radially expanded with regard to the expansion region in the not expanded state.

12. The mounting device according to claim 11, wherein in the not expanded state, the mounting sleeve comprises a maximum outer diameter equal to or slightly smaller than an inner diameter of a hollow cylindrical object to be received by the mandrel, and in the expanded state, the mounting sleeve comprises a maximum outer diameter greater than the inner diameter of the hollow cylindrical object to be received by the mandrel.

13. The mounting device according to any one of claims 9, wherein the mounting sleeve comprises a plurality of slots substantially extending along the longitudinal axis being arranged in a circumferential direction in relation to the longitudinal axis for forming the expansion region, wherein preferably the slots are in fluid communication with the heating fluid passage.

14. The mounting device according to claim 13, wherein the slots are arranged such that, in the expansion region, the mounting sleeve comprises a plurality of ribs extending along the longitudinal axis.

15. The mounting device according to claim 14, wherein one or more ribs comprise a spacer, wherein preferably each rib comprises a spacer.

16. The mounting device according to claim 1, wherein the heating device comprises a flow generating unit, preferably a pump or a fan, for providing a fluid flow, preferably an air flow in the heating device.

17. The mounting device according to claim 1, wherein the heating device comprises a fluid return conduit for redirecting fluid from the mandrel towards the heating unit.

18. The mounting device according to claim 1, wherein the mandrel is rotary supported on the support member, wherein preferably the heating device comprises a heating area arranged adjacent to the mandrel for heating an outer lateral surface of the hollow cylindrical object.

19. The mounting device according to claim 1, wherein a plurality of mandrels is arranged on the support member in a circumferential direction about a center axis, wherein preferably the support member is rotatable about the center axis.

20. The mounting device according to claim 1, further comprising a tilting device for tilting the support member relative to a reference plane.

21. The mounting device according to claim 1, wherein the heating device comprises a connection unit for connection to an external heat source.

22. The mounting device according to claim 1, further comprising a battery and/or a contact unit preferably comprising a sliding contact, preferably a brush, for electrical connection with an electrical power supply.

23. A printing system for printing on hollow cylindrical objects, preferably screw caps, comprising at least one mounting device according to claim 1, and at least one printhead configured to print on surfaces of cylindrical objects, preferably screw caps.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The above and further features and advantages of the invention will become readily apparent from the following detailed description of preferred embodiments of the invention with reference to the accompanying drawings, in which reference signs designate features, and in which:

[0076] FIG. 1 is a schematically a perspective side view of a mounting device for holding a plurality of hollow cylindrical objects;

[0077] FIG. 2 is a schematically shows a perspective sectional view through the mounting device of FIG. 1;

[0078] FIG. 3 is a schematically shows a perspective sectional view of the mounting device according to FIGS. 1 and 2;

[0079] FIG. 4 is a schematically shows a perspective side view of the mounting device according to FIGS. 1 to 3;

[0080] FIG. 5 is a schematically shows a perspective sectional view of a mandrel of the mounting device according to the embodiment shown in FIGS. 1 to 4; and

[0081] FIG. 6 is a schematically shows a perspective side view of the mandrel of FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

[0082] The person skilled in the art is well aware that these embodiments and items only depict examples of a plurality of embodiments. Hence, the embodiments shown here should not be understood as limiting. Any combination and configuration of the described features within the scope of the invention is encompassed as well.

[0083] FIG. 1 schematically shows a perspective side view of a mounting device 1 for holding a plurality of hollow cylindrical objects 6, here in the form of screw caps, in a printing system. The mounting device 1 comprises a support member 7 and a plurality of mandrels 2 for receiving a hollow cylindrical object 6, which are arranged at the support member 7 in a circumferential direction with respect to a center axis 9 of the mounting device 1. Each mandrel 2 is rotatable about a longitudinal axis 10 with respect to the support member 7 by means of bearings 8 (see FIG. 5).

[0084] The mounting device 1 further comprises a heating device 5 for heating the hollow cylindrical objects 6 mounted at the mandrels 2. The heating device 5 according to this exemplary embodiment is configured to heat the hollow cylindrical object 6 from an outer side of the hollow cylindrical object 6 and from an inner side of the hollow cylindrical object 6, as will be described in more detail below. The heating device 50 is substantially arranged radially inwards with respect to the circumferential arrangement of the plurality of mandrels 2.

[0085] FIG. 2 schematically shows a perspective sectional view through the mounting device 1 of FIG. 1. The heating device 5 comprises an internal heating unit 50 containing a plurality of heating wires 51, which are arranged in a circumferential direction with respect to the center axis 9.

[0086] Here, the heating unit 50 is configured to heat a fluid, which in this embodiment is air. For providing a flow of air to the heating unit 50, the heating device 5 comprises a flow generating unit (see FIGS. 3 and 4) which moves air from the radial inner side of the mounting device 1 towards and through the heating wires 51. The heating wires 51 heat the air when passing the wires 51 substantially by means of convection.

[0087] The heating device 5 further comprises a fluid supply conduit 52 through which the flow of heating fluid heated by the wires 51 is supplied to the mandrels 2. In detail, the heated air is directed from a heating chamber 57 accommodating the heating unit 50 via a plurality of tubes 56 into a supply ring chamber 58 and into heating fluid passages 21 of the mandrels (see FIG. 5). Hence, the tubes 56 and the supply ring chamber 58 substantially form the fluid supply conduit 52.

[0088] As will be described in more detail with respect to FIGS. 5 and 6, the flow of heated air is directed through the mandrels 2 to heat up an inner side of the hollow cylindrical objects 6. After the heated air has been conducted through a mandrel 2, it exits the mandrel 2 into a return chamber 59 which is in fluid communication with the flow generating unit 55, such that the air used for heating the hollow cylindrical objects 6 can be supplied back to the heating unit 50 and, thus, can be reused for heating the hollow cylindrical objects 6. With other words, a substantially closed loop of flow of heated and reheated air is generated.

[0089] According to this embodiment, the air is heated by the heating unit 50 to a temperature between 50° C. and 55° C., wherein the temperature is measured close to an inlet 21 of a heating fluid passage 21 arranged in the mandrel 2 by an optional temperature sensor (not shown). Alternatively or in addition, the temperature of an outer surface of the hollow cylindrical object 6 may be detected.

[0090] FIG. 3 is another schematic perspective sectional view of the mounting device 1 according to FIGS. 1 and 2, wherein loop merely one mandrel 2 holding a hollow cylindrical object 6 is shown. The sectional cut is slightly shifted with respect to the sectional cut shown in FIG. 2, such that the closed circle for the flow of air realized by means of the fluid supply conduit 52, the fluid return conduit 53 and the flow generating unit 55 can be seen in detail.

[0091] Moreover, the heating device 5 further comprises a heating area 54 arranged adjacent to the lateral outer side of the mandrels 6 such that an outer lateral surface 61 of the hollow cylindrical object 6 can be heated from an outer side of the hollow cylindrical object 6. An even heating effect on the lateral surface 61 of the hollow cylindrical object 6 may be achieved by rotating the hollow cylindrical object 6 about the longitudinal axis 10. Hence, heat radiated by the heating area 54 towards the hollow cylindrical object 6 is subsequently absorbed by the entire lateral surface 61. Hence, the heating area 54 supports heating or tempering the outer lateral surface 61 of the hollow cylindrical object 6.

[0092] With other words, the hollow cylindrical objects 6 are heated by the heating device 5 both from an inner side and an outer side of the hollow cylindrical objects 6.

[0093] FIG. 4 schematically shows a perspective side view of the mounting device 1 according to the preceding Figures, wherein the heating chamber 57 and the mandrels 2 are hidden, such that plain sight on the flow generating unit 55 is provided. The flow generating unit 55 comprises a plurality of fans 550 evenly distributed along a circumferential direction with respect to the center axis 9.

[0094] FIG. 5 is a schematic perspective sectional view of a mandrel 2 of the mounting device 1 according to the embodiment shown in FIGS. 1 to 4. The mandrel 2 comprises a mounting sleeve 23 comprising the form of a hollow cylinder, wherein the heating fluid passage 21 is arranged inside the mounting sleeve 23. The mounting sleeve 23 comprises a plurality of openings 22 being in fluid communication with the heating fluid passage 21. Thus, air fed from the heating chamber 57 via the inlet 210 into the heating fluid passages 21 is directed through the openings 22 and comes in contact with an inner surface 60 of the hollow cylindrical object 6. As can be seen in FIG. 6, which is a schematic perspective side view of the mandrel 2, the mounting sleeve 23 comprises a plurality of spacers 25, 25′, which are arranged on an outer surface of the mounting sleeve 23 for providing a gap between the outer surface of the mounting sleeve 23 and the inner surface 60 of the hollow cylindrical object 6. The spacers 25, 25′ are arranged both on the outer lateral surface of the mounting sleeve 23 and on an outer end face of the mounting sleeve 23 provided by a lid 24 of the mounting sleeve 23. Hence, the gap extends both on the end face and the lateral side of the mounting sleeve 23.

[0095] Heated air fed into the gap via the openings 22, thus, comes in contact with a majority of the inner surface 60 of the hollow cylindrical object 6, as the mounting sleeve merely makes contact with the hollow cylindrical object 6 via the spacers 25, 25′.

[0096] Hence, an air flow 11 is generated which enters through the inlet 210 into the heating fluid passage 21 into the mandrel 2, and is further directed through the openings 25, 25′ into the gap between the mounting sleeve 23 and the hollow cylindrical object 6. As air is constantly supplied to the mandrel, the air present in the gap is pushed towards the lower end of the hollow cylindrical object 6 and to an outlet 212 for the air flow 11. The heated air, thus, heats the inner surface of 60 of the hollow cylindrical object 6 via convection and then leaves the mandrel 2. Thereby, a substantially even heating of the hollow cylindrical object 6 may be obtained.

[0097] As the air flow 11 described above would remove the hollow cylindrical object 6 from the mandrel 2 if the hollow cylindrical object 6 was not held in position on the mandrel 2, the mandrel 2 comprises an expansion region 26, which can be expanded in the radial direction with respect to the longitudinal axis 10, such that an outer diameter of the expansion region 26 can be increased and decreased. The mandrel 2 further comprises a core 3 arranged inside the mounting sleeve 23, wherein the core 3 is movable in relation to the mounting sleeve 23 in direction of the longitudinal axis 10. The core 3 is configured to be positioned in a first position of the core 3 relative to the mounting sleeve 23 in which the expansion region 26 is in a not expanded state, and configured to be positioned in a second position of the core 3 relative to the mounting sleeve 23 as shown in FIG. 5, in which the core 3 exerts a radial force onto the expansion region 26 such that the expansion region 26 is radially expanded with regard to the expansion region 26 in the not expanded state.

[0098] In the not expanded state, the mounting sleeve 23 comprises a maximum outer diameter slightly smaller than an inner diameter of a hollow cylindrical object 6 to be received by the mandrel 2, and in the expanded state, the mounting sleeve 23 comprises a maximum outer diameter greater than the inner diameter of the cylindrical object 6 to be received by the mandrel. Due to the expansion of the expansion region 26, the mounting sleeve 23 applies a radial force onto the cylindrical lateral wall of the hollow cylindrical object 6, thus, generating a frictional fit between the outer surface of the spacers 25 arranged in the expansion region 26 and the lateral inner surface 60 of the hollow cylindrical object 6, such that the hollow cylindrical object 6 is firmly held in position on the mandrel 2.

[0099] The core 3 is located inside the mounting sleeve 23. It comprises a core wedge structure 30 formed by a plurality of wedge ring segments 300 arranged adjacent to each other along the longitudinal axis 10. The core wedge structure 30 is designed in conformity with a plurality of wedge ring segments 290 of a sleeve wedge structure 29 arranged on an inner lateral side of the cylindrical mounting sleeve 23 in the expansion region 26. The core ring segments 300 comprise contact surfaces which they are able to touch complementary formed contact surfaces of wedge ring segments 290 of the mounting sleeve 23. The contact surfaces 37 and the longitudinal axis 10 accordingly enclose an angle, which according to this embodiment comprises 17°. Alternatively, the angle may comprise another value, preferably between 1° and 40°.

[0100] According to this embodiment, the mounting sleeve 23 comprises a plurality of slots 27 substantially extending along the longitudinal axis 10 being arranged in a circumferential direction in relation to the longitudinal axis 10 for forming the expansion region 26. The slots 27 are in fluid communication with the heating fluid passage 21, and thus also form and function as the openings 25.

[0101] As can be seen in FIG. 6, the slots 27 are arranged such that, in the expansion region 26, the mounting sleeve 23 comprises a plurality of ribs 28 extending along the longitudinal axis 10. Thus, each single fin or rib 28 may be bent independently, as the fins or ribs 28 are not connected by each other in the circumferential direction due to the provision of slots 27.

[0102] The slots 27 according to this optional embodiment do not extend over the entire length of the mounting sleeve 23 with respect to the longitudinal axis 10, but are arranged in direction of the longitudinal axis 10 between a first end portion of the mounting sleeve 23 (corresponding to a right end portion of the mounting sleeve 23 with regard to the orientation of the mounting sleeve 23 in FIG. 6) and a second end portion of the mounting sleeve 23 (corresponding to a left end portion of the mounting sleeve 23 with regard to the orientation of the mounting sleeve 23 in FIG. 6). Hence, in this optional embodiment, the mounting sleeve 23 comprises end portions being rigid with respect to the expansion region 26, and which consequently do substantially not radially expand due to an exertion of radial force via the core 3 onto the sleeve 23.

[0103] For providing a particularly even pressure distribution via the expansion region 26 onto the hollow cylindrical object 6, each slot 27 and thus each rib 28 comprises a sinuous shape. Moreover, each rib 28 comprises a spacer 25 also comprising a substantial sinuous shape.

[0104] The core 3 here is biased into the second position as shown in FIG. 5 by a biasing member 31, which in this embodiment comprises the form of a helical compression spring. The core 3 can be moved relative to the mounting sleeve 23 against the biasing force of the biasing member 31 by actuating an actuator 32.

[0105] The mounting device 1 further comprises an optional battery (not shown) and an optional contact unit (not shown) which comprises a sliding contact, preferably a brush, for electrical connection with an electrical power supply.

[0106] It will be obvious for a person skilled in the art that these embodiments and items only depict examples of a plurality of possibilities. Hence, the embodiments shown here should not be understood to form a limitation of these features and configurations. Any possible combination and configuration of the described features can be chosen according to the scope of the invention.

REFERENCE SIGN LIST

[0107] 1 Mounting device [0108] 2 mandrel [0109] 21 heating fluid passage [0110] 210 inlet [0111] 211 return channel [0112] 212 outlet [0113] 22 opening [0114] 23 mounting sleeve [0115] 24 lid [0116] 25 spacer [0117] 26 expansion region [0118] 27 slot [0119] 28 rib [0120] 29 sleeve wedge structure [0121] 290 wedge ring segment [0122] 3 core [0123] 30 core wedge structure [0124] 300 wedge ring segment [0125] 31 biasing member [0126] 32 actuator [0127] 4 lid [0128] 5 heating device [0129] 50 internal heating unit [0130] 51 wire [0131] 52 fluid supply conduit [0132] 53 fluid return conduit [0133] 54 heating area [0134] 55 flow generating unit [0135] 550 fan [0136] 56 tubes [0137] 57 heating chamber [0138] 58 supply ring chamber [0139] 59 return chamber [0140] 6 hollow cylindrical object [0141] 60 inner surface [0142] 61 lateral surface [0143] 62 top surface [0144] 7 support member [0145] 8 bearing [0146] 9 center axis [0147] 10 longitudinal axis [0148] 11 air flow