Sheet feeding device equipped with a heating unit

Abstract

A sheet feeder (1) is provided, comprising a storage surface (11) for a stack of sheets (5), a blower arrangement comprising a plurality of side blower units (21) and a front blower unit (22), and at least one fan (23) configured to provide one or more air flows (3) to each of the side blower units and the front blower unit. The side blower units and the front blower unit are configured to direct the one or more air flows towards an upper region (12) of the sheet feeder to float a plurality of upper sheets (5a) of the stack of sheets. The sheet feeder further comprises a vacuum belt feeder (30) configured to grip and feed a topmost sheet (5b) of the plurality of floated sheets. The blower apparatus further comprises a heating unit (40) disposed between a first fan (23) of the at least one fan and the front blower unit and configured to heat one or more air flows supplied by the first fan to the front blower unit.

Description

Technical Field

[0001] The present disclosure relates to a sheet feeding device for the printing industry, for example, a sheet feeding device for a printer, a copier, or a sorter.

Background Art

[0002] Sheet feeding devices are generally incorporated into printers or copiers, and a large number of sheets are manually loaded to automatically feed the sheets one by one for subsequent operations on the sheets, such as printing or sorting.

[0003] An example of a prior art sheet feeding device by the present applicant is described in a Swedish patent specification published under SE 540 166 C2, which discloses a paper feeding device. The paper feeding device includes a storage surface for a stack of papers adapted to be moved between a lower position and an upper position, a vacuum feeder for feeding the papers from their positions on the storage surface, and a blower arrangement adapted to provide an air curtain for separating the top sheet of the paper from the remaining stack of papers.

[0004] The problems of sheet feeding devices are to handle sheets of various materials and qualities while minimizing or eliminating problems associated with double feeding, sheet jams, or manual settings and adjustments for operating the sheet feeding device with different sheet sizes and qualities. Therefore, it is important to reduce the problems associated with manual settings and adjustments for operating the sheet feeding device with double feeding, sheet jams, or different sheet sizes and qualities.

Summary of the Invention

[0005] Therefore, it is an object to provide a sheet feeding device in which problems associated with double feeding, sheet jams, or manual settings and adjustments for operating the sheet feeding device with different sheet sizes and qualities are reduced.

[0006] To achieve this objective, the present disclosure provides a sheet feeding device as defined by the independent claim. Further embodiments are provided in the dependent claims.

[0007] According to one aspect of the present disclosure, a sheet feeding device is provided. The sheet feeding device comprises a storage surface for a bundle of sheets. The storage surface has a front edge, a rear edge, and first and second side edges, and the storage surface moves vertically between a lower position and an upper position, or is adapted to move vertically. The sheet feeding device further comprises a blower device. The blower device comprises a plurality of side blower units provided along the first and second side edges of the storage surface, and a front blower unit provided along the front edge of the storage surface. The blower device further comprises at least one fan configured to supply one or more airflows to each of the side blower units and the front blower unit. The plurality of side blower units and the front blower unit are configured to direct one or more airflows toward the upper region of the sheet feeding device in order to lift a plurality of upper sheets of a bundle of sheets. The sheet feeding device further comprises a vacuum belt feeder configured to grab and feed the uppermost sheet from among a plurality of floating sheets. The blower device further comprises a heating unit positioned between a first fan of at least one fan and the front blower unit. The heating unit is configured to heat one or more airflows supplied to the front blower unit by the first fan.

[0008] This disclosure is based on the recognition that problems related to double feeding, sheet jamming, or manual setup and adjustment for operating sheet feeders with different sheet sizes and qualities are affected by the temperature and / or humidity of the sheets controlled by the sheet feeder. Furthermore, the adverse effects of humidity are emphasized when dealing with coated sheets.

[0009] The temperature and / or humidity of a bundle of sheets depends on the humidity and / or temperature of the environment in which the bundle of sheets was stored before being inserted into the sheet feeder. In normal operation, the bundle of sheets and the sheet feeder are stored in the same environment, i.e., the ambient air, for at least one or more days before the bundle of sheets is inserted into the sheet feeder, which is a sufficient length of time for the bundle of sheets to be affected by the characteristics of the environment. Therefore, the temperature and / or humidity of the bundle of sheets depends on the temperature and / or humidity of the ambient air. Since warmer air can hold more water than colder air, the relationship between air temperature and air humidity is that as the air gets hotter, the (relative) humidity of the air decreases. Therefore, by heating the ambient air and / or the bundle of sheets inserted into the sheet feeder, the humidity can be reduced, thereby mitigating the identified problem. However, heating the ambient air to a sufficient degree may not be appropriate or may not be cost-effective. Furthermore, heating a bundle of sheets is not advisable because it heats the bundle from the outside inward, resulting in the center of the bundle having a different temperature and therefore a different humidity than the outer part of the bundle.

[0010] This disclosure is further based on the recognition that excessively high humidity is only a problem for the top sheet. That is, if the humidity of the two top sheets is high enough that they stick together, it can result in double feeding and / or sheet clogging. On the other hand, if it can be ensured that the humidity of the two top sheets is low enough, double feeding and / or sheet clogging can be prevented. Thus, a sheet feeding device according to one aspect of this disclosure provides heating of the airflow used to lift the top sheet of a sheet bundle. The heated airflow is then precisely directed to where the heat is needed, thereby minimizing the risk of double feeding and / or sheet clogging of at least two top sheets and reducing energy consumption compared to heating the entire sheet bundle.

[0011] The front blower unit and multiple side blower units are positioned along the front edge and first and second side edges of the storage surface, resulting in airflow being directed from three different directions to the upper region of the sheet feeder for levitation. Thus, the levitation of multiple upper sheets can be understood as a coordinated operation performed by the side blower units and the front blower unit.

[0012] The front blower unit and heating unit of the blower system together provide a heated airflow, which reaches multiple upper sheets at the front edge of the storage surface and moves along the multiple upper sheets toward the rear edge of the storage surface. Furthermore, the side blower unit provides at least a portion of the floating of the multiple uppermost sheets, so the side blower unit helps to separate the uppermost sheets so that the heated airflow can move more easily along the multiple floating uppermost sheets from front edge to rear edge. Thus, the front blower unit and heating unit, together with the side blower unit, have a synergistic effect that enables the movement of hot air along the multiple floating uppermost sheets.

[0013] The first blower unit may be further configured to direct one or more airflows in a direction substantially perpendicular to the leading edge. Thus, the majority of the airflow heated by the heating unit moves along the multiple floating uppermost sheets from the leading edge to the trailing edge, thereby further minimizing problems caused by humidity.

[0014] The sheet feeding device may further include a flow path configured to guide the airflow(s) from the first fan to the front blower unit. This flow path can increase the amount of airflow(s) from the first fan reaching the front blower unit, thereby increasing the efficiency of the sheet feeding device. A heating unit may be placed within the flow path, which can increase the amount of airflow from the first fan exposed to the heating unit, thereby increasing the efficiency of the sheet feeding device. Furthermore, the flow path may be configured to guide the airflow from the first fan to the heating unit in order to further increase the amount of airflow from the first fan that will be exposed to the heating unit.

[0015] The heating unit may comprise at least one resistance wire configured to generate heat. The heating unit may further comprise one or more airflows supplied to the front blower unit via at least one resistance wire. At least one wire may be configured to receive an electric current passing through it, thereby heating the at least one wire. One of the resistance wires, and / or at least a portion of at least one wire, may extend along and / or across the path of one or more airflows supplied to the front blower unit by the first fan. Thus, one or more airflows may flow along and / or across the resistance wire or portion of the resistance wire on their way to the front blower unit, thereby being heated. The heating efficiency may be increased by arranging the resistance wire or portion of the resistance wire in contact with one or more airflows. At least a portion of the resistance wire, and / or one of the resistance wires, may be arranged along a coiled or wound path. The coiled or wound path may be arranged in a plane. However, the coiled or wound path may follow at least a portion of the surface of a three-dimensional geometric shape, where the geometric shape may be, for example, a cylinder, cone, pyramid, prism, tetrahedron, or cuboid. For example, a resistance wire may be arranged along a coiled path along the surface of a cone, where the coiled path is arranged along the surface of the cone so as to extend along the longitudinal direction of the cone and across a plane perpendicular to the longitudinal direction. The heating unit may comprise a plurality of arranged resistance wires, which may be positioned at different locations along one or more airflow paths.

[0016] The blower device may further include a second heating unit positioned between a second fan of at least one fan and the front blower unit. The second heating unit may be configured to heat one or more airflows supplied to the front blower unit by the second fan. The second heating unit may provide additional heating that can further minimize problems associated with double feeding and sheet clogging, for example. The second fan and the first fan may be two different fans of at least one fan, and may be positioned on different sides of the sheet feeding device, for example. However, the first fan and the second fan may be the same and may be configured to supply two or more airflows to the front blower unit.

[0017] The blower device may further include at least one side heating unit positioned between a third fan of at least one fan and a side blower unit of a plurality of side blower units. This allows heating of the floating uppermost sheet to be increased along the floating uppermost sheet and / or spread more uniformly. By supplying heated airflow from multiple directions, problems associated with, for example, double feeding and / or sheet clogging can be further mitigated. At least one side heating unit may be configured to heat one or more airflows supplied to the side blower unit by the third fan. The blower device may include two side heating units, each positioned between a side blower unit and a third fan of at least one fan. The blower device may include, for example, two third fans. The third fan(s), second fan, and / or first fan may be the same fan of at least one fan.

[0018] The sheet feeder may further include a sensor unit configured to measure the humidity and / or temperature of the air inside or within the sheet feeder and / or the ambient air. The ambient air may be the air surrounding the sheet feeder and / or the air in the environment in which the sheet feeder is located. The air inside the sheet feeder and the ambient air may be in fluid communication so that the ambient air can flow into the sheet feeder. At least one fan may be configured to draw air from the ambient air. The sheet feeder may further be configured to adjust the amount of air supplied by at least one fan and / or the amount of heat generated by a heating unit based on the measured humidity and / or temperature. If excess air and / or heat is supplied to the uppermost sheets that have risen, those sheets may dry out completely, which may cause static electricity to build up between the sheets and cause them to stick together. Adjusting the amount of air and / or heat can ensure that the floating top sheet is sufficiently dehumidified and / or not completely dry, thereby reducing the risk of double feeding and / or sheet clogging.

[0019] Other purposes, features, and advantages of the enclosed embodiments will become apparent from the following detailed disclosure, attached dependent claims, and drawings.

[0020] It should be noted that embodiments of the present invention relate to all possible combinations of the features described in the claims. Furthermore, it will be understood that the various embodiments described in the method defined according to the first embodiment, the fault detection system according to the second embodiment, and the fault detection device according to the third embodiment are all combinable with respect to each other. [Brief explanation of the drawing]

[0021] [Figure 1] Figure 1 shows a perspective view of a sheet feeding device according to an exemplary embodiment of the present disclosure. [Figure 2] Figure 2 shows a side view of a sheet feeding device according to an exemplary embodiment of the present disclosure. [Figure 3]FIG. 3 shows a perspective view of a sheet feeding device according to an exemplary embodiment of the present disclosure. [Figure 4] FIG. 4 shows a cross-sectional view of a sheet feeding device according to an exemplary embodiment of the present disclosure.

Mode for Carrying Out the Invention

[0022] FIG. 1 shows a perspective view of a sheet feeding device 1 according to an exemplary embodiment of the present disclosure.

[0023] The sheet feeding device 1 includes a storage surface 11 for a stack of sheets (not shown, see FIG. 3), a blower device including two side blower units 21 and a front blower unit (not shown, see FIG. 3), three fans 23 (two of which are shown in FIG. 1), and a vacuum belt feeder 30.

[0024] The two side blower units 21 are provided along the first and second side edges 11c, 11d of the storage surface 11, respectively. The front blower unit is provided below the vacuum belt feeder 30 along the front edge 11a of the storage surface 11. The first fan 23 of these fans 23 is configured to supply an air flow (not shown, see FIG. 3) to the front blower unit, and the second fan 23 of these fans 23 is configured to supply an air flow to the side blower unit 21. The front blower unit and the side blower unit 21 are configured to guide the air flow toward the upper region of the sheet feeding device 1 in order to lift a plurality of upper sheets of the stack of sheets.

[0025] The storage surface 11 is adapted to move vertically between a lower position and an upper position, where the vacuum belt feeder 30 is configured to grasp and feed out the uppermost sheet among a plurality of lifted sheets. Thereby, the storage surface 11, the blower device, and the vacuum belt feeder 30 cooperate to maintain a plurality of uppermost sheets within the upper region by raising or lowering the storage surface 11, lifting a plurality of uppermost sheets by the blower device, and feeding out the uppermost sheet by the vacuum belt feeder 30.

[0026] The sheet feeding device 1 further includes a heating unit (not shown, refer to FIG. 2 or FIG. 3) disposed between the fan 23 of at least one fan and the front blower unit and configured to heat one or more airflows supplied to the front blower unit by the first fan.

[0027] The sheet feeding device 1 may include a control device (not shown). The control device may be configured to move the storage surface 11 between a lower position and an upper position. The control device may be further configured to control the vacuum belt feeder 30, the fan 23, and the heating unit.

[0028] The sheet feeding device 1 may include a sensor unit (not shown) configured to measure at least one of the humidity and / or temperature of the air within the sheet feeding device 1 and the ambient air. The sheet feeding device 1 may be further configured to adjust the amount of air supplied by at least one fan and / or the amount of heat generated by the heating unit based on the measured humidity and / or temperature, where the adjustment may be performed by a control device of the sheet feeding device 1 communicably connected to the sensor unit.

[0029] FIG. 2 shows a side view of the sheet feeding device 1 according to an exemplary embodiment of the present disclosure. Note that FIG. 2 includes features, elements, and / or functions as shown in FIG. 1 and described in the associated text. Therefore, for a better understanding, reference is also made to FIG. 1 and the description related to FIG. 1.

[0030] Figure 2, a side view of the sheet feeding device 1, shows one side fan unit 21 and a second fan 23 positioned below the side fan unit 21 and configured to supply one or more airflows to the side fan unit 21. Furthermore, Figure 2 shows a first fan 23 positioned below a front fan unit (not shown, see Figure 3) and a vacuum belt feeder 30.

[0031] The sheet feeding device 1 shown in Figure 2 further comprises a flow path 24. The flow path 24 is located between the first fan 23 and the front blower unit. The flow path 24 is configured to guide one or more airflows from the first fan 23 to the front blower unit.

[0032] The sheet feeding device 1 includes a heating unit 40. The heating unit 40 is located in the flow path 24 and is configured to heat one or more airflows supplied to the front blower unit by the first fan 23. The heating unit 40 may include at least one resistance wire configured to generate heat. The heating unit 40 shown in Figure 2 is located on the same side of the sheet feeding device 1 as the front blower unit 23.

[0033] Figure 3 shows a side view of a sheet feeding device 1 according to an exemplary embodiment of the present disclosure. Note that Figure 3 has the same features, elements, and / or functions as shown in Figures 1 and 2 and described in the related text. Therefore, for further understanding, please also refer to Figures 1 and 2 and their related descriptions.

[0034] The sheet feeding device 1 includes a heating unit 40 located below the front blower unit 22, and therefore on the same side of the sheet feeding device 1. The heating unit 40 may be connected between one or more first fans of the sheet feeding device 1 (not shown, see Figures 1, 2, and 4) and the front blower unit 22. Furthermore, the sheet feeding device 1 may include one or more flow paths (not shown, see Figures 2 and 4). Furthermore, the heating unit 40 may be located within one or more flow paths or may form part of one or more flow paths.

[0035] Figure 4 shows a cross-sectional view of a sheet feeding device 1 according to an exemplary embodiment of the present disclosure. Note that Figure 4 has the same features, elements, and / or functions as shown in Figures 1 to 3 and described in the related text. Therefore, for further understanding, please also refer to Figures 1 to 3 and their related descriptions.

[0036] Figure 4 shows a portion of the sheet feeder 1 in which the sheet stacks 5 are located. The sheet stacks 5 are positioned on a storage surface (not shown) of the sheet feeder 1, which is adapted to move vertically, and it should be understood that this is how the sheet stacks 5 are moved vertically.

[0037] The sheet feeding device 1 includes a front blower unit 22 configured to receive one or more airflows from a first fan (not shown, see Figures 1, 2, and 3) as indicated by arrows in Figure 4, and to direct one or more airflows toward the upper region 12 of the sheet feeding device 1 in order to levitate multiple upper sheets 5b, 5a of the sheet bundle 5 within the upper region 12.

[0038] The vacuum belt feeder 30 is positioned above the front blower unit 22 and the sheet bundle 5, and is configured to grasp and feed out the uppermost sheet 5b of the multiple floating uppermost sheets 5a and 5b.

[0039] The sheet feeding device 1 further comprises a flow path 24. One end of the flow path 24 is connected to the front blower unit 22. The other end of the flow path 24 (not shown) may be connected to a first fan (not shown; see Figures 1, 2, and 3).

[0040] The sheet feeding device 1 further comprises a heating unit 40. The heating unit 40 is located within the flow path 24. The heating unit 40 is configured to heat one or more airflows flowing through the flow path 24. The heating unit 40 shown in Figure 4 comprises a resistance wire 41. The resistance wire 41 is arranged along a coiled or zigzag path and thereby extends along and across the paths of one or more airflows. The heating unit 40 may comprise or be connected to a power source (not shown) configured to supply electrical energy to the heating unit 40. This disclosure is not limited to the heating unit 40 as shown in Figure 2, and it should be understood that the heating unit 40 may, as an alternative, comprise an alternative heat source such as a conduit or container containing a heated fluid and / or a radiator.

[0041] While the present invention has been illustrated in the accompanying drawings and the foregoing description, such illustrations should be considered illustrative or exemplary and not limiting, and the present invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments may be understood and practiced by those skilled in the art when carrying out the claimed invention, by reference to the drawings, this disclosure, and the accompanying claims. In the accompanying claims, the term “~ comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude the plural. The mere fact that certain means are described in different dependent claims does not imply that combinations of these means cannot be used advantageously. None of the reference numerals in the claims should be construed as limiting.

[0042] The following provides a numbered list of embodiments of the concept of the present invention. However, the scope of protection is defined by the appended claims.

[0043] [List of numbered configurations] 1. Sheet feeding device (1), A storage surface (11) for a bundle of sheets (5), wherein the storage surface has a front edge (11a), a rear edge (11b), and a first side edge (11c) and a second side edge (11d), and is adapted to move vertically between a lower position and an upper position. A blower device, A plurality of side blower units (21) are provided along the first side edge (11c) and the second side edge (11d) of the storage surface, and a front blower unit (22) is provided along the front edge of the storage surface, At least one fan (23) configured to supply one or more airflows (3) to each of the side blower units and the front blower unit, Here, the plurality of side blower units and the front blower unit are configured to guide one or more airflows toward the upper region (12) of the sheet feeding device in order to levitate the plurality of upper sheets (5a) of the sheet bundle (5). A blower device equipped with, A vacuum belt feeder (30) is configured to grasp and feed out the uppermost sheet (5b) of the plurality of floating sheets (5a), Equipped with, The aforementioned blower device, A heating unit (40) is positioned between the first fan (23) of the at least one fan and the front blower unit, and is configured to heat the one or more airflows supplied to the front blower unit by the first fan. A sheet feeding device (1) further comprising the following: 2. The sheet feeding device (1) according to embodiment 1, wherein the first blower unit is further configured to guide one or more airflows in a direction substantially perpendicular to the leading edge. 3. Further comprising a flow path (24) configured to guide the airflow from the first fan to the front blower unit, Here, the heating unit is located within the flow path. A sheet feeding device (1) according to embodiment 1 or 2. 4. The heating unit comprises at least one resistance wire (41) configured to generate heat, and the heating unit is further configured to heat one or more airflows supplied to the front blower unit via the at least one resistance wire. A sheet feeding device (1) according to any one of the embodiments 1 to 3. 5. The sheet feeding device (1) according to embodiment 4, wherein the resistance wire of at least one of the resistance wires extends along and / or across the path of one or more airflows supplied to the front blower unit by the first fan. 6. The sheet feeding device (1) according to embodiment 5, wherein at least a portion of the at least one resistance wire is arranged along a coiled or wound path. 7. The blower device is A second heating unit (40) is positioned between the second fan of the at least one fan and the front blower unit, and is configured to heat the one or more airflows supplied to the front blower unit by the second fan. A sheet feeding device (1) according to any one of embodiments 1 to 6, further comprising the above. 8. The blower device is A side heating unit (40) is positioned between a third fan of the at least one fan and a side blower unit of the plurality of side blower units, and is configured to heat the one or more airflows supplied to the side blower unit by the third fan. A sheet feeding device (1) according to any one of embodiments 1 to 7, further comprising: 9. The sheet feeding device further comprises a sensor unit configured to measure the humidity and / or temperature of at least one of the air inside the sheet feeding device and the ambient air, Here, the sheet feeding device is further configured to adjust the amount of air supplied by the at least one fan and / or the amount of heat generated by the heating unit based on the measured humidity and / or temperature. A sheet feeding device (1) according to any one of embodiments 1 to 8.

Claims

1. Sheet feeding device (1), A storage surface (11) for a bundle of sheets (5), wherein the storage surface has a front edge (11a), a rear edge (11b), and a first side edge (11c) and a second side edge (11d), and is adapted to move vertically between a lower position and an upper position. A blower device, A plurality of side blower units (21) provided along the first side edge (11c) and the second side edge (11d) of the storage surface, and a front blower unit (22) provided along the front edge of the storage surface, At least one fan (23) configured to supply one or more airflows (3) to each of the side blower units and the front blower unit, Here, the plurality of side blower units and the front blower unit are configured to guide one or more airflows toward the upper region (12) of the sheet feeding device in order to levitate the plurality of upper sheets (5a) of the sheet bundle (5). A blower device equipped with, A vacuum belt feeder (30) is configured to grasp and feed out the uppermost sheet (5b) of the plurality of floating sheets (5a), Equipped with, The aforementioned blower device, A heating unit (40) is positioned between the first fan (23) of the at least one fan and the front blower unit, and is configured to heat the one or more airflows supplied to the front blower unit by the first fan, A third fan on the first side edge (11c) side of the at least one fan and a side blower unit provided along the first side edge (11c) of the plurality of side blower units, and at least one side heating unit (40) on the first side edge (11c) side, configured to heat the one or more airflows supplied to the side blower unit provided along the first side edge (11c) by the third fan on the first side edge (11c) side, A third fan on the second side edge (11d) side of the at least one fan and a side blower unit provided along the second side edge (11d) of the plurality of side blower units, and at least one side heating unit (40) on the second side edge (11d) side, configured to heat the one or more airflows supplied to the side blower unit provided along the second side edge (11d) by the third fan on the second side edge (11d) side, A sheet feeding device (1) further comprising the following:

2. The sheet feeding device (1) according to claim 1, wherein the front blower unit is further configured to guide one or more airflows in a direction substantially perpendicular to the leading edge.

3. The system further includes a flow path (24) configured to guide the airflow from the first fan to the front blower unit, Here, the heating unit is located within the flow path. The sheet feeding device (1) according to claim 1 or 2.

4. The heating unit comprises at least one resistance wire (41) configured to generate heat, and the heating unit is further configured to heat one or more airflows supplied to the front blower unit via the at least one resistance wire. The sheet feeding device (1) according to claim 1 or 2.

5. The sheet feeding device (1) according to claim 4, wherein the resistance wire of at least one of the resistance wires extends along and / or across the path of the one or more airflows supplied to the front blower unit by the first fan.

6. The sheet feeding device (1) according to claim 5, wherein at least a portion of the resistance wires among the at least one resistance wires is arranged along a coiled or wound path.

7. The aforementioned blower device is A second heating unit (40) is positioned between the second fan of the at least one fan and the front blower unit, and is configured to heat the one or more airflows supplied to the front blower unit by the second fan. A sheet feeding device (1) according to claim 1 or 2, further comprising the above.

8. The sheet feeding device further comprises a sensor unit configured to measure the humidity and / or temperature of at least one of the air inside the sheet feeding device and the ambient air, Here, the sheet feeding device is further configured to adjust the amount of air supplied by the at least one fan and / or the amount of heat generated by the heating unit based on the measured humidity and / or temperature. The sheet feeding device (1) according to claim 1 or 2.

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