spiral conveyor

Abstract

This allows for a simpler mechanism for driving the conveyed objects, resulting in a spiral conveyor with excellent maintainability. [Solution] The spiral conveyor comprises a plurality of drive rollers (20) arranged in a row along the conveying path, an outer peripheral driven roller (30), an inner peripheral driven roller (10), and one or more curved chains (23) stretched along the conveying path that drive a portion of the plurality of drive rollers together.

Description

[Technical Field]

[0001] The present invention relates to a spiral conveyor. [Background Art]

[0002] A spiral conveyor that conveys objects to be conveyed in the vertical direction is known. The spiral conveyor has a spiral conveying path, and can achieve vertical conveyance of objects to be conveyed with a device configuration having a small footprint. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] US Patent Publication No. 2017 / 0291770 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2003-72926 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] The conventional spiral conveyor of Patent Document 1 conveys objects to be conveyed placed on an endless belt laid along a spiral conveying path. However, the mechanism for driving the object to be conveyed is complicated, and replacement of such an endless belt requires large-scale work, resulting in a problem in maintainability of the apparatus.

[0005] The conventional spiral conveyor of Patent Document 2 includes a large number of elongated rollers arranged along a spiral conveying path. By sequentially transmitting driving force via belts stretched between adjacent rollers, the plurality of rollers are rotationally driven collectively, and the object to be conveyed is driven in the conveying direction. However, a belt is provided between every two adjacent rollers, which requires maintenance for a large number of belts, resulting in a problem in maintainability of the apparatus.

[0006] In view of the above issues, one aspect of this disclosure aims to realize a spiral conveyor with a simple mechanism for driving objects to be conveyed and excellent maintainability. [Means for solving the problem]

[0007] To solve the above problems, one aspect of the present disclosure is a spiral conveyor equipped with a spiral conveying path for transporting an object to be transported, comprising: a plurality of drive rollers arranged in a row along the conveying path that contact the object to be transported from below and drive the object to be transported in the transporting direction; a plurality of outer peripheral driven rollers arranged in a row along the conveying path on the outer circumference side of the drive rollers; a plurality of inner peripheral driven rollers arranged in a row along the conveying path on the inner circumference side of the drive rollers; and one or more curved chains stretched along the conveying path that drive a portion of the plurality of drive rollers together. [Effects of the Invention]

[0008] According to one aspect of this disclosure, the mechanism for driving the conveyed object can be configured simply, and a spiral conveyor with excellent maintainability can be realized. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing an overview of a spiral conveyor according to Embodiment 1 of the present disclosure. [Figure 2] This figure illustrates the configuration of a spiral conveyor according to Embodiment 1 of the present disclosure, and is a plan view showing one of the multiple units that make up the spiral conveyor. [Figure 3] This is a front view of the above unit. [Figure 4] This is a rear view of the above unit. [Figure 5] This is a schematic diagram illustrating the drive mechanism that drives the drive roller in the above unit. [Figure 6] This diagram illustrates how the first tray, which is the object to be transported by the spiral conveyor, is transported. The first tray is shown in conjunction with the plan view of the above unit. [Figure 7] This diagram illustrates how the second tray, which is the object to be transported by the spiral conveyor, is transported. The second tray is shown in conjunction with the plan view of the above unit. [Figure 8] This is a schematic diagram illustrating an example of how the first tray is transported by a spiral conveyor. [Figure 9] This is a schematic diagram illustrating a different example from Figure 8, showing the state in which the first tray is transported by a spiral conveyor. [Figure 10] This diagram shows the configuration of the outer peripheral driven rollers of a spiral conveyor according to Embodiment 2 of the present disclosure, viewed from directions perpendicular to the vertical and radial directions. [Figure 11] This figure illustrates the configuration of a spiral conveyor according to Embodiment 3 of the present disclosure, and is a plan view showing one of the multiple units that make up the spiral conveyor. [Modes for carrying out the invention]

[0010] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts may be denoted by the same reference numerals and the description will not be repeated. The following description is an example of a spiral conveyor according to the present disclosure.

[0011] [Embodiment 1] <Overview of spiral conveyors> Figure 1 is a schematic diagram showing the configuration of the main parts of the spiral conveyor 1 according to Embodiment 1. Figure 1 shows only the main parts of the spiral conveyor 1, and the display of members has been omitted as appropriate, including the display of columns and other support members for the spiral conveyor 1 to stand on its own.

[0012] The spiral conveyor 1 is a spirally shaped conveyor that transports goods 91 placed on trays 90 between an upper conveyor 80a, which is shown by a dashed line in Figure 1, and a lower conveyor 80b, which is positioned lower than the upper conveyor 80a. The tray 90 is an example of a "container" in the claims.

[0013] The tray 90 or the tray 90 loaded with luggage 91 (hereinafter referred to as the tray 90, etc.) is an example of the conveyed object in Embodiment 1. That is, the conveyed object of the spiral conveyor 1 may be a container loaded with luggage 91. The spiral conveyor 1 according to Embodiment 1, which conveys such conveyed objects, can be applied to, for example, a conveying system that conveys checked baggage at an airport.

[0014] In the description, the XYZ coordinate system is defined as follows. The direction parallel to the vertical line is defined as the Z-axis direction, with upward as the positive direction of the Z-axis direction and downward as the negative direction. The X-axis direction and the Y-axis direction are parallel to the horizontal plane. The central axis O of the spiral shape that constitutes the spiral conveyor 1 is parallel to the Z-axis. Let R be the symbol indicating the radial direction of the spiral shape. The radial direction (R direction) is the extending direction of a straight line that passes through the central axis O and is orthogonal to the central axis O. The radial direction (R direction) is parallel to the horizontal plane and orthogonal to the Z-axis direction. In the R direction, the direction away from the central axis is defined as the positive direction of the R direction.

[0015] In FIG. 1, guides 81a that guide the tray 90 conveyed by the upper conveyor 80a and are provided on both sides of the conveying path of the upper conveyor 80a are also shown by broken lines. In addition, guides 81b that guide the tray 90 conveyed by the lower conveyor 80b and are provided on both sides of the conveying path of the lower conveyor 80b are also shown by broken lines.

[0016] Similar to these conveyors, the spiral conveyor 1 includes an inner peripheral guide 40 and an outer peripheral guide 50 that guide the conveyed tray 90 and are provided on both sides of the conveying path 100 of the spiral conveyor 1. Therefore, the area sandwiched between the inner peripheral guide 40 and the outer peripheral guide 50 corresponds to the conveying path 100 of the spiral conveyor 1. In the entire spiral conveyor 1, each of the inner peripheral guide 40 itself and the outer peripheral guide 50 itself has a spiral shape. More specifically, each of the inner peripheral guide 40 and the outer peripheral guide 50 is a belt-shaped member having a width in the vertical direction (Z-axis direction).

[0017] The spiral conveyor 1 is a roller conveyor that supports objects to be conveyed, such as trays 90, with a large number of rollers and drives the objects to be conveyed in the conveying direction. The spiral conveyor 1 is equipped with an inner frame 11, a central frame 21, and an outer frame 31 that fix and support these rollers.

[0018] In the spiral conveyor 1 as a whole, the inner circumferential frame 11, the central frame 21, and the outer circumferential frame 31 are all spiral in shape. More specifically, the inner circumferential frame 11, the central frame 21, and the outer circumferential frame 31 are each strip-shaped members with width in the vertical direction (Z-axis direction).

[0019] In the following description of Embodiment 1, the spiral conveyor 1 will be specifically described using the example of conveying trays 90 etc. that have been transported from the upper conveyor 80a toward the lower conveyor 80b. However, the spiral conveyor 1 may also convey trays 90 etc. that have been transported from the lower conveyor 80b toward the upper conveyor 80a, or it may be configured so that the direction of transport can be switched.

[0020] <Units that make up a spiral conveyor> The spiral conveyor 1 is composed of multiple connected units 1a, each responsible for a portion of the spiral conveyor 1. Figure 2 is a plan view of such a unit 1a, corresponding to a view of the unit 1a from the positive Z-direction. Figure 3 is a front view of the unit 1a, corresponding to a view of the unit 1a from the positive Y-axis direction. Figure 4 is a rear view of the unit 1a, corresponding to a view of the unit 1a from the negative Y-axis direction.

[0021] As shown in Figure 2, in a specific example of Embodiment 1, unit 1a is responsible for a 90° circumferential portion of the conveying path 100 of the spiral conveyor 1. In Figure 2, the symbol ω represents the circumferential angle that unit 1a is responsible for. Therefore, the spiral conveyor 1, which has a spiral shape and makes three turns around the central axis O as a specific example shown in Figure 1, is constructed by connecting 12 units 1a along the conveying path 100. Note that the number of connected units 1a in the spiral conveyor 1 is just one example, and the spiral conveyor 1 of this disclosure may be constructed by connecting any number of units 1a. Furthermore, the circumferential angle ω that unit 1a is responsible for is not limited to 90°, but may be, for example, 60°, 120°, 180°, or any other arbitrary angle.

[0022] Unit 1a comprises an inner circumferential frame 11, a central frame 21, an outer circumferential frame 31, an inner circumferential guide 40, an inner circumferential guide fixing device 41, an outer circumferential guide 50, an outer circumferential guide fixing device 51, a pair of connecting plates 61, and a connecting plate 62. Unit 1a also comprises an inner circumferential driven roller 10, a drive roller 20, an outer circumferential driven roller 30, and a drive mechanism for driving the drive roller 20.

[0023] Unit 1a comprises the aforementioned inner circumferential frame 11, central frame 21, and outer circumferential frame 31, each extending 90° in the circumferential direction along the transport path 100. In the transport path 100, the inner circumferential frame 11 is positioned closer to the inner circumference, and the outer circumferential frame 31 is positioned closer to the outer circumference. The central frame 21 is positioned along the transport path 100 between the inner circumferential frame 11 and the outer circumferential frame 31.

[0024] At the upstream end of the transport path 100 of unit 1a, the inner circumferential frame 11, the central frame 21, and the outer circumferential frame 31 are fixed to each other via a connecting plate 61 at the upstream end. In other words, the connecting plate 61 at the upstream end is connected and fixed to the inner circumferential frame 11, the central frame 21, and the outer circumferential frame 31, respectively, at that upstream end.

[0025] Furthermore, at the downstream end of the transport path 100 of unit 1a, the inner circumferential frame 11, the central frame 21, and the outer circumferential frame 31 are fixed to each other via the connecting plate 61 at the downstream end. In other words, the connecting plate 61 at the downstream end is connected and fixed to the inner circumferential frame 11, the central frame 21, and the outer circumferential frame 31, respectively, at that downstream end.

[0026] Each connecting plate 61 is plate-shaped and is joined to the inner circumferential frame 11, the central frame 21, and the outer circumferential frame 31 at their respective connection points, perpendicular to each other. The connecting plates 61 are also used to connect adjacent units 1a along the transport path 100. For example, the connecting plates 61 of each of these units 1a may be bolted together as appropriate to connect the units 1a.

[0027] In the transport path 100 of unit 1a, connecting plates 62 are also provided to fix the inner circumferential frame 11, the central frame 21, and the outer circumferential frame 31 to each other. The connecting plates 62 are plate-shaped and are joined to the inner circumferential frame 11, the central frame 21, and the outer circumferential frame 31 at their respective connection points, for example, perpendicular to each of them. However, the connecting plates 62 may be joined to each of them at an angle other than 90°, rather than perpendicular.

[0028] The skeletal portion of unit 1a, that is, the substantial main body of unit 1a, is formed by the inner circumferential frame 11, the central frame 21, the outer circumferential frame 31, and connecting plates 61 and 62 that fix these relative to each other. An inner circumferential guide 40, positioned on its inner circumferential side (negative side in the R direction), is further fixed to the inner circumferential frame 11 via a plurality of inner circumferential guide fixing devices 41. An outer circumferential guide 50, positioned on its outer circumferential side (positive side in the R direction), is further fixed to the outer circumferential frame 31 via a plurality of outer circumferential guide fixing devices 51.

[0029] <Roller arrangement, drive mechanism> Multiple drive rollers 20 are arranged at equal pitches on the central frame 21. In other words, multiple drive rollers 20 are arranged in a row along the conveying path 100 in unit 1a and thus in the spiral conveyor 1. The drive rollers 20 contact the tray 90 (object to be conveyed) from below and drive the tray 90 in the conveying direction.

[0030] Multiple inner-circumferential driven rollers 10 are arranged at equal pitches on the inner-circumferential frame 11. In other words, in unit 1a and thus the spiral conveyor 1, the inner-circumferential driven rollers 10 are arranged in rows along the conveying path 100, on the inner circumference side of the drive rollers 20. In addition, multiple outer-circumferential driven rollers 30 are arranged at equal pitches on the outer-circumferential frame 31. In other words, in unit 1a and thus the spiral conveyor 1, the outer-circumferential driven rollers 30 are arranged in rows along the conveying path 100, on the outer circumference side of the drive rollers 20.

[0031] In a specific example of Embodiment 1, six of each of the inner-circumferential driven roller 10, drive roller 20, and outer-circumferential driven roller 30 are provided in a unit 1a that is responsible for 90° of the circumferential direction of the conveying path 100. In other words, each of the inner-circumferential driven roller 10, drive roller 20, and outer-circumferential driven roller 30 is arranged along the conveying path 100 at a 15° pitch in the circumferential direction.

[0032] Multiple drive rollers 20 provided on unit 1a, in the specific example of Embodiment 1, six drive rollers 20, are driven collectively by multiple curved chains 23 suspended along the central frame 21. Figure 2 schematically shows such curved chains 23 with dashed lines. Note that there may be one or more curved chains 23 for driving the six drive rollers 20 together.

[0033] In other words, the spiral conveyor 1 is equipped with one or more curved chains 23 stretched along the conveying path 100, which drive some of the multiple drive rollers 20 of the spiral conveyor 1 together. The connecting plate 62 has an opening, and the curved chains 23 are stretched so as to pass through this opening.

[0034] Next, using Figure 5, we will explain the drive mechanism that drives multiple (six) drive rollers 20 in unit 1a, which correspond to some of the multiple drive rollers 20 provided in the spiral conveyor 1. Figure 5 is a schematic diagram for explaining the drive mechanism in unit 1a shown in Figure 2.

[0035] The drive mechanism includes a motor 28, a gearbox 27, a shaft 26, and a drive sprocket 24. The drive mechanism also includes a driven sprocket 22 that rotates integrally with each drive roller 20. More specifically, two such driven sprockets 22 are fixedly connected to each drive roller 20.

[0036] The rotational driving force generated by the motor 28 is transmitted to the shaft 26 via the gearbox 27, causing the drive sprocket 24, which rotates integrally with the shaft 26, to rotate. An endless curved chain 231, which is one of the curved chains 23, is stretched between the drive sprocket 24 and one of the driven sprockets 22, which is fixedly connected to the drive roller 20 closest to the shaft 26. In this way, the rotational driving force generated by the motor 28 is transmitted to the drive roller 20 closest to the shaft 26.

[0037] Furthermore, an endless curved chain 232 is stretched between the other end of the driven sprocket 22 fixedly connected to the drive roller 20 closest to the shaft 26 and the other end of the driven sprocket 22 fixedly connected to the drive roller 20 second closest to the shaft 26. In addition, an endless curved chain 233 is stretched between the other end of the driven sprocket 22 fixedly connected to the drive roller 20 second closest to the shaft 26 and the other end of the driven sprocket 22 fixedly connected to the drive roller 20 third closest to the shaft 26.

[0038] Similarly, by sequentially arranging the curved chains 234 to 236, the rotational driving force generated by the motor 28 is transmitted from the shaft 26 to the drive roller 20, which is furthest away, via the curved chains 231 to 236. Note that the notation "curved chain 23" refers to the collective term for each of the curved chains 231 to 236, and does not distinguish between the individual curved chains 231 to 236. A free sprocket 25 for adjusting the tension of the chain may be appropriately provided in the circumference of the curved chain 23, for example, as shown in Figure 5.

[0039] As is clear from the above explanation, for the drive roller 20 furthest from the shaft 26, one of the two driven sprockets 22 fixedly connected to each drive roller 20 may be omitted. In this way, the multiple drive rollers 20 provided on the unit 1a are driven together by a drive mechanism having a single motor 28. The tray 90 on which the cargo 91 is placed is transported as the drive rollers 20 come into contact with the tray 90 from below.

[0040] The curved chains 231-236, which transmit driving force to each drive roller 20, are arranged in a curved direction along the spiral conveying path 100, as shown in Figure 2. Curved chains with this function are also called curved chains, and are commercially available and well-known products, so a detailed explanation will be omitted.

[0041] As described above, the spiral conveyor 1 according to Embodiment 1 is configured as a roller conveyor equipped with a large number of rollers (inner circumference driven rollers 10, drive rollers 20, and outer circumference driven rollers 30). In such a roller conveyor spiral conveyor 1, the multiple drive rollers 20 are driven collectively by a curved chain 23.

[0042] Furthermore, in the spiral conveyor 1, the driving force is transmitted by each curved chain 23 being arranged in a curved manner along the conveying path 100, corresponding to the drive rollers 20 which are arranged along the conveying path 100 while changing direction, thus enabling a simple conveying mechanism.

[0043] Furthermore, compared to mechanisms that transmit driving force by belts, the drive mechanism in the spiral conveyor 1 has superior durability in its function of transmitting driving force. When a drive mechanism has many belts, as in Patent Document 2, maintenance to deal with belt deterioration requires considerable effort. However, the drive mechanism of the spiral conveyor 1, which is driven by a chain, is far more durable in comparison, and therefore the spiral conveyor 1 has superior maintainability.

[0044] Furthermore, the spiral conveyor 1 according to Embodiment 1 is composed of multiple connected units 1a, each unit responsible for a portion of the conveying path 100, and each unit 1a has a curved chain 23 and a plurality of drive rollers 20 driven by the curved chain 23. Thus, each unit 1a connected in the direction of the conveying path is provided with a drive mechanism for driving the drive rollers 20, and the drive mechanisms of each unit 1a are independent of each other.

[0045] Therefore, compared to conventional technology using an endless belt laid collectively along a spiral conveying path as described in Patent Document 1, the conveying mechanism is not large-scale, repairs are easy if a problem occurs with the conveying mechanism, and the device has excellent maintainability. Furthermore, the spiral conveyor 1 can be assembled at the installation site by connecting units 1a, making installation work easy.

[0046] The spiral conveyor 1 according to Embodiment 1 can be adapted to conveying at various height differences by changing the number of connected units 1a. Furthermore, regardless of the set height difference, the area that each unit 1a is responsible for in the conveying path of the spiral conveyor 1 remains constant, thus enabling stable conveying.

[0047] In the specific example shown in Figure 2, etc., of the drive mechanism for driving multiple drive rollers 20 in unit 1a together, an endless curved chain 23 is placed around each adjacent drive roller 20, and the drive mechanism is composed of six endless curved chains 23. However, the number of endless curved chains 23 in the drive mechanism for driving multiple (six) drive rollers 20 together may be other than this number. That is, one curved chain 23 may be configured to circle around any number of drive rollers 20 other than 2.

[0048] Alternatively, as described above, the curved chain 23 may be singular. In the above description, the motor 28 and gearbox 27 are provided on the outside of the outer peripheral frame 31 of unit 1a, but the configuration is not limited to this, and they may be provided on the inside of the inner peripheral frame 11. Alternatively, the motor 28 and gearbox 27 may be provided near the inner peripheral frame 11, near the central frame 21, or near the outer peripheral frame 31.

[0049] Furthermore, in the above explanation, unit 1a was configured such that the shaft 26 is a different axis from the axis of the drive roller 20. However, the axis of one of the multiple drive rollers 20 may be shared with the shaft 26. In this case, the sprocket provided on the axis of that drive roller 20 becomes the drive sprocket 24.

[0050] <Transportation methods> Figure 6 is a diagram illustrating the situation in which the spiral conveyor 1 transports objects, and is a plan view corresponding to Figure 2, which shows one unit 1a of the spiral conveyor 1. In Figure 6, a first tray 90a, which is an example of a tray 90, is shown on which luggage 91a, such as a suitcase, is placed.

[0051] Figure 7 is also a diagram illustrating the situation in which the spiral conveyor 1 is transporting another object, and is a plan view corresponding to Figure 2, which shows one unit 1a of the spiral conveyor 1. In Figure 7, as an example of a tray 90, a second tray 90b is shown, which has a larger dimension in the transport direction than the first tray 90a. An example in which a long package 91b is placed on the second tray 90b is also shown.

[0052] As shown in Figures 6 and 7, the spiral conveyor 1 is capable of transporting containers (first tray 90a, second tray 90b) with different lengths in the transport direction. Therefore, long or large packages can be transported using the relatively longer second tray 90b, while smaller packages can be transported using the relatively shorter first tray 90a, thereby increasing the overall efficiency of transport.

[0053] In both cases, the spiral conveyor 1 is configured such that at least two drive rollers contact the bottom surface of the container (first tray 90a, second tray 90b). That is, in the spiral conveyor 1 or unit 1a, the distance between adjacent drive rollers 20 is configured to be smaller than the length in the container's transport direction. This configuration allows the spiral conveyor 1 to reliably transport the containers (first tray 90a, second tray 90b) using the drive rollers 20.

[0054] Figure 8 is a schematic diagram showing only the essential parts when viewed from directions perpendicular to the vertical direction (Z-axis direction) and the radial direction (R-direction), illustrating an example of the situation when an object is being transported. As shown in the figure, the drive roller 20 is positioned closer to the outer circumference than the center of the transport path 100. In other words, the distance D1 between the center of the drive roller 20 in the width direction (coinciding with the R-direction) and the inner circumference guide 40 is greater than the distance D2 between the center of the drive roller 20 in the width direction and the outer circumference guide 50. The sum of distances D1 and D2 corresponds to the width of the transport path 100.

[0055] Furthermore, as shown in Figure 8, the top end of the drive roller 20 is located higher than the top ends of both the outer peripheral driven roller 30 and the inner peripheral driven roller 10, which are located in the radial direction (R direction) of the conveying path 100 relative to the drive roller 20. Here, the top end refers to the upper side in the vertical direction, that is, the end on the positive side in the Z-axis direction.

[0056] As shown in Figures 6 to 8, the tray 90 is basically transported by the spiral conveyor 1 with the tray positioned towards the outer circumference (positive R direction). This is because the tray 90 moves outward from the transport path 100 due to inertia during movement. In this case, the outer circumference side of the tray 90 contacts the outer circumference guide 50 as the tray 90 is transported.

[0057] Furthermore, as described above, since the top of the drive roller 20 is at the highest position, the bottom surface of the tray 90 comes into contact with the drive roller 20 and the outer peripheral driven roller 30, causing the bottom surface of the tray 90 to be slightly tilted from horizontal. In this case, the bottom surface of the tray 90 is lifted away from the inner peripheral driven roller 10.

[0058] On the other hand, during transport on the spiral conveyor 1, the tray 90 may temporarily shift towards the inner circumference. Also, when the load 91 on the tray 90 is biased towards the inner circumference, the tray 90 may tend to shift towards the inner circumference. In these cases, as shown in Figure 9, the bottom surface of the tray 90 comes into contact with the drive roller 20 and the inner circumference driven roller 10, and the bottom surface of the tray 90 becomes slightly tilted in the opposite direction to the basic transport state described above.

[0059] The contact surface of the drive roller 20 with respect to the object being conveyed, that is, the outer circumferential surface of the roller itself, has a cross-sectional shape that bulges in the center in the radial direction (R direction) of the conveying path 100. Therefore, regardless of which direction the bottom surface of the object being conveyed is tilted in the radial direction (R direction), the contact surface of the drive roller 20 can reliably contact the object being conveyed and push the object out.

[0060] In both the case shown in Figure 8 and the case shown in Figure 9, the drive roller 20, whose top end is at the highest position, contacts the bottom surface of the tray 90, and therefore, a propulsive force in the conveying direction from the drive roller 20 is always applied to the tray 90. Thus, according to Embodiment 1, a spiral conveyor can be realized that can stably convey objects whether the objects to be conveyed are located closer to the outer circumference or closer to the inner circumference.

[0061] Furthermore, as described above, since the drive roller 20 is positioned closer to the outer edge than the center of the conveying path 100, it is possible for it to contact the bottom surface of the tray 90 near the center in the width direction of the tray 90. Therefore, in the basic conveying state, which is a normal conveying state, the driving force from the drive roller 20 is efficiently supplied to the tray 90 as a propulsive force in the conveying direction.

[0062] [Embodiment 2] Embodiment 2 of this disclosure will be described below. For the sake of clarity, components having the same function as those described in Embodiment 1 will be denoted by the same reference numerals, and their descriptions will not be repeated.

[0063] Figure 10 is a view from directions perpendicular to the vertical direction (Z-axis direction) and the radial direction (R-direction) to illustrate the configuration of the outer peripheral driven roller in Embodiment 2. The outer peripheral driven roller 30 will be described below based on Figure 10, but a similar structure may be provided for the inner peripheral driven roller 10.

[0064] In the spiral conveyor unit 1a according to Embodiment 2, the outer peripheral driven roller 30 rotates relative to the roller shaft 32, and the roller shaft 32 is a fixed shaft. The axial direction of the roller shaft 32 is approximately parallel to the radial direction (R direction). Near the end of the roller shaft 32 that is spaced apart from the outer peripheral driven roller 30, the fixed shaft roller shaft 32 is pivotably fixed to the connecting member 33 by a pivot shaft 34.

[0065] The axial direction of the pivot shaft 34 is approximately perpendicular to the vertical direction (Z-axis direction) and the radial direction (R-direction), respectively. The connecting member 33 is fixed to the outer peripheral frame 31 and is immovable. With this configuration, the outer peripheral driven roller 30 can move approximately vertically by oscillating on a circle around the pivot shaft 34.

[0066] Furthermore, an elastic member 35, such as a spring, which biases the pivot shaft 34 upward relative to the connecting member 33, is positioned between the connecting member 33 and the pivot shaft 34. In this way, in the unit 1a of the spiral conveyor 1 according to Embodiment 2, the roller shaft 32 of the outer peripheral driven roller 30 is movable in the vertical direction and biased upward. Note that the configuration for making the roller shaft of the inner peripheral driven roller 10 or the outer peripheral driven roller 30 movable in the vertical direction and biased upward is not limited to the above specific example, and any configuration realized by combining known means may be applied.

[0067] According to Embodiment 2, for example, since the roller shaft 32 of the outer peripheral driven roller 30 is movable in the vertical direction and biased upward, in a situation where multiple outer peripheral driven rollers 30 can simultaneously contact the bottom surface of the tray 90, each of the multiple outer peripheral driven rollers 30 can reliably contact the bottom surface of the tray 90.

[0068] [Embodiment 3] As described above in Embodiment 1, the unit may have only one curved chain 23. Figure 11 is a plan view showing a spiral conveyor unit 1b according to Embodiment 3, in which there is one curved chain 23 for driving a plurality of drive rollers 20 provided in the unit.

[0069] The spiral conveyor according to Embodiment 3 is constructed by connecting a plurality of such units 1b. As shown in Figure 11, in each unit 1b, an endless curved chain 23b is stretched across it so as to engage with the drive sprocket 24 and the driven sprockets 22 which are connected to and fixed to each of the drive rollers 20 of the unit 1b, and to rotate around them.

[0070] 〔summary〕 Aspect 1 of the present disclosure is a spiral conveyor having a spiral conveying path for conveying an object to be conveyed, comprising: a plurality of drive rollers arranged in a row along the conveying path that contact the object to be conveyed from below and drive the object to be conveyed in the conveying direction; a plurality of outer peripheral driven rollers arranged in a row along the conveying path on the outer circumference side of the drive rollers; a plurality of inner peripheral driven rollers arranged in a row along the conveying path on the inner circumference side of the drive rollers; and one or more curved chains stretched along the conveying path that drive a portion of the plurality of drive rollers together.

[0071] In the spiral conveyor of Embodiment 2 of the present disclosure, in Embodiment 1, the top end of the drive roller is located higher than the top end of either the outer peripheral driven roller or the inner peripheral driven roller, which are located radially in the conveying path relative to the drive roller.

[0072] In the spiral conveyor of embodiment 3 of the present disclosure, in embodiment 1 or 2, at least one of the outer peripheral driven roller or the inner peripheral driven roller has a roller axis that is movable in the vertical direction and biased upward.

[0073] In the spiral conveyor of embodiment 4 of the present disclosure, in any of embodiments 1 to 3 above, the drive roller is positioned closer to the outer periphery than the center of the conveying path.

[0074] In the spiral conveyor of aspect 5 of the present disclosure, in any of aspects 1 to 4 above, the contact surface of the drive roller with the object to be conveyed has a cross-sectional shape in which the central part in the radial direction of the conveying path is bulging.

[0075] In the spiral conveyor of embodiment 6 of the present disclosure, in any of embodiments 1 to 5 above, the object to be conveyed is a container on which goods are placed.

[0076] In the spiral conveyor of embodiment 7 of the present disclosure, in any of embodiments 1 to 6, the distance between adjacent drive rollers is smaller than the length of the container in the conveying direction.

[0077] The spiral conveyor of embodiment 8 of the present disclosure transports containers having different lengths in the transport direction as objects to be transported, in embodiment 6 above.

[0078] The spiral conveyor of aspect 9 of the present disclosure is configured by connecting a plurality of units that are responsible for a portion of the conveying path, each unit having one or more curved chains that drive a portion of a plurality of the drive rollers together, and a portion of the drive rollers that are driven together by the curved chains, in any of aspects 1 to 8 above.

[0079] The spiral conveyor of aspect 10 of the present disclosure is configured such that, in any of aspects 1 to 9 above, the object to be conveyed is conveyed in a state in which the drive roller and the outer peripheral driven roller are in contact with the bottom surface of the object to be conveyed, and the inner peripheral driven roller is not in contact with the bottom surface of the object to be conveyed.

[0080] The spiral conveyor of embodiment 11 of the present disclosure is configured such that, in any of embodiments 1 to 10, the object to be conveyed is conveyed in such a state that the drive roller and the inner circumferential driven roller are in contact with the bottom surface of the object to be conveyed, while the outer circumferential driven roller is not in contact with the bottom surface of the object to be conveyed.

[0081] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Furthermore, embodiments obtained by appropriately combining the technical means disclosed in each embodiment are also included within the technical scope of the present invention. [Explanation of symbols]

[0082] 1. Spiral conveyor 1a Unit 10 Inner circumference driven roller 11 Inner Circumference Frame 20 drive rollers 21 Central Frame 22 Passed sprocket 23 (231-236, 23b) Curved chain 24 drive sprocket 26 shafts 27 Gearbox 28 Motor 30 Outer peripheral driven roller 31 Outer frame 32 Roller shaft 33 Connecting Member 34. Oscillating axis 35 Elastic members 40 Inner circumference guide 41 Inner circumference guide fixing device 50 Outer edge guide 51 Outer circumference guide fixing device 61, 62 Connecting plate 90 trays 91 Luggage 100 transport paths

Claims

1. A spiral conveyor equipped with a spiral transport path for transporting objects, Multiple drive rollers are arranged in a row along the transport path, which contact the object to be transported from below and drive the object in the transport direction. Multiple outer peripheral driven rollers are arranged in a row along the transport path on the outer circumference side of the drive roller, Multiple inner-circumferential driven rollers are arranged in a row along the transport path on the inner circumference side of the drive roller, A spiral conveyor comprising one or more curved chains stretched along the conveying path, which collectively drive some of the multiple drive rollers.

2. The spiral conveyor according to claim 1, wherein the top end of the drive roller is located higher than the top end of either the outer peripheral driven roller or the inner peripheral driven roller, which are located radially in the conveying path relative to the drive roller.

3. The spiral conveyor according to claim 1, wherein at least one of the outer peripheral driven roller or the inner peripheral driven roller has a roller shaft that is movable in the vertical direction and biased upward.

4. The spiral conveyor according to claim 1, wherein the drive roller is positioned closer to the outer periphery than the center of the conveying path.

5. The spiral conveyor according to any one of claims 1 to 4, wherein the contact surface of the drive roller with the object to be conveyed has a cross-sectional shape in which the central part in the radial direction of the conveying path is bulging.

6. The spiral conveyor according to any one of claims 1 to 4, wherein the object to be conveyed is a container on which cargo is placed.

7. The spiral conveyor according to claim 6, wherein the distance between adjacent drive rollers is less than the length of the container in the conveying direction.

8. The spiral conveyor according to claim 6, which transports containers having different lengths in the transport direction as objects to be transported.

9. A spiral conveyor according to any one of claims 1 to 4, wherein a plurality of units responsible for a portion of the conveying path are connected, each unit having one or more curved chains that drive a portion of a plurality of the drive rollers together, and the portion of the drive rollers that are driven together by the curved chains.

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