U.S. patent application number 10/962574 was filed with the patent office on 2005-04-14 for pallet for transporting goods.
Invention is credited to Nakano, Hiroshi.
Application Number | 20050076816 10/962574 |
Document ID | / |
Family ID | 34419925 |
Filed Date | 2005-04-14 |
United States Patent
Application |
20050076816 |
Kind Code |
A1 |
Nakano, Hiroshi |
April 14, 2005 |
Pallet for transporting goods
Abstract
A planar rectangular pallet 1 comprises fork entries 2 to admit
two forks of a forklift on two sides 1a, 1b (or four sides) thereof
and a through hole 3 penetrating the sides 1a, 1b having the fork
entries 2. The through hole is located between the fork entries 2.
A non-contact IC tag (RFID tag 3) is provided inside the through
hole 3 and in a vicinity of a middle portion in a length direction
of the through hole.
Inventors: |
Nakano, Hiroshi; (Nara,
JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
34419925 |
Appl. No.: |
10/962574 |
Filed: |
October 13, 2004 |
Current U.S.
Class: |
108/51.11 |
Current CPC
Class: |
B65D 2519/00318
20130101; B65D 2519/00343 20130101; B65D 2203/10 20130101; G06K
19/07796 20130101; B65D 2519/00069 20130101; B65D 2519/00278
20130101; G05B 2219/49302 20130101; B65D 2519/00034 20130101; B66F
9/0755 20130101; G06K 19/07758 20130101; B65D 2519/00268 20130101;
B65D 19/0012 20130101; B65D 2519/00288 20130101 |
Class at
Publication: |
108/051.11 |
International
Class: |
B65D 019/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 14, 2003 |
JP |
2003-353754 |
Claims
What is claimed is:
1. A pallet for transporting goods, wherein the pallet is in the
shape of a planar rectangle, the pallet comprising: fork entries to
admit two forks of a forklift, the fork entries being provided on
two opposite sides of the panel; and a through hole penetrating
through the two sides on which the fork entries are provided, the
through hole being located between the fork entries, wherein a
non-contact IC tag is provided inside the through hole and in a
vicinity of a middle portion in a length direction of the through
hole.
2. The pallet according to claim 1, wherein an inner surface of the
through hole is covered with a conductive material.
3. The pallet according to claim 1 or 2, wherein a vertical
cross-section of the through hole has a rectangular shape, and a
length of either side of the rectangular through hole is equal to
or larger than .lambda./2 where .lambda. represents a wavelength of
a frequency used between the non-contact IC tag and an
interrogator.
4. The pallet according to claim 1 or 2, wherein a vertical
cross-section of the through hole has a circular shape, and a
radius of the circular through hole is equal to or larger than
.lambda./3.4 where .lambda. represents a wavelength of a frequency
used between the non-contact IC tag and an interrogator.
5. The pallet according to claim 1 or 2, wherein a vertical
cross-section of the through hole is in the shape of a ridge.
6. The pallet according to claim 1 or 2, wherein a cross-section
area of the through hole is increased from an inner portion of the
pallet toward the sides of the pallet.
7. The pallet according to claim 1 or 2, wherein a through hole is
provided in a vicinity of a middle portion of the pallet, and the
through hole intersects with the through hole penetrating through
the sides and extends vertically with respect to the pallet.
8. The pallet according to claim 3, wherein a cross-section area of
the through hole is increased from an inner portion of the pallet
toward the sides of the pallet.
9. The pallet according to claim 4, wherein a cross-section area of
the through hole is increased from an inner portion of the pallet
toward the sides of the pallet.
10. The pallet according to claim 5, wherein a cross-section area
of the through hole is increased from an inner portion of the
pallet toward the sides of the pallet.
11. The pallet according to claim 3, wherein a through hole is
provided in a vicinity of a middle portion of the pallet, and the
through hole intersects with the through hole penetrating through
the sides and extends vertically with respect to the pallet.
12. The pallet according to claim 4, wherein a through hole is
provided in a vicinity of a middle portion of the pallet, and the
through hole intersects with the through hole penetrating through
the sides and extends vertically with respect to the pallet.
13. The pallet according to claim 5, wherein a through hole is
provided in a vicinity of a middle portion of the pallet, and the
through hole intersects with the through hole penetrating through
the sides and extends vertically with respect to the pallet.
14. The pallet according to claim 6, wherein a through hole is
provided in a vicinity of a middle portion of the pallet, and the
through hole intersects with the through hole penetrating through
the sides and extends vertically with respect to the pallet.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. .sctn.
119(a) on Patent Application No. 2003-324860 filed in Japan on Sep.
17, 2003, the entire contents of which are hereby incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a pallet for transporting
goods and a pallet management system for managing the pallet.
[0004] 2. Description of the Related Art
[0005] Pallets used for goods transportation and the like generally
have the shape of a quadrangle (planar rectangle), and are provided
with fork entries on sides thereof into which the fork of a
forklift is inserted for transportation.
[0006] Examples of the above-described rectangular pallets include,
for example, a two-way entry pallet which has two fork entries,
into which two forks of a forklift can be inserted, on two sides
(two opposite sides of a rectangle) of the sides (four sides) of
the pallet, where the forks can be inserted into the pallet from
two directions; and a four-way entry pallet which has fork entries
on all the sides (four sides) of the pallet, where the forks can be
inserted into the pallet from four directions.
[0007] Pallets used for goods transportation and the like may be
carried in or out along with goods or products to be distributed,
in order to facilitate transportation by a forklift. In this case,
it is necessary to manage pallets which are transported into or out
of a storage.
[0008] Conventionally, pallets which are transported into or out of
a storage are managed by using slips. However, slips are likely to
be lost during transportation in complex distribution pathways, and
it is difficult to be aware of unauthorized use of pallets.
[0009] To avoid this, a management system has been proposed in, for
example, JP 2003-11973A (hereinafter referred to as Patent
Publication 1). In this management system, a PHS terminal or a
positional information transmitting/receiving terminal is mounted
on a pallet for transporting goods. By identifying a base station,
which is receiving an electric wave from the PHS terminal or the
positional information transmitting/receiving terminal, and
calculating a distance from the base station, the current location
of the pallet can be confirmed.
[0010] Another system has been proposed in, for example, JP
2003-36405A (hereinafter referred to as Patent Publication 2). In
this system, information, such as the date and hour of collecting
pallets (rental pallets), the number of collected pallets, or the
like, is transmitted to a manager's terminal via a network, such as
the Internet, bidirectional TV communication or the like, and a
database of pallet information is constructed in a manager's
server.
[0011] However, the system described in Patent Publication 1 is
problematic in that it is difficult to secure a power source for
the PHS terminal or the positional information
transmitting/receiving terminal mounted on a pallet. For example,
if the power of the terminal is 0, communication cannot be
performed. Further, time and effort are required for charging the
terminal. Furthermore, even when the location of a pallet is
identified, it cannot be determined whether the pallet is
effectively used or is missing. The system described in Patent
Publication 2 also is problematic in that the requirement of
entering information, such as the date and hour of collecting
pallets, the number of collected pallets, or the like, is likely to
lead to a situation in which the number of recorded pallets is
inconsistent with the number of pallets which are actually
transported into or out of a storage.
[0012] There is another management system, in which an ID tag is
attached to a pallet and information is read/rewritten from/to the
ID tag.
[0013] However, the antenna of an interrogator and the ID tag
(transponder) need to face each other in order to read/rewrite
information from/to the ID tag attached to the pallet. When a
plurality of ID tags are attached to a pallet, information can be
read from either of the ID tags. However, in order to write
information into the ID tags, the ID tags need to be synchronized
with one another (the ID tags need to have identical information).
It is very difficult to realize this.
[0014] When only one ID tag is attached to a pallet on a side of
the pallet, synchronization with other ID tags is no longer
required. In this case, however, when trying to read the ID tag
attached to the pallet from a side of the pallet opposite to the
side on which the ID tag is attached, the pallet itself is an
obstacle, so that information cannot be read/rewritten from/to the
ID tag.
[0015] A technology for solving the above-described problem has
been disclosed in, for example, JP 2002-240955A (hereinafter
referred to as Patent Publication 3). In this technology, one ID
tag (RF tag) can be detachably attached to a pallet side and the ID
tag can be selectively provided on either one of two sides of the
pallet. Another technology has been disclosed in, for example, JP
H10-250730A (hereinafter referred to as Patent Publication 4). In
this technology, an ID tag having an antenna is disposed along one
diagonal line of a planar rectangular pallet, the antenna being
erected.
[0016] However, in the above-described technology of Patent
Publication 3, the ID tag needs to be attached to a pallet side
that faces the antenna of an interrogator provided on a forklift,
after confirming the location of the antenna. Therefore, the
confirmation of the location of an antenna and the attachment of an
ID tag are additionally required. In the technology of Patent
Publication 4, the gain of the directional characteristics of the
antenna is decreased, so that information may not be correctly
read/rewritten.
SUMMARY OF THE INVENTION
[0017] In order to solve the above-described problems, the present
invention provides a pallet for transporting goods, which has a
non-contact IC tag capable of directly tracking a moving pathway or
the like of a pallet, and in which information can be easily and
reliably read/written from/to the non-contact IC tag by accessing
it from either of the pallet sides (two sides for the two-way entry
type; and four sides for the four-way entry type) on which fork
entries are provided.
[0018] The goods transportation pallet of the present invention is
in the shape of a planar rectangle and is provided with fork
entries to admit two forks of a forklift. The fork entries are
provided on two opposite sides of the pallet. The pallet is also
provided with a through hole penetrating through the pallet from
one to the other of the two sides having the fork entries
(hereinafter also simply referred to as a through hole penetrating
through the two sides). The through hole is located between the
fork entries. A non-contact IC tag is provided inside the through
hole and in the vicinity of the middle in the length direction of
the through hole.
[0019] As described above, the pallet is provided with a through
hole and a non-contact IC tag is placed inside the through hole.
Therefore, the through hole is a kind of transmission pathway to
the non-contact IC tag. A read signal or a rewrite signal
transmitted by the antenna of an interrogator mounted on a forklift
is propagated and transferred through the inside of the through
hole to the non-contact IC tag. Thereby, it is possible to
read/rewrite information from/to the non-contact IC tag from either
of the two sides (or four sides) of the planar rectangular
pallet.
[0020] In addition, a non-contact IC tag may be provided in a
vicinity of a middle portion in a length direction of the through
hole. In this case, information stored in the non-contact IC tag
attached inside the through hole can be read unbiasedly and
reliably from either of the two sides (or four sides) of the
pallet. Also, information can be reliably rewritten.
[0021] In the pallet of the present invention, it is preferable
that an inner surface of the through hole is covered with a
conductive material.
[0022] In the pallet of the present invention, when a cross-section
of the through hole is in the shape of a rectangle, the length of
either side of the rectangular through hole should be equal to or
larger than .lambda./2 where .lambda. represents the wavelength of
a frequency used between the non-contact IC tag and the
interrogator.
[0023] Alternatively, when a cross-section of the through hole is
in the shape of a circle, the radius of the rectangular through
hole should be equal to or larger than .lambda./3.4 where .lambda.
represents the wavelength of a frequency used between the
non-contact IC tag and the interrogator.
[0024] Further, when the through hole has a ridge-shaped
cross-section, the length of a side or the radius of the through
hole can be smaller than when the through hole has a rectangular or
circular cross-section, where comparison is performed using the
same frequency.
[0025] It is also preferable that a cross-section area of the
through hole is increased from an inner portion of the pallet
toward the sides of the pallet.
[0026] In the pallets of the present invention, a through hole may
be provided in a vicinity of a middle portion of the pallet, and
the through hole may intersect with the through hole penetrating
through the sides and extend vertically with respect to the
pallet.
[0027] An example of the non-contact tag attached to the pallet of
the present invention is an RFID tag used in an RFID (Radio
Frequency Identification) system. The non-contact IC tag
(hereinafter referred to as an RFID tag) may store information
about products/goods being transported, information about a truck
which transports products/goods, identification information about a
pallet itself, or the like.
[0028] The pallet of the present invention is provided with a
through hole penetrating through sides of the pallet and a
non-contact IC tag (e.g., an RFID tag, etc.) attached inside the
through hole. Therefore, the through hole is a kind of transmission
pathway to the non-contact IC tag. A read signal or a rewrite
signal transmitted from the antenna of an interrogator mounted on a
forklift is propagated and transferred through the inside of the
through hole to the non-contact IC tag. Therefore, information can
be simply and reliably read/written from/to the non-contact IC tag
from either of the two sides (or four sides) of the planar
rectangular pallet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1A is a front view showing a pallet according to an
embodiment of the present invention. FIG. 1B is a center vertical
cross-sectional view thereof FIG. 1C is a horizontal
cross-sectional view thereof.
[0030] FIG. 2A is a front view showing a pallet according to
another embodiment of the present invention. FIG. 2B is a center
vertical cross-sectional view thereof. FIG. 2C is a horizontal
cross-sectional view thereof.
[0031] FIG. 3A is a front view showing a pallet according to still
another embodiment of the present invention. FIG. 3B is a center
vertical cross-sectional view thereof. FIG. 3C is a horizontal
cross-sectional view thereof.
[0032] FIG. 4A is a front view showing a pallet according to still
another embodiment of the present invention. FIG. 4B is a center
vertical cross-sectional view thereof. FIG. 4C is a horizontal
cross-sectional view thereof.
[0033] FIG. 5A is a front view showing a pallet according to still
another embodiment of the present invention. FIG. 5B is a center
vertical cross-sectional view thereof. FIG. 5C is a horizontal
cross-sectional view thereof.
[0034] FIG. 6A is a front view showing a pallet according to still
another embodiment of the present invention. FIG. 6B is a center
vertical cross-sectional view thereof. FIG. 6C is a horizontal
cross-sectional view thereof.
[0035] FIG. 7 is a perspective view of the pallet of the embodiment
of FIGS. 6A to 6C.
[0036] FIG. 8 is a perspective view showing a stack of the pallets
of the embodiment of FIGS. 6A to 6C.
[0037] FIG. 9A is a front view of a forklift. FIG. 9B is a side
view thereof.
[0038] FIG. 10 is a block diagram showing a basic structure of an
RFID system.
[0039] FIG. 11 is a conceptual diagram showing an exemplary pallet
management system according to an embodiment of the present
invention.
[0040] FIG. 12 is a flowchart showing an exemplary pallet
management system using the pallet of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] Hereinafter, embodiments of the present invention will be
described with reference to accompanying drawings.
Embodiment 1
[0042] FIG. 1A is a front view showing a pallet according to an
embodiment of the present invention. FIG. 1B is a center vertical
cross-sectional view thereof FIG. 1C is a horizontal
cross-sectional view thereof
[0043] A pallet 1 shown in these figures is a resin molded product
in the shape of a planar rectangle. The pallet 1 is provided with
fork entries 2, 2, to admit two forks 101, 101 of a forklift 100
(see FIGS. 9A, 9B). The fork entries 2, 2 are provided on two sides
(two opposite sides of the rectangle) 1a, 1b of the pallet 1. The
forks can be inserted into the pallet 1 in two directions (two-way
entry type). The fork entries 2, 2 are located bilaterally
symmetrically with respect to a center (a center in a width
direction) of the pallet 1.
[0044] The pallet 1 is provided with a through hole 3 which extends
along the center of the pallet 1 and is located between the fork
entries 2, 2. The through hole 3 penetrates through the two sides
1a, 1b on which the fork entries 2, 2 are provided.
[0045] The through hole 3 has a rectangular cross section. A
cross-section area of the through hole 3 is gradually increased
toward the sides 1a, 1b at both ends of the through hole 3. An
inner surface of the through hole 3 is covered with a conductive
material, such as a metal or the like. An RFID tag 4 is attached
inside the through hole 3. The RFID tag 4 is provided in a vicinity
of a middle portion in a length direction of the through hole 3. It
should be noted that information about products/goods to be
transported on the pallet 1, identification information (e.g., a
pallet size, a type number, a pallet ID, etc.), and the like are
recorded into the RFID tag 4.
[0046] In the pallet 1 of this embodiment, the through hole 3
provided between the fork entries 2, 2 is a kind of transmission
pathway to the RFID tag 4. A read signal or a rewrite signal, which
is transmitted by an antenna 50 of an RFID interrogator 5 (see
FIGS. 9A, 9B) attached to a forklift, is propagated and transferred
through the through hole 3 to the RFID tag 4.
[0047] As described above, the RFID tag 4 is provided in the
vicinity of the middle portion in the length direction of the
through hole 3. Therefore, no matter whether the fork 101 of the
forklift 100 is inserted into the pallet 1 from the side 1a or the
side 1b, information stored in the RFID tag 4 attached inside the
through hole 3 can be read unbiasedly and reliably. Also,
information can be reliably rewritten.
[0048] It should be noted that the RFID tag 4 may be attached to
either of the lateral surfaces and the top and bottom surfaces
inside the through hole 3. The RFID tag 4 may be placed at any
position in the length direction of the through hole 3. However,
considering the above-described purpose that information stored in
the RFID tag 4 can be read unbiasedly and reliably from either of
the two sides 1a, 1b, it is preferable that the RFID tag 4 is
attached in the vicinity of the middle portion in the length
direction of the through hole 3.
[0049] Now, an exemplary method for reading/writing information
from/to the RFID tag 4 attached to the pallet 1 will be briefly
described. For example, as shown in FIGS. 9A and 9B, the antenna 50
of the RFID interrogator 5 is attached in a vicinity of a root of
the fork 101 of the forklift 100. In this case, when the fork 101
of the forklift 100 is inserted into the fork entry 2 of the pallet
1, information can be read/rewritten from/to the RFID tag 4 on the
pallet 1.
[0050] The antenna 50 of the RFID interrogator 5 may be attached to
an upper portion of a support bearing the fork 101 of the forklift
100. In the case where a plurality of pallets 1, . . . , 1 are
stacked when not in use, information can be read/rewritten from/to
the RFID tag 4 of each pallet 1 by lifting the pallets 1, . . . , 1
together with the fork 101 of the forklift 100.
[0051] When an empty pallet 1 is placed in a pallet storage site,
information stored in the RFID tag 4 may be read using the antenna
of an RFID interrogator provided in the pallet storage site. As a
result, identification information can be read from the empty
pallet 1, so that the availability of the pallet 1 can be
managed.
[0052] Next, examples of specific numerical values of the through
hole 3 will be described.
[0053] In the case of the pallet 1 of FIGS. 1A to 1C, the
cross-section of the through hole 3 is a rectangle. Therefore,
either of the sides of the rectangle needs to have a length of
.lambda./2 or more (.lambda.: the wavelength of a frequency used by
an RFID interrogator). The reason will be described below.
[0054] Rectangular waveguides (with a rectangular cross-section)
have the transmission characteristics of a HPF (high pass filter
which passes frequencies higher than a predetermined frequency
(fo)). In other words, rectangular waveguides have a property of
not transmitting frequencies lower than fo. In the case of
rectangular waveguides, the frequency fo is determined by the
length L of a side of the rectangular waveguide as follows.
fo*.lambda.=C(C: speed of light) L=.lambda./2
[0055] In the embodiment of FIGS. 1A to 1C, the through hole 3 of
the pallet 1 corresponds to a rectangular waveguide. When a
frequency used by RFID is 2.45 GHz, a dimension (lateral width) of
the through hole 3 needs to be broader than about 61.2 mm in order
to transmit the frequency through the through hole 3 and read the
tag information of the RFID tag 4 attached inside the through hole
3.
[0056] Therefore, for example, when a frequency of 2.45 GHz is
used, any one of the sides of the through hole 3 needs to be equal
to or larger than about 62 mm in order to transmit a read signal or
a rewrite signal of RFID through the inside of the through hole 3
of the pallet 1.
Embodiment 2
[0057] FIG. 2A is a front view of a pallet according to another
embodiment of the present invention. FIG. 2B is a center vertical
cross-sectional view thereof. FIG. 2C is a horizontal
cross-sectional view thereof.
[0058] FIGS. 2A to 2C show a pallet 11, which is a resin molded
product in the shape of a planar rectangle. The pallet 11 is
provided with fork entries 12, 12 to admit the two forks 101, 101
of the forklift 100 (see FIGS. 9A, 9B) on each of four sides 11a,
11b, 11c, 11d thereof. The forks can be inserted into the pallet 11
in four directions (four-way entry type).
[0059] The fork entries 12, 12, which are provided on the sides
11a, 11b of the pallet 11, are located symmetrically with respect
to a center (a center in a width direction) of the pallet 11. The
fork entries 12, 12, which are provided on the sides 11c, 11d of
the pallet 11, are located symmetrically with respect to a center
(a center in a length direction) of the pallet 11.
[0060] The pallet 11 is provided with two through holes 13, 13,
each of which extends along the center of the pallet 11. These two
through holes 13, 13 intersect orthogonally and are each disposed
between the fork entries 12, 12. The through holes 13 penetrate
through the two sides 11a, 11b and the two sides 11c, 11d,
respectively, on each of which the fork entries 12 are
provided.
[0061] Each through hole 13 has a rectangular cross-section. A
cross-section area of each through hole 13 is gradually increased
toward the sides 11a, 11b or 11c, 11d at both ends of the through
hole 13. An inner surface of each through hole 13, 13 is covered
with a conductive material, such as a metal or the like. An RFID
tag 4 is attached inside the through holes 13, 13. The RFID tag 4
is provided in a vicinity of a middle portion in a length direction
of each through holes 13, 13.
[0062] In the pallet 11 of this embodiment, each of the two through
holes 13, 13 is a kind of transmission pathway to the RFID tag 4. A
read signal or a rewrite signal, which is transmitted by the
antenna 50 of the RFID interrogator 5 (see FIGS. 9A, 9B) attached
to a forklift, is propagated and transferred through any one of the
two through holes 13, 13 to the RFID tag 4.
[0063] As described above, the RFID tag 4 is provided in the
vicinity of the middle portion in the length direction of each
through holes 13, 13. Therefore, no matter whether the fork 101 of
the forklift 100 is inserted into the pallet 11 from the side 11a,
11b, 11c or 11d, information stored in the RFID tag 4 attached
inside the through holes 13, 13 can be read unbiasedly and
reliably. Also, information can be reliably rewritten.
[0064] It should be noted that the RFID tag 4 may be attached to
either of the lateral surfaces and the top and bottom surfaces
inside the through holes 13, 13. The RFID tag 4 may be placed at
any position in the length direction of the through holes 13, 13.
However, considering the above-described purpose that information
stored in the RFID tag 4 can be read and rewritten unbiasedly and
reliably from any of the four sides 11a, 11b, 11c and 11d of the
pallet 11, it is preferable that the RFID tag 4 is attached in the
vicinity of the middle portion in the length direction of the
through holes 13, 13.
[0065] Also in Embodiment 2, the through hole 13 has a rectangular
cross-section. For the same reason as described in Embodiment 1,
either of the sides of the through hole 13 needs to have a length
of .lambda./2 or more (.lambda.: the wavelength of a frequency used
by an RFID interrogator). For example, when a frequency of 2.45 GHz
is used, the length of either of the sides of the through hole 13
needs to be equal to or larger than about 62 mm in order to
transmit a read signal or a rewrite signal of the RFID through the
inside of the through hole 13 of the pallet 11.
Embodiment 3
[0066] FIG. 3A is a front view of a pallet according to still
another embodiment of the present invention. FIG. 3B is a center
vertical cross-sectional view thereof. FIG. 3C is a horizontal
cross-sectional view thereof.
[0067] A pallet 21 shown in FIGS. 3A to 3C is characterized in that
a through hole 23 having a circular cross-section is provided
between fork entries 2, 2. The other structure is basically the
same as the embodiment of FIGS. 1A to 1C.
[0068] The pallet 21 is provided with a through hole 23 which
extends along a center of the pallet 21 and penetrates through two
sides 1a, 1b of the pallet 21. A cross-section area of the through
hole 23 is gradually increased toward the sides 1a, 1b at both ends
of the through hole 23. An inner surface of the through hole 23 is
covered with a conductive material, such as a metal or the
like.
[0069] In the pallet 21 of FIGS. 3A to 3C, the through hole 23 has
a circular cross-section. The radius of the through hole 23 needs
to be equal to or larger than .lambda./3.4 (.lambda.: the
wavelength of a frequency used by an RFID interrogator). The reason
will be described below.
[0070] Similar to rectangular waveguides, circular waveguides (with
circular cross-section) have the transmission characteristics of a
HPF (high pass filter which passes frequencies higher than a
predetermined frequency (fo)). In the case of circular waveguides,
a Bessel function is involved in calculation of the frequency fo,
and therefore, the calculation is complex. However, the frequency
fo is determined based on the radius r of a circular waveguide, and
the relationship between them is expressed as follows.
fo*.lambda.=C (C: speed of light) r=.lambda./3.4
[0071] In the embodiment of FIGS. 3A to 3C, the through hole 23 of
the pallet 21 corresponds to a circular waveguide. When a frequency
used by RFID is 2.45 GHz, the radius r of the through hole 23 needs
to be larger than about 36.0 mm in order to transmit the frequency
through the through hole 23 and read tag information of an RFID tag
4 attached inside the through hole 23.
Embodiment 4
[0072] FIG. 4A is a front view of a pallet according to still
another embodiment of the present invention. FIG. 4B is a center
vertical cross-sectional view thereof. FIG. 4C is a horizontal
cross-sectional view thereof.
[0073] A pallet 71 shown in FIGS. 4A to 4C is characterized in that
a through hole 73 having a cross-section in the shape of a ridge is
provided between fork entries 2, 2. The other structure is
basically the same as the embodiment of FIGS. 1A to 1C.
[0074] The pallet 71 is provided with the through hole 73 which
extends along a center of the pallet 71 and penetrates through two
sides 1a, 1b of the pallet 71. An inner surface of the through hole
73 is covered with a conductive material, such as a metal or the
like. As with the through hole 3 of FIGS. 1A to 1C, a cross-section
area of the through hole 73 is gradually increased toward the sides
1a, 1b at both ends of the through hole 73.
[0075] As described above, in the pallet 1 of Embodiment 1, when a
frequency of, for example, 2.45 GHz is used, the length of either
side of the through hole 3 needs to be equal to or larger than
about 62 mm in order to transmit a read signal or a rewrite signal
of RFID through the inside of the through hole 3. In the case of
the pallet 71 of FIGS. 4A to 4C, the length of either side of the
through hole 73 can be equal to or smaller than about 62 mm since
the through hole 73 has a ridge-shaped cross-section. The reason
will be described below.
[0076] Ridge waveguides, such as the through hole 73 having a
ridge-shaped cross-section of FIGS. 4A to 4C, can have a
considerably low cutoff frequency than rectangular waveguides
having the same length and width dimensions. In other words, when
the same frequency is used, a ridge waveguide can have smaller
length and width dimensions than those of a rectangular waveguide.
Therefore, if a through hole 73 having a ridge-shaped cross-section
of FIGS. 4A to 4C is used, when a frequency used by RFID is 2.45
GHz, the length of either side of the through hole 73 can be equal
to or smaller than about 62 mm so that a read signal or a rewrite
signal of the RFID can be transmitted through the inside of the
through hole 73 and tag information of an RFID tag 4 attached
inside the through hole 73 can be read. The ridge-shaped
cross-section of the through hole is not only a "concave" shape as
shown in FIGS. 4A to 4C (vertical cross-section, the through hole
73), but also can be, for example, an "H" shape as shown in FIGS.
6A to 5C (vertical cross-section, a through hole 83).
Embodiment 5
[0077] FIG. 6A is a front view of a pallet according to still
another embodiment of the present invention. FIG. 6B is a center
vertical cross-sectional view thereof. FIG. 6C is a horizontal
cross-sectional view thereof. FIG. 7 is a perspective view of the
pallet of FIGS. 6A to 6C.
[0078] The pallet 31 of FIGS. 6A to 6C and FIG. 7 is provided with
a through hole 3, which penetrates through two sides 1a, 1b of the
pallet 31, and a vertical through hole 33, which extends between
the top and bottom decks of the pallet 31. The vertical through
hole 33 is provided in a vicinity of a middle portion of the planar
rectangular pallet 31. The pallet 31 is characterized in that an
RFID tag 4 is attached in a vicinity of a middle portion of both
the vertical through hole 33 and the through hole 3 between fork
entries 2, 2. The other structure is basically the same as in the
embodiment of FIGS. 1A to 1C.
[0079] In the case of the pallet 31 of this embodiment, when the
empty pallets 31 are stacked in a pallet storage site, the middle
portions of the vertical through holes 33, . . . , 33 are
sequentially aligned as shown in FIG. 8. As a result, a through
hole which vertically penetrates the middle portions of the pallets
31 is formed. This through hole plays a role as a kind of
transmission pathway, as with the through hole 3 provided between
the fork entries 2, 2. In this case, for example, by providing a
planar antenna of an RFID interrogator on a bottom surface of the
pallet storage site, it is possible to read information stored in
the RFID tag 4 of each of the stacked pallets (empty pallets) 31, .
. . , 31 simultaneously. Also, information can be rewritten
simultaneously.
[0080] When a plurality of empty pallets 31, . . . , 31 are
transported together by the forklift 100, the antenna 50 of the
RFID interrogator 5 provided on the forklift 100 (see FIG. 9A, 9B)
can be used to read/write information from/to the RFID tag 4 of
each of the stacked empty pallet 31, . . . , 31. For example,
pallets can be managed in real time when the pallets are lent or
returned to/from a hirer.
[0081] Further, by transferring the read information to, for
example, a management center, the inventory of empty pallets can be
managed centrally, leading to an improvement in the utilization
rate of pallets.
[0082] As described above, empty pallets can be easily managed,
thereby also preventing loss and outflow of pallets.
[0083] In the case of the pallet 31 of this embodiment, the
vertical through hole 33 is provided at the middle portion thereof.
Therefore, when the RFID tag 4 attached to the pallet 31 needs to
be exchanged due to a defect, malfunction or the like, the RFID tag
4 can be exchanged by utilizing the vertical through hole 33.
[0084] If the vertical through hole 33 provided on the middle
portion of the pallet 31 has a circular cross-section as shown in
FIGS. 6A to 6C and FIG. 7, the radius of the vertical through hole
33 should be equal to or larger than .lambda./3.4 (.lambda.: the
wavelength of a frequency used by an RFID interrogator). For
example, when the frequency used by the RFID is 2.45 GHz, the
radius r of the vertical through hole 33 is larger than about 36.0
mm.
[0085] If the vertical through hole has a rectangular
cross-section, the length of either side of the through hole having
the rectangular cross-section should be equal to or larger than
.lambda./2 (.lambda.: the wavelength of a frequency used by an RFID
interrogator). For example, when the frequency used by the RFID is
2.45 GHz, the length of either side of the vertical through hole
should be equal to or larger than about 62 mm.
[0086] The pallets according to the embodiments of the present
invention may be made of either wood or synthetic resin. Pallets
made of synthetic resin are preferable since synthetic resin is
easy to shape.
[0087] The pallets according to the embodiments of the present
invention may be either of the two-way entry type, in which the
pallet is provided with fork entries to admit two forks of a
forklift on two sides thereof and the forks can be inserted into
the pallet in two directions, or of the four-way entry type, in
which the pallet is provided with fork entries on all sides (four
sides) thereof and the forks can be inserted into the pallet in
four directions.
[0088] Hereinafter, an exemplary pallet management system in which
a pallet of the present invention is used as a rental pallet will
be described below.
[0089] In this example, the pallet 31 of FIGS. 6A to 6C and FIG. 7
is used. It is assumed that identification information, such as a
pallet size, a type number, a pallet ID and the like, are stored in
the RFID tag 4 attached to the pallet 31. It is also assumed that
the forklift 100 is equipped with the RFID interrogator 5 and its
antenna 50 as shown in FIGS. 9A, 9B and a transceiver 6. It should
be noted that the antenna 50 of the RFID interrogator 5 is attached
in the vicinity of the root of the fork 101 of the forklift
100.
[0090] A basic structure of an RFID system used for management of
pallets will be described with reference to FIG. 10.
[0091] The RFID system of FIG. 10 comprises the above-described
RFID interrogator 5 and its antenna 50 mounted on the forklift 100,
the above-described RFID tag 4 and its antenna 40 attached to the
pallet 31, and the like.
[0092] The RFID interrogator 5 comprises a transmission section 51
for interrogation, a reception section 52 for reading, a
transmission section 53 for writing, a control section 54, and the
like. The RFID tag 4 comprises a modulation/demodulation section
41, a modulated signal generating section 42, a demodulation
section 43, an information memory section 44, and the like. The
RFID interrogator 5 and the RFID tag 4 communicate with each other
via the respective antennas 50 and 40.
[0093] This RFID system is operated as follows. The fork 101 of the
forklift 100 is inserted into the fork entry 2 of the pallet 31.
The antenna 40 of the RFID tag 4 is caused to substantially face
the antenna 50 of the RFID interrogator 5. The RFID interrogator 5
transmits a control signal and a non-modulated carrier from the
antenna 50 toward the RFID tag 4. The RFID tag 4 receives the radio
signal from the RFID interrogator 5 via the antenna 40, and decodes
the received control signal to know a data read operation. Data
such as an ID number, a pallet number, a hirer and the like are
retrieved from the information memory section 44 stored in the RFID
tag 4 and the data retrieved from the information memory section 44
is modulated with the received non-modulated carrier. The resultant
signal is transmitted (reflected) toward the RFID interrogator 5.
The reception section 52 (for reading) of the RFID interrogator 5
receives and demodulates the signal transmitted (reflected) from
the RFID tag 4 to obtain desired data. The RFID interrogator 5 also
transmits information to be written from the transmission section
53 (for writing) toward the RFID tag 4. This transmitted
information is demodulated by the demodulation section 43 of the
RFID tag 4 and is then accumulated (written) into the information
memory section 44.
[0094] RFID systems usually use frequency bands of 125 KHz, 13.56
MHz, 2.45 GHz and the like. Unless a radio set (transceiver) uses
the same frequency band as that of the RFID system, the RFID system
and the radio set can be operated independently with respect to
time. When the frequency of 2.45 GHz is used for both the RFID
system and the radio set, it is generally preferable that the RFID
system and the radio set are controlled not to perform simultaneous
transmission to avoid radio interference.
[0095] A specific exemplary system for managing rental pallets will
be described with reference to FIG. 11.
[0096] In this management system, it is assumed that a host
terminal 201 is managed by a rental pallet company.
[0097] The host terminal 201 possesses a database of lending
information (e.g., information about a hirer of rental pallets,
information about an entity which returns pallets, a rental period,
the number of rental pallets, etc.) and pallet-specific information
possessed by a rental pallet company (e.g., a pallet size, a type
number, a pallet ID, etc.).
[0098] Rental information is, for example, handled as follows.
Customers who want to hire pallets contact a rental pallet company
by telephone or the like. The contents of the customer's rental
order are input by the rental pallet company. Alternatively,
customers access a website run by a rental pallet company via the
Internet or the like and input the contents of their rental order
on a display screen by themselves. The contents of the orders are
accumulated.
[0099] The pallet specific information is the whole or a part of
information possessed by a rental pallet company. It is assumed
that a unique number or symbol is assigned as a pallet ID to each
pallet. For example, pallet IDs are assigned to newly purchased or
produced pallets and are registered into a master database.
[0100] A radio set base station 202 is connected to the host
terminal 201 and has a control section (not shown) for transmitting
and receiving various information. The radio set base station 202
transmits information stored in the host terminal 201 to a
transceiver 6 described elsewhere herein, and receives various
information about a pallet which is transmitted from the
transceiver 6.
[0101] A forklift 100 comprises two forks (fork portions) 101, 101
for lifting a pallet 31 as shown in FIGS. 9A, 9B. A control section
(not shown) of the transceiver 6 is provided in a driver's seat of
the forklift 100 so that a driver can manipulate the control
section. Also, an RFID interrogator 5 and an antenna 50 thereof are
provided in a vicinity of the middle of a root portion of the fork
101 of the forklift 100 (in a vicinity of the middle between the
two forks 101, 101). Therefore, when the fork 101 of the forklift
100 is inserted into the fork entry 2 of the pallet 31, information
can be read/written from/to the RFID tag 4 attached to the pallet
31. The transceiver 6 transmits various information about a pallet
to the radio set base station 202.
[0102] When the fork 101 is inserted into the fork entry 2 of the
pallet 31 in order for the forklift 100 to transport the pallet 31,
information such as the current date, the location (depot) of the
forklift 100, and the like can be written into the RFID tag 4 of
the pallet 31 via the antenna 50 of the RFID interrogator 5. Also,
information about a pallet hirer or information about an entity
which returns pallets can be read from the RFID tag 4 of the pallet
31.
[0103] Next, a method for managing the inventory, distribution
status and collection status of rental pallets will be described
with reference to FIG. 12.
[0104] Firstly, an exemplary rental system will be described, in
which the same pallet that is lent is returned and a rental fee is
paid later.
[0105] Step S1: the contents of a customer's rental order for a
pallet(s) are stored as lending information into the host terminal
201. The contents of a rental order include, for example, hirer:
company A, type number: T 11 pallet, desired number of pallets: 10,
desired date: June, 1, 12 o'clock, desired period: 10 days, and the
like.
[0106] Step S2: when the pallet 31 to be lent is transported (e.g.,
the fork 101 of the forklift 100 is inserted into the fork entry 2
of the pallet 31), the RFID interrogator 5 of the forklift 100
reads an ID number and the like stored in the RFID tag 4 of the
pallet 31. The RFID interrogator 5 of the forklift 100 can also
write lending information and the date of lending into the RFID tag
4 of the pallet 31.
[0107] Step S3: the transceiver 6 connected to the RFID
interrogator 5 of the forklift 100 transmits the pallet ID, which
has been read using the RFID interrogator 5, to the radio set base
station 202.
[0108] Step S4: the pallet ID transmitted to the radio set base
station 202 is stored into the host terminal 201.
[0109] Step S5: when the pallet 31 is returned (e.g., the fork 101
of a forklift 100 is inserted into the fork entry 2 of the returned
pallet 31) at a location (depot), an RFID interrogator 5 of the
forklift 100 reads the pallet ID stored in the RFID tag 4 of the
pallet 31.
[0110] Step S6: a transceiver 6 connected to the RFID interrogator
5 of the forklift 100 transmits the pallet ID, which has been read
by the RFID interrogator 5, to the radio set base station 202.
[0111] Step S7: the pallet ID transmitted by the radio set base
station 202 is stored into the host terminal 201.
[0112] Step S8: the host terminal 201 compares the lending
information of each pallet ID in its own database with the
collected pallet ID.
[0113] Step S9: the host terminal 201 calculates a pallet rental
fee based on a pallet size, a type number, the number of pallets,
the date of lending and the date of collection.
[0114] With the above-described steps, the rental pallet company
can read the pallet ID number of each pallet when a forklift moves
(transports) the pallet (e.g., the fork of the forklift is inserted
into the pallet). The rental pallet company can also write location
information about a collection location (depot) and information
about the date of collection when the fork of a forklift is
inserted into the collected pallet. As a result, it is possible to
know the distribution pathway and collection pathway of each
pallet, so that the inventory, distribution status and collection
status of rental pallets can be managed in association with the
actual movement (transportation) of the pallets.
[0115] Further, for example, when a program for a pallet rental fee
system is previously stored in the host terminal 201, a temporally
accurate and meticulous fee system can be constructed.
[0116] Next, an exemplary rental system will be described, in which
the same pallet that is lent is returned and a rental fee is paid
in advance.
[0117] In this example, it is assumed that a customer paid to a
rental pallet company in advance a rental fee, the amount of which
depends on the contents of the customer's rental order. It should
be note that steps S1 to S8 of this example are the same as those
in the above-described example in which a rental fee is paid later
and will not be explained. Only a portion of this example which is
different from the above-described example will be described
below.
[0118] From the above-described step S8, the process goes to
subsequent step S10 or S11.
[0119] Step S10: when the result of comparison in the host terminal
201 in step S8 shows that a rental pallet is returned to a location
(depot) before completion of the rental period of the pallet, the
balance of the rental fee to be refunded to the customer is
calculated. The refund may be prorated per diem for the rental fee
originally paid. Alternatively, the refund may be calculated based
on a rate defined for a predetermined period (e.g., on a weekly
basis).
[0120] Step S11: when a rental pallet is returned to a location
(depot) after completion of the rental period of the pallet, the
balance of the rental fee to be additionally collected from the
customer is calculated.
[0121] As described above, the pallets according to the
above-described embodiments of the present invention can be
effectively used in, for example, a pallet management system which
manages the inventory, distribution status, collection status and
the like of rental pallets. In such a pallet management system, a
non-contact IC tag (e.g., an RFID tag, etc.) is attached to a
pallet, and therefore, the moving pathway of the pallet can be
directly tracked, thereby making it possible to reduce the effort
to input data into a hand-written slip or a computer. Further, the
distribution of pallets can be correctly tracked, thereby making it
possible to clear the reason for loss or unauthorized use of a
pallet. Furthermore, since a person in charge of a distribution
stage can be identified, it is possible to, for example, demand an
unpaid fee or claim damage due to loss or unauthorized use of
pallets.
[0122] The present invention can be embodied and practiced in other
different forms without departing from the spirit and essential
characteristics thereof Therefore, the above-described embodiments
are considered in all respects as illustrative and not restrictive.
The scope of the invention is indicated by the appended claims
rather than by the foregoing description. All variations and
modifications falling within the equivalency range of the appended
claims are intended to be embraced therein.
* * * * *