Backpack

A backpack (1) comprising:

• an item storage portion (2) having an item housing space (2A) inside and including a back support surface (3a) that faces a back of a user in use;
• and
• a shoulder strap (9) attached so as to extend from the back support surface (3a) outwardly from the item storage portion (2),
• wherein
• the item storage portion (2) includes:
• a storage body (3) on one side having an opening portion (3A) on one side provided on a side opposite to the back support surface (3a);
• and
• a storage body (4) on another side having an opening portion (4A) on another side provided so as to correspond to the opening portion (3A) on the one side of the storage body (3) on the one side,
• wherein the item housing space (2A) is secured as a space covered by the storage body (3) on the one side and the storage body (4) on the other side by engaging the opening portion (3A) on the one side with the opening portion (4A) on the other side,
• the storage body (3) on the one side includes:
• a back surface wall (30) having the back support surface (3a) as an outer surface side;
• and
• a pair of side surface walls (33, 34) disposed so as to surround the back surface wall (30) and extending from a periphery (30a) of the back surface wall (30) toward the opening portion (3A) on the one side, a bottom surface wall (32), and a top surface wall (31),
• the storage body (4) on the other side includes:
• a front surface wall (40) disposed so as to oppose the back surface wall (30) when combined with the storage body (3) on the one side;
• and
• a pair of side surface walls (43, 44) disposed so as to surround the front surface wall (40) and extending from a periphery (40a) of the front surface wall (40) toward the opening portion (4A) on the other side, a bottom surface wall (42), and a top surface wall (41),
• the storage body (3) on the one side and the storage body (4) on the other side can be opened in a double-side opening manner by having a support piece (5) as a pivot point, the support piece (5) being provided so as to couple the side surface walls (33, 43), each of the side surface walls being the side surface wall on one side of each of the pairs of side surface walls that are respectively provided in the storage body (3) on the one side and the storage body (4) on the other side, and the opening portion (3A) on the one side and the opening portion (4A) on the other side can be freely opened and closed by a zipper (6), the zipper (6) being provided so as to extend from the side surface wall (33, 43) on the one side of each of the storage body (3) on the one side and the storage body (4) on the other side sequentially through the top surface wall (31, 41), the side surface wall (34, 44) on another side, and the bottom surface wall (32, 42) to reach the side surface wall (33, 43) on the one side,
• in the item housing space (2A), an upper section storage member (7) and a lower section storage member (8) that partition the item housing space (2A) on a side of the bottom surface wall (32, 42) and a side of the top surface wall (31, 41) are installed between the back surface wall (30) and the front surface wall (40) such that a degree of opening between the storage body (3) on the one side and the storage body (4) on the other side is limited to a predetermined range,
• in the item housing space (2A), the upper section storage member (7) is installed at a position near a middle between the bottom surface wall (32, 42) and the top surface wall (31, 41) and the lower section storage member (8) is installed at a position near the bottom surface wall (32, 42) so that the item housing space (2A) is partitioned into two spaces on the side of the bottom surface wall (32, 42) and the side of the top surface wall (31, 41) by the upper section storage member (7),
• the upper section storage member (7) and the lower section storage member (8) are formed in a bag shape opening toward the top surface wall (31, 41), the upper section storage member (7) and the lower section storage member (8) being able to be three-dimensionally developed by having a side of the side surface wall (33, 43) on the one side as a pivot point when the storage body (3) on the one side and the storage body (4) on the other side are separated to open the item storage portion (2), the upper section storage member (7) and the lower section storage member (8) being able to be folded to be housed in the item housing space (2A) when the storage body (3) on the one side and the storage body (4) on the other side are combined to be closed, and
• further, an interior of at least one of the upper section storage member (7) and the lower section storage member (8) is partitioned into two or more compartments by a partitioning plate (75), the at least one of the upper section storage member (7) and the lower section storage member (8) being able to be folded about a position of the partitioning plate (75) in a compressed manner to be housed in the item housing space (2A) when the storage body (3) on the one side and the storage body (4) on the other side are combined to be closed.