JP-7854581-B1 - A backpack with shoulder straps that conform to the user's shoulder shape and body movements.

Abstract

[Problem] The problem addressed by this invention is that conventional backpacks cannot adequately accommodate differences in shoulder width, height differences between the left and right shoulders, differences in carrying position, and vertical and rotational movements during walking, which often leads to the shoulder straps slipping off or causing discomfort. Furthermore, in structures where the base of the shoulder straps is sewn to the outer fabric, the outer fabric is constrained, causing deformation of its appearance and reducing design freedom. [Solution] As a solution to this problem, the upper ends of the left and right shoulder straps are supported in a folded manner at a pivot point inside the bag, and a configuration is adopted that allows them to rotate left and right around the pivot point. In addition, the base of the shoulder straps is sewn to the inner bag to prevent the outer fabric from being restricted, and the lower end of the rear shoulder strap is attached closer to the center of the lower back of the torso, allowing the bag to sway slightly to adjust the center of gravity and improve followability and stability during walking. [Selection Diagram] Figure 1

Inventors

• 三沢 慶子

Assignees

• 三沢 慶子

Dates

Publication Date

20260507

Application Date

20251116

Claims (6)

1. A backpack bag having a pair of front shoulder straps and a pair of rear shoulder straps on the upper edge of the bag body, wherein the upper end of each shoulder strap is supported at a pivot point provided inside the bag body, and the upper end of each shoulder strap is formed to be double-layered or superimposed along the longitudinal direction of each shoulder strap at the pivot point so that each shoulder strap can rotate left and right about the pivot point, and is connected to the bag body.
2. A backpack bag according to claim 1, wherein the upper end of the shoulder strap is sewn to the inner bag rather than to the outer fabric on the outside of the bag, and the outer fabric is not constrained by the base of the shoulder strap.
3. A backpack according to claim 1 , wherein the lower end of the rear shoulder strap is connected to an attachment point located near the center of the lower part of the back.
4. The backpack bag according to claim 3, wherein the rear shoulder strap is pivotable relative to the bag body by two-point support at the pivot point and the attachment position, and can change angle to follow the up-and-down and rotational movements of the shoulders accompanying walking.
5. A backpack bag according to claim 1 , wherein the double-layered or multi-layered portion formed at the upper end of the shoulder strap constitutes a pivot structure that ensures the degree of freedom of rotation at the pivot point .
6. A backpack bag according to claim 5 , wherein the left and right front shoulder straps and the left and right rear shoulder straps are connected to each other, and the opening of the bag is naturally guided in the closing direction when the user puts the bag on their back.

Description

This invention relates to a backpack, and more particularly to a backpack with a structure that easily accommodates the physical characteristics and movements of the user, such as differences in shoulder width and vertical movement of the shoulders during walking. Conventional backpacks typically use a structure where the left and right shoulder straps are sewn and fixed to the upper edge of the back panel with the seams generally perpendicular to the direction of gravity. In this structure, the load on the shoulder straps is concentrated as a lateral component against the seams, so a wide stitch width is necessary to ensure stitching strength, resulting in the shoulder strap base being pressed against the back panel with a wide contact surface. In other words, the wide stitch width required to ensure strength acts as a surface constraint on the shoulder strap base against the back panel, depriving the shoulder strap base of its freedom of rotation in the lateral direction. Therefore, the shoulder straps cannot properly follow the differences in height of the carrying position (upper, middle, and lower back) among users, the difference in height between the left and right shoulders, and the differences in shape, thickness, and inclination between the left and right shoulders. Furthermore, when walking, the left and right shoulders move up and down alternately, and small rotational movements occur in the shoulder girdle, so the left and right shoulders move on independent trajectories, but conventional structures do not have a mechanism to allow the left and right shoulder straps to move independently. As a result, the bag was prone to slipping off the shoulder, causing pain due to localized pressure and chafing on the shoulder, and discomfort during wear. Furthermore, the concentration of load on specific areas led to wear and tear on the seams and fabric, reducing durability. Additionally, conventional backpacks, despite having a generally three-dimensional shape, are suspended only by one side formed at the upper edge of the back panel. This means the weight of the contents is concentrated and transmitted to the upper edge of the back panel via the shoulder straps. In this situation, the other sides of the bag (front and sides) are unsupported, and a force pulling in the direction of the load acts on them, making the front and side panels prone to deformation. This is a front view of the backpack of the present invention, showing the bag body 10, back panel 20, front panel 30, opening 40, inner bag section 50, shoulder strap connection section 60, rear shoulder strap 70, front shoulder strap 80, and left and right shoulder strap connecting sections 90.This is a rear view of the backpack of the present invention, showing the back panel 20, left and right rear shoulder straps 70, a pivot point 100 supporting the upper ends of the rear shoulder straps, the attachment point 110 of the lower ends of the rear shoulder straps to the back panel, an opening 40 at the upper edge of the bag body, and an adjuster 95 provided on the rear shoulder straps.Figure 3 is an explanatory diagram showing the shoulder strap base structure (method 1), in which the rear shoulder strap 70 and the front shoulder strap 80 are rotatably supported via a pivot point 100 to the shoulder strap connection part 60 provided inside the bag 50. Figure 3A shows the state in which the shoulder strap base is formed by sewing the upper end of the shoulder strap in a folded shape. Figure 3B shows the state in which the folded upper end of the shoulder strap is sewn in an unfolded state and connected to the bag body side.Figure 4 is an explanatory diagram of the shoulder strap base structure (method 2), showing how the front shoulder strap 80 and rear shoulder strap 70 are rotatably supported via a pivot point 100, and how the lower end of the back shoulder strap is attached to a mounting position 110 near the center of the lower part of the back torso 20.Figure 5 is an explanatory diagram showing the movement of the shoulder straps when the bag 10 is carried on the back at a high or low position. Figure 5A shows the case when the bag is carried at a high position, and Figure 5B shows the case when the bag is carried at a low position. In both cases, the rear shoulder strap 70 and the front shoulder strap 80 move left and right around the pivot point 100, naturally following the shape of the user's shoulders.Figure 6 is an explanatory diagram showing how the bag body 10 swings while independently adjusting its center of gravity in response to the twisting of the user's body and the up-and-down movement of the left and right shoulders during walking. Figure 6A shows the case where the bag body 10 swings in the front-to-back direction, and Figure 6B shows the case where it swings in the left-to-right direction. In either case, the movement of the front shoulder strap 80 and the rear shoulder strap 70 is not hindered, so the shoulder straps continue t