Patent Application
20240315432
The present invention relates to a suspended-load backpack comprising an adjustable impedance suspension system.
In daily life, it is an inevitable part of routine activities to carry loads. The additional weight and inertial forces caused by the loads carried result in increased metabolic costs during movement. Moreover, continuous exposure to repetitive loads on the musculoskeletal system may cause long term injuries.
As a way to increase the user's energy efficiency while walking, suspended-load backpacks have been proposed. The suspended-load backpacks not only reduce maximum reaction forces during load carrying, but also change the timing of the loads in the walking cycle by generating a movement comprising a phase difference between the load carried and the human body. Typical applications of the suspended-load backpacks are based on a very flexible and low damping suspension. However, due to the fact that low stiffness suspensions are subject to excessive displacements under high loads, the effectiveness of such suspensions is limited to a relatively narrow range of payload and walking speed. Thus, it is difficult to effectively implement suspended-load backpacks.
A suspended-load backpack having a suspension system is described in the patent document EP2094126 (B1), which is in the state of the art.
A variable stiffness suspension system is described in the patent document U.S. Pat. No. 10,018,238 (B2), which is in the state of the art.
EP 2,094,126 A2 discloses a suspended-load backpack designed to permit the load to move relative to the wearer during walking and running so that the large movements between the load and the wearer of the backpack reduce the fluctuations of vertical motion of the load with respect to ground. Because the hip (and thus the pack body) goes up a down a good deal during walking, a large relative movement between the wearer and the load reduces the absolute excursion of the load.
The object of the present invention is to provide a suspended-load backpack having a suspension system, wherein when the suspended-load backpack is worn by the user, the movement of the loading chamber relative to the ground which is caused by the movement of the user is filtered.
The suspended-load backpack of the present invention comprises a loading chamber suitable for placing therein the loads to be carried; at least one strap; an adjustable impedance suspension system having a first connection portion where it is connected with the strap and a second connection portion where it is connected with the loading chamber, and enabling that the movements of the loading chamber caused by the movement of the user, when in use, are filtered; an adjustable stiffness module located on the suspension system, an end of which is connected with the first connection portion and the other end of which is connected with the second connection portion. The strap may be in the form of a shoulder strap suitable to be worn on the shoulder of the wearer, or a waist strap suitable to be worn on the waist of the wearer. The suspension system also comprises an inerter which is connected in parallel with the adjustable stiffness module and which increases the effective inertia. After the suspended-load backpack is worn by the user, the movements of the loading chamber perpendicular or parallel to the ground during the walking or running of the user are filtered and transmitted to the user's shoulder by means of the suspension system. The suspension system filters the movements of the loading chamber by changing the natural frequency of the system. While the inerter decreases the natural frequency of the system by increasing its total inertia, the adjustable stiffness module adjusts the natural frequency by changing the spring constant of the system.
Inerter was first suggested in 2002 by M. C. Smith. Inerter is a mechanical element having two terminals corresponding to a capacitor in an electrical circuit. Unlike to the inertia/mass, one terminal of which is always connected to the ground (grounded), both terminals of the inerter are individually movable. The forces applied to the two terminals are directly proportional to the relative acceleration between the two terminals. Said proportionality has the same unit with the mass. A number of different types of inerters have been produced and used. A number of inerters with many different structures are used in applications, such as mechanical inerters, electromechanical inerters, liquid or hydraulic inerters. Mechanical inerters can be examined in two common types: ball-screw inerters and rack-and-pinion inerters. The inertia required in both types of the mechanical inerter mechanisms is provided by a flywheel. Any inerter structure can be used in the suspension system proposed in the invention.
In an embodiment of the invention, the adjustable stiffness module comprises at least one bendable beam suitable to be connected to the loading chamber; a movement mechanism suitable for applying force to the beam from at least one end of the beam; a spring having one end connected with the first connection portion and the other end connected with the second connection portion. The spring is a positive stiffness spring. The value of the spring constant of the beam can be adjusted by applying force to the beam through the movement mechanism. In this way, an adjustable stiffness module is obtained. The movement mechanism is movable either manually or automatically.
In an embodiment of the invention, said adjustable stiffness module comprises a connection base, which is connected to the beam at one end and suitable for connecting the loading chamber thereon. With the connection base, the loading chamber can be connected to and disconnected from the suspension system. Furthermore, with the connection base, the connection of the beam with the loading chamber is facilitated.
In an embodiment of the invention, the suspension system comprises a first connection element, which is located on the connection base and allows the loading chamber to be mounted on the connection base in a removable manner. In this way, it is facilitated to place the loading chamber on the connection base and to detach it therefrom.
In an embodiment of the invention, the suspension-load backpack comprises a second connection element that facilitates the removable mounting of the loading chamber to the connection base by mating the loading chamber with the first connection element. Thus, when the loading chamber is placed on the connection base, the loading chamber is prevented from being displaced. Furthermore, if the first connection element and the second connection element are mated by the user, it facilitates the mounting of the loading chamber to the connection base.
In an embodiment of the invention, the suspension system comprises a connection base connected to the central point of the said beam. In this way, it is facilitated to guide the loading chamber to move perpendicularly to the ground.
In an embodiment of the invention, said adjustable stiffness module comprises a connection means allowing the beam and the connection base to be manually connected and disconnected. In this way, while the beam that allows the adjustment of the stiffness of the adjustable stiffness module is connected with the suspension system, it is ensured that the working area can be separated.
In an embodiment of the invention, the suspension system comprises a spring compression mechanism that is associated with the spring and suitable for applying force to the spring. In this way, the force that the spring will apply against the weight of the loading chamber can be increased.
In an embodiment of the invention, said suspension system comprises an auxiliary damping element. In this way, the damping efficiency of the suspension system is increased.
In an embodiment of the invention, the suspended-load backpack comprises a generator. In this way, it is possible to generate energy from the movements of the loading chamber or the elements in the suspension system. In this embodiment, the movements that occur perpendicular to the ground during walking are filtered by the suspension and the displacement formed on a moving element in the suspension system is used to drive the generator and generate electrical energy by means of a reducer. In this embodiment, the generator adds damping to the system.
In an embodiment of the invention, the inerter is a ball-screw inerter including a first flywheel, a ball, and a screw. The inertia required in the ball-screw inerter is obtained by the rotation of a rotating element. In the ball-screw inerters, when the gears rotate in the opposite direction, the gap between the gears is less than the other inerters, and thus the efficiency loss is reduced.
In an embodiment of the invention, the inerter is the one comprising a flywheel pivoted using flexible mechanisms. This inerter which is based on a flexible mechanism can add ideal interance to the system by minimizing undesirable effects such as backlash, friction and damping.
In an embodiment of the invention, the inerter is the one comprising a linear harmonic reducer embodied using pulleys and ropes. The use of pulleys and ropes reduces undesirable effects such as friction and damping, while the linear harmonic reducer allows high levels of interance with low mass.
The suspended-load backpack of the present invention is illustrated in the accompanying drawings for better understanding thereof, which drawings are just incorporated to better illustrate the present invention and are not intended to limit the invention, in which:
The invention will herein be explained in detail with reference to the accompanying drawings and the list of part numbers used in the figures is as follows.
The suspended-load backpack (10) of the present invention comprises a loading chamber (20) suitable for placing therein the loads to be carried; at least one strap (30); an adjustable impedance suspension system (40) having a first connection portion (41) where it is connected with the strap (30) and a second connection portion (42) where it is connected with the loading chamber (20), and enabling that the movements of the loading chamber (20) caused by the movement of the user, when in use, are filtered; an adjustable stiffness module (50) located on the suspension system (40), an end of which is connected with the first connection portion (41) and the other end of which is connected with the second connection portion (42). The suspension system (40) allows damping and/or filtering of the movements of the loading chamber (20) perpendicular to the ground, particularly during the walking of the user. Thus, it is possible to effectively reduce the metabolic cost of carrying loads at various payloads and walking speeds. As can be seen in
Here b is greater than 0 and corresponds to inertance. As can be seen from
The inerter (60) is incorporated into the suspension system (40) in order to lower the natural frequency (ωn) of the suspended-load backpack (10). The equation of the natural frequency (ωn) of the suspended-load backpack (10) is given in Equation 2:
In Equation 2, k is the spring constant; m is the inertia of the suspended-load backpack (10) before the inerter (60) is incorporated therein; M corresponds to the inertia added to the system by the inerter (60). The unit of the inertia added to the system is kilogram. The weight of the inerter (60) to be incorporated into the suspension system (40) should be chosen as low as possible and the inertia (M) that will affect the system should be chosen as large as possible. In this way, since an increase in the total weight of the suspended-load backpack (10) will be small, the total inertia of the suspended-load backpack (10) can be increased without increasing the weight acting on the user's body.
In
In the adjustable impedance suspension system (40), an adjustable stiffness module (50) with adjustable spring constant (k) is used in order to adjust the natural frequency (ωn) of the system. As can be seen in Equation 2, as the spring constant (k) is increased, the natural frequency of the system is increased and as the spring constant (k) is decreased, the natural frequency of the system is decreased. The adjustable stiffness module (50) can change the spring constant (k) of the system manually or automatically. In this way, while the user wearing the suspended-load backpack (10) is walking, the movements of the loading chamber (20) relative to the ground are dampened or filtered. The adjustable stiffness module (50) can be selected as any one of the adjustable stiffness modules (50) in the state of the art.
Referring to
Referring to
As can be seen in
In a preferred embodiment of the invention, the connection base (54) is connected to the central point of the beam (51). In this way, the connection base (54) and the loading chamber (20) are guided to move perpendicular to the ground.
In an embodiment of the invention, the suspension system (40) comprises a first connection element (541), which is located on the connection base (54) and allows the loading chamber (20) to be placed on the connection base (54) in a removable manner. In this way, it is facilitated to mount and remove the loading chamber (20) on the connection base (54). In another preferred embodiment of the invention, there is provided a second connection element that facilitates the mounting of the loading chamber (20) to the connection base (54) by mating the loading chamber (20) with the first connection element (541). The first connection element (541) and the second connection element are designed to be interlocked and separated. In this way, it is facilitated to mount and remove the loading chamber (20) on the connection base (54).
In an embodiment of the invention, the suspension system (40) comprises a spring compression mechanism (56), which is associated with the spring (53) and suitable for applying force against the spring (53). When the loading chamber (20) is disposed on the connection base (54), the weight of the loading chamber (20) is compensated by the spring (53). In order to facilitate the compensation of the weight of the loading chamber (20) by the spring (53), the spring compression mechanism (56) applies force to the spring (53). In this way, even when a spring (53) with low spring constant is used, by applying force to the spring (53) by the spring compression mechanism (56), the spring (53) is able to apply a force equal and opposite to the weight of the loading chamber (20) in cases where the loading chamber (20) reaches high weights.
In an embodiment of the invention, the suspension system (40) comprises an auxiliary damping element (70). With the auxiliary damping element (70), the filtering efficiency of the movements perpendicular or parallel to the ground caused by the movement of the suspended-load backpack (10) is increased. In
In an embodiment of the invention, the suspension system (40) comprises a generator (80). By way of the generator (80), it is possible to generate energy from the movements that will occur in the suspension system (40). The generator (80) can be disposed anywhere within the suspension system (40) where there is movement.
The inerter (60) illustrated in
The inerter (60) illustrated in
The inerter (60) illustrated in
The inerter (60) illustrated in
In an embodiment of the invention, the inerter (60) is based on a flexible mechanism. The inerter (60) illustrated in
The inerter (60) illustrated in
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022/002998 | Mar 2022 | TR | national |
This application is a national stage entry of International Application No. PCT/TR2023/050195, filed on Feb. 28, 2023, which is based upon and claims foreign priority to Turkey Patent Application No. 2022/002998, filed on Mar. 1, 2022, the entire contents of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/TR2023/050195 | 2/28/2023 | WO |
