Described herein is an arm supporting exoskeleton, comprising an arm link mechanism. The arm link mechanism comprises a proximal link, a distal link, an arm coupler, and a variable force generator. The distal link is rotatable relative to the proximal link. The arm coupler is adapted to couple an upper arm of a person to the distal link. The variable force generator comprises a first spring and a second spring, configured to create a torque between the proximal link and the distal link. In the first force mode, the variable force generator exhibits a first stiffness rate defined by the first spring that supports the upper arm of the person against gravity forces and. In the second force mode, the variable force generator exhibits a second stiffness rate defined by the first spring and the second spring that supports the upper arm of the person against the gravity forces.

Described herein is an arm supporting exoskeleton, comprising an arm link mechanism. The arm link mechanism comprises a proximal link, a distal link, an arm coupler, and a variable force generator. The distal link is rotatable relative to the proximal link. The arm coupler is adapted to couple an upper arm of a person to the distal link. The variable force generator comprises a first spring and a second spring, configured to create a torque between the proximal link and the distal link. In the first force mode, the variable force generator exhibits a first stiffness rate defined by the first spring that supports the upper arm of the person against gravity forces and. In the second force mode, the variable force generator exhibits a second stiffness rate defined by the first spring and the second spring that supports the upper arm of the person against the gravity forces.

Described herein is an arm supporting exoskeleton, comprising an arm link mechanism. The arm link mechanism comprises a proximal link, a distal link, an arm coupler, and a variable force generator. The distal link is rotatable relative to the proximal link. The arm coupler is adapted to couple an upper arm of a person to the distal link. The variable force generator comprises a first spring and a second spring, configured to create a torque between the proximal link and the distal link. In the first force mode, the variable force generator exhibits a first stiffness rate defined by the first spring that supports the upper arm of the person against gravity forces and. In the second force mode, the variable force generator exhibits a second stiffness rate defined by the first spring and the second spring that supports the upper arm of the person against the gravity forces.

A medium feeding apparatus includes: a feed tray on which media M are placed; a draw-out unit that draws out an uppermost medium among the media placed on the feed tray; a hanging member that hangs the feed tray; and a load member that applies, when an amount of the media placed on the feed tray is equal to or smaller than a predetermined amount, a downward load to a portion of the feed tray located on an upstream side in a draw-out direction of the media.

Described herein is an arm supporting exoskeleton, comprising an arm link mechanism. The arm link mechanism comprises a proximal link, a distal link, an arm coupler, and a variable force generator. The distal link is rotatable relative to the proximal link. The arm coupler is adapted to couple an upper arm of a person to the distal link. The variable force generator comprises a first spring and a second spring, configured to create a torque between the proximal link and the distal link. In the first force mode, the variable force generator exhibits a first stiffness rate defined by the first spring that supports the upper arm of the person against gravity forces and. In the second force mode, the variable force generator exhibits a second stiffness rate defined by the first spring and the second spring that supports the upper arm of the person against the gravity forces.

Described herein is an arm supporting exoskeleton, comprising an arm link mechanism. The arm link mechanism comprises a proximal link, a distal link, an arm coupler, and a variable force generator. The distal link is rotatable relative to the proximal link. The arm coupler is adapted to couple an upper arm of a person to the distal link. The variable force generator comprises a first spring and a second spring, configured to create a torque between the proximal link and the distal link. In the first force mode, the variable force generator exhibits a first stiffness rate defined by the first spring that supports the upper arm of the person against gravity forces and. In the second force mode, the variable force generator exhibits a second stiffness rate defined by the first spring and the second spring that supports the upper arm of the person against the gravity forces.

Described herein is an arm supporting exoskeleton, comprising an arm link mechanism. The arm link mechanism comprises a proximal link, a distal link, an arm coupler, and a variable force generator. The distal link is rotatable relative to the proximal link. The arm coupler is adapted to couple an upper arm of a person to the distal link. The variable force generator comprises a first spring and a second spring, configured to create a torque between the proximal link and the distal link. In the first force mode, the variable force generator exhibits a first stiffness rate defined by the first spring that supports the upper arm of the person against gravity forces and In the second force mode, the variable force generator exhibits a second stiffness rate defined by the first spring and the second spring that supports the upper arm of the person against the gravity forces.

Described herein is an arm supporting exoskeleton, comprising an arm link mechanism. The arm link mechanism comprises a proximal link, a distal link, an arm coupler, and a variable force generator. The distal link is rotatable relative to the proximal link. The arm coupler is adapted to couple an upper arm of a person to the distal link. The variable force generator comprises a first spring and a second spring, configured to create a torque between the proximal link and the distal link. In the first force mode, the variable force generator exhibits a first stiffness rate defined by the first spring that supports the upper arm of the person against gravity forces and In the second force mode, the variable force generator exhibits a second stiffness rate defined by the first spring and the second spring that supports the upper arm of the person against the gravity forces.

Described herein is an arm supporting exoskeleton, comprising an arm link mechanism. The arm link mechanism comprises a proximal link, a distal link, an arm coupler, and a variable force generator. The distal link is rotatable relative to the proximal link. The arm coupler is adapted to couple an upper arm of a person to the distal link. The variable force generator comprises a first spring and a second spring, configured to create a torque between the proximal link and the distal link. In the first force mode, the variable force generator exhibits a first stiffness rate defined by the first spring that supports the upper arm of the person against gravity forces and. In the second force mode, the variable force generator exhibits a second stiffness rate defined by the first spring and the second spring that supports the upper arm of the person against the gravity forces.

Described herein is an arm supporting exoskeleton, comprising an arm link mechanism. The arm link mechanism comprises a proximal link, a distal link, an arm coupler, and a variable force generator. The distal link is rotatable relative to the proximal link. The arm coupler is adapted to couple an upper arm of a person to the distal link. The variable force generator comprises a first spring and a second spring, configured to create a torque between the proximal link and the distal link. In the first force mode, the variable force generator exhibits a first stiffness rate defined by the first spring that supports the upper arm of the person against gravity forces and. In the second force mode, the variable force generator exhibits a second stiffness rate defined by the first spring and the second spring that supports the upper arm of the person against the gravity forces.