Abstract: A flexible tube includes a first connecting portion and a second connecting section. The second connecting section and the first connecting section are integrally connected to each other. The first connecting section has a first end surface, and the second connecting section has a second end surface, wherein there is an acute angle between the first end surface and the second end surface.

Abstract: A hinge device includes a fixed shaft, a rotating sleeve, a fixed connection member, a torsion spring, a rotating connection member and a friction resistance assembly. The rotating sleeve is rotatably mounted on the fixed shaft and is located between a fixed end and a free end. One end of the fixed connection member is fixedly connected to the free end, and the other end is provided with a first slot. Two ends of the torsion spring are respectively equipped with a first snap-in pin and a second snap-in pin. The first snap-in pin inserts into the first slot. An extension part protrudes from a fixed part of the of the rotating connection member and is provided with a second slot. The second snap-in pin inserts into the second slot. The friction resistance assembly is disposed on the fixed shaft to provide torsional resistance to the rotating sleeve.

Abstract: A torque-variable single-shaft rotary shaft structure with multiple frictional pairs includes a pivot shaft. A first support is secured to a pivot shaft and a second support is disposed on the pivot shaft. An adjustment wheel assembly, a frictional assembly and an elastic assembly are fitted on the pivot shaft. The adjustment wheel assembly and the frictional assembly have a first adjustment wheel and a second frictional member synchronously movable with the first support and a second adjustment wheel and a first frictional member synchronously movable with the second support. When the first and second supports are rotated, the first and second adjustment wheels are driven to contact and abut against each other so as to provide axial action forces. The frictional assembly has multiple first and second frictional members, which are alternately arranged in frictional contact with each other to form multiple frictional pairs.

Abstract: A torque-variable single-shaft rotary shaft structure with multiple frictional pairs includes a pivot shaft. A first support is secured to a pivot shaft and a second support is disposed on the pivot shaft. An adjustment wheel assembly, a frictional assembly and an elastic assembly are fitted on the pivot shaft. The adjustment wheel assembly and the frictional assembly have a first adjustment wheel and a second frictional member synchronously movable with the first support and a second adjustment wheel and a first frictional member synchronously movable with the second support. When the first and second supports are rotated, the first and second adjustment wheels are driven to contact and abut against each other so as to provide axial action forces. The frictional assembly has multiple first and second frictional members, which are alternately arranged in frictional contact with each other to form multiple frictional pairs.

Abstract: A dual-shaft synchronous transmission device includes a hinge structure, a driving structure, and a linkage assembly, which are linked with each other. The hinge structure includes a first shaft, a second shaft parallel to the first shaft, and a carrier fixed on the first shaft and having a track slot. The driving structure is sleeved at the first shaft and can be driven by the second shaft. A guiding slot is formed on the outer surface of the driving structure. The linkage assembly includes a linking member sleeved at the guiding slot, a first connecting rod connected to the linking member, a second connecting rod linked to the linking member. The linking member is configured to move along the guiding slot with respect to the driving structure and parallel to the first shaft for driving a column of the second connecting rod in the track slot.

Abstract: A dual-shaft synchronous transmission device includes a hinge structure, a driving structure, and a linkage assembly, which are linked with each other. The hinge structure includes a first shaft, a second shaft parallel to the first shaft, and a carrier fixed on the first shaft and having a track slot. The driving structure is sleeved at the first shaft and can be driven by the second shaft. A guiding slot is formed on the outer surface of the driving structure. The linkage assembly includes a linking member sleeved at the guiding slot, a first connecting rod connected to the linking member, a second connecting rod linked to the linking member. The linking member is configured to move along the guiding slot with respect to the driving structure and parallel to the first shaft for driving a column of the second connecting rod in the track slot.