A structure in which two worm wheels are disposed across a worm provides an increase in locking reliability while maintaining stable operation during rotation. At the time of rotation, respective rotating fulcrums set at both end portions in an axial direction of a worm are supported by bearing parts. At the time of locking, a locking fulcrum set at an eccentric position on one end portion in the axial direction of the worm is supported by one bearing part, while on the other end portion in the axial direction, the rotating fulcrum is supported by the other bearing part as is. As a result, the angle of lead of the worm supported by the pair of bearing parts is changed between the time of rotation and the time of locking and becomes smaller at the time of locking than at the time of rotation, whereby an increase in locking reliability can be achieved.

A structure in which two worm wheels are disposed across a worm provides an increase in locking reliability while maintaining stable operation during rotation. At the time of rotation, respective rotating fulcrums set at both end portions in an axial direction of a worm are supported by bearing parts. At the time of locking, a locking fulcrum set at an eccentric position on one end portion in the axial direction of the worm is supported by one bearing part, while on the other end portion in the axial direction, the rotating fulcrum is supported by the other bearing part as is. As a result, the angle of lead of the worm supported by the pair of bearing parts is changed between the time of rotation and the time of locking and becomes smaller at the time of locking than at the time of rotation, whereby an increase in locking reliability can be achieved.

A dynamic furniture system includes a first frame portion; a set of rollers mounted to the first frame portion; a second frame portion including one or more rockers having a roller-interface surface having a curved profile; wherein the set of rollers interface with the roller-interface surface of the rockers such that the second frame portion is moveable relative to the first frame portion; a set of one or more electromagnets mounted to or integrated with the first frame portion or the second frame portion; a set of one or more magnetically-interactive elements mounted to or integrated with a different one of the first frame portion or the second frame portion; and an electronic control system configured to vary a parameter of electrical energy supplied to the set of electromagnets over time to induce back and forth motion of one of the first frame portion or the second frame portion.

To increase strength without any weight increase due to a thickness increase and without causing the machining problem in half-blanking, an external gear and an internal gear are ring-shaped gears, and external teeth and internal teeth each have a tooth width substantially corresponding to the thickness of an outer circumferential surface of the external gear or an inner circumferential surface of the internal gear. The external gear and the internal gear are ring-shaped gears, that is, each can be formed through the punching of a plate, and strength resulting from the engagement of the external teeth and the internal teeth corresponds to strength resulting from the thickness of the material plates forming the external gear and the internal gear. Accordingly, the external teeth and the internal teeth can have a wider tooth width, achieving higher strength than when half-blanking is used.

To increase strength without any weight increase due to a thickness increase and without causing the machining problem in half-blanking, an external gear and an internal gear are ring-shaped gears, and external teeth and internal teeth each have a tooth width substantially corresponding to the thickness of an outer circumferential surface of the external gear or an inner circumferential surface of the internal gear. The external gear and the internal gear are ring-shaped gears, that is, each can be formed through the punching of a plate, and strength resulting from the engagement of the external teeth and the internal teeth corresponds to strength resulting from the thickness of the material plates forming the external gear and the internal gear. Accordingly, the external teeth and the internal teeth can have a wider tooth width, achieving higher strength than when half-blanking is used.

A multifunctional chair is disclosed, including: a first frame body unit, the first frame body unit including a head end and a tail end; a first supporting unit configured to support the first frame body unit, the first supporting unit connected with a first connecting position of the first frame body unit and a height of the tail end of the first frame body unit being lower than a height of the first connecting position; a first leaning unit arranged in a position of the first frame body unit close to the first connecting position; a second frame body unit arranged on a back portion of the first frame body unit, the second frame body unit and the first frame body unit being rotatably connected, the second frame body unit and the first frame body unit in rotatable connection being capable of moving between a first posture of a reclining chair or a seat and a second posture of fitness equipment, the second frame body unit and the first frame body unit being in the first posture when having an angle, and the second frame body unit and the first frame body unit being in the second posture when the tail ends of the second frame body unit and the first frame body unit are overlapped; and a second leaning unit arranged on the second frame body unit. The multifunctional chair has multiple functions and is also used for seats, recliners and fitness equipment, and has simple structure, simple and fast operation, convenient use, and easy to carry and transport.

A multifunctional chair is disclosed, including: a first frame body unit, the first frame body unit including a head end and a tail end; a first supporting unit configured to support the first frame body unit, the first supporting unit connected with a first connecting position of the first frame body unit and a height of the tail end of the first frame body unit being lower than a height of the first connecting position; a first leaning unit arranged in a position of the first frame body unit close to the first connecting position; a second frame body unit arranged on a back portion of the first frame body unit, the second frame body unit and the first frame body unit being rotatably connected, the second frame body unit and the first frame body unit in rotatable connection being capable of moving between a first posture of a reclining chair or a seat and a second posture of fitness equipment, the second frame body unit and the first frame body unit being in the first posture when having an angle, and the second frame body unit and the first frame body unit being in the second posture when the tail ends of the second frame body unit and the first frame body unit are overlapped; and a second leaning unit arranged on the second frame body unit. The multifunctional chair has multiple functions and is also used for seats, recliners and fitness equipment, and has simple structure, simple and fast operation, convenient use, and easy to carry and transport.

A drive bush configured to circumferentially rotate and drive a pair of wedge members in an eccentric space includes a cylindrical portion rotatably supported inside a boss portion of an internal tooth constituting member, a flange portion integrally formed at a first end portion in the axial direction of the cylindrical portion so as to face one side surface side of the wedge members, and a pushing portion integrally provided on the outer peripheral side of the flange portion, and configured to release a wedge effect by circumferentially pushing the wedge members. The inner surface of the cylindrical portion is integrally formed with a wall portion, and the wall portion is formed with, in the middle thereof, a female spline teeth meshing with the output shaft of a motor. The cylindrical portion, the wall portion including the female spline teeth and the flange portion have substantially the same thickness.

A drive bush configured to circumferentially rotate and drive a pair of wedge members in an eccentric space includes a cylindrical portion rotatably supported inside a boss portion of an internal tooth constituting member, a flange portion integrally formed at a first end portion in the axial direction of the cylindrical portion so as to face one side surface side of the wedge members, and a pushing portion integrally provided on the outer peripheral side of the flange portion, and configured to release a wedge effect by circumferentially pushing the wedge members. The inner surface of the cylindrical portion is integrally formed with a wall portion, and the wall portion is formed with, in the middle thereof, a female spline teeth meshing with the output shaft of a motor. The cylindrical portion, the wall portion including the female spline teeth and the flange portion have substantially the same thickness.

A drive bush configured to circumferentially rotate and drive a pair of wedge members in an eccentric space includes a cylindrical portion rotatably supported inside a boss portion of an internal tooth constituting member, a flange portion integrally formed at a first end portion in the axial direction of the cylindrical portion so as to face one side surface side of the wedge members, and a pushing portion integrally provided on the outer peripheral side of the flange portion, and configured to release a wedge effect by circumferentially pushing the wedge members. The inner surface of the cylindrical portion is integrally formed with a wall portion, and the wall portion is formed with, in the middle thereof, a female spline teeth meshing with the output shaft of a motor. The cylindrical portion, the wall portion including the female spline teeth and the flange portion have substantially the same thickness.