A system includes a rotating drive and a linear drive. An input driven gear may be coupled to the rotating drive while a sun gear is coupled to the shaft of the input driven gear. A first counterweight may support an idler gear and an output gear. The first counterweight is coupled to the driven gear and which rotates with the driven gear. The idler gear is coupled to the sun gear and an output gear. The idler gear may rotate the output gear when the idler gear is translated around the sun gear. A second counterweight is coupled to the output gear and which rotates with the output gear when the output gear is rotated by the idler gear. An end portion of the second counterweight coupled to the linear drive moves in substantially straight line as the second counterweight rotates while also being translated around the sun gear.

This invention is an all gear continuously variable transmission that is non-dependent on friction. It can me be used in high torque applications. It offers a steady and uniform output for a steady and uniform input. It allows a co-axial input and output thereby by using a planetary gear system the output can be made continuous from forward to reverse. This uses a scotch-yoke mechanism to convert rotational motion to a linear reciprocating motion. The linear distance of this reciprocating motion-stroke is changed by altering the crankpin location of the scotch-yoke mechanism. This reciprocating motion is converted to a rocking motion by using a rack and pinion and later converted to a unidirectional motion via a One-Way-Bearing. A set of non-circular gears are used to achieve a steady and uniform output. It employs a very simple mechanism to change the ratio between the input and output of the transmission.

This invention is an all gear continuously variable transmission that is non-dependent on friction. It can me be used in high torque applications. It offers a steady and uniform output for a steady and uniform input. It allows a co-axial input and output thereby by using a planetary gear system the output can be made continuous from forward to reverse. This uses a scotch-yoke mechanism to convert rotational motion to a linear reciprocating motion. The linear distance of this reciprocating motion-stroke is changed by altering the crankpin location of the scotch-yoke mechanism. This reciprocating motion is converted to a rocking motion by using a rack and pinion and later converted to a unidirectional motion via a One-Way-Bearing. A set of non-circular gears are used to achieve a steady and uniform output. It employs a very simple mechanism to change the ratio between the input and output of the transmission.

A drive transmission apparatus includes a first rotating unit rotated by driving force from a drive source and a second rotating unit rotated by the first rotating unit. The first and second rotating units includes first gear pair meshing at a first transmission ratio and second gear pair meshing at a second transmission ratio. A retention mechanism includes a protruded portion provided on the first rotating unit and a recessed portion provided on the second rotating unit, and is configured to retain a rotation angle of the second rotating unit by an engagement of the protruded portion and the recessed portion in a state where the first and second gear pairs are unmeshed.

Various mechanical drive devices, mechanical gears, combinations thereof and medical or dental treatment devices with such mechanical drive devices or gears are described. The mechanical drive devices and mechanical gears convert a unidirectional rotational movement received by a motor drive into a multidirectional movement, so that a tool-holding device of the treatment device can be induced to a multidirectional movement, in particular to a, preferably simultaneous, lifting and rotating movement or to a lifting and oscillating rotational movement with a reduced rotational speed.

Various mechanical drive devices, mechanical gears, combinations thereof and medical or dental treatment devices with such mechanical drive devices or gears are described. The mechanical drive devices and mechanical gears convert a unidirectional rotational movement received by a motor drive into a multidirectional movement, so that a tool-holding device of the treatment device can be induced to a multidirectional movement, in particular to a, preferably simultaneous, lifting and rotating movement or to a lifting and oscillating rotational movement with a reduced rotational speed.

A continuously variable transmission (CVT) that does not depend on friction to transmit power. A constant and uniform output angular velocity can be achieved when the input angular velocity is constant and uniform by modifying the rate of change of angular displacement of the input disk using a set of non-circular gears. Co-axial input and output can also be achieved.

A gearing device for discontinuously moving at least two elements, in particular barrier elements of a passageway device, having a drive axis, a first active axis of rotation, formed for a torque-transmitting operative connection with the first element, in particular barrier element, a first non-uniformly translating gearing stage between the drive axis and the first active axis of rotation, a second active axis of rotation formed for a torque-transmitting operative connection with the second element, in particular barrier element, a second non-uniformly translating gearing stage between the drive axis and the second active axis of rotation.

A gearing device for discontinuously moving at least two elements, in particular barrier elements of a passageway device, having a drive axis, a first active axis of rotation, formed for a torque-transmitting operative connection with the first element, in particular barrier element, a first non-uniformly translating gearing stage between the drive axis and the first active axis of rotation, a second active axis of rotation formed for a torque-transmitting operative connection with the second element, in particular barrier element, a second non-uniformly translating gearing stage between the drive axis and the second active axis of rotation.

The present disclosure describes innovations to improve the use of noncircular gear pairs in a transmission, e.g., an infinitely variable transmission. The noncircular gear pair includes a first noncircular gear with a first pitch curve; and a second noncircular gear with a second pitch curve. The first pitch curve includes a plurality of elliptical portions, and a curvature of the first pitch curve is positive along the entire first pitch curve; and wherein the second pitch curve is a conjugate of the first pitch curve.