Complex elastic unit for maximizing space utilization and elastic energy storage within limited space and variable gravity compensation module with the complex elastic unit and curved lever

A variable gravity compensation apparatus with a curved lever, the apparatus comprising:

• a housing;
• an interlocking cam which is installed to the housing, being rotated by a load;
• a curved lever which is rotated interlocked with the rotation of the interlocking cam and which provides elasticity to rotate the interlocking cam toward an initial position;
• an adjustment unit which adjusts a position of a pivot which is a center of rotation of the curved lever, allowing the pivot to move according to a strength of load;
• and
• an elastic unit which is equipped within the housing to provide elasticity to the curved lever, wherein
• a driving end which is adhered to the interlocking cam is formed on one end of the curved lever with respect to the pivot, a driven end which is adhered to an elastic follower equipped to the elastic unit is formed on the other end thereof, and the driven end is configured into a curved shape that a sectional side surface connecting the pivot to the elastic follower has a curvature,
• wherein a cam surface formed on an outer surface of the interlocking cam is formed to change a length of radius along a circumferential direction with respect to a center point, the housing is equipped with a cam follower which slides interlocked with the rotation of the interlocking cam, and the cam follower is adhered to the driving end,
• wherein a curved surface of the curved lever has a shape allowing neither the cam follower nor the elastic follower to be moved during a torque variation mode in which the position of the pivot is varied by the adjustment unit,
• wherein:
• in the housing, a cam follower slot in which the cam follower slides;
• and
• an elastic member slot which is equipped to one side of the elastic unit and along which a first elastic guide with an installed first elastic follower slides;
• are formed, respectively,
• wherein the elastic unit is configured with a coil spring set having at least two coil springs, in which at least one of the coil springs is connected in parallel with at least another of the coil springs, and at least one plate spring which is disposed in series with the coil spring set, and
• wherein, for each of one or more of the at least two coil springs of the coil spring set:
• the coil spring set further comprises an elastic spring slot into which the respective coil spring is inserted, a first elastic follower coupled to an end of one side of the respective coil spring and a second follower coupled to an end of another side of the respective coil spring.