Telescopic position adjustment mechanism

A telescopic position adjustment mechanism, comprising:

• a base;
• a telescoping element slidingly telescopically received by the base;
• a sink reservoir;
• a support reservoir defined between the base and the telescoping element;
• the support reservoir supporting the telescoping element against the base;
• the support reservoir having a variable volume according to a position of the telescoping element relative to the base;
• a housing defining a stepping chamber;
• a stepping piston slidingly sealingly received in the stepping chamber;
• the stepping piston reciprocable within the stepping chamber between a stepped position and an unstepped position;
• the stepping piston being biased toward the unstepped position;
• the stepping piston cooperating with the stepping chamber to define a variable-volume stepping reservoir whose maximum volume is defined by the stepped position of the stepping piston and whose minimum volume is defined by the unstepped position of the stepping piston;
• the support reservoir being in valve-governed fluid communication with the sink reservoir;
• the stepping reservoir being in valve-governed fluid communication with the support reservoir;
• the stepping reservoir being in valve-governed fluid communication with the sink reservoir;
• at least one valve governing fluid communication between:
• the stepping reservoir and the sink reservoir;
• and
• the stepping reservoir and the support reservoir;
• the at least one valve having:
• a locking configuration in which:
• fluid communication between the support reservoir and the stepping reservoir is obstructed;
• fluid communication between the support reservoir and the sink reservoir is obstructed;
• and
• fluid communication between the stepping reservoir and the sink reservoir is permitted;
• a stepping configuration in which:
• fluid communication between the support reservoir and the stepping reservoir is permitted;
• fluid communication between the support reservoir and the sink reservoir is obstructed;
• fluid communication between the stepping reservoir and the sink reservoir is obstructed;
• and
• at least one valve actuator coupled to the at least one valve for selectively driving the at least one valve into one of the locking configuration and the stepping configuration.