Hand tools including a hydraulic jack for the control of working members

An hydraulic hand-tool including an hydraulic jack capable of being operated manually using one hand comprising:

• (a) an elongate piston having a front end adapted to be connected to a tool and at lest two sections of different transverse cross-sectional areas having an exterior surface area;
• (b) a housing including a hollow front end portion having an interior surface defining a plurality of sections with different inner diameter corresponding in size, position and number so as to accommodate said sections of said piston in a manner which permits said piston to slide in a reciprocating manner within said hollow front end portion of said housing whereby a plurality of chambers including a main chamber and at least one auxiliary chamber for receiving hydraulic fluid are defined by said exterior surface area and said interior surface as said piston slides in a forward direction;
• (c) an hydraulic fluid supply conduit having a primary line with an end opening directly into said main chamber and at least one supplemental line having a port adapted to communicate with said at least one auxiliary chamber after said piston slides in a forward direction a predetermined distance to a position forward of said port;
• (d) an hydraulic fluid reservoir adapted to supply hydraulic fluid to another end of said primary line;
• (e) a pump in communication with said primary line adapted to transfer fluid from said reservoir through said primary line first into said main chamber to cause said piston to move in a forward direction for said predetermined distance and thereafter through said at least one supplemental line into said at least one of auxiliary chamber to cause said piston to continue to move in a forward direction, thereby successively placing said main chamber into fluid communication with said at least one auxiliary chamber as said piston moves in said forward direction;
• and
• (f) an hydraulic jack operably connected to said pump capable of being operated manually by one hand, wherein at least one section of said piston has an exterior surface adapted to maintain continuous contact with at least one section of said interior surface of said hollow front end portion of said housing as said piston slides in a forward direction, and wherein at least one section of said piston is provided with a seal adapted to engage a corresponding section of said inner surface of said hollow front end portion of said housing so as to prevent passage of fluid between said chambers.