Driving assembly

A driving assembly comprising:

• a. a first unit having a portion with the form of a first open container, a bottom wall of which defines a first bladder bearing surface, said first container having a first container side wall extending from the peripheral portion of said bottom wall, said side wall, together with said first container bottom wall, defines a first cavity, said first container being open on the end opposite said first container bottom wall;
• b. a second unit having a portion with the form of a second, open container, a bottom wall of which defines a second bladder bearing surface, said second container having a second container side wall extending from the peripheral portion of said second unit bottom wall, said second container side wall together with said second container bottom wall defines a second cavity, said second container being open on the end opposite said second container bottom wall, said second container being disposed within the cavity of said first container in telescopic, nested relationship therewith so that said first and second bearing surfaces are in opposed, spaced relationship, said first unit being movable relative to said second unit;
• c. an expansible bladder engaging said first and second units and disposed therebetween, said bladder having an outer surface area and an inner expansible chamber;
• said bladder having a pair of opposite end wall portions comprising the major portion of said outer surface area of said bladder;
• the remaining outer surface area being defined by a side wall portion of said bladder at least when said container is in a pressurized condition;
• d. means connected with said bladder for effecting communication with a pressure source, the shape of said bladder being changeable in response to a change in fluid pressure in said bladder to move said first unit with respect to said second unit, said communication means passing through said second bearing surface of said second unit and into said second container cavity, whereby said second container provides space for and protection for said communication means;
• e. said first container side wall and said first and second container bottom walls defining an enclosed area within which said bladder is entirely disposed;
• f. said bladder fully engaging the side of said second container bottom wall which faces away from said second container cavity, said bladder being disposed entirely outside said second container cavity, said bladder fully engaging the side of said first container bottom wall which faces toward said first container cavity of said first container, said bladder being disposed entirely within said first container cavity;
• g. the entirety of said first container side wall being disposed in parallel relationship with the entirety of said second container side wall, the major portions of the first and second container side walls overlapping each other in face-to-face relationship when said bladder is in the depressurized condition, said first and second container side walls being movable relative to each other when the pressure in said bladder increases, said first and second container side walls cooperating with each other during such movement to guide and stabilize the movement of said first unit relative to said second unit.