Push-pull apparatus adapted for assembling and disassembling a tubular body that is to be fitted into a ring retainer on a wall member

A push-pull apparatus adapted for assembling and disassembling a tubular body that is to be fitted into a ring retainer on a wall member, said push-pull apparatus comprising:

• a machine base;
• a coupling unit including a retractable main frame disposed on top of said machine base and longitudinally movable in forward and rearward directions relative to said machine base, said main frame having front and rear ends, said coupling unit further including a coupler mounted on said front end of said main frame and adapted to be extended into the ring retainer to engage the tubular body;
• an extension-unit mounted on said machine base and connected to said coupling unit, said extension unit being operable so as to move said coupling unit relative to said machine base;
• an impact unit provided on said coupling unit and movable along said coupling unit;
• and
• a drive unit mounted on said coupling unit and operable so as to move said impact unit along said coupling unit in order to enable said impact unit to impact a selected one of said front and rear ends of said main frame of said coupling unit and generate at said coupler of said coupling unit one of a pushing force for assembling the tubular body and a pulling force for disassembling the tubular body, wherein said main frame of said coupling unit has a rear end portion with a bottom side, said push-pull apparatus further comprising a cushioning device which is mounted on said bottom side of said rear end of said main frame and which interconnects said extension unit and said coupling unit.