Fluid arrangement

A fluid actuating apparatus of the type including a fluid circuit and a plurality of actuating members which have imparted thereto alternating movement governed by said fluid circuit, said apparatus comprising:

• a working cylinder;
• a working piston mounted for movement in opposite first and second directions within said working cylinder;
• a control cylinder;
• a control piston mounted for movement in opposite first and second directions within said control cylinder;
• a fluid feeding line for a source of fluid under pressure permanently connected to a return chamber in said working cylinder and to a first chamber in said control cylinder;
• a working chamber in said working cylinder permanently connected to a second chamber in said control cylinder;
• a fluid discharge line for discharging fluid permanently connected to a discharge chamber in said working cylinder and to a third chamber in said control cylinder;
• a control chamber in said working cylinder permanently connected to a fourth chamber in said control cylinder;
• and
• said working piston and said control piston each including means cooperating with said working cylinder and said control cylinder, respectively, for opening and closing communication between selected ones of said chambers in said working cylinder and said control cylinder, such that in an initial stage of the cycle of operation of the apparatus said working piston is in a first position thereof adapted to contact a percussion tool and said control piston is in a first position thereof whereat said second and third chambers thereof are in communication, thereby permitting driving of said working piston to a second position thereof spaced from the percussion tool, at which second position of said working piston said return chamber and said control chamber are in communication, thereby causing driving of said control piston to a second position thereof at which said first and second chambers are in communication, thereby causing said working piston to be moved toward said first position thereof to strike the percussion tool, at which first position said control chamber and said discharge chamber are in communication, thereby permitting said control piston to be moved to said first position thereof, whereat the cycle of operation starts anew.