In a tool reciprocator for operation with a source of pressured fluid and a sump, the tool reciprocator having a housing;
- a fluid-operated reciprocatory motor having cylinder and piston elements on the housing;
- a pair of motor conduits in communication with spaced points in the motor cylinder element on opposite sides of the motor piston element and with the sump and source of pressured fluid;
- a pressured fluid responsive and operated movable shifter valve member common to the motor conduits and disposed therein between the motor cylinder element and source of pressured fluid and sump adapted, when moved to and occupying one position, to connect a motor conduit, communicating with the motor cylinder element on one side of the motor piston element, with the source of pressured fluid and the other motor conduit, communicating with the motor cylinder element on the other side of the motor piston element, with the sump and, when moved to and occupying another position, to connect the first mentioned motor conduit with the sump and the second mentioned motor conduit with the source of pressured fluid and thereby to reciprocate one of the motor elements;
- a tool engaging part operatively connected to the reciprocative of the motor elements and adapted to be reciprocated thereby;
- and means for moving the movable shifter valve member to and from the mentioned positions thereof comprising:
- a pilot conduit individual to and operatively connected with one end of the mentioned movable shifter valve member and to the source of pressured fluid and to the sump for communicating pressured fluid and for venting spent pressured fluid to and from the mentioned movable shifter valve member end;
- a second pilot conduit individual to and operatively connected with the other end of the movable shifter valve member, opposite to the first mentioned shifter valve member end, and to the source of pressured fluid and to the sump for communicating pressured fluid and for venting spent pressured fluid to and from the second mentioned movable valve shifter member end;
- a pilot valve member individual to and disposed in the first mentioned pilot conduit between the source of pressured fluid and the sump and the first mentioned end of the movable shifter valve member and supported for movement to and from a first position in closed relation to the sump and open relation to the source of pressured fluid from and to a second position in open relation to the sump and closed relation to the source of pressured fluid and providing, when in the first mentioned position, communication between the source of pressured fluid and the first mentioned end of the movable shifter valve member and, when in the second mentioned position, communication between the sump and the first mentioned end of the movable shifter valve member;
- a second pilot valve member individual to and disposed in the second mentioned pilot conduit between the source of pressured fluid and the sump and the second mentioned end of the movable shifter valve member and supported for movement to and from a first position in closed relation to the sump and open relation to the source of pressured fluid from and to a second position in open relation to the sump and closed relation to the source of pressured fluid and providing, when in the first mentioned position, communication between the source of pressured fluid and the second mentioned end of the movable shifter valve member and, when in the second mentioned position, communication between the sump and the second mentioned end of the movable shifter valve member;
- means in engagement with the mentioned pilot valve members and operative to bias each of the same to normally occupy the pilot valve member first mentioned position, whereby pressured fluid is normally communicated to and exerts against both ends of the mentioned opposite ends of the movable shifter valve member at the same time;
- and means operatively connected to and actuated by the reciprocative of the motor elements to individually and selectively move one of the pilot valve members from its respective first mentioned position to the second mentioned position thereof, when the reciprocative of the motor elements approaches a certain stage in a stroke thereof,
- whereby the movable shifter valve member responds to the pressured fluid being communicated and exerted on the end of the mentioned opposite ends of the movable shifter valve member through the pilot conduit in which the unmoved pilot valve member is located causing the movable shifter valve member to move from an occupied to an unoccupied position of the mentioned positions thereof with alacrity and substantially coincidentally with the arrival of the reciprocative of the motor elements at the mentioned stage in its stroke and thus to speedily reverse the direction of movement of the reciprocative of the motor elements.