Service tool for coupling to a service port receiver associated with a gearbox

In combination a service tool and service port receiver comprising:

• (1) a service port receiver adapted for connection to a service port associated with a gearbox;
• (2) a service tool comprising:
• a coupling arrangement for releasable coupling with the service port receiver, said arrangement configured for rotational movement about the service port receiver between (a) a released position where the coupling arrangement is released from the service port receiver permitting axial movement of said coupling arrangement relative to said service port receiver, and (b) an engaged position where the coupling arrangement engages the service port receiver preventing axial movement of said coupling arrangement relative to said service port receiver,
• a locking actuator operatively coupled to the coupling arrangement and arranged for axial movement between (i) a locked position where the locking actuator releasably engages the service port receiver preventing rotation of the coupling arrangement thereby retaining it in the engaged position, and (ii) an unlocked position where the locking actuator disengages the service port receiver permitting rotation of the coupling arrangement to the released position for its release from said service port receiver;
• a plunger actuator adapted for connection to a fluid conduit, said plunger actuator being slidably coupled to the coupling arrangement for movement between an open position and a closed position where in the open position, with the coupling arrangement in the engaged position and the locking actuator in the locked position, the plunger actuator is adapted to contact a check valve of the service port receiver and open it thereby permitting fluid flow between the gearbox and the fluid conduit via a fluid pathway formed at least in part by the plunger actuator;
• the plunger actuator including a plunger member arranged for sliding movement within the coupling arrangement between the open and closed positions, the plunger member partly defining the fluid passageway;
• the coupling arrangement including a coupling body surrounding at least part of the plunger actuator, and a key member having an operative end radially projecting inward of the coupling body for guided movement along an axially directed keyway formed in the plunger member of the plunger actuator during movement of said plunger actuator between its open and closed positions.