Patent ID: 8448769
Filing Date: 2013-05-28
Classification: F16D,F24D,F24F,G05D

Abstract:
1. Apparatus for engaging a rotary driving member with an element to be driven, the apparatus including: first and second rotatable members each having an engagement portion, the first rotatable member being axially movable to interengage the respective engagement portions, and one of the first or the second rotatable members being drivably connectable to the rotary driving member and the other of the first or the second rotatable members being drivably connectable to the element to be driven such that interengagement of the respective engagement portions effects positive engagement of the rotary driving member with the element to be driven; a slidable piston connected to the first rotatable member such that pressure acting on one end of the piston causes axial movement of the piston and the first rotatable member; a clutch device having a plurality of axially movable friction plates, a first set of which are rotatably engaged with the first rotatable member and a second set of which are rotatably engaged with the second rotatable member, the plurality of friction plates being arranged to provide a friction drive when the first and second set are pushed together; wherein one of the engagement portions includes a base unit drivably connected to the rotary driving member or the element to be driven and an engagement unit mounted on the base unit and arranged to interengage with the other of the engagement portions, the base unit and the engagement unit being rotatable relative to each other within a predetermined angle to permit the respective engagement portions to occupy an orientation suitable for interengagement, wherein the slidable piston includes a passageway arranged to permit pressure acting on the end of the piston also to act on the base unit, wherein the base unit is axially movable to activate the friction drive to substantially synchronise the rotation speeds of the first and second rotatable members before interengagement of the respective engagement portions, and wherein the base unit comprises an inner annular element and the engagement unit comprises an outer annular element mounted coaxially on the inner annular element, the inner and outer annular elements having one or more circumferentially interlocking stopper elements arranged to limit the rotation of the outer annular element relative to the inner annular element.