Abstract: Methods and systems for a gear mechanism that includes one or more actuators operable to activate or deactivate in order to drive or be driven by sequential engagement with one or more cam features incorporated within an interior of a ring gear.

Abstract: A method of forming a plug-like member comprises placing a consumable member (4) in a bore (1) of a workpiece (2). The consumable member (4) is rotated relative to the workpiece (2) while they are urged together so as to generate frictional heat and the formation of plasticised material (5). The plasticised material (5) is allowed to solidify so as to form a plug-like member having an outer surface conforming to the inner surface of at least part of the bore (1). The plug-like member is either left in situ or, following formation of the complete plug-like member, removed from the workpiece.

Abstract: A method of operating on a workpiece comprises offering a probe of material harder than the workpiece material to a continuous surface of the workpiece causing relative cyclic movement between the probe and the workpiece while urging the probe and workpiece together whereby frictional heat is generated as the probe enters the workpiece so as to create a plasticized region in the workpiece material around the probe, stopping the relative cyclic movement, and allowing the plasticized material to solidify around the probe. This technique, which we refer to as "friction plunge welding" provides a very simple method of joining a probe to a workpiece. The method can be used for repairing cracks and the like within a workpiece or for joining members, such as studs or bushes, to a workpiece.

Abstract: A method of joining a covering layer (9) onto a substrate (10) comprises placing part of the covering layer (9) on the substrate (10) with the remaining part of the covering layer spaced from the substrate so as to expose a region of contact (5) between the covering layer and substrate. A focussed power beam such as a laser or electron beam impinges on the contact region (5) so as to bond or fuse the substrate (10) and covering layer (9) together. The spaced part of the covering layer (9) is then moved towards the substrate (10) so as to change the position of the contact region (5) and the focussed power beam is caused to impinge on the new contact region. These steps are repeated until the covering layer is bonded or fused to the substrate.