Method and apparatus for making aerosol cans for metered dose inhaler

1. Apparatus for forming an aerosol can for a metered dose inhaler, the apparatus including a turret rotatable about a central axis and having a plurality of tool sets for carrying out a forming operation on a respective plurality of workpieces as the turret rotates, wherein each tool set is configured and arranged to move about said central axis as the turret rotates and wherein each tool set comprises two rotatably driven tools that are configured and arranged to carry out a the forming operation which is a beading operation or a trimming operation on a workpiece, and the turret has drive means comprising a drive ring that surrounds the turret and a respective drive shaft for each tool of each tool set, each drive shaft driven by the drive ring for rotating each tool of each tool set.

2. Apparatus according to claim 1 wherein the turret is a beading turret wherein said two rotatably driven tools of each tool set include a pressure wheel tool and a mandrel tool for performing a beading operation on a workpiece by rotatively nipping the workpiece between complementary profiles of the tools.

3. Apparatus according to claim 1 wherein one of the tools of each tool set is positioned within the workpiece (the internal tool) and the relative movement between the tools brings the other tool into contact with an outer surface of the workpiece (the external tool) to trap locally the wall of the workpiece between the tools for carrying out a beading operation or a trimming operation on the wall of the workpiece;

wherein co-operating profiles of the tools run at the same velocity to reduce or eliminate slippage against the workpiece;

wherein each tool set has an associated lifting module arranged to receive a workpiece loaded into the turret and to raise the workpiece to position one tool of the tool set within the workpiece for a beading operation or a trimming operation, and, after the beading operation or trimming operation, the lifting module is arranged to lower the workpiece to clear said one tool so that the workpiece can be unloaded from the turret;

wherein the rotatably driven tools of each tool set are mounted for rotation about axes parallel to each other and to the central axis and the tools are relatively movable in a direction transverse to the central axis only for performing a beading operation or a trimming operation on a workpiece according to whether the turret is beading turret or a trimming turret.

4. Apparatus according to claim 1 wherein each tool set is co-operable with a stationary cam that extends about the turret for controlling relative movement of the tools for performing a beading operation or trimming operation on a workpiece.

5. Apparatus according to claim 4 wherein said two rotatably driven tools of each tool set are biased away from each other and the tool set includes a cam follower co-operable with the stationary cam for relatively moving said two rotatably driven tools towards each other for carrying out a beading operation or a trimming operation.

6. Apparatus according to claim 5 wherein the cam follower is pivotally mounted and is adjustable to vary the relative movement of said two rotatably driven tools towards each other.

7. Apparatus according to claim 4 wherein the tool sets are positioned in the vicinity of, preferably adjacent to, the stationary cam such that the stationary cam and tools of each tool set are arranged in a generally horizontal plane and the cam is configured to control relative movement between the tools of each tool set radially with respect to the central axis of the turret.

8. Apparatus according to claim 7 wherein the tools of each tool set are both movable towards and away from each other for performing a beading operation or a trimming operation;

wherein the position of one of the tools of each tool set is fixed relative to the central axis of the turret and the position of other tool is movable relative to the central axis of the turret towards and away from the fixed tool for performing a beading operation or a trimming operation.

9. Apparatus according to claim 1 wherein the drive shafts for the tools of each tools set are configured to accommodate relative movement of the tools while maintaining the rotational axes of the tools parallel to each other and to the central axis of the turret;

wherein one or both drive shafts of a tool set includes one or more flexible couplings to accommodate angular and/or axial movement of the drive shafts;

wherein the tools of each tool set are mounted at a lower end of the drive shafts that are rotatably received in respective tool blocks defining the rotational axes of the tools.