Holder for machining units

1. A system for mounting and aligning a machining unit to a machine, said system comprising:

a) a holder including a first part, said first part being mountable on a machine or being part of a machine, a second part which is releasably coupled to said first part in a defined first position, said second part being coupled to a third part with third coupling means for coupling said third part with a machining unit, wherein positioning means are located between said second part and said third part to allow moving said third part relative to said second part in at least one spatial direction; and

b) at least one alignment station, said alignment station comprising first coupling means for releasably coupling the second part of the holder to said alignment station in said first defined position and at least one measuring device arranged on said alignment station, said measuring device configured to measure the position of said third part or of a machining unit coupled to said third part relative to the second part.

2. A method for mounting and aligning a machining unit to a machine using a system according to claim 1 , comprising the steps of:

a) mounting the first part onto the machine;

b) coupling the machining unit to the third part by means of said third coupling means;

c) coupling said second part to the alignment station;

d) aligning of said third part or of the machining unit relative to said second part by means of the positioning means and of the measuring device;

e) removal of the second part from said alignment station;

f) coupling of said second part to said first part in said first defined position relative to each other.

3. A system according to claim 1 , wherein said machine is a rotary transfer machine.

4. A holder for mounting and aligning a machining unit to a machine, said holder comprising:

a) a first part with first coupling means, said first part being mountable on a machine or being part of a machine;

b) a second part with second coupling means, said second coupling means being configured to interact with said first coupling means such as to releasably couple said second part to said first part in a first defined position;

c) a third part coupled to said second part by means of positioning means located between said second part and said third part, said positioning means being configured such as to move said third part relative to said second part in at least one spatial direction;

d) third coupling means arranged on said third part allowing to couple said third part to a machining unit.

5. The holder according to claim 4 , wherein said positioning means are configured to move said third part relative to said second part at least along a linear axis and/or at least around one rotational axis.

6. The holder according to claim 4 , wherein the positioning means comprise at least two translational elements, said translational elements being preferably selected from one of an eccentric bushing and/or a linear guide member.

7. The holder according to claim 4 , wherein said first coupling means and said second coupling means comprise a plurality of screws and complementary screw holes.

8. Machine comprising at least one holder according to claim 4 .

9. A holder according to claim 4 , wherein said machine is a rotary transfer machine.