Apparatus and method for expanding preforms into containers

Patent metadata

Field	Value
Publication number	US-9486952-B2
Application number	US-201314060468-A
Country	US
Kind code	B2
Filing date	Oct 22, 2013
Priority date	Oct 22, 2012
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

The invention relates to an apparatus as well as to a method for expanding preforms into containers within a blow mold by means of a pressurized pneumatic medium, wherein a compressor piston unit for compressing the pneumatic medium is in flow communication with the blow mold, in order to introduce a volume flow of the pneumatic medium into an inner region of the blow mold, and wherein an actuator unit that can be activated by a hydraulic medium interacts with at least one element of the compressor piston unit, in order to drive the compressor piston unit during an expansion process of the container for compressing the pneumatic medium, and in order to be driven itself, during a relaxation process that temporally follows the expansion process, due to the returning volume flow of the pneumatic medium into the compressor piston unit.

First claim

The invention claimed is:

1. Method for expanding preforms into containers ( 20 ) within a blow mould ( 1 ) by means of a pressurised pneumatic medium (M G ),
wherein
during an expansion process for expanding the container ( 20 ), a compressor piston unit ( 11 ) for compressing the pneumatic medium (M G ) is controlled by means of an actuator unit ( 12 ) that is driven by a hydraulic medium (M F ) and interacts with at least one element of the compressor piston unit ( 11 ), in order to transport the pneumatic medium (M G ) into an inner region of the blow mould ( 1 ), and that
during a relaxation process that follows the expansion process, the pneumatic medium (M G ) is returned into the compressor piston unit ( 11 ), as a result of which the actuator unit ( 12 ) is caused to a return of the hydraulic medium (M G ); and
wherein
a piston element ( 11 b ) and at least a component or module of the actuator unit ( 12 ) are coupled together in such a way that as a result of a movement of the piston element ( 11 b ) the module or the component of the actuator unit ( 12 ) is moved.

2. The method as claimed in claim 1 , wherein during the relaxation process, the hydraulic medium (M F ) is fed to a pump unit ( 13 ) via at least one connection line ( 17 ), wherein the pump unit ( 13 ) is in operative connection with a drive machine ( 15 ).

3. The method as claimed in claim 2 , wherein the pump unit ( 13 ) activated by a volume flow of the hydraulic medium (M F ) therethrough drives the drive machine ( 15 ) as a drive generator for generating electric energy and/or delivers the fluid into a pressurised container.

4. The method as claimed in claim 2 , wherein a control unit controls the drive machine ( 15 ) and/or at least one valve unit ( 19 ) provided between at least one storage container ( 14 ) for storing the hydraulic medium (M F ) and the actuator unit ( 12 ), in order to allow, during the expansion process, the hydraulic medium (M F ) to be discharged from the storage container ( 14 ) to the actuator unit ( 12 ), and during the relaxation process, from the actuator unit ( 12 ) to the storage container ( 14 ).

5. Method for expanding preforms into containers ( 20 ) within a blow mould ( 1 ) by means of a pressurised pneumatic medium (M G ),
wherein
during an expansion process for expanding the container ( 20 ), a compressor piston unit ( 11 ) for compressing the pneumatic medium (M G ) is controlled by means of an actuator unit ( 12 ) that is driven by a hydraulic medium (M F ) and interacts with at least one element of the compressor piston unit ( 11 ), in order to transport the pneumatic medium (M G ) into an inner region of the blow mould ( 1 ), and that
during a relaxation process that follows the expansion process, the pneumatic medium (M G ) is returned into the compressor piston unit ( 11 ), as a result of which the actuator unit ( 12 ) is caused to a return of the hydraulic medium (M G )
and wherein the actuator unit ( 12 ) itself comprises an actuator piston element ( 12 b ) and an actuator medium space ( 12 a ) within a hydraulic medium (M F ) is introduced in order to move the actuator piston element ( 12 b ) in such a way that the movement of the actuator piston element ( 12 b ) also moves the piston element ( 11 b ) of the compressor piston unit ( 11 ) which is in operative connection with the actuator piston element ( 12 b ) so that during an expansion process of the container to be expanded the piston element ( 11 b ) of the compressor piston unit ( 11 ) compresses a pneumatic medium (M G ) present in the compression space ( 11 a ) which is then transferred to a blow nozzle or to a blow mold ( 1 ).

6. The method according to claim 1 , wherein as a result of the movement of the actuator piston element ( 12 b ) also the piston element ( 11 b ) of the compressor piston unit ( 11 ) which is in operative connection with the actuator piston element ( 12 b ) is moved.

7. The method according to claim 1 wherein the actuator unit ( 12 ), or at least a component of the actuator unit ( 12 ), receives an electronic signal from a control unit and translates this signal into corresponding mechanical movements.

8. The method according to claim 2 wherein the drive machine ( 15 ) alternately acts as an electric drive motor and as an electric drive generator.

9. The method according to claim 1 , wherein the movement of the piston element ( 11 b ) initiates a movement of the actuator unit ( 12 ).

10. The method according to claim 1 , wherein the hydraulic medium (M F ) which is located in an actuator medium space ( 12 a ) is pressed by the movement of the actuator piston element ( 12 b ) out of the actuator medium space ( 12 a ) into adjacent connection lines ( 17 ) connected to the actuator medium space ( 12 a ) for transporting the hydraulic medium (M F ).

11. The method according to claim 4 , wherein two storage containers ( 14 ) are provided which contain the hydraulic medium (M F ) and which are in fluid communication with the at least one pump unit ( 13 ) via connection lines ( 17 ).

12. The method according to claim 11 , wherein the pump unit ( 13 ) establishes a pressure differential between the two storage containers ( 14 ).

Assignees

• Krones Ag

Inventors

• Bielmeier Heinrich

Classifications

• B29C2049/7831

  characterised by pressure values or ranges · CPC title

• B29C49/4237

  Pneumatic drive means · CPC title

• B29C49/42362

  Electric drive means, e.g. servomotors · CPC title

• B29C49/12

  Stretching rods · CPC title

• B29C49/4273

  Auxiliary operations after the blow-moulding operation not otherwise provided for · CPC title