A Capsule for Producing A Beverage

Abstract

Capsule ( 1 ) for the preparation of a beverage having a cup-shaped body ( 2 ) adapted to contain a dose of substance to be brewed and bounded by a lateral wall ( 6 ), a bottom wall ( 8 ) and a tubular appendage ( 9 ), which extends from the bottom wall ( 8 ) towards the inside of the capsule ( 1 ), and is closed at an inner end thereof by a membrane ( 23 ) connected firmly to the same end and provided with a plurality of through slots ( 24 ) configured to widen when, following the feeding of a pressurised fluid into the capsule ( 1 ), the pressure inside the capsule ( 1 ) reaches a threshold pressure.

1 . A capsule for preparing a beverage, the capsule ( 1 ) comprising a cup-shaped body ( 2 ), which is adapted to contain a dose of a substance to be brewed, has a longitudinal axis ( 3 ), and comprises a lateral wall ( 6 ) coaxial with the axis ( 3 ), a bottom wall ( 8 ), and a tubular appendage ( 9 ), which extends from the bottom wall ( 8 ) towards the inside of the capsule ( 1 ) and defines a beverage outflow channel ( 16 ); the capsule ( 1 ) is also provided with a cover ( 4 ) to close the cup-shaped body ( 2 ), and the tubular appendage ( 9 ) has a first axial end facing the cover ( 4 ) and defining the inlet of the beverage outflow channel ( 16 ), and a second axial end defining the outlet of the beverage outflow channel ( 16 ); the capsule ( 1 ) is characterised in that it further comprises a membrane ( 23 ) firmly connected to the first end of the tubular appendage ( 9 ) and provided with a plurality of through slots ( 24 ) configured to widen when the pressure inside the capsule ( 1 ) reaches a predetermined threshold pressure as a consequence of a pressurised fluid being injected into the capsule ( 1 ). 
     
     
         2 . The capsule according to  claim 1 , wherein the membrane ( 23 ) is obtained from a film of polymeric material and the number, shape and size of the slots ( 24 ) are such as to define said predetermined threshold pressure and the flow rate of the beverage delivered from the capsule ( 1 ). 
     
     
         3 . The capsule according to  claim 2 , wherein the slots ( 24 ) are configured to reclose at least partially when the pressure inside the capsule ( 1 ) drops below said predetermined threshold pressure. 
     
     
         4 . The capsule according to  claim 1 , wherein the membrane ( 23 ) is obtained from a multilayer sheet comprising a polymeric film provided with said through slots ( 24 ), and an unslotted metallic foil firmly welded to the first end of the tubular appendage ( 9 ) and configured to tear when the beverage flows through the polymeric film. 
     
     
         5 . The capsule according to  claim 1 , wherein the beverage outflow channel ( 16 ) has a converging portion ( 17 ) immediately upstream from outlet of the beverage outflow channel ( 16 ). 
     
     
         6 . The capsule according to  claim 5 , wherein the length of the converging portion ( 17 ) of the beverage outflow channel ( 16 ) is at least equal to ⅓ of the total length of the beverage outflow channel ( 16 ). 
     
     
         7 . The capsule according to  claim 5 , wherein the bottom wall ( 8 ) has a central portion ( 13 ) coaxial with the axis ( 3 ) and sunken towards the inside of the capsule ( 1 ); the tubular appendage ( 9 ) extends from an inner end of said central portion ( 13 ) and comprises a first section ( 14 ) prolonging from the central portion ( 13 ) towards the inside of the capsule ( 1 ), and a second section ( 15 ) prolonging from the central portion ( 13 ) towards the outside of the capsule ( 1 ); the converging portion ( 17 ) of the beverage outflow channel ( 16 ) is provided in the second section ( 15 ). 
     
     
         8 . The capsule according to  claim 1 , wherein the lateral wall ( 6 ), the bottom wall ( 8 ), and the tubular appendage ( 9 ) are formed in one piece by an injection moulding process.