Reduction of pump nuisance

Abstract

A pump ( 800 ) for a beverage preparation machine ( 1 ) has: a pump inlet ( 810 ); a pump outlet ( 820 ); a liquid driver ( 815, 816 ) for pressurising and circulating a liquid from the pump inlet to the pump outlet; and a downstream pump conduit ( 870, 871, 872 ) connecting in fluid communication the liquid driver to the pump outlet. The downstream pump conduit comprises a liquid dampener ( 860 ) for dampening upstream the pump outlet vibrations in such liquid which are generated by the liquid driver so as to circulate via the pump outlet dampened pressurised liquid from the liquid driver.

1 . A pump for a beverage preparation machine comprising: a pump inlet; a pump outlet; a liquid driver for pressurising and circulating a liquid from the pump inlet to the pump outlet; and a downstream pump conduit connecting in fluid communication the liquid driver to the pump outlet; and
 the downstream pump conduit comprises a liquid dampener for dampening upstream the pump outlet vibrations in the liquid which are generated by the liquid driver so as to circulate via the pump outlet dampened pressurised liquid from the liquid driver.   
     
     
         2 . The pump of  claim 1 , wherein the liquid driver comprises:
 a pump chamber in fluid communication with the pump inlet and the pump outlet via the downstream pump conduit.   
     
     
         3 . The pump of  claim 1 , wherein the downstream pump conduit comprises a liquid dampening section delimited defined by the liquid dampener. 
     
     
         4 . The pump of  claim 1 , wherein the liquid dampener comprises a flexible membrane defining a liquid dampening section, the flexible membrane constructed from a material selected from the group consisting of silicone, rubber and TPE. 
     
     
         5 . The pump of  claim 1 , wherein the liquid dampener comprises a gas cavity that is separated from a liquid dampening section by a flexible membrane. 
     
     
         6 . The pump of  claim 5 , wherein the liquid dampener comprises a cap defining the gas cavity. 
     
     
         7 . The pump of  claim 6 , wherein the cap is secured in a pump housing. 
     
     
         8 . The pump of  claim 6 , wherein the cap is arranged to secure the flexible membrane against the liquid dampening section. 
     
     
         9 . The pump of  claim 1 , wherein the downstream pump conduit comprises a liquid directing section guiding liquid from the liquid driver into the liquid dampening section against the liquid dampener, so that liquid guided by the directing section is redirected by the liquid dampener. 
     
     
         10 . The pump of  claim 9 , wherein the liquid directing section and the liquid dampening section define respective flow directions that are at an angle of from 30 to 150 deg. 
     
     
         11 . The pump of  claim 1 , wherein the downstream pump conduit comprises a liquid redirecting section guiding liquid from the liquid dampening section to the pump outlet. 
     
     
         12 . The pump of  claim 11 , wherein the liquid redirecting section and the liquid dampening section define respective flow directions that are at an angle of from 30 to 150 deg. 
     
     
         13 . The pump of  claim 1 , wherein the downstream pump conduit is made: of a rigid member extending from the liquid driver to the pump outlet; and of the liquid dampener extending over at least part of the rigid member, the rigid member and the liquid dampener containing together the downstream pump conduit. 
     
     
         14 . The pump of  claim 13 , comprising a pump housing that is integral with the rigid member. 
     
     
         15 . A beverage preparation machine comprising a pump having a pump inlet; a pump outlet; a liquid driver for pressurising and circulating a liquid from the pump inlet to the pump outlet; and a downstream pump conduit connecting in fluid communication the liquid driver to the pump outlet; and
 the downstream pump conduit comprises a liquid dampener for dampening upstream the pump outlet vibrations in the liquid which are generated by the liquid driver so as to circulate via the pump outlet dampened pressurised liquid from the liquid driver.   
     
     
         16 . The pump of  claim 1 , wherein the liquid driver comprises:
 a reciprocating pump piston contained in a pump chamber for pressurizing and circulating liquid from the pump inlet through the pump chamber to the pump outlet.