Patent ID: 6994465

Claim:
A mixing assembly for mixing bone cement, said mixing assembly comprising: a housing having at least one interior wall; a lid removably attachable to said housing and movable between an open position where the bone cement can be added to said housing and a sealed position where said lid is hermetically sealed to said housing to define a sealed mixing chamber between said lid and said interior wall of said housing for mixing the bone cement; a handle having a portion extending through said lid and being rotatable about said lid for mixing the bone cement; a mixing paddle operatively coupled to said portion of said handle for rotating with said portion wherein said mixing paddle is movable between an extended position when said lid is in said open position and a retracted position where said mixing paddle is adapted to scrape the bone cement from said interior wall when said lid is in said sealed position; and a resilient member disposed between said portion and said mixing paddle, said resilient member normally-biasing said mixing paddle into said extended position and said resilient member compressing in response to contact between said mixing paddle and said interior wall as said lid is moved from said open position to said sealed position thereby permitting said mixing paddle to retract into said retracted position such that said lid can be hermetically sealed to said housing in said sealed position, yet said mixing paddle can still scrape the bone cement from said interior wall.