Extraction device for preparation of a beverage

In a device for extraction of a material contained in a cartridge for preparation of a beverage having a housing member which has a base, having an injector member which extends longitudinally about a longitudinal axis from the housing member base for piercing a cartridge and which has outlets displaced at a position away from the base and disposed for directing water from the injector member into a cartridge for extraction of a material in a cartridge and having a seal member which has a first seal surface and a second seal surface which opposes the first seal surface and wherein the seal member is positioned at the base of the housing member so that the first and second seal surfaces extend in a direction perpendicular to the longitudinal axis of the injector member and so that the first seal surface is positioned adjacent the base and wherein the seal member has a centrally disposed bore therethrough from the first surface to the second surface to provide an opening for sealably surrounding a periphery of the injector member, wherein the improvements comprise:

• the seal member second surface having a first centrally disposed flat surface portion, a second flat surface portion and a third surface portion, wherein the bore is centrally disposed in the first portion and wherein the third portion extends between and connects the first and second portions and is concave with respect to the first and second portions and forms a cavity between the first and second portions;
• the injector member having outlets disposed for directing water ejected from the injector member at an angle of from 90.degree. to 65.degree. with reference to the longitudinal axis;
• and
• a cartridge holder and a tightening ring wherein
• the cartridge holder has a base and has a wall having inner and outer surfaces which extends transversely from the base to a wall edge disposed between the inner and outer surfaces and displaced from the base and has lugs which extend transversely from the outer surface, and
• the tightening ring extends from the housing member and has a surface which extends from the housing member transversely with respect to the first and second surface portions and from a position about the seal member second surface portion and has ramps which extend transversely from the tightening ring surface for engaging the cartridge holder lugs for supporting the cartridge holder, and
• wherein the seal member second surface portion has a size sufficient so that upon engagement of the ramps and lugs for supporting the cartridge holder, the cartridge holder wall edge is aligned with and adjacent to the seal member second surface portion for effecting compression of a cartridge against the second surface portion.