Patent ID: 11375846

Abstract:
An infuser unit (1) includes a closing piston (3) and an infusion cylinder (2) which are axially movable selectively or in combination for reciprocal engagement and disengagement to close and open an infusion chamber inside the infusion cylinder (2). An ejection piston (5), engaged in the infusion cylinder (2) and axially movable to expel spent coffee grounds, can also be included. A first radial hydraulic sealing means may be located between the closing piston (3) and the infusion cylinder (2), and a second radial hydraulic sealing means may be located between the infusion cylinder (2) and the ejection piston (5), where at least one of the first and the second hydraulic sealing means has at least one seal (100, 101) having an anti-friction surface coating made of a material free of grease and lubricating oils and compatible with use in contact with foodstuffs and drinking water.