the invention is described in more detail hereinbelow by means of examples illustrated in the following figures : fig1 describes an embodiment of a device according to the invention during the introduction of a cartridge . fig2 describes the device from fig1 at rest , after the cartridge holder and cartridge cage assembly has been closed . fig3 describes the device from fig1 after the cartridge holder and cartridge cage assembly has been clamped . fig4 illustrates the device from fig1 in the active position when water is passing through the device . the device illustrated in fig1 to 4 includes a cartridge cage 3 comprising in its upper part a water inlet 5 which is connected to a water tank ( not illustrated ) and to a pump ( not illustrated ). the cartridge cage 3 is furthermore fastened to an upper unit 15 of the device . the device also includes a clamping piston 4 mounted in a sliding manner with respect to the assembly formed by the cartridge cage 3 and the upper unit 15 , an upper spring 16 being located in the space formed between the inner wall of the upper unit 15 and the upper face of the clamping piston 4 . the inside of the cage 3 comprises a space intended to hold a cartridge 1 having a flexible membrane 7 in its lower part . the lower part 14 of the cage 3 is designed to come into contact with the flange 12 of the cartridge 1 . an ejection part 17 is located in the upper part of the cage 3 and mounted in a sliding manner with respect to the latter . the lower part of the ejection part 17 comprises spikes 9 intended to pierce the upper face of the cartridge 1 . an expansion space 10 is formed between the outer upper face of the cage 3 and the inner upper wall of the clamping piston 4 . the variation in the expansion space 10 will be discussed later in the text . a cartridge holder 2 formed mainly of a perforated horizontal plate is located in the lower part of the device . a set of spikes 6 that are fixed to a support 8 located under the cartridge holder 2 is mounted in a movable manner in relation to the cartridge holder 2 through the perforations in the latter . a cartridge 1 is initially introduced into the cage 3 ( fig1 ). the assembly consisting of the upper unit 15 , the clamping piston 4 and the cage 3 is then lowered and reaches an intermediate position ( fig2 ) which is characterized by contact between the lower end 13 of the clamping piston 4 and the spike support 8 . it should be noted that at this stage the spikes 6 emerge slightly from the cartridge holder 2 but do not pierce the membrane 7 because the latter has a certain flexibility and , moreover , pressurized water has not yet been introduced into the cartridge 1 . the assembly consisting of the upper unit 15 , the clamping piston 4 and the cage 3 continues to be lowered until the device is located in a starting position ( fig3 ). this latter movement has the effect of moving the spike support 8 and the spikes 6 downward , thereby causing the spikes 6 to retract into the cartridge holder 2 . at the same time , the lower part 14 of the cage 3 butts against the flange 12 of the cartridge 1 , thus ensuring optimal sealing between the cartridge 1 and the inside of the cage 3 . it is noted , furthermore , that in the starting position the ejection part 17 has been retracted into a housing located in the upper part of the cage 3 , thereby having the effect of compressing an ejection spring 18 which is located between the ejection part 17 and the inner wall of the housing . pressurized water is then introduced into the device ( fig4 ). by filling in particular the expansion space 10 , this has the effect of driving the clamping piston 4 upward . at the same time , the water enters the cartridge 1 . this results in an increase in pressure inside the latter and the membrane 7 stretches . the upward movement of the clamping piston 4 also drives the spike support 8 upward . the spikes 6 emerging through the cartridge holder 2 pierce the membrane 7 . the mixture of water with the contents of the cartridge 1 ( for example coffee ) thus flows out through the drink outlet orifice 11 . once the extraction operation has been carried out , the assembly consisting of the upper unit 15 , the clamping piston 4 and the cage 3 is raised . the ejection spring relaxes , thereby driving the ejection part 17 downward . this movement has the effect of making it easier to eject the capsule 1 from the device . it goes without saying that the invention is not limited to the device illustrated in fig1 to 4 . it also covers any mechanism as described in the claims .
device for preparing a drink by extracting a measured quantity , for example of ground coffee , contained in a capsule equipped with an extraction membrane , said device comprising a water inlet , a capsule holder , a capsule cage , clamping means and means for extracting said drink through the membrane ; characterized in that the capsule cage comprises capsule ejecting means .