according to the invention , and as shown in fig1 - 3 of the accompanying drawings , the connector for a guarantee tap 1 provided with a dispensing piston 2 , actuated by the intermediate appendages 3 secured to the piston 2 , is essentially constituted by a body 4 for mounting of the tap 1 , by a device 5 for sealed connection of the outlet end of the tap 1 , by means 6 for holding the tap 1 and for actuating the dispensing piston 2 , and by a coupling 7 to a dispensing conduit 8 . as shown more particularly in fig3 of the accompanying drawings , the mounting body 4 for the tap 1 is in the form of a semi - cylindrical element for receiving the body of the tap 1 and is provided on a level with appendages 3 for actuating the piston 2 of the tap 1 , with cutouts 9 for receiving said appendages 3 with the possibility of displacement of these latter , said body 4 being closed at its upper portion by means 6 for holding the tap 1 and at its lower portion by the device 5 for sealed connection of the outlet end of the tap 1 . the sealed connection device 5 for the outlet end of the tap 1 is constituted by a sleeve 10 prolonging the lower portion of the body 4 of the connector and receiving a valve 11 , mounted with the possibility of sealed sliding by means of a joint 12 in said sleeve 10 and provided with a joint 11 &# 39 ; pressed by the liquid outlet end of the tap 1 , said valve 11 being urged in its closing direction by a joint 14 engaging below a shoulder 15 prolonging the sleeve 10 on the side opposite the body 4 . the connection coupling 7 to a dispensing conduit 8 is secured by screwing in the cylindrical portion 16 prolonging the shoulder 15 of the lower portion of the sleeve 10 and is of greater diameter than this sleeve 10 , and comprises a bearing against which bears the return spring 13 acting on the valve 11 , the free portion of the coupling 7 comprising a grooved tube 18 for securement of the conduit 8 . the bearing 17 is , in a known manner , in the form of a central bearing element connected to the internal edge of the coupling 7 by radial elements , so as to permit passage of the liquid . the valve 11 is in the form of a hollow piston provided , near its end opposite the bearing surface against the end of the liquid outlet of the tap 1 , lateral openings 19 . thus , by displacement of the valve 11 against the action of the return spring 13 , the lateral openings 19 are freed and liquid issuing from the tap 1 can flow into the chamber delimited below the sleeve 10 in the direction of the coupling 7 and through this latter into the conduit 8 for its dispensing . the holding means 6 for the tap 1 and for actuation of the dispensing piston 2 are in the form of a bearing 20 forming the upper portion of the body 4 , in which is displaceably mounted , against the action of the return spring 21 , a piston 22 provided with a member 23 bearing on the top of the body of the tap 1 , said piston 22 being actuated in displacement by means of a hollow button 24 or the like secured to the upper end of the piston 2 and coacting , by means of at least one lug 25 , with a spiral cam 26 provided on the bearing 20 . by rotation of the plug 24 or the like , there takes place a displacement of the piston 22 with its bearing member 23 against the action of the return spring 21 , by displacement of the lug or lugs 25 in the corresponding spiral cam or cams 26 . this displacement has for its effect to apply the member 23 against the top of the tap body 1 and , because of this , to displace said body in the direction of the device 5 for sealed connection of the outlet end of the tap 1 . as a result , there is an application of said end against the joint 11 &# 39 ; of the valve 11 . upon continued rotation of the plug 24 , the valve 11 is displaced to its position clearing the lateral openings 19 and , simultaneously , the appendages 13 for actuating the piston 2 are applied against the corresponding surfaces of the cutouts 9 of the body 4 for mounting the tap 1 , such that the piston 2 is subjected to a traction having for its effect freeing the passage of liquid . fig1 of the accompanying drawings shows the connector according to the invention before emplacement on a guarantee tap . to this end , the plug 24 must be displaced to its upper position for withdrawing piston 22 and the bearing member 23 , such as shown in fig3 of the accompanying drawings . the body 4 of the connector can then be engaged on the body of the tap 1 , then the plug 24 is actuated so as to bring the assembly into connected position , such as shown in fig2 of the accompanying drawings . by dismounting the connector , the valve 11 closes automatically , simultaneously with the closing of the piston 2 , which follows from the unscrewing of the plug 24 and the action of the return spring 13 on the valve 11 . this unscrewing of the plug 24 also has the result of relaxing the traction on the appendages 3 of the piston 2 and , because of this , effecting closure of the latter . thanks to the invention , it is possible to provide a connector for a guarantee tap , of the drawn piston type , permitting rapid and effective connection to a supply conduit of a distributor . of course , the invention is not limited to the embodiment described and shown in the accompanying drawings . modifications remain possible , particularly as to the constitution of various elements or by substitution of technical equivalents , without thereby departing from the scope of protection of the invention .