Beer keg tapping assembly
FIELD OF THE INVENTION 
     This invention relates to a cask or container for liquid under pressure, and is of the type in which the bung hole has a spring loaded ring seal within a collar around the bung hole, there being an extractor tube extending downwardly to near the bottom of the container this tube having a head the top of which is substantially co-planar with the top surface of the ring seal and located therein so that before broaching the seal forms a closure between a seating of the collar and head, the cask being broached by securing a dispensing head on to the collar, and moving a plunger in the dispensing head to depress the seal, this action also putting an outlet from the extractor head in communication with a liquid outlet through the dispenser head, and applying also through the head, gas under pressure on to the surface of the liquid to dispense same. 
     BRIEF DESCRIPTION OF PRIOR ART 
     With casks as above it is customary to secure a collar to the top wall of the cask so as to upstand around the bung hole in which collar a metal insert engages this insert being internally screw threaded to receive a closure fitting which fitting carries the ring seal and extractor tube. 
     OBJECTS OF THE INVENTION 
     Objects of this invention are to provide a simplified construction for mounting the seal and tube and in which no metal insert is used, and which results in a preferred construction which is substantially tamper proof in that it is difficult without a special tool, to remove the extractor tube. 
     SUMMARY OF THE INVENTION 
     According to this invention there is provided a cask or like container for pressurised liquid, wherein a housing is secured to the top wall of the cask at the bung hole outlet to upstand therearound said housing having a skirt portion depending into the cask said skirt having an inturned flange at its lower end in which a bush or sleeve engages the extractor tube passing through the bush or sleeve to which it is secured, the extractor tube head being located within the housing above the bush, the ring seal and loading spring also being located in the housing around the head, so that the periphery of the seal engages a seating within and at the upper end of the housing, and the top of the head is received in the ring seal. 
     Preferably the bush engages in the skirt flange by screw threads and the bush and extractor tube are integral. 
     With the above arrangement, the use of a liner is dispensed with. Also, the extractor tube can be removed only by upsetting the sealing ring to remove same, and then removing the extractor tube which calls for the use of a special tool to engage the head. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The accompanying drawing illustrates a preferred embodiment in section. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     As shown, the top wall 10 of the container has a bung hole 11 and a housing 12 is secured around the hole by welding. The housing has a skirt portion 13 with an inturned flange 13a. A bush 14 engages in the flange by screw threads and the extractor tube 15 is secured to the bush or preferably moulded thereto, the bush and tube being of synthetic plastic material. 
     A collar 16 seats on the upper surface of the flange 13a and a compression spring 20 extends between this collar and a cup seat 17 for a ring seal 18, so that unless the cask has been broached the seal engages by its periphery a seating 12a and the undercut top of the extractor tube head 15a of the tube 15. 
     The skirt is gapped, e.g. at 19, to allow gas under pressure to enter the cask after the dispenser head has been fitted and the cask broached this also depressing the ring seal against its spring loading. 
     If it is desired to remove the extractor tube, then the seal is upset and removed and the tube, head, and bush unscrewed. A special tool is required for this operation e.g. one to engage in the liquid outlet apertures 15b of the head.