Dispenser head

Abstract

A dispenser unit comprising a dispenser can and a dispenser head which is provided with a delivery tube. The delivery tube has a longitudinal section with a lumen tapering in flow direction and a tube-like extension having an approximately constant inner diameter which corresponds to the smallest diameter of the adjacent section with the tapering lumen. A plug whose cross-sectional dimensions correspond to the lumen of the extension so that the discharge tube can be sealed by receiving the plug in its discharge opening. The length of the constant diameter extension is so chosen that in case of clogging small sections of the extension can be cut off to reopen the delivery opening of the delivery tube.

1 .- 21 . (canceled) 
     
     
         22 . A dispenser head for opening a valve of a can containing a fluid and dispensing the fluid from the can under pressure of a propellant medium, the dispenser head comprising:
 a base for mounting the dispenser head on the can,   a valve seat adapted to fit to the valve of the can in a fluid-tight manner,   an orifice in fluid connection with the valve seat, and   a delivery tube to dispense the fluid under pressure of the propellant medium when the tube is arranged at the orifice of the dispenser head in a fluid-tight manner,   the delivery tube having a first end arranged at the dispenser head orifice and a second opposite end of the tube having a discharge opening from which the fluid is dispensable, the delivery tube comprising:
 at least one longitudinal section between the two ends of the tube, wherein the at least one longitudinal section has a lumen which tapers toward the discharge opening and which has a first inner diameter at a first end portion and a second narrower inner diameter at a second end portion, wherein the first end portion of the lumen is directed toward the dispenser head orifice and the second end portion is directed toward the discharge opening of the tube, and 
 a tubular extension positioned between the second end portion of the at least one longitudinal section and the discharge opening, the discharge opening being positioned at a free end of the tubular extension, the tubular extension having an approximately constant inner diameter equal to at least a smallest diameter of the tapering longitudinal section, and a minimum length of the tubular extension being selected to receive and hold a plug having a cross-sectional shape suitable to completely fill the discharge opening such that the discharge opening is effectively sealed. 
   
     
     
         23 . The dispenser head according to  claim 22 , wherein the tapering longitudinal section comprises at least first and second sub-sections having different tapering angles, the tapering angle of the first sub-section adjacent to the tubular extension being smaller than the tapering angle of the second sub-section having a tapering lumen. 
     
     
         24 . The dispenser head according to  claim 22 , wherein the tubular extension has a length that allows shortening of the tubular extension without interfering with the at least one tapering longitudinal section which is adjacent to the tubular extension. 
     
     
         25 . The dispenser head according to  claim 22 , wherein the tubular extension has a length at least equal to a length of the plug. 
     
     
         26 . The dispenser head according to  claim 22 , wherein the tubular extension has a length of at least about 10 mm. 
     
     
         27 . The dispenser head according to  claim 22 , wherein the tubular extension has a maximum length of less than about 33% of a length of the delivery tube. 
     
     
         28 . The dispenser head according to  claim 22 , wherein the tubular extension has a length essentially not adversely affecting a foam volume of a predefined aliquot of the fluid under pressure, when the fluid is dispensed from the can by the propellant medium. 
     
     
         29 . The dispenser head according to  claim 22 , wherein the tubular extension has a length about 2 to about 25 times an inner diameter of the discharge opening. 
     
     
         30 . The dispenser head according to  claim 22 , wherein the at least one tapering longitudinal section arranged adjacent to the tubular extension tapers over its length with an essentially constant tapering angle. 
     
     
         31 . The dispenser head according to  claim 22 , wherein the plug is adapted to be arranged in frictional connection with the tubular extension when in sealing engagement within the tubular extension. 
     
     
         32 . The dispenser head according to  claim 22 , wherein the plug is fastened by a detachable, one-piece connection with the dispenser head. 
     
     
         33 . The dispenser head according to  claim 22 , wherein the plug has an end portion tapered toward a free end of the plug for insertion of the plug in the discharge opening. 
     
     
         34 . The dispenser head according to  claim 22 , further comprising a tamper evident device, wherein the tamper evident device is provided with the plug adapted for insertion into the discharge opening. 
     
     
         35 . The dispenser head according to  claim 22 , further comprising a manually operable actuator for actuating the valve of the can when the dispenser head is mounted on the can, and a tamper evident device positioned between the manually operable actuator and an outer casing of the dispenser head, wherein the tamper evident device is provided with the plug adapted for insertion into the discharge opening. 
     
     
         36 . The dispenser head according to  claim 22 , further comprising a fastening device to fasten the delivery tube when not in use to dispense fluid from the can, wherein the fastening device is detachable from the dispenser head, and wherein the plug is arranged at or adjacent to the fastening device. 
     
     
         37 . The dispenser head according to  claim 36 , wherein the fastening device has a projection whose cross-sectional shape is adapted to a cross-sectional shape of a mounting section of the delivery tube to mount the delivery tube to the dispenser head when the mounting section is in engagement with the projection. 
     
     
         38 . The dispenser head according to  claim 22 , further comprising a manually actuated lever for actuating the valve of the can when the dispenser head is mounted on the can, the dispenser head having a tamper evident device positioned between the manually actuated lever and an outer casing of the head, and the tamper evident device having a projection whose cross-sectional shape is adapted to a cross-sectional shape of a mounting section of the delivery tube. 
     
     
         39 . The dispenser head according to  claim 22 , wherein the delivery tube comprises plastic. 
     
     
         40 . The dispenser head according to  claim 22 , further comprising a mount for mounting the delivery tube, the mount having a circumferentially closed flange encircling a recess for receiving a mounting section of the delivery tube. 
     
     
         41 . A dispenser unit comprising a dispenser head according to  claim 22  and a pressurized can, wherein the can comprises a valve for dispensing fluid content of the can, the valve being adapted to connect with the valve seat of the dispenser head in a fluid-tight manner. 
     
     
         42 . A delivery tube adapted for mounting at a dispenser head for opening a valve of a can containing a fluid to dispense the fluid under pressure of a propellant medium from the can and through the delivery tube when the dispenser head is mounted on the can and is tightly fitted to the valve by a valve seat so that an orifice of the dispenser head is in fluid connection with the valve seat on one side and with the delivery tube on another side,
 the delivery tube having a first end adapted to be arranged at the orifice in a fluid-tight manner and a second opposite end having a discharge opening from which the fluid is dispensable, the delivery tube comprising:
 at least one longitudinal section between the two ends of the tube, wherein the at least one longitudinal section has a lumen which tapers toward the discharge opening and which has a first inner diameter at a first end portion and a second narrower inner diameter at a second end portion, wherein the first end portion of the lumen is directed toward the dispenser head orifice and the second end portion is directed toward the discharge opening of the tube, and 
 a tubular extension positioned between the second end portion of the at least one longitudinal section and the discharge opening, the discharge opening being positioned at a free end of the tubular extension, the tubular extension having an approximately constant inner diameter equal to at least a smallest diameter of the tapering longitudinal section, and a minimum length of the tubular extension being selected to receive and hold a plug having a cross-sectional shape suitable to completely fill the discharge opening such that the discharge opening is effectively sealed.