Cleaner head

Abstract

A cleaner head that includes an agitator and a drive assembly for driving the agitator. The drive assembly includes a dog for transmitting torque to the agitator. One of the dog and the agitator includes a shank having a screw thread, and the other of the dog and the agitator includes a bore having a complementary screw thread. The shank projects into the bore and the two threads mate such that, as the dog rotates, the agitator screws on to and tightens against the dog.

1 . A cleaner head comprising an agitator and a drive assembly for driving the agitator, the drive assembly comprising a dog for transmitting torque to the agitator, wherein one of the dog and the agitator comprises a tapered head, a shank that extends from the head, and a screw thread formed around the shank, the other of the dog and the agitator comprises a bore having a countersink and a complementary screw thread formed around a wall of the bore, the shank projects into the bore, and the two threads mate such that, as the dog rotates, the agitator screws on to the dog and the tapered head mates with the countersink. 
     
     
         2 . The cleaner head of  claim 1 , wherein each screw thread has a lead angle of no more than 60 degrees. 
     
     
         3 . The cleaner head of  claim 1 , wherein each screw thread has a lead angle of no less than 40 degrees. 
     
     
         4 . The cleaner head of  claim 1 , wherein each screw thread has a plurality of starts. 
     
     
         5 . The cleaner head of  claim 4 , wherein each start turns through an angle of no less than 120 degrees. 
     
     
         6 . The cleaner head of  claim 4 , wherein each start turns through an angle of no more than 360 degrees. 
     
     
         7 . The cleaner head of  claim 1 , wherein each screw thread has a buttress thread form. 
     
     
         8 . The cleaner head of  claim 1 , wherein the agitator is removable from the cleaner head, and rotation of the agitator relative to the dog causes the agitator to unscrew and separate from the dog. 
     
     
         9 . A cleaner head comprising an agitator and a drive assembly for driving the agitator, the drive assembly comprising a dog for transmitting torque to the agitator, wherein one of the dog and the agitator comprises a shank having a screw thread, the other of the dog and the agitator comprises a bore having a complementary screw thread, each of the screw threads has a buttress profile, the shank projects into the bore, and the two threads mate such that, as the dog rotates, the agitator screws on to and tightens against the dog. 
     
     
         10 . The cleaner head of  claim 9 , wherein each screw thread has a lead angle of no more than 60 degrees. 
     
     
         11 . The cleaner head of  claim 9 , wherein each screw thread has a lead angle of no less than 40 degrees. 
     
     
         12 . The cleaner head of  claim 9 , wherein each screw thread has a plurality of starts. 
     
     
         13 . The cleaner head of  claim 9 , wherein each screw thread has a plurality of starts. 
     
     
         14 . The cleaner head of  claim 13 , wherein each start turns through an angle of no less than 120 degrees. 
     
     
         15 . The cleaner head of  claim 13 , wherein each start turns through an angle of no more than 360 degrees. 
     
     
         16 . The cleaner head of  claim 9 , wherein the shank extends from a tapered head and the bore comprises a countersink, and as the dog rotates, the agitator screws on to the dog and the tapered head mates with the countersink. 
     
     
         17 . The cleaner head of  claim 9 , wherein the agitator is removable from the cleaner head, and rotation of the agitator relative to the dog causes the agitator to unscrew and separate from the dog. 
     
     
         18 . A cleaner head comprising an agitator and a drive assembly for driving the agitator, the drive assembly comprising a dog for transmitting torque to the agitator, wherein one of the dog and the agitator comprises a shank having a screw thread, the other of the dog and the agitator comprises a bore having a complementary screw thread, each of the screw threads has a lead angle of no more than 60 degrees, the shank projects into the bore, and the two threads mate such that, as the dog rotates, the agitator screws on to and is tightened against the dog. 
     
     
         19 . The cleaner head of  claim 18 , wherein each screw thread has a lead angle of no less than 40 degrees. 
     
     
         20 . The cleaner head of  claim 18 , wherein each screw thread has a plurality of starts. 
     
     
         21 . The cleaner head of  claim 20 , wherein each start turns through an angle of no less than 120 degrees. 
     
     
         22 . The cleaner head of  claim 20 , wherein each start turns through an angle of no more than 360 degrees. 
     
     
         23 . The cleaner head of  claim 18 , wherein each screw thread has a buttress thread form. 
     
     
         24 . The cleaner head of  claim 18 , wherein the shank extends from a tapered head and the bore comprises a countersink, and as the dog rotates, the agitator screws on to the dog and the tapered head mates with the countersink. 
     
     
         25 . The cleaner head of  claim 18 , wherein the agitator is removable from the cleaner head, and rotation of the agitator relative to the dog causes the agitator to unscrew and separate from the dog.