An air chuck for use in a capping or uncapping machine, in which air chuck a plurality of hard members are circularly disposed and a cap receiving recess is formed in the central portion of the hard members. The hard members are so arranged as to be slid in the directions of the radii of the cap receiving recess and the sliding movement of the hard members enlarges or reduces the inner diameter of the cap receiving recess, the air chuck thereby grasping or releasing a bottle cap which is introduced into the cap receiving recess. The hard members are made of materials which are excellent in wear resistance and deterioration resistance, such as metals and synthetic resins, so as to be usable for a long period of time. The sliding movement of the hard members is effected by a driving member which is driven by compressed air.
A rotary application head for applying a screw-threaded closure to a container includes a collet 26 for gripping the closure, the collet being secured to a drive member 31 having an external flange 36 disposed between a thrust bearing 37 supported by the main body 10 and a friction clutch plate 38 backed by a pressure plate 40 which is driven by the body through pins 42. A piston 17 disposed in a pneumatic cylinder 16 in the body acts through push rods 19 to apply a predetermined axial loading between the pressure plate 40, friction clutch plate 30 and the flange 36. When the closure reaches a predetermined tightness, the reaction torque causes the collet and drive member to slip relative to the pressure plate and body, preventing over-tightening of the closure. External axial forces applied to the collet cause the piston 17 to be displaced axially to compensate for these forces without altering the torque at which slipping occurs.
A magnetic clutch is provided for transmitting and limiting the torque in screw-on heads for screw closures. The clutch has a high number of poles (at least eight and preferably twelve poles) and the spacing between the clutch magnets, is at least six times the total axial tolerances between the clutch magnets.
An improved cap disc air clutch mechanism is provided, in which a pair of improved cap disc air clutch mechanisms will sense the torque between a cap and neck of a container and will allow cap tightening discs thereon to stop once the desired torque is reached and at the same time, allow the respective spindle shafts to continue to rotate. The improved cap disc air clutch mechanisms are adjustable to different torques by varying air pressure thereto, since the torque required for caps and containers varies considerably.
A magnetic clutch is provided for transmitting and limiting the torque in screw-on heads for screw closures. The clutch has a high number of poles (at least eight and preferably twelve poles) and the spacing between the clutch magnets, is at least six times the total axial tolerances between the clutch magnets.
Capping head assemblies that are useful for applying pre-threaded closures onto containers with improved sensitivity.The novel features of the devices are a simple and novel means of adjusting the torque in a magnetic clutch assembly. In addition, the advantage of preventing contamination by water and other liquids during the filling and capping of liquid containers, and further, have the capability of being greased without having to disassemble the device. In addition, these can be accomplished without changing the capability of being able to read the adjustment scales on the outside surface of the magnetic clutch assembly and the adjustment scales on the outside surface of the upper spring assembly for adjusting the tension in the spring.
