Vacuum Cleaner Overload Clutch

Abstract

A vacuum cleaner overload clutch having an overload cog, a spring mount, and an overload spring. The spring is engaged with the cog to provide torque transfer, and disengaged from the cog to terminate torque transfer. The spring may not reengage until the parts stop rotating. A weight may be provided to bias the spring into the disengaged position, and the spring may have an engagement portion that is captured between the overload cog and a wall on the spring holder when the clutch is engaged. The clutch may be part of a system including a motor and agitator, and may have other features, such as a graduated engagement clutch.

1 . A vacuum cleaner overload clutch system comprising:
 a motor adapted to selectively provide a drive torque;   an agitator adapted to contact a surface to be cleaned;   an overload cog operatively connected between the motor and the agitator and adapted to rotate about a rotating axis, the overload cog having one or more first cog portions that extend a first distance from the rotating axis;   a spring mount operatively connected between the motor and the agitator and adapted to rotate about the rotating axis;   an overload spring mounted on the spring mount, the overload spring having:
 an engaged configuration in which the overload spring wraps around at least a portion of the overload cog and has one or more first spring portions that contact the one or more first cog portions to thereby transfer the drive torque between the overload cog and the spring mount, and 
 a disengaged configuration in which the one or more first spring portions do not substantially contact the one or more first cog portions to thereby not substantially transfer the drive torque between the overload cog and the spring mount, and 
 wherein the overload spring is adapted to move to the disengaged configuration when the drive torque exceeds a predetermined torque value, and remain in the disengaged configuration until the overload cog and spring mount substantially stop rotating. 
   
     
     
         2 . The vacuum cleaner overload clutch system of  claim 1 , wherein:
 the overload cog further comprises one or more second cog portions that extend a second distance from the rotating axis, the second distance being less than the first distance; and   the overload spring further comprises one or more second spring portions that conform generally to the second cog portions when the overload spring is in the engaged configuration.   
     
     
         3 . The vacuum cleaner overload clutch system of  claim 1 , wherein resilient tension in the overload spring biases the overload spring towards the engaged configuration, and a centrifugal force generated by the mass of the overload spring biases the overload spring away from the engaged configuration when the overload spring is in the disengaged configuration. 
     
     
         4 . The vacuum cleaner overload clutch system of  claim 1 , further comprising a weight adapted to generate a centrifugal force that biases the overload spring away from the engaged configuration when the overload spring is in the disengaged configuration. 
     
     
         5 . The vacuum cleaner overload clutch system of  claim 4 , wherein the weight is pivotally mounted to the spring mount and has a free end adapted to contact the overload spring. 
     
     
         6 . The vacuum cleaner overload clutch system of  claim 1 , wherein the overload cog comprises one or more notches and the spring mount comprises a pivoting pawl that prevents the overload cog and spring mount from rotating relative to one another in a first direction. 
     
     
         7 . The vacuum cleaner overload clutch system of  claim 6 , wherein the pivoting pawl comprises a weight adapted to generate a centrifugal force that biases the overload spring away from the engaged configuration when the overload spring is in the disengaged configuration. 
     
     
         8 . A vacuum cleaner overload clutch comprising:
 an overload cog adapted to rotate about an axis;   a spring mount adapted to rotate about the axis;   an overload spring mounted on the spring mount and adapted to contact the overload cog in an engaged position, and not substantially contact the overload cog in a disengaged position; and   a movable weight adapted to bias the overload spring into the disengaged position upon rotation of the spring mount.   
     
     
         9 . The vacuum cleaner overload clutch of  claim 8 , wherein the movable weight is movably mounted to the spring mount. 
     
     
         10 . The vacuum cleaner overload clutch of  claim 8 , wherein the movable weight is pivotally mounted to the spring mount. 
     
     
         11 . The vacuum cleaner overload clutch of  claim 8 , wherein:
 the overload cog comprises at least one protrusion extending radially therefrom;   the spring mount comprises a wall facing the overload cog; and   the overload spring comprises a first engagement portion that is captured between the at least one protrusion and the wall when the overload spring is in the engaged position, and is not captured between the at least one protrusion and the wall when the overload spring is in the engaged position.   
     
     
         12 . A vacuum cleaner overload clutch comprising:
 an overload cog adapted to rotate about an axis and having at least one protrusion extending radially therefrom;   a spring mount at least partially surrounding the overload cog and adapted to rotate about the axis, the spring mount having a wall facing the overload cog;   an overload spring mounted on the spring mount and adapted to contact the overload cog in an engaged position, and not substantially contact the overload cog in a disengaged position; and   wherein the overload spring comprises a first engagement portion that is captured between the at least one protrusion and the wall when the overload spring is in the engaged position, and is not captured between the at least one protrusion and the wall when the overload spring is in the engaged position.   
     
     
         13 . The vacuum cleaner overload clutch of  claim 12 , wherein the first engagement portion comprises a resiliently-deformable loop. 
     
     
         14 . The vacuum cleaner overload clutch of  claim 12 , wherein the at least one protrusion comprises a plurality of protrusions, and the overload spring further comprises one or more second engagement portions that resiliently contact at least a second one of the plurality of protrusions when the overload spring is in the engaged position. 
     
     
         15 . The vacuum cleaner overload clutch of  claim 12 , further comprises holding means for holding the overload spring substantially out of contact with the overload cog when the overload spring is in the disengaged position. 
     
     
         16 . The vacuum cleaner overload clutch of  claim 15 , wherein the holding means comprises a centrifugal force generated by rotation of the overload spring about the axis. 
     
     
         17 . The vacuum cleaner overload clutch of  claim 15 , wherein the holding means comprises a weight adapted to generate a centrifugal force upon rotation of the vacuum cleaner overload clutch. 
     
     
         18 . A vacuum cleaner clutch assembly comprising:
 a motor;   an agitator;   an overload clutch adapted to receive a drive torque generated by the motor and transmit the drive torque to the agitator when the drive torque is less than a predetermined torque limit, and not transmit the drive torque to the agitator when the drive torque is greater than a predetermined torque limit; and   an engagement clutch adapted to transmit the drive torque from the motor to the agitator in a graduated manner.   
     
     
         19 . The vacuum cleaner clutch assembly of  claim 18 , wherein the engagement clutch is adapted to transmit the drive torque from the motor to the overload clutch in one or more stages. 
     
     
         20 . The vacuum cleaner clutch assembly of  claim 18 , wherein the engagement clutch is adapted to smoothly increase the amount of drive torque the engagement clutch transmits from the motor to the overload clutch. 
     
     
         21 . The vacuum cleaner clutch assembly of  claim 18 , wherein the engagement clutch comprises at least two mechanical clutches. 
     
     
         22 . The vacuum cleaner clutch assembly of  claim 18 , wherein the engagement clutch is operatively positioned between the motor and the overload clutch.