Suction tool

Abstract

A suction tool for a vacuum cleaner includes an outlet for connection to a vacuum cleaner; a main inlet in fluid communication with the outlet via a main suction passage; and an auxiliary inlet in fluid communication with the outlet via an auxiliary suction passage. The auxiliary suction passage includes a flow limiting device which is movable between first and second configurations, the flow limiting device obstructing air flow through the auxiliary suction passage to a greater extent when in the second configuration than when in the first configuration. The flow limiting device is configured to move to the second position in response to the pressure within the main suction passage dropping beneath a predetermined threshold.

1 . A suction tool for a vacuum cleaner, the suction tool comprising:
 an outlet for connection to a vacuum cleaner;   a main inlet in fluid communication with the outlet via a main suction passage; and   an auxiliary inlet in fluid communication with the outlet via an auxiliary suction passage,   wherein:   the auxiliary suction passage includes a flow limiting device which is movable between first and second configurations, the flow limiting device obstructing air flow through the auxiliary suction passage to a greater extent when in the second configuration than when in the first configuration; and wherein:   the flow limiting device is movable from the first configuration to the second configuration via an intermediate configuration;   when in the intermediate configuration the flow limiting device obstructs air flow through the auxiliary suction passage to a greater extent than when in the first configuration but a lesser extent than when in the second configuration; and   the flow limiting device is configured to move from the first position to the intermediate position in response to the pressure within the main suction passage dropping beneath a higher predetermined threshold, and to move from the intermediate position to the second position in response to the pressure within the main suction passage dropping beneath a lower predetermined threshold.   
     
     
         2 . The suction tool according to  claim 1  wherein the suction tool comprises a rotatable brush bar and the auxiliary suction passage is associated with a drive mechanism of the brush bar. 
     
     
         3 . The suction tool according to  claim 2  wherein the drive mechanism comprises an electric motor, and the auxiliary suction path runs through or near the electric motor so that air running through the auxiliary suction path can cool the electric motor. 
     
     
         4 . The suction tool according to  claim 1  wherein the brush bar is hollow, and the auxiliary suction passage extends into the brush bar. 
     
     
         5 . The suction tool according to  claim 2  wherein the flow limiting device is configured to substantially close the auxiliary flow passage when in the second configuration. 
     
     
         6 . The suction tool according to  claim 1  wherein the flow limiting device is configured to allow air flow through the auxiliary flow passage when in the second configuration. 
     
     
         7 . The suction tool according to  claim 1  wherein the primary suction passage and auxiliary suction passages intersect and form a common suction passage which extends to the outlet. 
     
     
         8 . The suction tool according to  claim 7  wherein the primary suction passage includes a suction chamber, and the auxiliary suction passage intersects the primary suction passage at the suction chamber. 
     
     
         9 . The suction tool according to  claim 1  wherein the primary suction passage includes a suction chamber, and the auxiliary suction passage intersects the primary suction passage downstream of the suction chamber. 
     
     
         10 . The suction tool according to  claim 1  wherein the flow limiting device is biased to the first position, and is movable to the second position, against said bias, under action of air flowing through the auxiliary suction passage. 
     
     
         11 . The suction tool according to  claim 10  wherein the flow limiting device comprises a valve element movable relative to a valve seat, respective surfaces of the valve element and valve seat being positioned closer together when the flow limiting device is in the second position than when in the first position. 
     
     
         12 . The vacuum cleaner according to  claim 11  wherein the valve element is moveable along a spindle relative to the valve seat. 
     
     
         13 . The vacuum cleaner according to  claim 12  wherein the flow limiting device comprises a compression spring positioned around the spindle and held between the valve element and the valve seat. 
     
     
         14 . The vacuum cleaner according to  claim 11  wherein the valve element comprises a set of through-holes which allow air flow through the auxiliary flow passage when the flow limiting device is in the second configuration. 
     
     
         15 . A vacuum cleaner comprising the suction tool according to  claim 1 . 
     
     
         16 . A suction tool for a vacuum cleaner, the suction tool comprising:
 an outlet for connection to a vacuum cleaner;   a main inlet in fluid communication with the outlet via a main suction passage;   an auxiliary inlet in fluid communication with the outlet via an auxiliary suction passage;   a rotatable brush bar; and   an electric motor configured to drive the brush bar,   wherein:   the auxiliary suction passage includes a flow limiting device which is movable between first and second configurations, the flow limiting device obstructing air flow through the auxiliary suction passage to a greater extent when in the second configuration than when in the first configuration; and   the flow limiting device is configured to move to the second position in response to the pressure within the main suction passage dropping beneath a predetermined threshold.   
     
     
         17 . The suction tool according to  claim 16  wherein the auxiliary suction passage is associated with a drive mechanism of the brush bar. 
     
     
         18 . The suction tool according to  claim 17  wherein the auxiliary suction path runs through or near the electric motor so that air running through the auxiliary suction path can cool the electric motor. 
     
     
         19 . The suction tool according to  claim 16  wherein the brush bar is hollow, and the auxiliary suction passage extends into the brush bar. 
     
     
         20 . The suction tool according to  claim 16  wherein the flow limiting device is configured to substantially close the auxiliary flow passage when in the second configuration.