Surface treating apparatus

Claim 1

IN A SURFACE TREATING APPARATUS (10) OF THE CLASS DESCRIBED, A ROTATABLE MEMBER (32) ADAPTED TO BE POSITIONED OVER A SURFACE FOR ROTATION ABOUT A VERTICAL AXIS AND BE MOVED OVER THE SURFACE, A BRUSH (11) INCLUDING A BRUSH BACK (42) AND BRISTLES (41) FIXED THERETO, SAID BRUSH BACK (42) HAVING A CENTRALLY DISPOSED OPENING (44) EXTENDING THERETHROUGH DEFINING AN INTERNAL SHOULDER (45), SAID ROTATABLE MEMBER (32) INCLUDING MEANS (43) FORMING A UNITARY PART THEREOF FOR DETACHABLY CONNECTING SAID BRUSH BACK (42) THERETO, SAID DETACHABLE CONNECTING MEANS (43) COMPRISING FASTENING STRUCTURE (47) WHICH IS CARRIED BY AND EXTENDS AXIALLY FROM SAID ROTATABLE MEMBER (32) THROUGH THE OPENING (44) IN SAID BRUSH BACK (42) AND INCLUDES A PLURALITY OF ELONGATED ELEMENTS (47) HAVING RADIALLY MOVABLE CATCHES (47A), SAID ELONGATED ELEMENTS (47) BEING RELATIVELY STIFF IN A LENGTHWISE DIRECTION AND RESILIENT AND BENDABLE IN DIRECTIONS TRANSVERSE TO THEIR LENGTH AND NORMALLY ASSUMING FIRST POSITIONS IN WHICH SAID CATCHES (47A) ENGAGE THE SHOULDER (45) AT THE OPENING (44), SAID ELONGATED ELEMENTS (47) BEING MOVABLE RADIALLY INWARD FROM THE FIRST ENGAGING POSITIONS RESPONSIVE TO FORCE APPLIED THERETO IN DIRECTIONS TRANSVERSE TO THEIR LENGTH TO PROVIDE CLEARANCE BETWEEN SAID CATCHES (47A) AND THE SHOULDER (45) AT THE OPENING (44)