Trowelling blade assemblies

Claim 1

IN A TROWELLING MACHINE COMPRISING A MOTOR-DRIVEN MEMBER ROTATABLE ABOUT A GENERALLY VERTICAL AXIS, AND AT LEAST ONE TROWELLING BLADE CARRYING ARM CARRIED BY THE MEMBER AND EXTENDING RADIALLY THEREFROM WHEREBY A BLADE CARRIED BY THE ARM IS ROTATED IN A GENERALLY HORIZONTAL PLANE UPON ROTATION OF THE MEMBER AND THE ARM ABOUT THE SAID AXIS, THE PROVISION OF A TROWELLING BLADE AND ATTACHING MEANS FOR DETACHABLY ATTACHING THE SAME TO THE SAID ROTATABLE ARM; SAID TROWELLING BLADE HAVING AN UPPER SURFACE, A WORKING SURFACE OPPOSITE TO SAID UPPER SURFACE TWO ENDS AND TWO SIDES; SAID ATTACHING MEANS COMPRISING AN ATTACHING PORTION SECURED TO THE UPPER SURFACE OF THE TROWELLING BLADE AND A COOPERATING ATTACHING PORTION SECURED TO THE SAID ROTATABLE ARM, ONE OF SAID ATTACHING PORTIONS COMPRISING TWO SPACED STRADDLING MEMBERS AND THE OTHER ATTACHING PORTION BEING INTERPOSED BETWEEN SAID SPACED STRADDLING MEMBERS OF THE SAID ONE ATTACHING PORTION, EACH MEMBER ATTACHED TO THE BLADE BEING POSITIONED BETWEEN THE SIDES OF THE BLADE, AND EXTENDING GENERALLY TOWARDS THE ENDS OF THE BLADE, ONE OF THE TWO ATTACHING PORTIONS HAVING FOR EACH MEMBER THEREOF A FREE EDGE WITH TWO SPACED SLOTS FORMED THEREIN, EACH SLOT COMMENCING AT SAID FREE EDGE OF THE ASSOCIATED MEMBER, HAVING AN ENTRY PORTION EXTENDING INTO THE MEMBER AWAY FROM THE FREE EDGE, AND BRANCHING INWARDLY OF THE FREE EDGE TOWARDS BOTH OF THE ENDS OF THE MEMBER TO CONSTITUTE TWO CORRESPONDING RETAINING PORTIONS AND THEREBY PERMIT REVERSING END-FOR-END OF THE ATTACHMENT OF THE BLADE TO THE SAID ROTATABLE ARM, THE OTHER OF SAID TWO ATTACHING PORTIONS HAVING SECURED THERE TO TWO TRANSVERSLY EXTENDING PINS SPACED APART A DISTANCE CORRESPONDING TO THE SPACING OF THE SAID SLOTS, THE SAID PINS BEING ENGAGED IN THE SAID SLOT ENTRY PORTIONS BY MOVEMENT OF THE TROWELLING BLADE TOWARD THE SAID ARM AND THEREAFTER ENGAGED IN RESPECTIVE RETAINING PORTIONS OF THE SLOTS TO RETAIN THE BLADE ON THE SAID ARM BY LONGITUDINAL SLIDING OF THE SAID TWO ATTACHING PORTIONS RELATIVE TO ONE ANOTHER UPON CORRESPONDING ENDWISE MOVEMENT OF THE BLADE RELATIVE TO THE SAID ARM.