Releasable tool attachment means for power trowels

Abstract

A tool driver for a power trowel, the tool driver comprising a combination of a magnetic fastening arrangement and a friction based fastening arrangement for releasably holding an abrasive tool to the tool driver, wherein the magnetic fastening arrangement is configured symmetrically around a rotational center of the tool driver, wherein the friction based fastening arrangement is adapted to provide increased shear strength during abrasive operation of the tool, and wherein the magnetic fastening arrangement is adapted to provide increased pull strength during lifting of the tool driver.

1 . A tool driver for a power trowel, the tool driver comprising a combination of a magnetic fastening arrangement and a friction based fastening arrangement for releasably holding an abrasive tool to the tool driver, wherein the magnetic fastening arrangement is configured symmetrically around a rotational center of the tool driver, wherein the friction based fastening arrangement is adapted to provide increased shear strength during abrasive operation of the tool, and wherein the magnetic fastening arrangement is adapted to provide increased pull strength during lifting of the tool driver. 
     
     
         2 . The tool driver according to  claim 1 , wherein the friction based fastening arrangement comprises a tool driver surface with protrusions configured to engage with a yielding surface material on the abrasive tool to provide the increased shear strength. 
     
     
         3 . The tool driver according to  claim 1 , wherein the friction based fastening arrangement comprises a material with hooks for holding respective loops on the abrasive tool or wherein the friction based fastening arrangement comprises a material with loops for holding respective hooks on the abrasive tool. 
     
     
         4 . The tool driver according to  claim 2 , wherein the yielding surface material or the material with loops is a felt-like cloth, a fibrous material, a foam, rubber, and/or a non-synthetic material. 
     
     
         5 . The tool driver according to  claim 1 , wherein the magnetic fastening arrangement comprises a plurality of magnets arranged symmetrically around a rotational center of the tool driver. 
     
     
         6 . The tool driver according to  claim 1 , wherein the magnetic fastening arrangement comprises a metal element responsive to a magnetic force from the abrasive tool. 
     
     
         7 . The tool driver according to  claim 1 , wherein the tool driver comprises centering means for centering the abrasive tool with respect to the rotational center of the tool driver. 
     
     
         8 . The tool driver according to  claim 1 , wherein the tool driver has a diameter between 7 and 25 inches. 
     
     
         9 . The tool driver according to  claim 1 , wherein the tool driver is arranged to interface with a secondary tool driver. 
     
     
         10 . The tool driver according to  claim 9 , wherein the magnetic fastening arrangement comprises magnets extending through the tool driver to engage with the abrasive tool on one side of the tool driver and to engage with the secondary tool driver on the other side of the tool driver. 
     
     
         11 . The tool driver according to  claim 9 , comprising protruding elements having shapes matched to corresponding recesses formed in the secondary tool driver. 
     
     
         12 . The tool driver according to  claim 9 , comprising one or more notches formed in the rim of the tool driver, to allow a better grip by a hand removing the tool driver from the secondary tool driver. 
     
     
         13 . An abrasive tool for a power trowel, the abrasive tool comprising a combination of a magnetic fastening arrangement and a friction based fastening arrangement for being releasably held by a tool driver on a first side of the abrasive tool, wherein the magnetic fastening arrangement is configured symmetrically around a rotational center of the tool, wherein the friction based fastening arrangement is adapted to provide increased shear strength during abrasive operation of the tool, and wherein the magnetic fastening arrangement is adapted to provide increased pull strength during lifting of the tool. 
     
     
         14 . The abrasive tool according to  claim 13 , wherein the friction based fastening arrangement comprises a yielding surface material configured to engage with protrusions on arranged on the tool driver surface to provide the increased shear strength. 
     
     
         15 . The abrasive tool according to  claim 13 , wherein the friction based fastening arrangement comprises a surface material with hooks for holding respective loops on the tool driver or wherein the friction based fastening arrangement comprises a surface material with loops for holding respective hooks on the tool driver. 
     
     
         16 - 20 . (canceled) 
     
     
         21 . The abrasive tool according to  claim 13 , comprising an abrasive component or compound arranged on a second side of the abrasive tool opposite to the first side. 
     
     
         22 . The abrasive tool according to  claim 21 , wherein the abrasive component is supported at least partly by a flexible supporting element. 
     
     
         23 . The abrasive tool according to  claim 13 , wherein the magnetic fastening arrangement comprises a metal ring having a diameter smaller than a diameter of the tool. 
     
     
         24 . The abrasive tool according to  claim 13 , comprising;
 a fibrous pad including an upper surface, a floor-facing lower surface and a peripheral surface;   a reinforcement layer attached to the bottom surface of the pad, the reinforcement layer including an internal edge defining a hole therethrough; abrasive disks attached to a floor-facing surface of the reinforcement layer;   a central area of the pad being exposed through the hole of the reinforcement layer such that a linear dimension of the central area within the hole is greater than a linear dimension of one side of the reinforcement layer between the hole and a periphery thereof; and where   a magnetic ring arranged on the upper surface constitutes the magnetic fastening arrangement, wherein the magnetic ring has an outer diameter smaller than an outer diameter of the reinforcement layer.   
     
     
         25 . (canceled) 
     
     
         26 . (canceled) 
     
     
         27 . A method of attaching an abrasive tool to a tool driver for a power trowel, comprising;
 configuring a combination of a magnetic fastening arrangement and a friction based fastening arrangement for releasably holding an abrasive tool to the tool driver, wherein the magnetic fastening arrangement is configured symmetrically around a rotational center of the tool driver; and   releasably holding the tool by the tool driver.