A flexible polishing drum segment for use with a polishing or grinding hub. The segment comprises a plurality of abrasive flaps of uniform size and shape, joined together along a common edge to a metal strip. The metal strip comprises first and second, substantially flat plate sections extending parallel to one another in surface-to-surface abutment. One of the plate sections is longer than the other and it is to this longer plate section that the packet is joined. The first and second plate section are integral with and joined together by a root element which is generally circular in configuration. A core is located within the root element to substantially fill the entire volume thereof.

The drum-like wheel is provided radially outwardly of its rotative driver hub portion with a circumferentially spaced series of axially elongated and continuous, keyholeshaped sectional slots or grooves. These parallel one another in the series; and each slot slidably and removably receives one of a set of like circumferentially spaced abrasive finishing packs or fills, said packs each including a forked clip member clamping a stack of abrasive sheets as part of the pack. The clips are solid in cross section, being extrusion molded, and each has a reduced width neck portion of optional radial dimension integrally connecting the forked portion of the clip with an integral, radially inner mounting portion of enlarged bead-like cross section, at which the clip and its sheet stack have an axially slidable mating interfit in the keyhole slots of the wheel hub. As thus mounted the clips have a fixed, non-pivotal relationship to the hub.

An improved sanding and buffing wheel characterized by a cup-shaped hub element the outer surface of which is formed with circumferentially spaced, longitudinally extending slots. The slots terminate adjacent the cup base and are adapted to receive end portions of abrasively surfaced strip material. The strips of material are so formed and mounted to extend in a sense generally radial to and/or to fan outwardly from the hub wall to present abrasive surfaces thereof in a circumferentially spaced following relation, with respect to the direction of the wheel travel in use. The base of the cup-shaped hub element is apertured to accommodate one end of a simple mounting shaft. In preferred embodiment each slot will have slip fit therein, through an open end thereof at the cup lip, a plurality of abrasively surfaced strips, the inserted portions of which are stacked one upon the other and frictionally retained by the slot sides. The open ends of the slots are covered, in preferred embodiments, by an external flange on a cup-shaped cap element, which is nested in and thereby secured to the cup shaped hub element. It is a feature of preferred embodiments that the connection and placement of the abrasively surfaced strips are such that they present themselves in groups having a fanned out form and with their outer ends cupped or curved away from the direction the wheel will travel in use.

An abrasive flap wheel assembly including abrasive packets having their inner end portions disposed in recesses in the hub and being attached so that they project at about a right angle to a radius of the hub through the area of attachment between the hub and the abrasive packet to provide a small assembly that facilitates contact between a large portion of the major outer abrasive faces of the packets. Also the outer ends of the pieces of abrasive-coated material in the packets are spaced to provide exposed abrasive-coated end portions for the underlying pieces of abrasive-coated material in the packets.

A cylindrical drum has at its circumferential edge a number of recesses, each adapted for accommodating a replaceable grinding element including a retainer in which is mounted a sandpaper, support brushes and/or retainer brushes. The recesses in the cylindrical drum are made with side walls. The retainer is made with corresponding outer side walls. During use, by wedge action between the side walls of the recesses and the outer side walls of the retainer, a squeezing force on the side walls of the retainer directed in the circumferential direction arises. The retainer is designed with grooves for fastening at least one sandpaper, and the grooves extend from an upper side of the retainer and into the retainer for forming at least one elastic and pliable flap which is disposed between the grooves and at least one outer side wall.