US3382521A - Rotary brush - Google Patents

Description

y 1968 L. G. HOLDER ET AL 3,382,521

ROTARY BRUSH Filed Feb. 27. 1967 INVENTORS L0) GENE HOLDER JOSEPH A. KAS/VY/K MJW M y ATTORNEYS United States Patent 3,382,521 ROTARY BRUSH Loy Gene Holder, Sheffield Lake, and Joseph A. Kasnyik, Parma, Ohio, assignors to The Osborn Manufacturing Company, Cleveland, Chin, a corporation of Ohio Filed Feb. 27, 1967, Ser. No. 618,659 7 Claims. (Cl. 15-198) ABSTRACT OF THE DISCLOSURE A power driven rotary cup brush having relatively shallow sheet metal inner and outer cup portions formed to facilitate controlled bodily radially outwardly swinging movement of the twisted wire bristle knots or tufts for more effective brushing action coupled with much increased brush life.

This invention relates as indicated to a rotary brush and more particularly to a power driven cup brush having twisted wire knots or tufts.

Power driven cup brushes are well-known in the art and have been employed for many years for such purposes as cleaning castings, removing weld spatter, and the like. They are commonly mounted on the ends of flexible shafts driven by power tools which are frequently held by the operator for off-hand use. Particularly when the tufts are made of heavy gauge wire such brushes are difficult to handle and consequently tiring to the operator. Also, in view of the harsh working conditions to which they are frequently subjected the working life of such brushes may be relatively short, on the order of five hours, the brushes deteriorating due to long fracture of the bristle wires long before the bristles are worn down to unusably short lengths from actual wear. A primary object of the invention is to provide a novel power driven rotary cup brush which will have a much increased useful working life, which will be much easier for the operator to manage, and which will have improved brushing action on the work. These and other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative however of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

FIG. 1 is a plan view of a power driven rotary cup brush illustrating the principle of the invention, a number of the twisted tufts being omitted better to disclose the internal construction of such brush; and

FIG. 2 is a transverse diametral section taken on the line 2-2 of FIG. 1, also indicating in dash line the generally radially outward position assumed by the tufts under the influence of centrifugal force.

Referring now in more detail to the drawing, wherein like parts are indicated by like reference numerals, such brush comprises a shallow outer sheet metal cup portion 1 having a flat inner disc portion 2 and a generally radially outwardly turned lip portion 3. Juxtaposed against the inner face of such flat cup portion 2 is a much heavier sheet metal disc 4 the outer peripheral portion of which is dished and provided with a large number of closely spaced circumferentially arranged apertures 5 through which the wire bristle tufts 6 are threaded. Such apertures are desirably chamfered to facilitate radially outwardly swinging movement of such tufts and to avoid sharp edges 3,382,521 Patented May 14, 1968 "ice engaging the wires comprising the latter. An inner sheet metal cup 7 is juxtaposed to the inner face of disc 4 and has a peripheral flange portion 8 adapted to engage the radially inner sides of the bight portions of the twisted wire bristle knots or tufts 6. Cup 1, disc 4 and cup 7 are concentrically apertured at 9 for mounting upon a flexible shaft or the like which is ordinarily provided with a retaining nut (not shown) internally of cup 7. Such cups and discs are integrally joined together as by means of spot welds such as 10.

The outer sheet metal cup 1 is more shallow than has been the case in the usual prior art cup brush and the lip 3 thereof will desirably extend only very slightly further than the edge of disc 4 in a direction parallel to the axis of rotation of the brush, thereby enabling the tufts 6 to swing or pivot in their retaining apertures in a radially outward direction under the influence of centrifugal force when the brushing tool is rotated at high speed, the outwardly flaring lip portion serving to control the extent of such outward swinging movement and to support the tufts or knots when they have thus swung outwardly into positions very nearly those of tufts in a conventional wheel brush. Cups 1 and 7 thus provide a brush tuft bight receiving channel therebetween which serves to regulate the positions which may be assumed by such tufts without however tightly clamping the bight portions of the tufts therebetween.

In the manufacture of the brush of this invention cups 1 and 7 will ordinarily be preformed sheet metal stamp ings prior to assembly, but the tufts of wire bristles may be inserted through the apertures 5 of the flat heavy gauge steel disc prior to deformation of the latter, the outer peripheral portion of such disc being then deformed as shown in FIG. 2. Alternatively, the tufts of wire brush bristle material may be inserted through apertures 5 and twisted into knots after the outer peripheral portion of disc 4 has been preformed. The depth of flange 8 of inner cup member 7 is selected such that it extends in a direction axially of the brush only slightly beyond the edge of deformed disc 4 and preferably likewise only very slightly more in such direction than lip 3 of outer cup member 1. Consequently, the bight portions of the knots or twisted tufts are embraced between the sides of such respective cup members to control and regulate the positioning of such tufts without substantially clamping or compressing such bight portions in the manner of prior art cup brushes where such knots are tightly constrained Within a relatively deep retaining channel portion. Not only are the tufts thus permitted to pivot or swing outwardly as above described, but also the brush bristles are permitted to flex throughout substantially their entire length, thereby achieving the action of a relatively long trim brush in use, in contrast to prior art cup brushes wherein substantial lengths of the brush tufts are held between the sides of a channelform back with bristle flexure accordingly limited largely to the portion of the bristle length protruding from such channel. The apertures 5 through which the bristle tufts are inserted may desirably be somewhat elongated, or oval, in radial directions. The ends of the brush bristle tufts may be trimmed to proper uniformity before disc 4 is deformed from the fiat to the FIG. 2 shape. In a typical brush, the twisted tufts may be 2 /2" in overall length with 1%" extending outwardly beyond lip 3 of the outer cup 1.

It will be seen from the foregoing that a novel power driven rotary brush of the twisted tuft type has been provided having numerous advantages and benefits. When mounted on the usual power driven rotary shaft, the nut securing the brush to the end of the shaft will normally be within the confines of inner cup 7 where there is no danger of contacting and marring the work. Since the knots of twisted wire brush bristle material 6 are enabled to swing bodily toward a may accordingly be operated in much the same manner and for many of the same purposes as anordinary wheel type brush, but is also very effective in acting upon interior angles of workpiecesfor example. The inner cup 7 is so shallow that it serves principally merely to support the bight portions of the bristle tufts, preventing radially inward pivoting of, such tufts beyond a position generally parallel to the axis of rotation of the tool without however tightly clarnping or constricting such tufts. The outer edge or lip 3 of the outer cup 1 is turned generally radially outwardly to support the tufts when they have swung outwardly under the influence of centrifugal force without however providing asharp edgecontact against such tufts which .mighttend to encourage long fracture of the bristles. As afpracticalmatter, it has been found that brushes in accordance, with this invention are capable of withstanding more than twice the amount of hard use,

measured in time, than the most closely similar cup brushes previously known to applicants, and operators find themmuch easier to handle for oif-hand brushing operations and the likelt has been found that for certain standard brush sizes the brush bristle tufts should be twistedtwo full turns as shown, a smaller degree of twist usually providing appreciably inferior results. While twisted wire tufts or knots are usually preferred, other abradingelements such as tufts of crimped wire or even of straight wire held. in bundles may be employed, and the individual tufts or bundles may be impregnated with an elastomeric material such as foamed polyurethane; It may also be noted, as best shown in FIG. .2, that the outward slope or inclination of flange portion 8 of inner cup member 7 ispreferablysubstantially" less than the outward inclination of the corresponding side flange portion of outer cup. member 1, it being desired thatoutward pivotal. movement of the tufts be facilitated whereas corresponding radially inwardly swinging movement of the tufts should be relatively limited in use.

In the preferred embodiment of the iriventionillustrated, the cup brush thus comprises an outer sheet metal cup portion having .aperipheral outwardly flaring flange,

a concentric inner sheet metal cup portion having a peripheral side flangespaced from such first flange to provide .a circumferential channel therebetween, brush tuft retaining means interposed and secured betweensuch inner and outer cup portions, and a plurality of brush tufts having innerend orbight portions secured to such retaining means. for a tsubstantial amount of outward swinging movement when the brush is rotated at high Speed in use. The channel formed by the cup flanges is preferably inclined to the axis of rotation of the brush,

and the outer side of such channelmay desirably be thus portion having a peripheral side flange spaced from said first flange to provide a circumferential channel therebetween, brush tuft retaining means interposed and secured between said inner and outer cup portions, and a plurality of brush tufts having inner end portions secured to said retaining means, characterized in that said brush tuft re taining means comprises a sheet metal disc having a plurality of apertures about its periphery through which twistedwire bristle tufts are inserted and secured for a substantial amount of outward swinging movement when said brush is rotated at high speed in use, the, bight por tions onlyof said tufts being within the confines of said channel, and said side flange of said inner cup portion flares outwardly to a lesser degree than said outwardly flaring flange of said outer cup portion.

2. The brush of claim 1, further characterized in that said outwardly flaring flange of said outer cup portion said cups and discs are concentrically apertured and joined together for rotation as a unit when mounted on a drive shaft or the like.

4. The brush of claim 3, further characterized in that the length of bristle tuft within the confines of such channel is much less than the length of bristle tuft extending beyond such channel. I, I I

5. A power driven rotary brush comprising a circular back adapted to be mounted for rotation about a central axis normal to the plane of such circle, a circumferential channel portion of said back inclined to such plane, the outer side of said channel flaring outwardly at a substantial angle to such axis, brush'material retaining means within said channel, and a single circular row of twisted tufts of brush material secured to saidretaining means within said channel for substantial bodily outwardly swinging movement to the extent permitted by said flaring outer side of said channel, the lip of said outer side I of said channel being turned generallyradially outwardly in a planesubstantially parallel to such plane of such circle substantially directly opposite the region where said brush material is thus swingingly secured to said retaining means to permit said brush material to swing outwardly under the influence of centrifugal force intogenerally radially outward disposition.

6. The brushof claim 5, wherein the outer side of said channel extends only'slightly further than said retaining "means in the direction parallel to such brush axis.

7. A power driven rotary brush comprising a circular back adapted to be mounted for rotation about a central axis normal to the plane of such circle, a plurality of twisted tufts of brush bristle material pivotally mounted circumferentially of said back for bodily swinging movement from positions generally parallel to the axis of rotation of said'brush to positions generally radially outward- I ly thereof, outer circumferential flange means effective to limit such outward swinging movement, and inner circumferential flange means effective to limit such inward- I ly swinging movement, said outer flange means terminatthe following claimsor theequivalent of such be em- We, therefore, particularly point out and distinctly claim as ourinvention: I

1. A power driven rotary cup brush comprising an outer sheet metal cup portion having a peripheral outwardly flaring flange, a concentric inner sheet metal 7 cup ing in an outwardly projecting lip'in a plane substantially parallel to such plane of such circle.

References Cited. UNITED STATES PATENTS 2,062,047 11/1936 Bickel'et al. e;.' 15-480

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