US 3436876 A
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April 8, 1969 T. R. MCAVOY ET AL 3,436,876
ADAPTER Filed May 12, 1966 INVE NT 0R5 7/10/1445 P. MC/4I/O) JOHN A. 4N05Q50/v flrrogrvgi 3,436,876 ADAPTER Thomas R. McAvoy, Stillwater, and John R. Anderson,
Maplewood, Minn, assignors to Minnesota Mining and Manufacturing Company, St. Paul, Minn a corporation of Delaware Filed May 12, 1966, Ser. No. 549,613 Int. Cl. B24d 17/00; A471 11/40 US. Cl. 51-378 6 Claims ABSTRACT OF THE DISCLOSURE This invention relates to adapters for attaching compressible abrading, cleaning, or polishing pads over the bristle face of an annular floor maintenance brush.
For many years floors have been cleaned with machines which drive a brush having a rigid annular block with bristles mounted in the lower face. The bristles of the brush may either provide the cleaning action directly or serve to grip and drive a steel wool pad or nonwoven fibrous low density abrasive disc of the type disclosed in Hoover et al. US. Patent 2,958,593. Special driving pads, which have no cleaning ability per se, have also been developed as replacements for the brush. Neither brushes nor driving pads, however, have been completely satisfactory, both requiring careful positioning and permitting the cleaning or polishing pad to fall off when the machine is lifted or tilted.
It has been recognized that it would be desirable to modify a floor surfacing brush so it could be used either as a brush or as a means to hold and drive a low density abrasive fibrous disc product, thereby both eliminating the need for a separate driving pad and preventing the disc from becoming disengaged when the machine is lifted or tilted. Thus, brushes have been modified by mounting a base which spans the center hole of the brush and is attached to the bristle-free area of the brush block adjacent the center hole. A flanged depressed-center plate is then inserted through the center hole of the low density abrasive pad and connected to the base. As the plate is moved toward the base, the pad is contacted on one side by the flange and on the other side by the bristles of the brush. Although such devices have been successful in keeping the pads from falling off the brush, a major problem has remained unsolved. In all the prior art adapters of which we are aware, the low density abrasive disc has tended to slip between the flanged plate and the brush bristles, thereby greatly reducing its effectiveness. Such slippage is particularly likely to occur when the bristles are soft, as
States Patent when they have been recently exposed to water, or when the brush has been used and the bristles have acquired a tendency to lean.
The present invention provides, for the first time, it is believed, an adapter for attaching a low density fibrous abrasive pad over the bristle surface of a conventional floor scrubbing brush while simultaneously firmly gripping the pad in a manner which effectively prevents slippage.
In its simplest terms, the invention comprises three component parts-a flanged base member which spans the center hole of an annular floor surfacing brush and is attached to the brush block in conventional manner, a hat-shaped member, and an adjustable gripping means adapted for engaging a post which extends from the lower face of the base member through a hole in the crown of the hat-shaped member. Integral with the base and connected thereto by a wall means is an annular flange means generally corresponding to the dimensions of the brim of the hat-shaped member. The crown of the hat-shaped member is so sized that it can readily fit inside the wall means on the base member, cooperative means on the two members being provided to prevent relative rotation between the two. In accordance with the invention a low density abrasive disc having a center hole is gripped firmly between the flange of the base member and the brim of the hat-shaped member in the area immediately adjacent the center hole. Although similar in some respects to prior art devices, this novel gripping feature imparts an eflectiveness not heretofore attainable.
Understanding of the invention will be facilitated by referring to the accompanying drawing in which like numbers refer to like parts in the two views, and in which:
FIGURE 1 is an exploded view of a preferred embodiment of the invention, and
FIGURE 2 is a diametric cross-sectional view of the parts shown in FIGURE 1 as they are assembled in operation.
In the drawings, base 10 comprises generally circular end 11, from peripheral portions of which wall portions 12 are turned up at approximately right angles. At the distal portions of wall portions 12 are flanged portions 13 extending circumferentially outward in a plane substantially parallel to that of end 11. Extending radially in substantially the same plane as end 11 are legs 14, each provided with a plurality of holes 15 for attachment to the backing of an annular brush in the area immediately surrounding the central opening thereof. Holes 15 are separated by break lines 16, so that legs 14 can be sized to the dimension appropriate for the brush to which base 10 is to be attached. Extending centrally from end 11 at substantially right angles thereto is threaded bolt 17. Extending radially inward at diametrically opposite locations on wall 12 are lugs 18.
Hat-shaped member 20 comprises crown portion 21 and brim portion 22. Hole 23 is located in crown 21 in a location corresponding to that of threaded post 17, the diameter of hole 23 being somewhat greater than that of post 17. The external dimensions of crown 21 are such that it will fit inside the area defined by wall portions 12 on base 10. Located at diametrically opposite portions of crown 21 are openings 24, designed to cooperate with and fit over lugs 18 on base 10.
Wing nut 30 comprises cylindrical end portion 31 and disc-shaped shoulder portion 32, arms 33 extending radially from the latter. Axial hole 34, extending through both cylindrical portion 31 and disc-shaped portions 32, is threaded to engage the threads on post 17. The external dimensions of wing nut 30 are such that it will fit inside the area defined by crown 21 of hat-shaped member 20.
Rotary brush 50, on which the foregoing assembly is to be mounted, comprises annular brush block 51, on one face of which are mounted bristles 52, the area 53 of brush block 51 immediately adjacent the center hole customarily being left free from bristles. Spanning the center hole is attaching means 54-, by which the brush assembly is affixed to the driving means of a fioor surfacing machine.
To utilize the adapter of this invention, base is attached to brush 50 by placing it in the bristle-free annular portion thereof in the area 53 spanning the center hole, breaking off legs 14 at break lines 15 to an appropriate length, if necessary. Screws 19 are then inserted through holes 15, and into brush block 51 in area '53. Crown 21 of hat-shaped member is then inserted through the center hole 41 of low density abrasive disc 40 and hole 23 slipped over post 17, taking care to insure that slots 24 are aligned with lugs 18. Wing nut is then threaded over post 17 and turned as tight as necessary to insure proper gripping of disc between flange 13 and brim 22.
Base 10 is so positioned that the end of bolt 17 does not extend quite as far as the end of bristles 52, thereby preventing bolt 17 from contacting the floor when the brush is being used in conventional manner. Flange 13 is positioned within the bristle-free portion of the brush and typically spaced from block 51 a distance of about A inch less than the length of the bristles, the exact distance depending on the condition of the bristles. If the brush is new, or if the bristles are particularly long, it may be necessary to insert spacers (not shown) between legs 14 and the center 53 of rotary brush to provide the proper positioning.
The particular configuration of wing nut 30 offers advantages in assembling the device of this invention. For example, where abrasive pad 40 is relatively thick (e.g., inch or more), insertion of the cylindrical end portion 31 through center hole 23 of hat-shaped member 20 permits threading of wing nut 30 on bolt 17 more readily than would otherwise be the case. On the other hand, where the abrasive pad is relatively thin (e.g., less than /2 inch), wing nut 30 may be inverted, so that shoulder portion 32 is threaded on bolt 17 first. It is desirable to provide diametrically opposed peripheral areas of cylindrical end portion 31 with flat surfaces, so as to permit gripping with a wrench.
Regardless of the manner in which Wing nut 30 is applied, it should be tightened sufficiently to depress brim 22 of hat'shaped member 20 with respect to the operating face of disc 40, thereby preventing brim 22 from contacting the floor. Applying this amount of pressure serves the further advantageous purpose of firmly gripping the portion of disc 40 immediately surrounding center hole 41 between flange 13 and brim 22, thus minimizing any possibility that disc 40 will slip with respect to the adapter. Any tendency to Slip may further be minimized by providing the opposing faces of flange 13 and/or brim 22 with a friction-increasing surface, e.g., a coating of abrasive granules, slight projections, corrugations, a compressible rubbery material, etc.
The cooperation of lugs 18 with slots 24 to prevent hatshaped member 20 from rotating with respect to base It) has previously been discussed. It will be readily apparent that numerous other cooperating means might be employed to achieve this same effect. For example, crown 21 of hat-shaped member 20 and the geometric area defined by wall 12 of base 10 might both be similarly polygonal, e.g., hexagonal. Likewise, crown 21 of hat-shaped member 20 might be provided with slots corresponding to lugs on the radially inner surface of wall 12 of base 10. Either end 11 or crown 21 might be provided with an eccentrically located post, the other member being provided with a hole to accommodate the post. Similarly, threaded post 17 may be flat on diametrically opposite sides and hole 23 made in rectangular shape corresponding to the cross-sectional axes of post 17.
Although preferably formed from a single sheet of metal with threaded post 17 welded in position, base 10 may comprise a plurality of separable pieces which are joined to each other. For example, a flat plate member spanning the center hole of brush block 51 may be attached in area 53, with a separate dish-shaped member, having portions corresponding to wall 12 and flange 13, connected to the plate by a bolt which passes through a central hole in both members, the members being gripped between the bolt head on one side and a nut on the other.
The adapter of this invention may also be attached to floor machine accessories other than brushes. For example, an annular block, analogous to brush block 51, may be surfaced with sponge rubber, resilient protuberances, or other material, preferably having a high-friction surface. It is, of course, to be understood that the specific geometric shape of the block is not critical.
The foregoing, and other variations which do not depart from the spirit of the invention, are included in the scope of the appended claims.
What we claim is:
1. An adapter which is particularly suited for attaching a compressible disc over the bristled surface of a conventional annular floor surfacing brush and firmly gripping the disc to effectively eliminate slippage, said adapter comprising in combination: a base member having extending radially therefrom legs adapted for mounting on a flat surface, said base member having a generally circular end portion, a peripheral wall portion extending from one side of said end portion at substantially right angles thereto, and a flange extending circumferentially outward from and at substantially right angles to the distal portion of said wall, a post extending from the center of the same side of said end portion as said wall portion; a generally hat-shaped member having a crown portion and a brim portion, the periphery of said crown portion being geometrically similar to and slightly smaller than the area defined by inner aspects of said wall portion, said crown portion having a central hole slightly larger than the cross-section of said post, said base member and said hatshaped member being provided with cooperating means for preventing rotation of one member with respect to the other; and an adjustable gripping means adapted to engage said post and overlie the portion of said crown portion adjacent said hole, said gripping means being of such external dimensions as to fit inside the area defined by said crown portion, whereby a compressible disc having a center hole of about the same size as the periphery of said crown portion can be gripped snugly between said flange and said brim at the portion peripherally adjacent said center hole of said disc.
2. The adapter of claim 1 wherein the cooperating means for preventing rotation comprises (1) a lug extending radially inward from the wall portion of the base member and (2) a lug-accommodating slot in the crown portion of the hat-shaped member.
3. The adapter of claim 1 wherein the post is threaded and the adjustable gripping means is a complementarily threaded locking nut.
4. The adapter of claim 3 wherein the locking nut comprises a cylindrical body portion and a disc-shaped shoulder portion of greater cross-sectional area than said body portion, an aixal hole passing through both said portions and being internally threaded throughout its length.
5. The adapter of claim 4 wherein the central hole in the crown portion of the hat-shaped member is larger than the diameter of the cylindrical body portion of the locking nut but smaller than the diameter of the shoulder portion, and the thickness of the material forming said crown ortion is significantly less than the length of said cylindrical portion.
6. The adapter of claim 5 wherein diametrically opposite areas of the cylindrical body portion of the locking nut are parallel to permit gripping with a wrench.
References Cited UNITED STATES PATENTS 2,501,524 3/1950 Jones 51-378 5 LESTER M. SWINGLE, Primary Examiner.
D. G. KELLY, Assistant Examiner.
US. Cl. X.R.