Molded Pole-Type Sandpapering Tool Having Resilient Paper Retention Means

This application is related to my contemporaneously filed copending U.S. patent application entitled Molded Pole-type Sandpapering Tool, naming Donald Gringer, one of the joint inventors herein, as sole inventor thereof.

The present invention relates to sanders and particularly to improvements in pole-type sanders of the type used for joints in dry wall plaster or wallboard and the like.

Pole-type sanders of the type used for sanding joints in wallboard or dry wall plaster or the like are well known in the art. Such sanders, by way of example, are disclosed in U.S. Pat. Nos. 3,483,662; 2,711,059; 3,123,946 and 2,523,884, and are commercially available from such companies as Hyde Tools, such as its model No. 45390 pole sander. In addition, pole-type sanders have also been employed in connection with floor sanders such as disclosed in U.S. Pat. No. 1,501,192. These prior art pole-type sanders have all employed some type of universal joint in order to permit the flat sandpaper surface, which is generally secured to a flat backing surface, to parallel the wall or ceiling or floor surface against which the sandpaper is applied during the sanding operation. In utilizing these pole-type sanders, the user is generally a considerable distance away from this surface at the other end of the pole or broom handle through which the pressure is applied to the sandpaper surface against the surface or joint being sanded. These prior art pole-type sanders although satisfactory in many instances, have several undesirable features which affect their function. Thus, although it is well known that optimum pressure can be applied against the surface being sanded if the handle or pole can be as low or horizontal as possible in reaching for corners, the structure of the universal joint in conjunction with the sandpaper retention means has prevented this, acting as an impediment rather than an aid in achieving this objective. In addition, the prior art universal joints employed do not generally employ positive friction so that sure control of movement of the sanding surface is lost. Moreover, these prior art pole-type sanders are generally costly to manufacture, employing several components, such as by way of example, fourteen separate components in the aforementioned Hyde Tools pole sander, and require a relatively long time of assembly during the manufacturing process. In addition, although the use of wire clips to retain sandpaper on a sanding block is well known in connection with hand type sanders, such as disclosed in U.S. Pat. Nos. 734,954; 1,415,171 and 2,201,645, they have not generally been employed in the same manner. The previous art hand sanders retained the sandpaper by the friction of the wire clip against the abrasive surface of the sandpaper, thereby providing a not too secure clamping arrangement. These disadvantages of the prior art have been overcome by the present invention which employs, among other things, peripheral contoured guide ramps adjacent to substantially orthogonally disposed slots for a universally movable handle which permit planar disposal of the handle, and a locking spring action clip which provides positive locking and unlocking arrangement to retain sandpaper. This provides the lowest possible profile so that an extremely acute universal joint angle may be obtained when needed. This angle is considerably lower than any others now on the market.

The present invention comprises a molded pole-type sandpapering tool comprising a molded body member having a flat backing surface for the sandpaper and a handle mounting surface on the opposite side thereof which includes a two-piece resilient molded universal joint to which a molded handle mount is attached and two pairs of spaced apart peripherally disposed molded contoured guide ramps adjacent opposite side of the universal joint and defining a pair of substantially orthogonally disposed slots for the universally mounted handle for enabling planar positioning thereof for applying optimum positive pressure to the abrasive surface. The contoured guide ramps comprise sloped contoured surfaces which positively guide the handle on a contoured path between the orthogonal slots during universal movement of the handle substantially in the plane of the abrasive surface while maintaining optimum pressure. A pair of resilient wire spring clips are pivotally mounted to the guide ramps for removably securing the ends of the sandpaper to the body member to hold the sandpaper against the backing surface. The contoured guide ramps have retention notches therein for removably locking the spring clips in a sandpaper securing position against the handle mounting surface.

FIG. 1 is a top plan view of the presently preferred embodiment of the present invention;

FIG. 2 is a side elevational view of the embodiment of FIG. 1, taken from either side thereof;

FIG. 3 is an end elevational view of the embodiment of FIG. 1, taken from either end thereof;

FIG. 4 is a bottom plan view of the embodiment of FIG. 1;

FIG. 5 is a front elevational view of the male clevis portion of the preferred universal joint portion of the embodiment of FIG. 1; and

FIG. 6 is a side elevational view of the male clevis portion of FIG. 5; and

FIG. 7 is a cross-sectional view of the embodiment of FIG. 1 taken along line 7--7 in FIG. 1.

Referring now to the drawings in detail, and initially to FIG. 1 thereof, a top plan view of the presently preferred embodiment of the pole-type sandpapering tool or pole sander of the present invention, generally referred to by the reference numeral 10, is shown. Preferably pole sander 10 includes a molded body member portion 12 which is preferably molded from a plastic such as foam polypropylene, to form the various portions thereof. As shown and preferred in FIGS. 1 and 2, body portion 12 preferably comprises a backing surface 14 and a handle mounting surface 16 on the opposite side of said backing surface 14. The handle mounting surface 16 preferably contains a universal joint 18 thereon for universally mounting a pole handle 20 to the body member 12 via a handle mounting socket 22 having internal threads 24 therein which are preferably threadably engageable with the threads disposed on the end of a standard broom type handle 20.

The universal joint 18 preferably comprises a two-piece molded resilient universal joint formed from the same material as the body member 12 for providing a positive friction engagement for the joint 18. This positive friction engagement is achieved by the resilient mounting of a bifurcated male clevis portion 18a (FIG. 5) in a pair of spaced apart arcuate female clevis portions 18b extending upwardly from handle mounting surface 16. As shown and preferred in FIGS. 5 and 6, as well as FIGS. 1-3, the male clevis portion 18a comprises a pair of integrally molded pins 108a and 108b (FIG. 5) disposed at the respective ends of the bifurcated portion 18a and another pair of integrally molded pins 108c and 108d (FIG. 6) disposed at the apex of the bifurcated portion 18a. As shown in FIG. 6, the bifurcated portion 18a may be resiliently squeezed together prior to insertion in the corresponding aperture in the spaced apart female clevis portions 18b, with the pins 108a and 108b then being resiliently biased into a rest position in these apertures creating the aforementioned positive frictional engagement with the pins 108a and 108b being rotatable in the directions of arrow 110 (FIG. 2) about the axis through the pins 108a and 108b. This provides the end to end rotation of the broom handle 20 in socket 22. With respect to the mounting of pins 108c and 108d, the socket 22, as shown and preferred in FIGS. 2 and 3, and which is again preferably molded of the same material as body member 12, includes a pair of spaced apart resilient downwardly extending arms 112 and 114 having apertures therein which may be resiliently spread apart to receive pins 108c and 108d, respectively, to thereafter provide a positive frictional engagement when pins 108c and 108d are at rest in these apertures, with pins 108c and 108d being rotatable in the directions of arrow 116 (FIG. 3) about the axis through the pins 108c and 108d. By combining the two axial rotations defined by arrows 110 and 116 the molded universal joint 18 is provided which, as stated above, may be readily assembled without additional separate pins.

In addition to the universal joint 18, which is preferably centrally disposed on the handle mounting surface 16, the handle mounting surface 16 preferably includes a pair of spaced apart peripheral contoured guide ramps 200a-200b and 200c-200d, respectively, disposed on opposite sides of the universal joint 18 which define a series of substantially orthogonal slots 202a, 202b, 202c, 202d, 202e and 202f, respectively, for the broom handle socket 22 on the handle mounting surface 16 so as to positively guide socket 22 and, hence, handle 20, into these slots 202a-202f and into a planar position parallel to the flat backing surface 14 for enabling optimum pressure applied through handle 20 to bear against the mounted sandpaper surface. As shown and preferred in FIGS. 1 and 2, the contoured guide ramps 200a-200b and 200c-200d each comprise a series of sloped surfaces defined by the contour of the smallest possible angle with the sanding plane as the socket 22 rotates 360 degrees via universal joint 18 over the guide ramps 200a-200d to positively guide the socket 22 between the various orthogonal slots 202a-202f. The various slopes may be empirically defined prior to finally molding body member 12.

In addition to the above, as further shown and preferred in FIGS. 1-3, a pair of contoured wire spring clips 204 an 206, such as spring steel clips, are preferably employed to removably secure the sandpaper 210 to the body member 12 and hold it in place against the backing surface 14. The spring clips 204 and 206 are preferably pivotally mounted to the guide ramps 200a-200d, with spring clip 204 being pivotally mounted to guide ramps 200a-200b and with spring clip 206 being pivotally mounted to guide ramps 200c-200d. Each of the guide ramps 200a-200d preferably has a retention slot 212a-212d, respectively, in the front surface thereof for removably locking the resilient spring clips 204, 206 in place in a sandpaper securing position against the handle mounting surface 16. The ends of the unmounted sandpaper 210 preferably extend past the ends of backing surface 14 and are preferably wrapped around these ends and over underneath these clips 204 and 206 which are then resiliently locked in place in the retention slots 212a-212d to provide positive pressure against the sandpaper 210 without having to first slide over the sandpaper 210 to get into position. In order to release the clips 204, 206, the finger acts as a wedge against mounting surface 16 to force the clips 204 or 206 up. With this arrangement the sandpaper 210 can be locked in place without the clip having to slide over the sandpaper 210. Moreover, the clip may easily be moved out of the way to load the sandpaper 210.

If desired, as further shown and preferred in FIG. 2, a backing pad 218, such as one comprised of rubber, may be provided between backing surface 14 and the sandpaper 210.

By utilizing the present invention, a pole sander having as few as six pieces can readily be assembled together and will enable optimum pressure to be applied against the abrasive surface.