Patent Document

BACKGROUND OF THE INVENTION 
     1. Technical Field 
     This invention relates generally to floor sanding and more particularly to a two wheel hand truck for moving the floor sander from one location to another, from a vehicle to work station via ramps, and supporting the floor sander with the wheels thereof in a no load state when the sander is not in use. 
     2. Background Information 
     Floor sanders conventionally have a sanding drum on a frame that is carried by a front pair of wheels and a single rear caster type wheel. The wheels have a rubber tire (relatively hard) and because of the weight of these machines the tires develop a flat spot when they sit idle for any length of time. Flat spots on the tires are most undesirable as they cause the machine to go up and down while the machine traverses the floor area during sanding. This leaves an undulating surface when all the flat spots are in sync or gouges when they are not. The resultant surface in either event is most unsatisfactory and unacceptable for more reasons than just the undesirable aesthetic effect. For one thing polishing an undulating surface will cause more wear to the surface finish on the crests than in the valleys of the undulating surface. The end result is a premature failure of the surface finish. 
     A two wheel hand truck, commonly referred to as a dolly, has a vertical section with two wheels on the lower end thereof and a forwardly projecting spaced pair of arms, or a plate, for supporting the load. The upper end of the frame is a handle and the center of gravity of the unit is such that the unit stands upright on the two wheels when the unit in not in use. In this at rest position the plate is disposed in a slight decline and the leading end thereof engages the ground surface. During use, after the load is located on the arms, or the plate as the case maybe, the wheels serve as a pivot point while the user tilts the handle to a load transport position where the center of gravity of the dolly frame and the load passes through or is located near the axle on which the wheels are mounted. With heavy loads, such as a floor sander, the wheels of the dolly tend to roll while attempting to tilt the dolly making it necessary to block at least one of the wheels with some object and normally the user puts one foot on one wheel to prevent the dolly from moving. 
     When a heavy load is carried by a dolly it is relatively easy to move and control the same while traversing a level surface but this is not so on a sloping surface, for example on a steep driveway or ramp for loading and unloading the sander in a vehicle. 
     A floor sanding machine with a transport carriage is disclosed in United States Utility Patent 1,640,933 granted Aug. 30, 1927 to L. M. Gries. It is an integrated unit that does not teach discuss the problems regarding preventing rubber tired wheels on a sander from developing flat spots when not in use. 
     SUMMARY OF INVENTION 
     The present invention is for a hand truck for transporting a floor sander. More particularly, the present invention is for a combination of a conventional floor sander that is rollingly supported on rubber tired wheels during use of the machine to sand a floor and a wheeled hand truck. The hand truck or dolly includes a pair of spaced apart arms projecting forwardly therefrom adjacent a lower end thereof. Also included are means removably mounted on the arms and supporting the sander on the dolly forwardly projecting arms with the wheels of the sander in a no load state and thereby preventing the tires from developing flat spots during idle time of the machine while in storage and transport from one work site to another. Means for detachably anchoring the sander to the dolly are also included. 
     The dolly may also include means removably mounted on the arms such as a pair of cross members slidably mounted on the arms. A means of interconnecting the pair of arms to maintain the same in a fixed spaced apart relation such as a flat strap may also be used with the dolly and sander arrangement. The cross members may also have a slot adjacent each of opposite ends thereof slidably receiving therein respective ones of the forwardly projecting arms. 
     Moreover, the dolly has an upwardly projecting frame portion with handle means on the upper end thereof, a forwardly projecting load carrying member on the lower end of the frame and a pair of wheels on opposite edges of the frame adjacent the lower end thereof the improvement comprising a hand operated brake operable on at least one of the wheels to selectively restrain rotation of the same, the brake having a hand operable lever mounted on the frame adjacent the handle means. The handle means may define a laterally spaced pair of loops on the upper end of the frame and projecting forwardly therefrom. The load carrying member on the lower end of the frame may define a pair of laterally space apart arms, and each of the arms are may be positioned so that they are right angular in cross-section. The dolly may also include a pair of cross members slidably mounted on and extending from one of the arms to the other for supporting an object thereon. 
     A principal object of the present invention is to provide a floor sander with a dolly that can be used to support the sander and transport the same from one location to another with the sander wheels in a no load state thereby eliminating the development of flat spots on the wheels that otherwise occurs during down time between sanding jobs. 
     A further object of the present invention is to provide a dolly, for transporting objects, with a hand operated wheel brake to facilitate tilting the dolly from an object pick-up position to an object transport position. 
     A still further object of the present invention is to provide the forgoing sander and dolly combination and in which the dolly is a stair type and including a hand operated wheel brake. 
     In keeping with the forgoing there is provided in accordance with one aspect of the present invention the combination of a conventional floor sander that is rollingly supported on rubber tired wheels during use of the machine to sand a floor and a hand truck on which the floor sander is detachably supported and carried such that the wheels are in a no load state during idle time of the machine while in storage and transport from one work site to another. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A better understanding of the present invention will be had upon reference to the following description in conjunction with the accompanying drawings in which like numerals refer to like parts throughout the several views and wherein: 
     FIG. 1 is a side elevational view of the combined floor sander and dolly therefor provided in accordance with the present invention; 
     FIG. 2 is a rear elevational view of the apparatus shown in FIG. 1; 
     FIG. 3 is an oblique front view showing the dolly in a tilted position for transporting the sander from one location to another; 
     FIG. 4 is an oblique side view showing the dolly in a tilted position for transporting the sander from one location to another; 
     FIG. 5 is an oblique view of only the dolly; 
     FIG. 6 is an oblique view illustrating a hand brake on the dolly; and 
     FIG. 7 is a partial oblique view illustrating a modified cross piece that supports the sander on the forks of the dolly. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Illustrated in FIGS. 1 to  4  is a drum type conventional floor sander  10  having forward positioned motor and drum and a plurality of small rubber wheels used to support the floor sanding during the sanding process. The floor sander has a rigid robust frame  11  on which there is mounted a sanding drum  12  and a drum drive motor  13 . There is also a handle  14  and a saw dust exhaust system  14 A on the frame. The embodiment shown is typical and includes a frame  11  supported by a pair of front, laterally spaced apart, rubber tired wheels  15  and a single rear caster type rubber tired wheel  16 . 
     The floor sander is removably carried by a two wheel cart  20  hereinafter referred to as a dolly. The sanding machine is anchored to the dolly by suitable anchor means  30 , by for example, a criss-crossed pair of straps shown in FIGS. 1 &amp; 3 and designated  31  and  32 , respectively. 
     The dolly  20  includes an upright frame portion  21  in the form of a weldment of tubular members having at the upper end thereof a pair of forwardly projecting loop handles  22 . The handles of the preferred embodiment are typically shorter in length than that of a conventional dolly to facility loading and transporting the dolly and floor sandy in a van and thus, it must be of a height to allow it to stand in an upright position. Moreover, the loops afford a means of supporting and pushing or pulling the dolly and floor sander up a ramp and into the van door where the accessibility is limited and holding the dolly securely is difficult with a conventional handle having a curved distal holding end. The loops allow the dolly to be lowered to almost ground level while the user remains upright and balanced. 
     The dolly is supported at the lower end on a spaced apart pair of rubber tired wheels  23 . The wheels are journal led on a transverse axle  24  that is secured to the lower end of the frame. A spaced apart pair of load carrying arms  25  are attached to and project forwardly from the lower end of the frame portion  21 . With the frame portion  21  upright in an at rest position the arms  25  are slightly downwardly inclined but essentially in a horizontal plane. In the embodiment illustrated in FIGS. 1 to  6 , the pair of arms  25  are interconnected adjacent their free outer end by a relatively thin metal strap  26  to ensure the arms remain in a fixed spaced apart position. 
     The load carrying arms are right angle in cross-section and have a lower flange  27  and a vertical upwardly directed flange  27 A. The flanges  27  are directed inwardly toward one another and support opposite ends of each of a pair of spaced apart cross-members  28 A and  28 B. The lower face of the frame  11  of the floor sander rests on the cross members  28 A &amp;  28 B at a suitable position such that the wheels  15  and  16 , respectively, of the sander are out of contact with the surface supporting the dolly. The sander wheels thus are in a no-load state thereby eliminating flat spots that otherwise develop when the weight of the sander is carried by its rubber tired wheels during idle time of the sander between sanding jobs. The upwardly directed flanges  27 A are outboard of and adjacent the ends of the cross members  28 A and  28 B thereby holding the same captive between the arms  25 . 
     As shown best in FIGS. 5 and 6, an alternate embodiment includes as an option for traversing steps or stairways, at least one laterally spaced apart endless tracks  29 A and  29 B that project from the rear face of the upright frame portion  21  of the dolly at a position adjacent the lower end thereof. A plurality of tracks or a single wide track may be utilized with the present invention. 
     The width of the sander  10  is less than the spacing between the pair of forwardly projecting dolly arms  25  and with the arms interconnected adjacent their free outer end by a relatively thin strip of material the sander is easily pulled by its handle over the strip  26  and positioned between the arms  25  with the rear caster wheel  16  abutting a shallow V-shaped cross piece  21 A on the lower end of the frame  21 . One end of the sander is then raised and one of the cross pieces  28 A,  28 B placed under the sander frame and on the flanges  27  of the pair of arms. The other end of the sander is then lifted and same done to place the other of the cross pieces  28 A,  28 B under another portion of the frame of the sander. The sander is then anchored to the dolly by the straps  31  and  32  where after the combination is readily wheeled from one location to another including up and down flights of stairs. 
     FIGS. 3 and 4 show the dolly in a tilted transport position while FIGS. 1 and 2 show the combination in an at rest storage and loading position. As previously mentioned tilting the frame to the transport position can often be difficult because of the tendency of the dolly to roll on its wheels. Also the dolly with a heavy load thereon can be difficult to control when being wheeled down a steep incline as maybe the case with some driveways. 
     In accordance with another aspect of the present invention the dolly is provided with at least one and preferably a pair of hand operated wheel brakes. In this regard attention is directed to FIG. 6, illustrating a pair of wheel engaging plates  41  and  42  attached to a shaft  43  that is mounted on the upright frame  21 . A lever arm  44  is attached to and projects from the shaft  43  and the free end thereof is connected to a sheathed flexible tension cable  45 . The other end of the tension cable is connect to a hand operated lever  46  that is pivotally connected to the frame  21  at a location readily grasped while using the dolly, for example on one of the handles  22 . 
     Referring to FIG. 7, there is illustrated a cross piece  50  that is slidable longitudinally along the arms  25  and a pair of the same replaces the previously described cross pieces  28 A and  28   b  as well as the flat stripe  26  that interconnects the outer ends of the arms. The cross piece  50  has a notch  51  in each of opposite ends thereof that receives therein the flanges  27 A to thereby maintain, in an obvious manner, a fixed spacing between the arms  25 . If desired means maybe provided to restrain the cross pieces  28 A,  28 B and/or  50  from sliding along the arms  25  once they are in place under the frame of the sander. For example there may be a set screw that can finger turned to project into the notch  51  and abut against the flange  27 A. 
     The brake can be designed to work on one or both of the dolly&#39;s wheels and also if desired a hand operated brake can be provided to selectively restrain movement of one or the other or both of the endless belts  29 A and  29 B. 
     The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom, for modifications will become obvious to those skilled in the art based upon more recent disclosures and may be made without departing from the spirit of the invention and scope of the appended claims.

Technology Category: 7