as shown in fig1 the invention relates to a machine 10 commonly known as a rotary floor cleaner having a base 12 . within the base 12 is a rotatable cleaning rotor 20 , as shown in the cutaway portion of fig1 . a drive mechanism 16 mounted above the base 12 comprises an electric motor , a protective housing 22 , and a gear box . power is supplied to the electric motor by means of a conventional electric cord 24 . attached to the base 12 is an operating handle 14 , on which there is mounted a solution tank 18 . in operation , the electric motor drives the gear box which , in turn , operates to rotate the cleaning rotor 20 at high speeds . cleaning solution from the solution tank 18 is fed through tube 26 to the cleaning rotor 20 , whereupon it is applied to the surface to be cleaned . typically , the flow of the solution is controlled by the operator through controls 28 . such machines typically are provided with wheels 30 to facilitate maneuverability . the present invention provides an improved means by which the drive mechanism 16 may be quickly and easily separated from the base 12 , when desired , while being securely mounted thereupon at other times . as best shown in fig2 base 12 includes a motor mount 32 on which there are mounted at least one and preferably two wedge blocks 34 . these are secured by any conventional means , such as screws or bolts , or the wedge blocks may be integrally formed with the base . also , mounted on base 12 is a cam 38 , which is rotatably mounted around a first axis substantially normal to the plane of the motor mount 32 . motor mount 32 of base 12 defines an opening 40 . when in the operating position , the gear box , which is not shown but which is enclosed by the motor housing 22 , is in driving engagement with the cleaning rotor 20 through the opening 40 . mounted on the exterior side surface of housing 22 is a mounting flange 36 is proximity to the lower end of the housing 22 . mounting flange 36 is adapted to rest upon motor mount 32 . as shown in fig3 wedge block 34 comprises an upright stanchion mounted on the motor mount 32 of base 12 . stanchion 42 includes a projecting arm 44 , which projects in the direction of opening 40 . the arm 44 includes a front surface 50 , which , as is best shown in fig3 is inclined horizontally with respect to the plane of the opening 40 . this is accomplished by locating the outer edge 46 of front surface 50 such that it is in closer proximity to the opening 40 and at a higher elevation from the base 12 than the inner edge 48 of front surface 50 . with reference to fig4 and 5 , cam 38 is rotatably mounted on motor mount 32 of base 12 . cam 38 rotates about a first axis a , which is best shown in fig5 . cam 38 comprises an upright pillar 60 with a projecting limb 62 . formed in the limb 62 is an arcuate first edge 52 , an arcuate first edge 52 , an arcuate second edge 54 in closer proximity to the opening 40 relative to the first edge 52 , and a shoulder surface 56 connecting the first edge 52 and the second edge 54 . second edge 54 is also at a higher elevation from the base 12 relative to the first edge 52 , whereupon shoulder surface 56 is inclined horizontally with respect to the plane of the opening 40 in a manner similar to the front surface 50 of the wedge block 34 being inclined . first edge 52 and second edge 54 , and consequently , shoulder surface 56 , are radially disposed about a second axis b , which is offset from the first axis a , as best shown in fig5 . as a result of the offset of second axis b , the shoulder surface 56 moves relative to the opening 40 when cam 38 is rotated about first axis a . in the embodiments depicted in fig2 and 4 , the cam 38 includes grip 64 which is useful for rotating the cam 38 by hand . in the embodiment shown in fig4 the grip 64 is formed as a separate piece from the case 38 and is attached thereto by any suitable means allowing it to swing freely . cam 38 also includes a substantially flat face 66 formed in a plane perpendicular to the plane containing first axis a and second axis b . face 66 is relatively more distant from second axis b than from first axis a . to assemble the machine , drive mechanism 16 is lowered from above so that the mounting flange 36 rests upon motor mount 32 . such movement is facilitated when cam 38 is rotated such that face 66 is adjacent to opening 40 . drive mechanism 16 is slid such that mounting flange 36 contacts front surface 50 of each wedge block 34 . in this position , the gear box comes into driving engagement with cleaning rotor 20 . cam 38 is rotated about axis a so that shoulder surface 56 of cam 38 also comes into contact with mounting flange 36 . as cam 38 is rotated , and as shoulder surface 56 becomes relatively closer to opening 40 and mounting flange 36 , the mounting flange 36 is incrementally forced into wedging engagement between wedge blocks 34 and cam 38 , thereby securely attaching drive mechanism 16 to the base 12 . in the machine shown in fig2 the cleaning rotor 20 turns counterclockwise , when viewed from the top , as indicated by arrow 90 . in the embodiment of the invention described herein , the resulting reaction forces on the housing 22 and mounting flange 36 , which tend to urge the same in a relative clockwise direction , cooperate with the cam 38 , which , like the cleaning rotor 20 , also rotates in a relative counterclockwise direction when moving from the unlocked position to the locked position , by urging the mounting flange 36 into the shoulder surface 56 such that the assembly is self - tightening . of course , the direction of rotation of the cleaning rotor 20 , and the cam 38 , can be reversed with the same effect . in the preferred embodiment shown , opening 40 is circular in shape and there are two wedge blocks 34 disposed about the opening 40 . also , the wedge blocks 34 are approximately radially equidistant from each other and from the cam 38 . the use of two wedge blocks , each approximately one and one half inches wide , is preferred . the facilitate mounting of the drive mechanism 16 on the base 12 when the cam 38 is in the fully unlocked position , wedge blocks 34 preferably are spaced at least at an angle of 100 ° from cam 38 . in this embodiment , there is an unobstructed opening of at least 200 ° into which mounting flange 36 may be set and slid towards wedge blocks 34 . the present invention facilitates not only disassembly of a rotary floor cleaner for movement to and from a job site , but also for purposes of removal and replacement of drive mechanism 16 for routine maintenance while allowing continued operation of the remainder of the device . a single preferred embodiment of the present invention has been disclosed and described in the drawings herein . it is to be understood , however , that various changes and modifications can be made without departing from the true scope and spirit of the present invention as set forth and defined in the following claims .
this invention provides a rotary floor cleaner having means for detachably securing the drive mechanism to the base of the unit , said means including wedge blocks against which the drive mechanism may be wedged and a rotatable cam for incrementally forcing the drive mechanism into wedging engagement between the wedge blocks and the cam .