Wood floor sanding machine

A power sanding machine (10) has three circumferentially spaced cogged belts (40) to drive three discs (52) rotatably mounted to an inner bowl (30) which is rotatably mounted to a housing (12), which in turn is connected to an operating handle (14). Mechanical lock can rotationally affix the inner bowl (30) to the housing to circumferentially position a pulley at the left or right edge (326, 322) of the sanding machine or at the front end (330) of the sanding machine. Power cleaning and sanding machines (412, 500, 600) incorporate the three disc (52) arrangement or a direct-drive one disc arrangement (572, 672). The machines (412, 500, 600) include multiple floor finishing units (420, 514, 614) ganged together in unique arrangements.

TECHNICAL FIELD

The field of this invention relates to power floor sanding machines with interchangeable attachments and more particularly to wood floor sanding machines.

BACKGROUND OF THE DISCLOSURE

Hardwood floors have long been a desirable trait in a home and are also common in gymnasiums, bowling alleys, and ballrooms. However, sanding and refurbishing a hardwood floor is one of the more difficult do-it-yourself tasks for a homeowner or business owner.

There are at present two basic types of sanding machines on the market. Firstly, there is a drum sander that has a single large drum that retains a sheet of abrasive material thereon. The large drum aggressively sands the floor but much care and skill must be used in feathering the machine to avoid gouging of the floor. This type of drum is usually not recommended for the do-it yourself market.

Another type of machine is a disc sander. The present sanding machines on the market commonly have a single belt that drive all three sanding discs which creates a side torque that drives the machine to one side as it sands the floor. The operator then needs to always counter the torque that promotes an uneven surface finishing and fatigue on the operator for larger sanding jobs.

Many machines also have higher operating speeds that allow little error in operating the machines. The high operating speeds can quickly cause gouging and knicks in the wood floor without having time to control or eliminate these gouges. Furthermore, the high operating speeds produce significant amount of noise.

The disc sander machines are not as aggressive as the drum type machines. Attempts have been made to increase the sanding force of the discs by increasing the weight of the sander. These weights are obtrusive horseshoe shaped steel members that are mounted on top of the sander housing. The external weights require an extra fastening device and if not tightly mounting the weights, extra chatter and vibration may occur.

These sanding machines also have a housing edge that is widely spaced from the operating sanding discs. This prevents the machine to sand close to walls. Furthermore the housing may have a high periphery which prevents it from intruding under the toe recess under many kitchen cabinets. As a result, even after adding a shoe molding to the edge of the floor, an unsanded edge may be showing. Therefore, additional smaller edge sanders need to be extensively used to approach the edge of the floor which further make the sanding process difficult.

Furthermore, the sanding creates great amount of sawdust, which needs to be controlled. The sawdust if not controlled can fill the room creating a mess and interfering with the visibility of the floor as it is being sanded. Secondly, uncontrolled sawdust, particularly when air born, may under certain circumstances be combustible from sparks or other ignition sources. If a vacuum is difficult to use on a floor sander, complacency is promoted in allowing loose saw dust to accumulate.

Furthermore, for do-it-yourself applications, an operator often leases or rents a machine which therefore requires the operator to carry the machine from the rental outlet. If the machine is not easily disassembled to easily carried components, the weight of the machine may cause difficulty for the operator to transport the sander between the rental place and his home. Furthermore, the need to rent separate, aggressive drum sanders, disc sanders, and square buffers limits the marketplace. Any person attempting to sand a floor himself may become discouraged if too many different pieces of equipment are needed or if the length of the job is too long and difficult.

The drum sanders, orbital sanders, and square buff sanders not only make it difficult for the do-it-yourself person but also for rental outlets in that the market is relatively small and the rental outlet must store a plurality of specialized machines.

Moreover, large-scale floor refinishing projects can be expensive due to the time-consuming, labor-intensive techniques that exist today. Large-scale floor refinishing projects include resurfacing gymnasiums, bowling alleys, ballrooms, and the like. Such projects usually involve hundreds of hours of cleaning and sanding the floor with an individual floor finishing machine. Thus, a large-scale project can often take several days to several weeks to complete.

What is needed is a machine that with appropriate attachments can replace a drum sander, orbital sander, square buff sander, as well as a diamond grinder, scarifier, and carpet scrubber.

What is also needed is a floor sander that can be aggressive in order to accomplish a commonly sized residential job within a reasonable amount and also be safe enough to significantly reduce gouging of the floor. What is also needed is a floor sander that can approach an edge of a floor within the distance of an ordinary shoe molding while reducing noise, that increases control and ease of use, reduces saw dust, and provides other conveniences for making a do-it-yourself operation feasible.

What is likewise needed is an apparatus that enables relatively faster cleaning and sanding of a floor to reduce the labor hours required to finish a large-scale project.

SUMMARY OF THE DISCLOSURE

In accordance with one aspect of the invention, a power sander for a wood floor includes a housing, and a motor mounted to the housing and having a centrally positioned downwardly extending drive shaft. An inner bowl member, i.e., inner housing member, is positioned within the housing and is rotatably mounted on the drive shaft to allow rotation of the inner bowl with respect to both the housing and drive shaft. Pulleys are circumferentially spaced about the drive shaft and are rotatably connected to the inner bowl member. The axis of rotation of each pulley is parallel to the axis of rotation of the drive shaft. Each pulley constructed to have sander discs mounted thereon. A plurality of belts, with each belt preferably having a cogged inside and mounted about one pulley and engageably driven by the drive shaft.

The drive shaft and said pulleys having respective cogged peripheries for creating a positive engagement with said inner side of the respective belts. A plurality of pulley tensioners engage the outer side of a respective belt with the outer side preferably being flat and frictionally engaged by the pulley tensioners in the form of bearings.

The belts are vertically spaced with respect to the drive shaft at a vertical position adjacent from one another. Each respective pulley is respectively vertically positioned to engage its respective belt horizontally from the engaging vertical position on the drive shaft. Each tensioner also is vertically positioned to a proper height to operably engage its respective belt.

The housing is preferably bell shaped with a downwardly extending side wall and connectable to a vacuum motor for suction of saw dust up through the bell shaped housing. The housing has an aperture for connection to a vacuum hose for allowing vacuuming of sawdust up through the housing and through the aperture. A weighted metal plate is attached to an inner bowl member. The weighted metal plate has apertures for allowing the pulley to extend therethrough. The plate has an outer periphery spaced from the side wall of said housing to define a path for the vacuuming of the saw dust.

It is desirable that a weighted plate is mounted to the inner bowl and has notches at its outer periphery to create widened gaps with the housing to increase air flow therebetween. It is also preferred that the housing has its side walls spaced within ⅜ inches from a sanding disc edge. The housing has handles mounted thereon near a front and rear portion thereof and extending upwardly therefrom. The housing also has a plurality of quick connect pins that removably connect the housing to the operating handle.

In accordance with another embodiment of the invention, the center drive shaft has a gear section, these gears are circumferentially spaced about the drive shaft and are rotatably mounted on the inner bowl member in a coplanar fashion and operably engage the center gear section of the drive shaft. The gears having respective pulley sections affixed thereto with the pulley sections being coplanar with each other. The pulleys are coplanar with each other and with the pulley sections. The belts are also coplanar and engage a pulley section of the respective gear and the pulleys.

In accordance with another aspect of the invention, a vacuum cleaner is mounted to the operable handle. A vacuum hose operably extends from the vacuum cleaner and is resiliently flexible and stretchable from a rest length to an increased length. The distal end of the hose has a shaped nozzle that can receive a hose coupling on the housing. This structure allows the hose to be directly connected to the hose coupling without removal of the shaped nozzle for vacuuming sawdust out of the housing. The hose is also being detachable from the hose coupling to allow the shaped nozzle to be operably used. The vacuum is grounded to the power sanding machine and preferably has a metal canister.

In accordance with another embodiment of the invention, a power sander for a wood floor includes a housing, and a motor mounted to the housing with a drive shaft. An inner housing member preferably in the form of a bowl is positioned within the housing and is rotatably mounted on the drive shaft to allow rotation of the inner housing with respect to both the housing and drive shaft. Pulleys are circumferentially spaced about the drive shaft and are operably connected to the drive shaft and also rotatably connected to the inner housing member.

Each pulley is constructed to have a sanding member mounted thereon. The sanding member includes a plate mounted to the pulley and at least one roller rotatably mounted about a horizontal axis on said plate. Each roller is fittable with an abrasive sanding layer about its outer surface and abuttable to a floor surface at its bottom section.

Preferably, each roller has its axis of rotation being transverse to and intersecting the axis of rotation of the respective plate that is mounted on the pulley. It is also desirable that each roller is freewheeling on the respective plate.

In one embodiment, a plurality of rollers are circumferentially spaced about the plate with each of its axis of rotation intersecting with each other and the axis of the plate. It is preferred that the plate has cutouts for allowing the rollers to be partially recessed in the cutouts. Each roller has an axial length that is greater than its own diameter.

In accordance with a broader aspect of the invention, a power sander for a wood floor includes a housing and a motor mounted to the housing with a drive shaft. An inner rotatably driven member is positioned within the housing and is driven by the drive shaft to allow rotation of the inner rotatably driven member with respect to the housing about a vertical axis. At least one roller is rotatably mounted about a horizontal axis on the inner rotatably driven member. The roller is fittable with an abrasive sanding layer about its outer surface and abuttable to a floor surface at its bottom section.

In accordance with another aspect of the invention, a power sander for a wood floor includes a rotating member that rotates about a vertical axis. Rollers are circumferentially spaced about the rotating member with each roller rotatably mounted about a horizontal axis on the rotating member. Each horizontal axis of rotation intersects with each other and an axis of rotation of the rotating member. Each roller is freewheeling on the rotating member. Each roller is fitted with an abrasive outer sanding layer about its outer surface and abuttable to a floor surface at its bottom section.

In accordance with another aspect of the invention, an attachment for a power sander includes a plate for attachment to a rotatable pulley. At least one roller is rotatably mounted about a horizontal axis onto the plate. The roller is fittable with an abrasive sanding layer about its outer surface and abuttable to a floor surface at its bottom section. Each roller has its axis of rotation being transverse to and intersecting the axis of rotation of the plate. Each roller is freewheeling on the plate. Preferably, rollers are circumferentially spaced about the plate with each roller having its axis of rotation intersecting with each other. Furthermore it is desired that the plate has cutouts for allowing the rollers to be partially recessed in the cutouts. Each roller is dimensioned to have an axial length that is greater than the roller diameter.

In accordance with another aspect of the invention, an attachment for a power sander includes a plate mountable to a power sander. The plate has a plurality of carbide steel shaped cutting members mounted circumferentially about the plate. The carbide steel tips having a planar bottom surface and tapered sides to create a sharp scarifying edge.

In accordance with another aspect of the invention, a power cleaning and sanding machine for a wood floor includes a housing, a motor mounted to the housing and having a drive shaft. An inner housing member is positioned within the housing and is rotatably mounted on the drive shaft to allow rotation of the inner housing member with respect to both the housing and drive shaft. A plurality of pulleys is circumferentially spaced about the drive shaft and is operably connected to the drive shaft, and rotatably connected to said inner housing member. Each pulley is constructed to have a abrasive member mounted thereon. The inner housing is selectively rotationally affixed to the housing by a mechanical lock that is able to lock a pulley in a circumferentially selected position about the drive shaft.

In one embodiment, the mechanical lock is in the form of a pin movable between a lower position extendable through an aperture in the housing and engaging a recess in the inner housing and an upper position where it is removed from the recess in the inner housing. Preferably, the recess in the inner housing is circumferentially positioned about the inner housing such that when the pin engages the recess, one of the pulleys is positioned toward one of the right or left sides of the housing member. In another embodiment, the housing recess in the inner housing is circumferentially positioned about the inner housing such that when the pin engages the recess, one of the pulleys is positioned at the front end of the housing.

The mechanical lock is preferably constructed to selectively lock any of the pulleys to be positioned at the left or right sides of said housing. The mechanical lock can also be constructed to selectively lock any of the pulleys at the left or right side or front end of the housing.

The housing has a first and second recess with the first recess, when engaged with the pin, locks one pulley at the left side of the housing and with the second recess, when engaged with the pin, locks one pulley at the right side of the housing member. In another embodiment, the housing has a third recess with the third recess, when engaged with the pin, locks the pulley at the front end of the housing.

In accordance with another aspect of the invention, an operable handle extends behind the rear end of the housing. A motor is mounted to the housing and has a centrally positioned downwardly extending drive shaft. An inner housing member is positioned within the housing and is rotatably mounted on the drive shaft to allow rotation of the inner housing member with respect to both the housing and drive shaft. A plurality of pulleys is circumferentially spaced about the drive shaft and rotatably connected to the inner housing member. The axis of rotation of each pulley is parallel to the axis of rotation of the drive shaft. Each pulley is constructed to have abrasive elements mounted thereon. Belts mounted about respective pulleys are engageably driven by the drive shaft. A mechanical lock is constructed to selectively lock the inner housing against rotation with respect to the housing. The inner housing member is freely rotatable with respect to the housing when the mechanical lock is disengaged and for affixing a pulley at a side edge of the housing when engaged to affix the inner housing member with the housing.

In another embodiment of the present invention, there is provided a power cleaning and sanding machine having a plurality of floor finishing units that are positioned in a tandem arrangement.

In yet another embodiment of the present invention, there is provided a power cleaning and sanding machine having a frame and a plurality of floor finishing units that are mounted to the frame. The plurality of floor finishing units include a housing and a motor that is mounted to the housing and that has a drive shaft. An inner housing member is positioned within the housing and is rotatably mounted on the drive shaft to allow rotation of the inner housing member with respect to both the housing and the drive shaft. A plurality of pulleys are circumferentially spaced about the drive shaft, are operably connected to the drive shaft, and are rotatably connected to the inner housing member. Each pulley is constructed to have an abrasive member mounted thereon.

In a further embodiment of the present invention, there is provided a frame for use in combination with a floor finishing unit. The frame includes one or more struts, one or more uprights attached to the struts, one or more cross-members attached to the struts, one or more beams attached to the struts, and one or more links attached to the beams.

In yet a further embodiment of the present invention, there is provided a power cleaning and sanding machine having a frame and a plurality of floor finishing units that are mounted to the frame and that are positioned in a tandem arrangement.

In still a further embodiment of the present invention, there is provided a riding floor finisher including a pusher trailer and a power cleaning and sanding machine. The power cleaning and sanding machine includes a frame and a plurality of floor finishing units mounted to the frame and positioned in a tandem arrangement.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now toFIG. 1, a floor sander10has a housing12connected to an operating handle14. A vacuum16is mounted on the operating handle. The housing12has a generally bell shape with a side peripheral section18that mounts a peripheral brush20. A motor22is mounted on the top portion24of the housing12.

As shown inFIG. 9, the motor has a drive shaft26that extends down through the top portion24of the housing. The motor22is electric and is operably connected to a power cord (not shown) that can conventionally be plugged into a 110 volt receptacle.

The drive shaft also extends through a center hole28of an inner bowl30. The inner bowl is rotatable with both the housing12and the drive shaft26. The bowl has a top portion32that rotatably mounts three pulleys34and three bearings36as best shown inFIGS. 5,7, and9. The pulleys34have a cogged periphery38that engages a respective cogged inner wall or inside side42of a belt40. The cogged inner wall42of the belt also engages a central cogged pulley44affixed to the drive shaft26. As the drive shaft rotates, the belt has a positive engagement with both the cogs44and the pulleys34. As shown, three pulleys are each spaced about the drive shaft 120 degrees from each other.

The bearings36on the other hand are positioned to frictionally engage a flat outerside46of the belt40. Each bearing is also positioned to place tension of a respective belt40and to provide enhanced engagement area between the belt and the pulleys34and cogs44. As best shown inFIG. 5, each belt is actually tensioned by two bearings36which provide a pinching of the belt40about cog44. The belts are vertically positioned at different heights from each other to provide non-interference. As shown inFIG. 8the three cogs44are vertically positioned to engage a respective belt40. The bearings36are split into an upper and lower sections35and37which each independently rotate with respect to the two adjacent belts that engage the bearing as best shown inFIG. 7. As shown inFIGS. 3 and 4, the pulleys have a mounting system50which are a plurality of pins for engaging cleaning elements or other abrasive elements commonly referred to as abrasive or sanding discs52in a snap fit fashion. The abrasive discs are sized to approach the outer periphery18of the housing12. A peripheral brush20comes within one inch and preferably within ⅜ inches from the sanding disc52. In this fashion, the power sander can sand or clean floors to within the edge of the floor that will normally then be covered by conventionally dimensioned shoe molding.

As the discs are driven by the motor in the direction as shown inFIGS. 3 and 4, the torque exerted by the rotation of the discs on the floor is greater at distances farther away from the central axis68of the drive shaft26. As such, the discs' torque tends to pull and rotate the inner bowl in the direction shown inFIGS. 3 and 4. Hence the inner bowl30and the assembly of pulleys34and discs52counter rotate with respect to the rotation of the individual pulleys34and discs52. The equal circumferential spacing of the pulleys34and discs54about the central drive shaft26eliminates virtually all side torque forces and provides for a balanced machine.

The inner bowl30has a side periphery54that mounts a steel weight plate56. The plate has a dual purpose for reducing wood dust from intruding into the bowl30where it may interfere with the operating cogs44, pulleys34, and belts40and for adding the proper amount of weight to the sander to enhance sanding forces and balance to the machine. The balance significantly reduces chatter and provides for a faster machine. It can be easily appreciated, that chatter besides reducing control of the machine can put gouges into a floor surface and ruin the objective of a smoothly sanded floor. With the balance, built in weight and lack of sideways torque, the machine can operate with disc speeds as low as 350 rpms and still provide for effective sanding of wood floors.

There is a gap60between the inner bowl32and the outer bowl18to allow a vacuum passage to an outlet nozzle62for the vacuum cleaner16. As shown inFIG. 6, the inner bowl periphery54may have notches66to increase and assure air flow for the vacuum.

The vacuum16has a bottom mounted motor70and an inlet hose72mounted at a top portion of a vertically oriented canister housing74. A vacuum bag76is also mounted in the vertically oriented canister74. In this way, gravity also assists in settling the wood dust particles to the bottom of the bag76and to reduce airborne particulate. In addition, the canister74is made of metal and grounded to the machine such that the probability of an static spark occurring is reduced. Sparks should be reduced near wood dust and airborne wood particulate.

A flexible stretchable hose72connects the vacuum16to the housing12. The hose can resiliently stretch well over triple its initial rest length. The end78of the hose connects to the nozzle62. As best shown inFIG. 11, the end78has a brush or other shaped nozzle attachment80affixed thereto can be used by an operator as an independent vacuum cleaner to clean up saw dust and other particulates.

However, when the sanding machine10is operating, the hose end78with the attachment80still affixed thereto can be operably connected to the nozzle62. The attachment80is shaped to receive the nozzle62and let the nozzle extend up to the hose and bypass the attachment80effective shape. In this way, the vacuum can be easily used both with the sanding machine and as an effective cleanup tool independent of the sanding machine. The machine10has a power switch which allows independent actuation of the vacuum without the actuation of the pulleys34and discs54.

The motor for the vacuum is a two speed motor that has one speed for use during operation of the discs52and another higher speed when only the attachment80is being used for cleanup. The two speed motor allows for less noise during usage of the sanding machine. The low rpms of the power sanding discs and the lower vacuum operation provide for a sanding machine that is as quiet as a conventional wet/dry vacuum cleaner.

For ease of transportation, the housing12can easily disengage from and re-engage to the operating handle14via quick connect coupling pins82. Furthermore to aid in transportation, the housing12has separate lifting handles84at its front and back.

A second embodiment is of the machine is disclosed inFIGS. 12 and 13. This embodiment has three coplanar belts140that are mounted on pulleys34and smaller drive pulleys142. The three coplanar drive pulleys142are driven via gear teeth139vertically spaced from the belt engaging section to a drive cog144on drive shaft26. The three drive pulleys142are equally circumferentially spaced about the drive shaft26. The belts may be optionally tensioned by bearings (not shown) on the exterior side of the belts in the same fashion as the first described embodiment. In this way, all three belts are coplanar which provides for a more compact lower profile housing18.

FIGS. 14–16discloses an attachment to the power sander that render a more aggressive sanding operation to cut down the time it takes to remove old varnish and worn out coating on hardwood floors. The conventional discs52that snap fit on pins50are replaced by three plate assemblies152. The plates have snap receptacles251like those shown inFIG. 17for engaging pins50. The plate also mounts three freewheeling rollers85circumferentially mounted about the rotating axis92of each plate152. The terms “freewheel” and “freewheeling” in this context means that the rollers are not powered or directly connected to the motor such as conventional drum sanders. Any rolling of the rollers is caused by the frictional action exerted from the floor as the plates and inner housing rotate.

The rollers85are rotatably mounted via a pin87. The pin can be a conventional with a threaded end88and an engageable head89that engage the mounting lugs83that are welded to the plate152. The roller rotates about the shank91. If desirable, the roller may be affixed to the shank and the pin may be rotatably journalled in the lugs83.

The roller desirably is made from a commercially available sponge rubber that has some flex to it. The outer surface93is fitted with a properly sized sand paper cylinder90. The rollers and sand paper cylinder have an axial length98greater than their respective diameters99. The roller and sand paper provide for a long narrow bottom section101along the roller that actively engages and sands that floor. It has been found that a sand paper cylinder with a grit rating of 50 provides sufficient aggressive action for sanding hardwood floors.

The plate has a cutout section95to allow the roller85to be recessed into the plane of the plate152to lower the vertical profile of the plate assembly152. In this way when discs52replace the attachments152and vice versa, the machine retains the same vertical height and the brush20retains a proper orientation to the ground.

In operation, the pulleys are driven by the motor via the belts to rotate the plate member about the vertical axes92. The rollers78rotate about a horizontal axis94defined by the pin80. The axes92and94are transverse with each other and intersect. As the pulleys drive the plates152, the rollers are free to rotate about their respective horizontal axis94. However, due to the relative great axial length98of the roller, a significant amount of scrub takes place when the rollers freewheel. The sand paper thus works on the floor and the inner bowl30is free to counter rotates about its axis68.

A modified version of the freewheeling drum roller is illustrated inFIG. 20. In this embodiment, three rollers185are mounted for free wheeling via lugs183on the inner bowl130. The rollers185like rollers85have an abrasive sand paper drum mounted thereon. In this embodiment, the motor conventionally rotates the inner bowl130at a desired speed depending on the application. The rollers185freewheel as the inner housing is rotated about its axis68. Due to scrub action, the sandpaper drum sands the floor during the operation of the power sander.

Another plate attachment device252is shown inFIGS. 17–19. In these Figures, the plate attachment252has six carbide steel tips254mounted about the periphery of the plate. The carbide steel tips have a planar bottom surface256and tapered sides258to create a sharp scarifying edge260. This attachment252mounts onto the pins50via snap fit connections151. This attachment is suitable for paint and adhesive removal from concrete floors, scarifying, and filing down high spots in cracked concrete floors.

The attachments152,252, and sanding discs52are all interchangeable on the pin connection50of power sander machine10. The single machine10has the ability to aggressively sand hardwood floors, finely sand hardwood floors, and work on concrete floors. The ability of this machine to have proper floor attachments eliminates the need for renting or using multiple machines. The aggressiveness of the rollers not only eliminates the need for a separate drum sander but also speeds up the operation such that most common sized jobs may be easily completed within one half to one work day.

The embodiments shown inFIGS. 1–13can be modified to work as an edger. The embodiments shown inFIGS. 21–28incorporate a mechanical lock300mounted on the housing12. The lock300can be in front of the motor22as shown inFIGS. 21 and 22along the longitudinal axis of the sander. The lock300includes a pin302with an upper handle304and locking shaft306. A bayonet pin308passes through the shaft306. The shaft306intrudes through a cylindrical holder310affixed to housing12. The holder310has opposing slots312to receive bayonet pin308. The pin can be in a disengaged position as shown inFIG. 22with the bayonet pin308resting on a recess314on top edge316of holder310. The shaft306extends through an aperture318in the housing. The pin302can be rotated to and lifted over retaining hump311to align bayonet pin308with the slots312and lowered in holder310and through aperture318. The lower end of shaft306can engage a recess or aperture320in inner housing member. As shown inFIG. 24, the pin302when in aperture320rotatably locks the inner bowl30relative to the housing12such that a pulley34and a respective sander disc52is adjacent the right edge322of the housing12.

In this manner, when a operator wants to concentrate on sanding or cleaning near an edge of a floor, he can lock the pulley34near the right edge of the sander and place the right edge of the machine at the edge of the floor. In this way, on pulley is always correctly positioned to provide more aggressive abrasive application at the edge of the floor by affixing the pulley and sander discs thereover.

In a similar manner, as illustrated inFIG. 25, if a pulley32and sanding disc needs to be affixed near the left edge326of the housing12, the pin302can be received in an aperture324positioned on the opposite side of the rotating axis92of a pulley or disc.

As such, whichever side edge is more convenient or accessible can be placed against the wall to sand an edge of the floor. A pulley and sanding disc is then locked in position and can rotate about its own axis92for more aggressive application to the edge of the floor.

For added convenience, similar apertures320and324can be placed in inner bowl member30such that a choice of any of the pulleys and sanders can be used for right or left edge sanding or cleaning. The pin302can engage any one of the set of apertures320for right edge sanding and any one of the set of apertures324for left edge cleaning.

If there are three pulleys34each spaced 120° from each other as illustrated, the apertures320and324need to be 60° from each other to properly and circumferentially position and affix a pulley34and sander disc52at the left or right edge. In the illustrated embodiment aperture 32° is 30° clockwise from axis92while aperture324is 30° counterclockwise from axis92. Both sets of apertures320and324are circumferentially spaced about a circle327of radius R.

FIGS. 26–28show an alternative arrangement of aperture320and324. In this arrangement the pin302, holder310and the aperture318can be circumferentially offset from the central longitudinal axis92of the sander disc, for example by 45° in the counterclockwise direction as shown.

The set of apertures320and the set of apertures324are similar circumferentially rotated 45° in the counterclockwise direction on inner bowl member from the embodiment shown inFIGS. 21–25. In this fashion a third set of apertures326can be placed in inner bowl circumferentially between aperture320and324, i.e., 30° from each aperture320and324and also on circle327.

As with the previous embodiment, when pin302engages one of the apertures320, the respective pulley32is positioned along the right edge322as shown inFIG. 26. When the pin302engages one of the apertures324, a respective pulley32is positioned along the left edge326as shown inFIG. 27.

In addition, when pin302engages any one of the apertures328, a pulley and sander disc is then affixed along the front edge, i.e., front end330at the central longitudinal axis of the sander machine. The sander then can sand an edge of a floor from the front where it might be inaccessible from the right or left edges due to a tight fit that would not let the handle and the operator near the respective edge of the floor.

As with the right and left rear set of apertures320and324, a third set of apertures328allows a choice of each pulley and disc to be used as the primary sander at the front edge330of the sander10.

According to another embodiment of the present invention,FIG. 29illustrates a riding floor finisher400adapted for relatively expansive and fast cleaning and sanding of a floor to reduce the labor hours required to finish a large-scale project. The finisher400generally includes a pusher trailer410used for pushing a power cleaning and sanding machine412.

The pusher trailer410is an off-the-shelf powered vehicle such as a Floor Mack Ryder that is readily available from Floor-Style Products of Hastings, Mich. The pusher trailer410is powered by an electric motor, is driven by a hydraulic transmission, gear box, axle, and two driving wheels. The pusher trailer410also generally includes a body, and seat mounted thereto. The pusher trailer410includes neither independent steering nor braking, and may include a front hitch point for connecting to the power cleaning and sanding machine412, thereby establishing one part of an overall articulated vehicle or riding floor finisher400.

The power cleaning and sanding machine412may also include a hitch point for attaching to the pusher trailer410to establish the other part of the articulated vehicle or riding floor finisher400. Alternatively, the machine412need not be rigidly connected to the pusher trailer400via hitch points. Rather, the pusher trailer410may freely ride behind, and in abutment with, the machine412, whereby an operator rides on the pusher trailer410and pushes the machine412. The machine412generally includes a main frame414, a utilities sub-frame416, wheeled jacks418, and floor finishing units420.

The main frame414is preferably composed of steel, but may be composed of any material including plastic, composites, or other metals including iron, aluminum, and the like. The material choice is not critical as long as the material selected is sufficiently rigid and durable. The main frame414includes longitudinally extending struts422and cross-members424extending transversely therebetween, and welded thereto, to provide rigidity to the main frame414. The main frame414extends forward from a rearward portion proximate the pusher trailer410to a forward portion distal the pusher trailer410. Beams430are welded to the struts422, and extend transversely in an outboard direction away therefrom.

The utilities sub-frame416is preferably composed of the same material as the main frame414and is welded to the rear portion426thereof. The sub-frame416includes upwardly and longitudinally extending struts432that are interconnected by transversely extending cross-members434welded therebetween. A U-shaped portion436is welded to the upper end of the struts432. Handles438are welded to the top of the U-shaped portion436, and service panels440are fastened to a service panel weldment442that is welded to the underside of the U-shaped portion436.

Referring now toFIG. 30, the wheeled jacks418are off-the-shelf devices, such as trailer jacks, that are readily available from several manufacturers including Fulton Performance Products of Mosinee, Wis. As shown, a cylinder443of the wheeled jack418is welded to bracketed upright supports444that are welded to the main frame414. To provide additional support and stability, the wheeled jack418is specially adapted with guide cylinders446welded to the main frame414that accept guide rods448therethrough. The guide rods448terminate in a caster body450having caster wheels452mounted thereto. The end of a piston454is welded centrally to the caster body450and, as is known in the art of trailer jacks, is upwardly and downwardly displaceable by rotating a handle455. Accordingly, the wheeled jacks418are specially adapted for this floor finisher application for adjusting the height of the main frame414with respect to the floor to be finished.

Referring now toFIGS. 31–33, the floor finishing units420are typically positioned between the beams430of the main frame414and mounted thereto by links456. Some of the floor finishing units420are mounted centrally along the main frame414between the struts422instead of between the beams430. Nonetheless, the below-described fastening arrangement is the same, and the individual floor finishing units420are substantially the same as the floor finishing units previously described, except for the following described modifications.

The floor finishing units420have threaded bosses462mounted thereon, to which the links456are pivotably or flexibly fastened by cap screws458extending through holes in ends of the links456. The links456extend upwardly and terminate in opposite ends that are translatably or flexibly fastened to outboard sides of the beams430by pairs of cap screws458that extend loosely through longitudinally extending slots460in the links456.

Instead of welding, the links456are preferably fastened outboard of the beams430by a pair of bolts, cap screws458, or the like. The cap screws458extend loosely through a longitudinally extending slot460in the link456and thread into the beam430. At an opposite end of the link456, a single cap screw458extends loosely through the link456and threads into a threaded boss462of the floor finishing unit420. This fastening arrangement allows for the link456, and therefore the floor finishing unit420, to be upwardly and downwardly displaceable with respect to the main frame414, as depicted by phantom lines inFIG. 33. Similarly, the floor finishing unit420is pivotable about the single cap screw458, as depicted by phantom lines inFIG. 34. Accordingly, the floor finishing units420have at least two degrees of freedom with respect to the main frame414. Such freedom allows the present invention to be particularly forgiving and effective in finishing floors that have uneven surfaces—as many floors requiring finishing do.

As shown inFIG. 34, the floor finishing units420are positioned in a tandem arrangement. This tandem arrangement can be described in terms of longitudinally extending columns of floor finishing units420. In other words, there are three columns of tandem floor finishing units420including two outboard columns A and B that are outboard of the main frame414, and one inboard column C that is inboard of the main frame414. The columns A, B, and C are laterally spaced apart such that the floor finishing units420diametrically overlap in the longitudinal direction of travel of the main frame414.

Likewise, the floor finishing units420are longitudinally spaced apart such that they diametrically overlap in a direction transverse to the direction of travel of the main frame414. The overlapping tandem arrangement can also be described in terms of sub-groups of floor finishing units420. In other words, there are three sub-groups including a front trio T1, a middle trio T2, and a rear trio T3. The trios T1, T2, and T3are nested together in delta shaped patterns. Accordingly, the above-described overlapping arrangements ensure that no portion of a floor will go unfinished in the path of the machine412.

Preferably, the trios T1, T2, T3all incorporate different abrasive grit material. For example, it is desirable to use the following grits: a coarse grit, such as 20 or 30 grit, for the front trio T1to remove an old floor coating or to rough up a bare floor; a medium grit, such as 60 grit, for the middle trio T2to smooth out the roughed up floor; and a fine grit, such as 120 grit, for the rear trio T3to finish sand the floor.

As shown inFIG. 29, the floor finishing units420are connected with electrical cords464that extend from the floor finishing units420along the struts432of the main frame414, up the utilities sub-frame416and into the service panels440. Each sub-group or trio of floor finishing units420is wired directly to and independently controlled by one of the three service panels440. In turn, the service panels440are powered by power supply cords466with 110 V AC. The power supply cords466drag behind the finisher400and plug into an available outlet.

Similarly, but not shown, the floor finishing units420are connected with vacuum lines that extend from outlet nozzles468to one or more vacuum canisters. The vacuum lines preferably extend behind the finisher400and connect with a centrally located vacuum canister. Alternatively, the vacuum lines may connect to one or more canisters mounted on-board the pusher trailer410, the main frame414, or sub-frame416. In yet another alternative, the vacuum lines may connect directly to a vacuum unit mounted on each floor finishing unit420.

In operation, an operator should lower the height of the machine412by cranking the handles of the wheeled jacks418in the appropriate direction. The operator should be satisfied when most of the cap screws458are positioned approximately in the longitudinal middle of the slots460of the links456, so as to enable the floor finishing units420to float up or down with deviations in the floor surface. This will help to avoid a non-contact condition, wherein one or more of the floor finishing units420might otherwise fail to maintain contact with the floor. Next, the operator ensures that the appropriate electrical and vacuum connections are in place, and then the operator sits in the seat of the pusher trailer410. The operator then activates the floor finishing units420by activating appropriate levers on one or more of the three service panels440. Subsequently, the operator activates the pusher trailer410according to the manufacturer's instructions. With one of his hands on the handles438of the machine412, the operator engages the pusher trailer410in a forward drive mode. Then, the operator grasps the other of the handles438in order to steer the articulated riding floor finisher400. Ordinarily, the operator will have activated all of the floor finishing units420and will drive the riding floor finisher400in any desired pattern across the floor. When backing up, or when traveling across already finished floor space, an operator may desire to stop and raise the machine412so as to avoid dragging the floor finishing units420across an already finished floor.

Referring now in general toFIGS. 35–38, there is provided according to yet another embodiment of the present invention, another power cleaning and sanding machine500. The machine500generally includes a chassis510to provide structural support for a housing512which is mounted to the chassis510, and includes floor finishing units514that are mounted to the housing512for finishing a floor.

The chassis510includes a frame516that is welded together from square tube-stock including uprights518and cross members520. Attached to the frame516at a lower portion thereof are support arms522for supporting the housing512. The support arms522are preferably fastened with fasteners524such as bolt, cap screws, or the like, or may be welded to the frame516. At each rearward end of the support arms522, there is a wheel526rotatably mounted thereto, that permits the machine500to be moved about like a dolly or hand truck, typically when not in operation. At the opposite end of the frame516, there are handles528welded to either the uprights518or one of the cross members520, to facilitate movement of the machine500. Finally, an electrical service panel530is mounted to the cross members520of the chassis510. The service panel530is preferably a HOFFMAN type 12 disconnect enclosure that houses SIEMENS disconnect electronics.

The housing512includes a deck532that is preferably stamped or formed from sheet metal. The deck532includes a top or mounting surface534, an underside or fastening surface (not shown), sides536, and front and rear faces538and540, that collectively define a chamber542. The housing512also includes a skirt544that peripherally mounts to and surrounds the deck532and that seals or partially defines the chamber542. The skirt544may be attached to the deck532by a hook-and-loop fastener, rivets, screws, and the like. Vacuum ports546are provided through the mounting surface534to fluidly communicate the chamber542externally of the housing512. As is well known in the art, the vacuum ports546may be vented by either an on-board vacuum system or a remote vacuum system (not shown). Inboard of the vacuum ports546there are located a pair of mounts548that are rigidly attached to the mounting surface534of the deck532, such as by welding. The mounts548are pivotably attached to a forward end of the support arms522by pivot members550, such as pins, bolts and nuts, and the like. Accordingly, the housing512is pivotably attached to the chassis510.

The floor finishing units514include electric motors552that are mounted to the mounting surface534of the deck532of the housing512. The electric motors are preferably three horsepower GLEASON or MARATHON ELECTRIC motors that are driven by NORTHERN INDUSTRIAL motor drives. The motors552are relatively high speed motors capable of about 3,500 RPM. As best shown inFIG. 35, the units514are arranged in a front row554of three units514and back row556of two units514, wherein the units514within the rows554and556are equally spaced apart in a lateral direction and the rows554and556are offset to define a delta pattern558of three units514. To finish particularly wide aisles of large warehouses, it is preferable to arrange the floor finishing units514in a six by five arrangement. Each motor552is fastened to the deck532by four flexible mounts560. As best shown inFIG. 36A, the flexible mounts560include a fastener562, such as a bolt or cap screw that extends through the deck532and threads into a portion of the motor552. A spring564is interposed the deck532and a head566of the fastener562. To allow flexible movement between the floor finishing units514and the housing512there is some clearance between the outer diameter of the fastener562and a passage568in the deck532through which the fastener562extends. Drive shafts570extend from the motors552and terminate in finishing discs572attached thereto, as is well known in the art. Finishing pads574are attached to the finishing discs572, as is also well known in the art. The finishing units514are arranged as discussed above, such that the finishing discs572and/or finishing pads574diametrically overlap one another as the machine500travels in operation. Accordingly, all surface area of the floor underneath the deck532and within the footprint of the finishing discs572gets treated by the machine500. As with the previously described embodiment, any one of the finishing discs and/or pads572,574may have a different grit than any of the other finishing discs and/or pads572,574. Finally, the motors552are all electrically powered via wires576that communicate with the service panel530. Accordingly, each floor finishing unit514is capable of independent operation. Moreover, each finishing disc572and/or finishing pads574are urged into contact with the floor by the direct overhead weight of a respective motor552. Accordingly, the present invention is particularly effective as a result of the relatively high speed of the motors552combined with the weight of each motor552bearing down directly over the respective finishing disc572.

The manufacture and assembly of the machine500is very simple compared to prior art floor finishing machines. First, the chassis510may be constructed of readily available tube stock, boilerplate material, fasteners, service panel, and off-the-shelf wheels. Second, the housing512may be constructed of bent and torched sheet metal, boilerplate material, rubber molding, and tube stock. Third, the floor finishing units514are primarily composed of off-the-shelf motors that are mounted to the housing512by standard fasteners and springs in a unique manner.

In operation, the machine500is activated by plugging a power cord (not shown) in a nearby power outlet, tilting the machine500backward as shown inFIG. 38, and throwing a main switch at the service panel530. Preferably, the service panel530controls the operation of the vacuum system (not shown) and the motors552. Once the motors552achieve a desired speed, an operator may begin floor finishing by tilting the machine500forward such that the housing512engages the floor and by pushing the machine500in a forward direction across the floor. Care should be taken, however, to keep the machine500moving across the floor when the motors552are operating and the housing512is lowered, due to the aggressive nature of this embodiment.

Another alternative embodiment is provided inFIGS. 39 and 40, that reduces the risk of gouging the floor with an aggressive floor sanding assembly. A power cleaning and sanding machine600generally includes a chassis610to provide fixed structural support for a rotatable housing612, which is rotatably mounted to the chassis610, and also includes floor finishing units614that are mounted to the housing612for finishing a floor.

The chassis610includes a frame616and a stator618attached to the frame616, such as by welding. The frame616includes a generally planar deck620having a stator bore622formed in one end thereof, through which a portion of the stator618extends. At a generally opposite end of the deck620, there is welded a base624that is supported by wheels626. Upwardly from the base624, a pair of uprights628extend and terminate in handles630. A service panel632mounts to the uprights628atop reinforcements634. The stator618is a generally cylindrical and stepped component having a first diameter636that pilots through the stator bore of the deck620, and a second diameter638. The first and second diameters636,638together define a shoulder640. Likewise the second diameter638and a third diameter642together define another shoulder644. The stator618further includes a main vacuum port646that is formed in internal vacuum passages648that extend generally longitudinally through the stator618.

The housing612generally includes a mounting ring650, a deck652, and supports654connecting the deck652and mounting ring650together, such as by welding to each. A bearing656is interposed the mounting ring650and the shoulder640of the stator618to provide rotational support to the housing612, such that the housing612is rotatable with respect to the housing612. Similarly, another bearing658is interposed the mounting ring650and the deck620of the chassis610. The supports654extend downwardly from the mounting ling650and attach to a mounting surface660of the housing deck652. The housing612is further supported by the chassis610using yet another bearing662that is interposed the housing deck652and the second shoulder644of the stator618. The deck652is preferably shaped as an annular ring that is fabricated from a flat sheet of metal such as boilerplate. An annular skirt664is attached to the periphery of the deck652. Like the previously described embodiment, the deck652and skirt664define a chamber666, which is ventilated by the vacuum passages648of the stator618. As is well known in the art, the vacuum port646may be vented by either an on-board vacuum system or a remote vacuum system (not shown).

The floor finishing units614include electric motors668that are mounted to the mounting surface660of the deck652of the housing612. As best shown inFIG. 39, the units614are six in number, are equidistantly spaced apart, and are concentrically arranged about the operational axis A of the stator618. Each motor668is fastened to the deck652by four flexible mounts670, just like the previously described embodiment. Drive shafts (not shown) extend from the motors668and terminate in finishing discs672attached thereto, as is well known in the art. Finishing pads674are attached to the finishing discs672, as is also well known in the art. Accordingly, all surface area of the floor underneath the deck652and within the footprint of the finishing discs672gets treated by the machine600. As with the previously described embodiments, any one of the finishing discs and/or pads672,674may have a different grit than any of the other finishing discs and/or pads672,674. The motors668are all powered via wires676that communicate with the service panel632via a slip ring678. Slip rings678are readily available devices and come in a number of styles and configurations, such as an annular ring as shown, or as a smaller hub and ring coupling. Slip rings are commercially available from a number of sources including MERCOTAC of Carlsbad, Calif. Accordingly, each floor finishing unit614is capable of independent operation. Moreover, each finishing disc672and/or finishing pads674are urged into contact with the floor by the direct overhead weight of a respective motor668.

Finally, a motor and gear assembly680is provided for rotating the housing612relative to the chassis610. The motor and gear assembly680is mounted to the deck620of the chassis610such that a pinion682rotatably engages an external ring gear684that is either mounted to the mounting ring650or is cut in the periphery thereof. The motor and gear assembly680is wired to the service panel632and powered thereby. Preferably, the motor and gear assembly680rotates the housing612in a direction opposite that of the rotation of the individual motors668.

The manufacture and assembly of the machine600is very simple compared to prior art floor finishing machines having independently and collectively rotating finishing discs. First, the chassis610may be constructed of readily available tube stock, boilerplate material, aluminum, fasteners, service panel, and off-the-shelf wheels. Second, the housing612may be constructed of sheet metal, boilerplate material, rubber molding, and tube stock. Third, the floor finishing units614are primarily composed of off-the-shelf motors that are mounted to the housing612by standard fasteners and springs in a unique manner. Fourth, rotation of the housing is accomplished using a relatively straightforward pinion and ring gear arrangement, compared to the more complicated planetary gear drives and belt drives of prior art devices.

In operation, the machine600is activated by plugging a power cord (not shown) in a nearby power outlet, tilting the machine600slightly backward to bring the machine600out of working engagement with the floor, and throwing a main switch at the service panel632. Preferably, the service panel632controls the operation of the vacuum system (not shown) and the motors668,680. Once the motors668,680achieve a desired speed, an operator may begin floor finishing by tilting the machine600forward such that the housing612engages the floor and by pushing the machine600in a forward direction across the floor. Compared to the previously described embodiment, there is a reduced risk of gouging when the machine600moves across the floor when the motors668are operating and the housing612is lowered. This is because the independent rotation of the floor finishing units614in concert with the collective rotation of the floor finishing units614by way of the rotation of the entire housing612, tends to reduce the operational wear of any given floor finishing unit on any given spot on the floor.

Each of the above-disclosed embodiments includes elements and features that may be interchanged with any and all of the other above-disclosed embodiments to produce a novel and nonobvious power cleaning and sanding machine.

Variations and modifications are possible without departing from the scope and spirit of the present invention as defined by the appended claims.