BACKGROUND OF THE INVENTION [0002] This invention generally relates to apparatus, such as a floor scrubber, for treating a floor surface. In particular, the invention relates to such apparatus having an improved head assembly.

[0003] Floor scrubbers and other apparatus for treating a floor surface, such as floor polishers and extraction machines, typically include a head assembly in which one or more brushes, pads or other floor surface treatment devices are configured for engagement with the floor surface and are rotatably driven relative to the floor surface to scrub, polish or otherwise treat the floor surface as desired. In particular, the head assembly of a conventional floor scrubber typically includes one, or in a dual scrubbing machine two, circular or ring-shaped brush plates each having a depending bristle brush adapted for engagement with the floor surface. The brush plate is operatively connected to a drive motor for rotation of the brush plate relative to the floor surface to scrub the floor surface. More particularly, the drive motor has a drive shaft corresponding to each brush plate and terminating in a three lug configuration. Each brush plate has notches, or grooves, corresponding to the lugs of the drive shaft for releasably connecting the brush head to the drive shaft. The releasable connection allows for replacement of the brush head in the event the bristles become worn or a different floor treatment is desired.

[0004] However, removing and replacing the brush head is often cumbersome and frustrating for the operator because the operator must either lay down on the floor to see underneath the machine or blindly reach under the machine to manipulate the brush head relative to the lugs of the drive shaft. It is therefore difficult for the operator to properly align the notches or grooves of the brush plate with the lugs of the drive shaft, often requiring the operator to rotate the entire head assembly relative to the shaft up to 60° to connect the brush head to the drive shaft.

SUMMARY OF THE INVENTION [0005] Among the several objects and features of the present invention is the provision of apparatus for treating a floor surface having an improved head assembly; the provision of such apparatus in which servicing of the head assembly is easier and less time consuming; and the provision of such apparatus in which a brush head of the head assembly is more easily replaced.

[0006] In general, apparatus of the present invention for treating a floor surface comprises a drive motor having a drive shaft rotatable on a rotation axis, and a drive assembly drivingly connected to the drive shaft for conjoint rotation therewith about the rotation axis of the drive shaft. A floor surface treatment device is releasably connected to the drive assembly for conjoint rotation therewith about the rotation axis of the drive shaft relative to the floor surface. The floor surface treatment device is adapted for engagement with the floor surface to treat the floor surface upon rotation of the device relative to the floor surface.

[0007] A head assembly of the present invention for use with floor surface treatment apparatus of the type having a motor and a drive shaft rotatably driven by the motor about a rotation axis of the drive shaft generally comprises a drive assembly adapted for driving connection to the drive shaft for rotation about the rotation axis of the drive shaft. A floor surface treatment is device releasably connected to the drive assembly for conjoint rotation therewith about the rotation axis of the drive shaft relative to the floor surface. The floor surface treatment device is adapted for engagement with the floor surface to treat the floor surface upon rotation of the device relative to the floor surface.

[0008] A floor surface treatment device of the present invention for use with a floor scrubber of the type having a motor and a drive shaft rotatably driven by the motor about a rotation axis of the drive shaft generally comprises a plate and bristles connected to the plate and depending therefrom for engagement with a floor surface to be scrubbed. The floor surface treatment has gear teeth for drivingly connecting the floor surface treatment device to the drive shaft of the floor scrubber.

[0009] Other objects and features will be in part apparent and in part pointed out hereinafter.

DESCRIPTION OF THE DRAWINGS [0010] Figure 1 is a perspective view of an apparatus of the present invention for treating a floor surface.

[0011] Figure 2 is a side elevational view of the apparatus of Figure 1 including a drive motor and head assembly.

[0012] Figure 3 is a top view of a drive assembly of the head assembly.

[0013] Figure 4 is a bottom view of the drive assembly of the head assembly.

Figure 5 is a perspective view of a floor surface treatment device of the head assembly.

Figure 6 is a perspective view of a head assembly of a second alternative embodiment of apparatus of the present invention for treating a floor surface, with a drive assembly and floor surface treatment device shown separated.

Figure 7 is a top view of the drive assembly of the head assembly for the second alternative embodiment as shown in Figure 6.

Figure 8 is a top view of the floor surface treatment device of the head assembly for the second alternative embodiment as shown in Figure 6.

Figure 9 is a bottom view of the underside of the floor surface treatment device of the head assembly for the second alternative embodiment as shown in Figure 6.

Figure 10 is a top view of the head assembly of Figure 6 with the drive assembly overlaying the floor surface treatment device.

Corresponding reference characters indicate corresponding parts throughout the drawings.

DETAILED DESCRIPTION CF THE PREFERRED EMBODIMENTS Now referring to the drawings, and in particular to Figure 1, a preferred apparatus of the present invention for treating a floor surface is illustrated and described herein as a floor scrubber and is indicated in its entirety at 21. The floor scrubber 21 comprises a frame 23 supported by a fixed wheel assembly 25 so that an operator can readily move the scrubber over a floor surface. A handle (a portion of which is shown in Figure 1 and indicated at 27) is connected to the frame 23 for maneuvering the floor scrubber over the floor surface. The frame 23 includes a mounting assembly, generally indicated at 29, for mounting a drive motor 31 on the frame.

The drive motor 31 has a drive shaft 33 (Figure 2) extending down from the motor for rotation about a rotation axis of the shaft.

[0022] With reference to Figure 2, a head assembly of the floor scrubber 21 is generally indicated at 41. The head assembly 41 includes a drive assembly, generally indicated at 43, configured for operative connection with the drive shaft 33 of the motor 31 and a floor surface treatment device, generally indicated at 45, configured for releasable, operative connection with the drive assembly. As shown in Figure 3, the drive assembly 43 comprises a generally circular plate 47 having a central opening 49 therein centered on the axis of rotation of the drive shaft 33. A collar 51 is secured to the upper surface of the plate 47 within the central opening 49 and has three notches 53 formed therein for releasably and drivingly connecting the plate to corresponding lugs (not shown) on the drive shaft 33 of the drive motor 31. It is contemplated that the drive plate 47 may be releasably and drivingly connected to the drive shaft 33 other than by a three-lug configuration, such as by a threaded connection, by suitable fasteners, by keyed arrangement or by other suitable connection, or the drive plate may be formed integrally with or otherwise permanently mounted on the free end of the drive shaft without departing from the scope of this invention.

[0023] A drive ring (Figure 4) is secured concentrically to the underside of the plate 47 by a plurality of fastener assemblies 57, the drive ring being located generally at the outer edge margin of the plate. However, it is understood that the drive ring 55 may be disposed radially inward of the outer edge margin of the plate 47 and remain within the scope of this invention. As best seen in Figure 2, each fastener assembly 57 includes a threaded fastener 59 extending up through the drive ring 55 and the plate 47, a tubular spacer 61 disposed between the drive ring and the plate to space the drive ring from the plate, and a retaining nut 63 threaded onto the end of the fastener to secure the drive ring and plate in assembly with each other. Gear teeth 65 formed in the inner periphery of the drive ring 55 extend generally radially inward for driving interengagement with the head 45 as will be further described. The gear teeth 65 of the embodiment shown in the Figures are generally triangular in shape.

However, the gear teeth 65 may be of any shape, such as trapezoidal, curvilinear or other suitable shape without departing from the scope of this invention.

[0024] Magnets 67 are secured to the underside of the drive plate 47, such as by being bonded thereto, radially inward of the drive ring 55 for releasably retaining the floor surface treatment device 45 in an axial position wherein gear teeth 83 of the treatment device are in driving interengagement with the gear teeth 65 of the drive ring. While twelve magnets 67 are shown in Figure 4, there may be any number of magnets secured to the plate 47, or they may be one continuous magnetic strip secured to the plate, as long the magnetic force generated by the magnets is sufficient to support the weight of the treatment device 55. It is also understood that retention devices other than magnets 67 may be used to releasably secure the treatment device 45 to the drive plate 47, such as hook and loop fasteners, adhesives or other suitable retention devices, without departing from the scope of this invention.

[0025] Now referring to Figure 5, the floor surface treatment device 45 comprises a generally circular plate 71 having a central opening 73, and a bristle brush 75 secured to the underside of the plate and depending therefrom for engagement with the floor surface. It is understood, however, that the bristle brush 75 may be replaced by a polishing pad, an abrasive pad or other suitable device. A generally circular gear is rigidly affixed to the upper surface of the device plate 71 for opposed relationship with the drive plate 47 and has a central opening 79 therein aligned coaxially with the central opening 73 of the device plate. The gear 77 shown in Figure 5 is secured to the device plate 71 by fasteners 81. However, the gear 77 may be secured to the device plate 71 other than by fasteners 81, such as by being bonded thereto, without departing from the scope of this invention. The gear 77 is sized in diameter for seating generally within the inner diameter of the drive ring 55, and has gear teeth 83 formed about its outer periphery extending radially outward therefrom for interengagement with the radially inward extending gear teeth 55 of the drive ring 55. The gear 77 is constructed of, or coated with, a metal material that is magnetically attracted to the magnets 67 secured the underside of the drive plate 47.

The combined thickness of the gear 77 and each respective magnet 67 is substantially similar to the spacing between the drive ring 55 and the drive plate 47 so that the gear teeth 83 are generally radially aligned with the gear teeth 65 of the drive ring 55 when the gear 77 is magnetically connected to the magnets 67.

[0026] As best seen in Figures 4 and 5, the number of gear teeth 65, 83 formed in the drive ring 55 and the gear 77, respectively, is sufficient so that little rotation, if any, is needed to properly align the gear with the drive ring for interengagement therewith.

In the illustrated embodiment, the drive ring 55 and gear 77 each have about 180 gear teeth 65, 83 so that the gear and the drive ring can be properly aligned by rotating the floor surface treatment device 45 one degree, or less, relative to the drive ring of the drive plate 47 It is contemplated that the respective number of gear teeth 65,83 on the drive ring 55 and gear 77 may vary without departing from the scope of this invention. However, the number of gear teeth 65,83 is preferably sufficient to limit the angle through which the treatment device 45 must be rotated relative to the drive ring for proper alignment of the gear therewith to be less than or equal to about 30°.

[0027] To install the floor surface treatment device 45 in the floor scrubber 21 for use in cleaning a floor surface, the treatment device, with the gear 77 secured thereto, is positioned under the drive plate 47 and lifted until the gear teeth 83 are either interengaged (e. g. , become intersticed) with the gear teeth 65 of the drive ring 55 or axially engage the drive ring. If necessary, while still lifting the treatment device 45, the device is rotated slightly relative to the drive ring 55, such as through a rotation angle of one degree or less, until the gear teeth 83 interengage the gear teeth 65 of the drive ring 55. The floor surface treatment device is then lifted further until the top of the gear 77 engages the magnets 67 secured to the underside of the drive plate 47 whereby the magnetic force of the magnets further retains the floor surface treatment device in connection with the drive assembly 43, with the gear teeth 83 radially aligned and interengaged with the gear teeth 65 of the drive ring 55.

[0028] In operation, the motor 31 is operated to drive rotation of the drive shaft 33 to thereby conjointly drive rotation of the drive plate 47 and drive ring 55 about the rotation axis of the drive shaft. The interengagement of the gear teeth 65,83 drivingly connects the drive ring 55 and the gear 77 so that the gear, device plate 71 and bristle brush 75 are conjointly driven by the drive assembly 43 about the rotation axis of the drive shaft 33 relative to the floor surface. The bristles of the brush 75 thereby engage the floor surface for scrubbing the floor surface.

[0029] While the head assembly 41 is shown and described herein with the drive ring 55 connected to the drive plate 47 and the gear 77 connected to the device plate 71, it is understood that the drive ring may alternatively be connected to the device plate, with the gear connected to or fully replacing the drive plate and the magnets 67 being attached to the device plate.

[0030] For example, Figures 6-10 illustrate a second alternative embodiment of a head assembly, generally indicated at 141, of the floor scrubber 21. The head assembly 141 of this second embodiment comprises a drive assembly, generally indicated at 143, configured for operative connection with the drive shaft 33 (Figure 2) of the motor 31 (Figure 1) and a floor surface treatment device, generally indicated at 145, configured for releasable, operative connection with the drive assembly. As shown in Figures 6 and 7, the drive assembly 143 comprises a generally circular gear 147 having a collar 151 centrally positioned on and secured to the upper surface of the gear 147 by suitable fasteners 153. The collar 1. 51. has a key hole 155 formed centrally therein for a corresponding key arrangement (not shown) of the drive shaft 33 of the drive motor 31 to releasably and drivingly connect the gear 147 to the drive shaft. It is contemplated that the gear 147 may be releasably and drivingly connected to the drive shaft 33 other than by a key arrangement, such as by a lug connection, a threaded connection, by suitable fasteners, or by other suitable connection, or the gear 147 may be formed integrally with or otherwise permanently mounted on the free end of the drive shaft 33 without departing from the scope of this invention.

[0031] The gear 147 has gear teeth 157 formed about its outer periphery and extending radially outward therefrom for driving interengagement with the floor surface treatment device 145 as will be further described. The gear teeth 157, as shown in Figures 6-10, are generally triangular in shape. However, the gear teeth may be of any shape, such as trapezoidal, curvilinear or other suitable shape without departing from the scope of this invention. While not shown, the underside of the gear 147 may be coated with a metal that is magnetically attractive, or a plate (not shown) constructed of a metal that is magnetically attractive may be secured to the underside of the gear, for reasons which will become apparent.

[0032] With reference to Figures 8 and 9, the floor surface treatment device comprises a generally circular plate 159 having a pad holder 161 (Figure 9) secured to the underside of the plate for holding a pad, such as a polishing pad or an abrasive pad, in a conventional manner. A ring 163 (Figure 8) is secured concentrically to the top of the plate 159 by a plurality of fastener assemblies 165, with the ring 163 being located generally at the outer edge margin of the plate. However, it is understood that the ring 163 may be disposed radially inward of the outer edge margin of the plate 159 and remain within the scope of this invention. Each fastener assembly 165 includes a threaded fastener 167 extending up through the ring 163 and the plate 159, a tubular spacer (not shown, but substantially the same as the spacer 61 shown in Figure 2) disposed between the ring 163 and the plate 159 to space the ring 163 from the plate 159, and a retaining nut (not shown, but substantially the same as the retaining nut 63 shown in Figure 2) threaded onto the end of the fastener to secure the ring 163 and the plate 159 in assembly with each other. Gear teeth 169 formed in the inner periphery of the ring 163 extend generally radially inward for driving interengagement with the radially outward extending gear teeth 157 of the drive assembly gear.

[0033] Counterbores 171 are formed in the top of the device plate 159 radially inward at the ring 163 for receiving magnets (not shown but substantially the same as the magnets 67 shown in Figure 4) that releasably secure the floor surface treatment device 145 to the metal on the underside of the gear 147. The magnets are secured in the counterbores 171, such as by being bonded to the device plate 159. While twelve counterbores 171 are shown in Figure 8 for accommodating twelve magnets, there may be any number of magnets secured to the device plate 147, or there may be one continuous magnetic strip secured thereto, as long as the magnetic force generated by the magnets is sufficient to support the weight of the floor surface treatment device 145 on the drive assembly gear 147. It is also understood that retention devices other than magnets 67 may be used to releasably secure the floor surface treatment device 145 to the drive assembly gear 147, such as hook and loop fasteners, adhesives or other suitable retention devices, without departing from the scope of this invention.

[0034] As best seen in Figures 6 and 10, the number of gear teeth 157,169 formed in the gear 147 and ring 163, respectively, is sufficient so that little rotation, if any, is needed to properly align the ring with the gear to interengage their gear teeth. In the illustrated embodiment, the ring 163 and gear 147 each have about 180 gear teeth 169,157 so that the ring and gear can be properly aligned by rotating the floor surface treatment device 145 one degree, or less, relative to the drive assembly gear.

It is contemplated that the respective number of gear teeth 169,157 on the ring 163 and gear 147 may vary without departing from the scope of this invention. However, the number of gear teeth 169,157 is preferably sufficient to limit the angle through which the floor surface treatment 145 device must be rotated relative to the drive assembly gear 147 for proper alignment therewith to be less than or equal to about 30°.

[0035] To install the floor surface treatment device 145 in the floor scrubber 21 for use in treating a floor surface, the treatment device, with the ring 163 secured thereto, is positioned under the drive assembly gear 147 and lifted until the gear teeth 169 of the ring are either interengaged (e. g. , intersticed) with the gear teeth 157 or axially engage the gear 147. If necessary, while still lifting the floor surface treatment device 145, the treatment device is rotated slightly relative to the drive assembly gear 147, such as through a rotation angle of one degree or less, until the gear teeth 169 of the ring interengage the gear teeth 157. The device 145 is then lifted further until the magnets secured to the top of the device plate 159 engage the metal on the underside of the gear 147 whereby the magnetic force of the magnets further retains the device in connection with the drive assembly 143, with the gear teeth 169 of the ring 163 radially aligned and interengaged with the gear teeth 157 at the drive assembly gear 147.

[0036] The floor scrubber. 21 shown and described herein is a single brush scrubber, having a single floor surface treatment device 45,145. However, a dual scrubber (not shown) having a pair of devices, with each device driven by a respective drive shaft, is contemplated to be within the scope of this invention. Moreover, the head assembly 41,141 of the present invention may also be incorporated in other apparatus for treating floor surfaces, such as floor polishers, liquid extraction machines or other like apparatus, with the floor surface treatment device having a bristle brush, a polishing pad, an abrasive pad or other device, without departing from the scope of this invention.

[0037] As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.