Device for Scrubbing Surfaces

The use of devices for scrubbing surfaces including carpets is well known. However, most of the prior art devices have relatively low energy inputs to the carpet and lead to streaking when used with the powdered ureaformaldehyde cleaning compositions disclosed in allowed U.S. application Ser. No. 433,707. It is thought that this streaking is due to non-uniform energy input to the carpet from the scrubber.

It is therefore an object of this invention to provide a scrubbing device which has a reduced tendency to cause streaking when used with powdered urea-formaldehyde cleaning compositions. It is another object of this invention to provide a scrubbing device which provides a relatively large but uniform energy input to the surface to be scrubbed.

The device of the present invention has eccentrically driven scrubbers which are mounted on a rotating support plate. Each scrubber is rotatably mounted on the center from which it is eccentrically driven.

FIG. 1 is a side elevation of carpet scrubbing machine which embodies the present invention;

FIG. 2 is a sectional view taken along line 2-2 in FIG. 1;

FIG. 3 is a schematic sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a sectional view taken along line 5-5 in FIG. 4;

FIG. 6 is a schematic side elevation of a brush which is adapted for counterclockwise rotation as viewed from above; and,

FIG. 7 is a schematic side elevation of a brush which is adapted for clockwise rotation as viewed from above.

Referring now in more detail to the drawings, FIG. 1 shows a scrubber embodying the present invention. Housing 10 is mounted on suspension frame 11. Wheels 13 on frame 11 provide increased stability when the device is operating and allow the device to be moved easily when not operating. Vacuum means 15 is mounted on handle 19 and is connected to the housing by flexible hose 17. In FIG. 2, 12 represents the frame upon which motor 14 is vertically mounted. Drive shaft 22 extends downward from motor 14 and is encircled by sleeve 21 which rotatably supports rotating support member 50 shown here as comprising upper rotating support plate 56 and lower rotating support plate 54. Preferably support member 50 will be mounted on sleeve 21 by a bearing such as shown at 27. Drive sheave 20 engages rubber belt 44 and is rigidly mounted on sleeve 21 which is mounted on drive shaft 22. Scrubbing elements 66, 66', 67 and 67' are rotatably mounted on the rotating support member 50 by means of shafts 30, 30', 34 and 34' which have offset tip portions 31, 31', 35 and 35' upon which the respective scrubbing elements 66, 66', 67 and 67' are mounted. Each shaft 30, 30', 34 and 34' has rigidly mounted upon it a drive sheave shown at 28, 28', 32 and 32', respectively. Drive sheaves 32 and 32' engage the inside of belt 44 and as shown in FIG. 3 are driven clockwise thereby. Idler sheaves 52 and 52' are fixed to shafts 53 and 53' which are rotatably mounted in bearings 51 and 51' mounted between support plate 54 and 56 closely adjacent to drive sheaves 28 and 28'. Idler sheaves 52 and 52' engage the inside of belt 44 but hold the exterior of belt 44 against drive sheaves 28 and 28', thereby causing drive sheaves 28 and 28' to rotate counterclockwise. To facilitate installation of belt 44, adjustable tensioning sheave 24 is rotably mounted on adjustable plate 25 which is adjustably mounted on rotating support plate 56.

The exterior of belt 44 also engages drive sheave 82 which is rigidly mounted on shaft 80 which is mounted on rotating support plate 50 by bearing 84. The rotating support member 50 is caused to rotate relatively slowly within housing 10 through the mechanism shown in FIGS. 4 and 5. Adjustable support platform 92 is pivotably mounted on lower rotating support plate 54 and supports shaft 74 which has drive disc 72 mounted upon it. Drive disc 72 engages the substantially cylindrical portion of the interior of housing 10 and also engages intermediate shaft 78 which is mounted in bearing 86 which is fixed in intermediate support platform 88. Intermediate disc 76 is mounted upon intermediate shaft 78 and engages driven shaft 80 which is mounted in bearing 84 which is mounted on upper rotating support plate 56.

Advantageously intermediate support platform 88 is pivotably mounted upon adjustable support platform 92 and biasing means such as spring 90 are provided for holding intermediate shaft 78 in engagement with drive disc 72 while holding intermediate disc 76 in engagement with the shaft 80 which is driven by drive sheave 82. Since the diameter of drive disc 72 is much larger than the diameter of intermediate shaft 78 and since the diameter of intermediate disc 76 is much larger than the diameter of driven shaft 80, rotating support member 50 can be caused to rotate relatively slowly compared to the speed of rotation of motor 14.

Scrubber elements 66, 66', 67 and 67' are rotatably mounted on the offset tip portions 31, 31', 35 and 35' of shafts 30, 30', 34 and 34' respectively. Upon activation of motor 14, drive sheave 20 mounted on shaft 22 rotates driving belt 44. If in FIG. 3, shaft 22 is rotating counterclockwise, than shafts 30 and 30' will rotate counterclockwise while shafts 34 and 34' will rotate clockwise.

Since each scrubber element is mounted on the offset tip portion of the shaft, when shafts 30, 30', 34 and 34' are rotated, the centers of scrubber elements 66, 66', 67 and 67' will orbit around the centers of rotation of shafts 30, 30', 34 and 34'.

Preferably, each scrubber element comprises a body portion and bristles which serve as scrubbing means and may also serve as biasing means to impede rotation of the scrubbers in the direction which is opposite to the direction of rotation of the offset shaft upon which it is mounted. For example, scrubber 66 comprises body 62 and bristles 68. Advantageously, scrubber elements 66 and 66' have slanted bristles which are slanted to facilitate counterclockwise rotation, while scrubber elements 67 and 67' have bristles which are slanted to facilitate clockwise rotation.

Upon activation of motor 14, drive sheave 20 mounted on sleeve 21 is rotated which drives belt 44. If in FIG. 3, shaft 22 is rotating counterclockwise, then scrubber elements 67 and 67' will be caused to rotate clockwise while scrubber elements 66 and 66' will be caused to rotate counterclockwise. Simultaneously, rotating support member 50 will rotate clockwise.

Ideally, the scrubber of the present invention will be forcebalanced. This is accomplished by balancing each shaft and by adjusting the phase of the brushes with respect to each other. For example, in FIG. 2 counterweights 70 and 70' are provided for each shaft 30 and 30' and in FIG. 3 the phase of the shafts has been adjusted so that the offset tip portions 35 and 35' of shafts 34 and 34' will be nearest to shaft 22 when the offset tip portions 31 and 31' of shafts 30 and 30' are farthest away from shaft 22. Since the drive sheaves 28, 28', 32 and 32' are all the same size, the phase relationship is maintained as the device operates. Advantageously, belt 44 will be double-sided timing belt having evenly spaced teeth on both sides which engage corresponding teeth on the sheaves 20, 28, 28', 32, 32' and 82. By this means slippage can be eliminated and the proper phasing can be maintained.