Absorbent pad and holder assembly for carpet cleaning

This invention comprises an absorbent pad unit covered by a coarse mesh screen and mounted on the head of a carpet cleaning device having a handle for manipulating it. The pad has an outer sheet of highly absorbent, acid-resistant paper reinforced with fiberglass strands and located next to the screen, an inner sheet of the same construction, and a relatively thick core of soft, highly absorbent material sandwiched between its outer and inner sheets for absorbing carpet cleaning residue which passes through the outer sheet when the screen rubs against the carpet as the cleaning head is moved across the carpet.

SUMMARY OF THE INVENTION 
This invention relates to an absorbent pad unit and a holder for mounting 
it on the head of a carpet cleaning apparatus or tool, with a screen on 
the holder covering the outside of the pad unit for rubbing on the carpet 
to improve the penetration into the carpet of a previously-applied 
cleaning solution. The pad unit absorbs cleaning residue from the carpet. 
Preferably, the pad unit comprises a soft, relatively thick, highly 
absorbent core sandwiched between thin outer and inner sheets of 
acid-resistant, highly absorbent paper reinforced with fiberglass strands. 
The pad unit is readily replaceable in the holder so that a clean dry pad 
unit may be substituted for a residue-soaked pad unit whenever desirable. 
The present absorbent pad and holder assembly preferably is used in 
conjunction with a carpet cleaning solution containing an ingredient, such 
as hydrogen peroxide or carbon dioxide, which produces an effervescing or 
foaming action when the holder screen covering the absorbent pad is rubbed 
across carpet to which that cleaning solution has been applied. This 
effervescing action causes the cleaning solution to penetrate more 
effectively into the carpet and clean it more completely. Dirt removed 
from the carpet and the residue of the cleaning solution are absorbed by 
the pad. 
A principal object of the present invention is to provide a novel and 
improved absorbent pad and screened holder assembly for attachment to the 
cleaning head of a carpet cleaning apparatus or tool. 
Another object of this invention is to provide such a pad and holder 
assembly for use with a motor-operated floor buffing machine to clean 
carpet. 
Another object of this invention is to provide such a pad and holder 
assembly for use as part of a manually operated carpet cleaning tool. 
Another object of this invention is to provide such a pad and holder 
assembly for use on the pickup head of a conventional vacuum cleaner to 
rub a cleaning solution into the carpet and absorb dirt and other cleaning 
residue from the carpet. 
Further objects and advantages of this invention will be apparent from the 
following detailed description of three presently preferred embodiments, 
shown in the accompanying drawings.

Before explaining the disclosed embodiments of the present invention in 
detail, it is to be understood that the invention is not limited in its 
application to the details of the particular arrangements shown, since the 
invention is capable of other embodiments. Also, the terminology used 
herein is for the purpose of description and not of limitation. 
DETAILED DESCRIPTION 
FIGS. 1-3 
As shown in FIG. 1, an absorbent pad and holder assembly 10 in accordance 
with a first embodiment of the present invention is engaged below the head 
11 on the lower end of a floor buffing machine provided with an upwardly 
inclined handle 12. The buffing machine may be any of several brands of 
such machines now on the market. The head of the buffing machine carries 
an electric motor 13 which drives a rotary drive block 14 having a toothed 
bottom face 15 for frictional engagement with the top of the present pad 
and holder assembly 10. Normally, as shown, the weight of the motor 13 and 
the head 11 of the buffing machine rests on the present pad and holder 
assembly 10. This weight and the frictional engagement between the drive 
block 14 and the pad and holder assembly 10 are sufficient to impart the 
motor-driven rotation of the drive block to the pad and holder assembly 
10. 
The buffing machine has rollers 16 at the lower end of the handle 12 which 
normally are raised from the floor and do not support the weight of the 
head 11. By tilting the upper end of the handle 12 down far enough, the 
head 11 can be raised from the floor and the rollers 16 brought down into 
engagement with the floor to facilitate moving the buffing machine to or 
from a working location. 
The pad and holder assembly 10 is shown in detail in the exploded 
perspective view of FIG. 2. It includes a rigid, inverted, dished upper 
holder member 17 of suitably strong, impact-resistant plastic or metal. 
This holder member has a flat top wall 18 of circular outline and a 
peripheral flange 19 of substantial vertical and radial thickness 
extending down from the top wall 18. At the bottom on the outside, this 
flange is formed with a peripheral recess 20 of rectangular cross-section. 
The bottom of the holder consists of a peripheral ring 21 and a coarse mesh 
screen 22, which preferably are molded in a single piece of suitable 
plastic which does not tend to develop an electrostatic charge due to 
triboelectricity when rubbed across a carpet. The marginal ring 21 
projects above the screen 22, as best seen in FIG. 3, and it has a 
rectangular cross-section substantially complementary to the cross-section 
of groove 20 in holder member 17 so that it fits snugly in this groove. 
When the bottom piece 21, 22 fits on the holder member 17 as shown in FIG. 
3, a circular recess 23 of substantial vertical depth is formed between 
the top wall 18 of holder member 17 and the screen 22 below. In addition, 
bordering the recess 23 an annular recess 23a of shallow vertical depth is 
formed between the bottom of the flange 19 on holder member 17 and the 
screen 22. 
These connecting recesses are filled by an absorbent pad having a circular 
outer bottom sheet 24 of highly absorbent paper which is resistant to mild 
acids and is reinforced with fiberglass strands 24a embedded in the paper, 
a circular, inner top sheet 25 of the same construction as the bottom 
sheet, and sandwiched between the top and bottom sheets a relatively thick 
core 26 of cellullosic fluff made from wood pulp, multiple layers of 
cellulose wadding, absorbent cotton or rayon fibers or other highly 
absorbent material. For most of its vertical depth, as shown at 26a in 
FIG. 2, the absorbent core has a snug, sliding fit in the recess 23 
between holder member 17 and the bottom screen 22. At the bottom the core 
26 has a vertically thin, annular marginal flange 26b which is snugly 
received between the bottom of the holder flange 19 and screen 22, with a 
snug sliding fit inside the ring 21 surrounding the screen 22. The inner 
top sheet 25 of the absorbent pad has a snug, sliding fit inside the 
holder recess 23. The outer bottom sheet 24 has a snug, sliding fit inside 
ring 21. 
The bottom and top sheets 24 and 25 and the core 26 of the absorbent pad 
are suitably bonded together to form a unitary assembly which may be 
conveniently handled as a single replaceable unit. 
A friction pad 27 of natural or synthetic rubber or other suitable 
wear-resistant, frictional material is adhesively bonded to the top face 
of the upper holder member 17 and extends completely across it. This pad 
27 is frictionally engageable by the teeth 15 on the buffing machine's 
drive block 14 when the weight of the head 11 of the machine rests on the 
present holder and pad assembly 10, as shown in FIG. 1. 
The upper holder member 17, frictional pad 27, and bottom ring 21 and 
screen 22 are permanent parts of the present assembly. The absorbent pad 
unit, consisting of the top sheet 25, core 26 and bottom sheet 24, is a 
replaceable part of the present assembly which requires replacement from 
time to time because it becomes soaked with cleaning residue which it 
absorbs from the carpet. 
This holder and pad assembly is positioned below the motor-driven drive 
block 14 on the head 11 of the floor buffing machine and rotates in unison 
with it as the buffing machine is moved slowly across a carpet to which 
has been applied previously a cleaning compound in liquid form containing 
an ingredient which effervesces when agitated. The screen 22 on the bottom 
of the holder rubs across the carpet and causes the cleaning compound to 
effervesce and penetrate down into the carpet for more effective cleaning 
action. Dirt and other residue from this cleaning operation is absorbed 
through the outer, bottom layer 24 into the absorbent core 26. Also, soap 
or detergent that may have remained in the carpet from previous cleanings 
will be soaked up by the absorbent pad. 
When the drive motor 13 in the buffing machine begins to act as if the load 
on it is excessive, this indicates to the user that the absorbent pad 24, 
25, 26 has soaked up enough residue that it should be replaced by a clean, 
dry pad. 
FIGS. 4-6 
FIGS. 4-6 show a second embodiment of the invention in which the head of 
the carpet cleaning tool is a channel-shaped body 111 attached to the 
lower end of an elongated handle 112. The body 111 has a flat top wall 
111a, which is inclined downward to the right in FIG. 4, as best seen in 
FIG. 6, a vertical side wall 111b extending down from the top wall at its 
left side in FIGS. 4 and 6, and a shorter vertical side wall 111c 
extending down from the top wall at its right side in FIGS. 4 and 6. The 
longer side wall 111b is formed with upper and lower horizontal grooves 
130 and 131, which face inward and extend the full length of this wall. 
The shorter side wall 111c is formed with a single horizontal groove 132, 
which faces inward and extends the full length of this wall. The body 111 
is open at its front end in FIG. 4 and is closed by a vertical end wall 
111d (FIG. 5) at its opposite end. 
The holder and pad assembly in this embodiment of the invention includes a 
tray-like holder 117 having opposite, parallel, vertical side walls 117b 
and 117c, a vertical inner end wall 117d (FIG. 5) extending 
perpendicularly between the side walls at one end, and a vertical outer 
end wall 117e extending perpendicularly between the side walls at the 
opposite end. The inner end wall 117d of the holder is slightly smaller 
than the generally rectangular downwardly-facing recess defined by the 
head 111. The holder side wall 117b has horizontal outwardly projecting, 
upper and lower ribs 133 and 134, which are slidably received respectively 
in the grooves 130 and 131 on the inside of the side wall 111b of the head 
111. The holder side wall 117c has a horizontal, outwardly projecting rib 
135 which is slidably received in the groove 132 on the inside of the side 
wall 111c of the head. With this arrangement, the holder is slidably 
insertable into and removable from the open end of the head 111. The outer 
end wall 117e of the head projects above, below and laterally beyond the 
side walls 117b and 117c at the open end of the head 111 so that it abuts 
against the top wall 111a and side walls 111b and 111c of the head at its 
open end when the holder is fully inserted into the head, as shown in FIG. 
5. The inner end wall 117d of the holder extends contiguous to the end 
wall 111d at the closed end of the head 111. 
On the bottom the holder 117 carries a horizontally disposed coarse mesh 
screen 122 (FIGS. 5 and 6) which extends between its side walls 117b and 
117c and between its end walls 117d and 117e and is bonded to these walls 
in any suitable fashion. 
The holder 117 carries an absorbent pad having a thin, outer, bottom sheet 
124 of absorbent mildly acid-resistant paper with fiberglass reinforcing 
strands embedded therein, a thin inner, top sheet 125 of the same 
construction, and a relatively soft, thick, absorbent core 126 sandwiched 
between these sheets and bonded to both of them. This core is composed of 
any suitable highly absorbent material, such as cellulosic fluff made from 
wood pulp, multiple layers of cellulose wadding, absorbent cotton or rayon 
fibers. The absorbent pad 124-126 is insertable and removable as a unit 
into and from the holder 117. As shown in FIG. 6, in cross-section the 
absorbent pad is complementary to the recess in the holder above its 
bottom screen 122, with the top sheet 125 of the pad being inclined 
downward to the right in FIG. 6 so as to extend substantially coplanar 
with or slightly below the top edges of the holder side walls 111b and 
111c. 
The user of the tool first deposits in the carpet a liquid cleaning 
solution containing an effervescing or foaming ingredient. Then, using the 
handle 112, the user pushes the head 111 back and forth across the carpet 
with the screen 122 on the holder 117 rubbing the carpet to cause the 
cleaning solution to effervesce and penetrate down into the carpet. Dirt 
and other residue of the cleaning operation is absorbed by the pad 124, 
125, 126. When required, a used absorbent pad may be removed by first 
sliding the holder 117, 122 out of the head 111 and then taking out the 
pad and putting in a clean, dry pad of the same type. 
FIGS. 7-9 
FIGS. 7-9 show a third embodiment of the invention in which the holder for 
the absorbent pad is a roller on the pickup head of a vacuum cleaner. The 
vacuum cleaner may be of the upright type, with its motor on the pickup 
head at the lower end of a handle, or it may be of the tank or canister 
type in which the motor is in a tank or canister connected through a 
flexible hose to the upper end of a hollow handle or "wand" which has the 
pickup head at its lower end. 
Referring to FIG. 7, this roller includes a central rotatable shaft 211 
extending between an end piece 211a affixed to one end of the shaft and a 
removable end piece 211b on the opposite end. As shown in FIGS. 7 and 8, 
the removable end piece has an axial projection 240 on its inner end which 
is cylindrical for most of its extent and has a radially projecting rib 
241 at one location on its periphery. This projection on the end piece 
fits snugly in a complementary keyhole-shaped recess 242 formed in this 
end of the roller shaft 211. 
The holder for the absorbent pad also includes a wrap-around, coarse mesh 
screen 222 extending between the end pieces 211a and 211b of the roller. 
The wrap-around absorbent pad includes a thin outer sheet 224 of 
acid-resistant, absorbent paper with fiberglass reinforcing strands 
embedded therein and fitting slidably just inside the screen 222. The pad 
also has a thin inner sheet 225 of the same material as the outer sheet 
224 concentrically disposed inside the outer sheet 224 and fitting closely 
around the roller shaft 211. Sandwiched between the outer and inner sheets 
224 and 225 is a relatively thick, soft core 226 of highly absorbent 
material, such as cellulosic fluff from wood pulp, multiple layers of 
cellulose wadding, absorbent cotton or rayon fibers. 
The pad 224, 225, 226 is wrapped circumferentially around the roller 211 to 
bring the opposite ends of the pad close together at one circumferential 
location on the roller, but with a slight circumferential gap between 
them. The outer screen 222 is wrapped around the outside of the pad, and 
the opposite ends of the screen are positioned in the circumferential gap 
of the pad. On one side of this gap (FIG. 8) is a fixed rod 243 extending 
longitudinally of the roller between the end pieces 211a and 211b. On the 
opposite side of this gap is a rotatably adjustable locking cam 244, which 
extends longitudinally of the roller, with its opposite ends rotatably 
supported by the end pieces 211a and 211b. This cam is turned to clamp 
the ends of the screen 222 tightly against rod 243, thereby closing the 
screen around the pad 224-226 and tightening the pad itself on the roller 
shaft 211. 
After first applying an effervescing cleaning solution to the carpet, the 
vacuum cleaner is pushed across the carpet, with the screen 222 on the 
roller rubbing across the carpet to cause the cleaning solution to 
effervesce or foam for more effective penetration into the carpet. Dirt 
and other cleaning residue is absorbed by the pad 224-226 on the roller.