Surface working pad assembly

A novel surface working pad assembly is described which assembly comprises a fibrous generally disc shaped pad support element having a circular raised portion at its center; the raised portion is sized and configured to fit closely within a circular aperture of a cooperating surface working pad element, but preferably remains recessed and out of contact with the work surface during use thus reducing drag and wear. The surface working pad element of the assembly is removably attached to the pad support element so that by reversing the working pad both surface may be used. The mating of the raised portion of the pad support element into the aperture of the working pad enables the working pad to be quickly; and accurately mounted on a machine and prevents unwanted displacement of the pad due to centrifugal forces, even during use in high speed rotary floor polishers or the like.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a working pad assembly for use in surface 
maintenance machines such as the familiar power driven, rotary floor 
maintenance machines which are used to strip wax, apply wax, buff, polish, 
etc. 
2. Background of the Invention 
Many different types of working pads and assemblies therefor have been used 
over the years. The present standard is an approximately 1" thick pad of 
non-woven plastic fibers of polyester, nylon, etc. Various means have also 
been adopted for releasably or removably attaching the pads to the drive 
disc of the machines, including clamps, snap rings, etc. "Velcro" (fibrous 
hook-and-loop connectors) is also now widely used for this purpose. 
According to my invention a working pad assembly is provided that greatly 
saves on material and cost, provides for "Velcro"-type ease of mounting, 
and retains the feel and performance of the standard 1" pad, by providing 
the cushioning and pliability for the working pad to scrub, clean, and 
polish uneven floors which contain dips, ridges, and other irregularities, 
even when employed in high speed rotary machines. Since standard 1" 
working pads absorb old wax and dirt generally about 1/4" into the working 
surface, the center 3/4" of the working pad is unused while my invention, 
preferably using an approximately 3/4" thick resilient pad support element 
and an approximately 3/4" surface working pad, provides the necessary 
cushioning and allows old wax and dirt to penetrate approximately 1/4" 
into each side of the 3/4" thick working surface pad. 
DESCRIPTION OF PRIOR ART 
The most relevant prior art of which applicant is aware is believed to be 
U.S. Pat. No. 3,703,739 Young et al which discloses multiple layer surface 
working pads stacked and affixed each to the other and to the drive disc 
of a rotary polisher by "Velcro"-type connectors. 
In this system the operator essentially carries a pad inventory stacked up 
under the polisher. While applicant has not tested the Young et al system, 
it seems to present serious problems, such as centrifugal dislocation or 
separation, especially as the number of stacked pads is increased, 
alteration of the normal working height of the machine, and probable 
increase in drag by having full surface contact of pad surface and work 
surface. In ultra high speed polishers in use today, which operate at 
2,000 RPM and higher, the stack approach of Young seems to be of 
especially doubtful feasibility. 
By contrast, however, it will be seen that the present invention permits 
pad reversal while at the same time providing substantially the same shape 
and performance of the standard integral pad. 
Other patents in this field of which I am aware are listed below, but I 
believe they are even less relevant than the above discussed patent of 
Young et al: 
______________________________________ 
3,115,660 
Hunt 3,823,516 Christian 
3,346,904 
Armstrong 4,407,040 Scharf 
3,522,681 
Lampert 4,541,207 Antonson 
3,527,001 
Kleemeier et al 
4,747,176 Parks 
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SUMMARY OF THE INVENTION 
The present invention relates to a surface working pad assembly for use in 
surface maintenance equipment, especially, power driven rotary disc floor 
polishers or the like. 
The assembly comprises two basic elements, namely, a pad support element 
and a surface working pad element. Each is preferably formed of the same 
material, e.g., non-woven plastic fibers, such as nylon, polyester, etc. 
The pad support element is disc shaped and means are provided to removably 
attach its upper flat surface to the drive disc of the equipment on which 
the assembly is used. The lower face of the pad support element has a 
raised portion shaped to be received in a similarly shaped aperture in the 
surface working pad element. 
The apertured surface working pad element has two working surfaces, so that 
after one surface is clogged or glazed over, the pad can be reversed to 
use the fresh surface of the pad. 
While not critical it is most convenient that the aperture in the surface 
working pad and the raised portion of the pad support element be 
configured to be approximately equi-diameter circles, so that they will 
engage snugly when pressed in face-to-face contact. 
The height of the raised portion of the pad support element should be such 
that it remains recessed when fully inserted into the aperture of the 
surface working pad element, so as to reduce drag on the machine, and 
prevent the pad support element from being worn. 
Any convenient means may be employed to removably mount the surface working 
pad on the pad support; the most satisfactory means so far contemplated by 
me is to employ a series of strips or tapes of fibrous hooks 
("Velcro"-type material) on the underside of the pad support element which 
can engage the loops present in the non-woven plastic fiber working pad 
element. 
In commercial use it is contemplated that a pad support element and a 
quantity of surface working pads would be sold as a kit. The assembly is 
immediately useful on all machines which are adapted to receive a standard 
1" surface working pad which is bonded to the drive disc by "Velcro"-type 
connectors, or stiff bristles, or the like. The thickness of the pad 
support and surface working pad elements would preferably be such as to 
give a thickness about equal to the thickness of the standard 1" pad thus 
mimicking for the operator the feel and performance of the standard 
integral pad while providing two useable working surfaces in a surface 
working pad about one half the thickness.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION 
Referring to the drawings, FIG. 1 shows a plan view the under surface of 
the pad support element 1 of the invention. In practice, this pad support 
element 1 is a circular, generally disc-shaped body of non-woven plastic 
fibers which can be formed from the same material as the surface working 
pad element, thereby providing comparable resiliency and "feel." Surface 
working pads are available in various diameters, usually from about 17" to 
22". A popular, widely useful size would be 20" in diameter and about 1/4" 
in thickness. A raised portion 2 preferably of the same material, and 
preferably, but not necessarily, of a generally circular configuration is 
centered on the under side (surface facing side) of element 1. For an 
element having a diameter of 20", the raised portion will generally be 
about 8"-10" in diameter and its thickness or height will be less than the 
thickness of the surface working pad element 6. The raised portion 2 may 
be formed integrally with pad support element 1, or it may be formed 
separately and bonded onto element 1, adhesively or otherwise. 
In the preferred embodiment, a plurality of radially extending 
"Velcro"-type strips 3 containing fibrous hooks for engaging the surface 
working pad element are provided as the means for removably connecting pad 
support element 1 to surface working pad element 6. These strips or tapes 
3 may be fusion bonded, glued, stapled or otherwise attached to the lower 
surface of pad support element 1. 
FIG. 2 shows the pad support element 1 in cross-section taken along line 
a--a of FIG. 1 with the raised portion 2 facing downwardly, i.e., toward 
the work surface. In this view the main body 4 of the element is seen to 
be disc-shaped and to have an upper flat surface 5 which is composed of an 
open mass of bonded, non-woven fibers capable of being engaged by 
attachment means of "Velcro"-type fibrous hooks carried on the face of a 
rotary drive disc 12 of a surface treating apparatus. (See FIG. 5). 
FIG. 3 illustrates, in plan view, a surface working pad element 6 with a 
centered aperture 7, preferably of circular configuration roughly 
corresponding in shape and size to the raised portion 2 of element 1 of 
FIG. 2. Raised portion 2 of element 1 should preferably make a snug fit in 
aperture 7 of element 6. 
FIG. 4 illustrates surface working pad 6 in cross-section, along line a--a 
of FIG. 3, showing aperture 7 and two working surfaces 8 and 9. Surfaces 8 
and 9 are removably attachable to element 1 via any suitable means, but 
preferably by use of the "Velcro"-type strips 3 shown in FIGS. 1 and 2 on 
the lower surface of element 1. Surfaces 8 and 9 are of open, non-woven, 
fibrous material, the structure of which enables such surfaces to be 
engaged readily by the fibrous hooks of strips 3. 
FIG. 5 is a cross-sectional view of the complete assembly of the invention 
mounted on the rotary drive disc 12 of a surface working apparatus. As 
will be seen the drive disc 12 is connected to a drive shaft 11 which is 
driven directly or indirectly by motor 10. The upper surface of element 1 
is removably bonded preferably by "Velcro"-type material 3 on the face of 
drive disc 12. Element 1 has mounted on it surface working element 6. 
Raised portion 2 of element 1 is snugly engaged in aperture 7 of element 
6, and is preferably recessed 13. When exposed surface 8 is used up, 
surface working pad element 6 may be detached, reversed, and replaced to 
expose surface 9 for use.