U.S. patent application number 10/543902 was filed with the patent office on 2006-07-27 for anchor sheet.
Invention is credited to John Anthony Pacione, Joseph Rocco Pacione.
Application Number | 20060162269 10/543902 |
Document ID | / |
Family ID | 32825347 |
Filed Date | 2006-07-27 |
United States Patent
Application |
20060162269 |
Kind Code |
A1 |
Pacione; Joseph Rocco ; et
al. |
July 27, 2006 |
Anchor sheet
Abstract
An improved anchor sheet is described. The anchor sheet can be
injection molded from polypropylene and can have a thickness of
between 0.031 inches and 0.75. Such an anchor sheet can be molded
with hooks and can have an attached resilient layer. Stems integral
with the anchor sheet are used to form the hooks, and may be 1 mm
high and 0.55 mm in diameter. The density of stems may be
approximately 230 per square inch, or approximately 128,000 stems
on a plate. An anchor sheet made in this way makes an excellent
field of hooks when installed onto a supporting surface such as a
floor. This field of hooks can take an overlying decorative
covering such as pieces of loop backed carpet. When a resilient
layer is attached, for example by ultrasonic welding, to the
underside of the anchor sheet, between the anchor sheet and the
floor, the anchor sheet can have the right degree of "give", so
that a user can experience some cushioning effect from the
resilient layer below the anchor sheet, but with some level of
rigidity so that the load of walking is transmitted across a larger
surface and does not "dig" into the resilient layer.
Inventors: |
Pacione; Joseph Rocco; (New
Market, CA) ; Pacione; John Anthony; (New Market,
CA) |
Correspondence
Address: |
ICOS CORPORATION
22021 20TH AVENUE SE
BOTHELL
WA
98021
US
|
Family ID: |
32825347 |
Appl. No.: |
10/543902 |
Filed: |
January 29, 2004 |
PCT Filed: |
January 29, 2004 |
PCT NO: |
PCT/CA04/00117 |
371 Date: |
September 30, 2005 |
Current U.S.
Class: |
52/403.1 ;
52/181 |
Current CPC
Class: |
B32B 2323/10 20130101;
B32B 2307/546 20130101; A47G 27/0468 20130101; B32B 27/32 20130101;
B32B 3/30 20130101; B32B 3/266 20130101; B32B 2307/544 20130101;
B32B 27/08 20130101; B32B 2471/00 20130101; B32B 2274/00 20130101;
B32B 5/18 20130101; B32B 2307/102 20130101; B32B 2471/02 20130101;
B32B 2250/242 20130101; B32B 2250/02 20130101; B32B 7/02 20130101;
B32B 2451/00 20130101; B32B 2323/046 20130101; B32B 27/065
20130101; A47G 27/0475 20130101; B32B 7/12 20130101 |
Class at
Publication: |
052/403.1 ;
052/181 |
International
Class: |
E04F 11/16 20060101
E04F011/16; E04F 15/22 20060101 E04F015/22 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 30, 2003 |
US |
60443564 |
Claims
1. An anchor sheet for underlying a floor covering, the sheet
comprising: (a) a plastic sheet having a thickness of between 1/16
inches and 1/4 inches and having a flexural modulus (ASTM D790) of
between 700 and 3600 MPa; and (b) a resilient layer secured to a
first side of the plastic sheet and having a compression force
deflection (ASTM D3574-C) that is within about 30 percent of the
compression force deflection of a low density polyethylene layer
3/8 inches thick and a density of 30 kg/m.sup.3.
2. The anchor sheet of claim 1 wherein in the plastic sheet is an
injection-molded thermoplastic.
3. The anchor sheet of claim 1 wherein the plastic is
polyethylene.
4. The anchor sheet of claim 1, wherein the plastic sheet has a
thickness of between about 1/8 inches.
5. The anchor sheet of claim 1, wherein a second side of the
plastic sheet is covered by hooks integrally molded therewith.
6. The anchor sheet of claim 6, wherein the hooks having a density
between 160 hooks per square inch to 1200 hooks per square inch, or
approximately 230 hooks per square inch, or approximately 330 hooks
per square inch.
7. The anchor sheet of claim 1, wherein the resilient layer
comprises, or consists essentially of, polyethylene.
8. The anchor sheet of claim 1, wherein the plastic sheet has a
flexural modulus of between 1200 and 2600 MPa, or a flexural
modulus of between 1300 and 2500 MPa, or a flexural modulus of
between 1400 and 2400 MPa, or a flexural modulus of between 1500
and 2300 MPa, or a flexural modulus of between 1600 and 2200 MPa,
or a flexural modulus of between 1700 and 2100 MPa, or a flexural
modulus of between 1800 and 2000 MPa.
9. The anchor sheet of claim 1, wherein the anchor sheet is a
square and having an outer planar dimension in the range of between
approximately 12 inches by 12 inches and approximately 36 inches by
36 inches.
10. The anchor sheet of claim 9, wherein the anchor sheet is
approximately 24 inches by 24 inches.
11. An anchor sheet comprising: a sheet with a first and second
surface; the sheet being made of a polypropylene; hooks projecting
from said first surface; and a resilient layer made of low density
polyethylene attached to the second surface; wherein the sheet has
a thickness between 0.062 inches and 0.50 inches.
12. The anchor sheet of claim 11, wherein the sheet has a thickness
of approximately 0.125 inches.
13. The anchor sheet of claim 12, wherein the sheet is injection
molded.
14. The anchor sheet of claim 3, wherein the anchor sheet is a
square in the range of approximately 12 inch by 12 inch to
approximately 36 inch by 36 inch.
15. The anchor sheet of claim 14, wherein the anchor sheet is
approximately 24 inch by 24 inch.
16. The anchor sheet of claim 13, wherein the first surface bears a
field of hooks, the hooks having a density between 160 hooks per
square inch to 1200 hooks per square inch.
17. An anchor sheet shaped to have a substantially flat square
lower layer part having an underside covered in a resilient layer
and a substantially flat square upper layer part of the same size
as the lower layer part having an upper side substantially covered
in hooks in which the upper layer part is offset from the lower
layer part an equal amount along two adjacent edges to expose two
adjacent portions of the lower layer part and in which countersunk
holes are formed through the anchor sheet centred on the corners
formed by the lower layer part wherein, the sheet has a total
thickness between 0.020 inches and 0.75 inches in its thickest
part.
18. The anchor sheet of claim 17, wherein the sheet has a thickness
between 0.062 and 0.75 inches in its thickest part.
19. The anchor sheet of claim 18, wherein the sheet has a thickness
of approximately 0.125 inches at its thickest.
20. The anchor sheet of claim 19, wherein the sheet is injection
moulded.
21. An anchor sheet for use in a subfloor for detachable attachment
to a decorative covering, the anchor sheet comprising: an upper
surface having a means for detachable attachment to the decorative
covering; a lower surface opposite the upper surface, the lower
surface being covered with a resilient layer; a recess of a first
shape reducing the thickness of the anchor sheet in a first area;
and a complete cut through the anchor sheet of a smaller second
area within the first area of a second shape; wherein the sheet has
a thickness between 0.020 inches and 0.75 inches.
22. The anchor sheet of claim 21, wherein the sheet has a thickness
between 0.062 and 0.75 inches in its thickest part.
23. The anchor sheet of claim 22, wherein the sheet has a thickness
of approximately 0.125 inches at its thickest.
24. The anchor sheet of claim 21, wherein the sheet is injection
molded.
25. An anchor sheet comprising: a sheet with a first surface and a
second surface; the sheet being made of one of a polypropylene and
a polyethylene, and a resilient layer attached to the second
surface; wherein the first surface bears a field of hooks, the
hooks having a density between 160 hooks per square inch to 1200
hooks per square inch.
26. The anchor sheet of claim 25, wherein the field of hooks has a
density of approximately 330 hooks per square inch.
27. The anchor sheet of claim 25, wherein the anchor sheet is a
square in the range of approximately 12 inch by 12 inch to
approximately 36 inch by 36 inch.
28. The anchor sheet of claim 27, wherein the resilient layer has a
thickness between 1/4 of an inch and 3/8 of an inch.
29. The anchor sheet of claim 28, wherein the sheet has a thickness
between 0.020 inches and 0.75 inches.
30. The anchor sheet of claim 29, wherein the sheet has a thickness
between 0.062 inches and 0.75 inches.
31. The anchor sheet of claim 30 wherein the sheet is 0.125 inches
thick.
32. An anchor sheet for use in a subfloor for detachable attachment
to a decorative covering, the anchor sheet comprising: an upper
surface having a means for detachable attachment to the decorative
covering; a lower surface opposite the upper surface, the lower
surface being attached to a resilient layer; one of an overlay and
an underlay area located adjacent an edge of the anchor sheet,
wherein the anchor sheet has a reduced thickness in the area, and
the area is configured to overlap with the other of an overlay and
underlay area of a complementary anchor sheet; and wherein the
anchor sheet has a maximum thickness of between 0.020 inches and
0.75 inches.
33. An anchor sheet for use in a subfloor for detachable attachment
to a decorative covering, the anchor sheet comprising: an upper
surface having a means for detachable attachment to the decorative
covering; a lower surface opposite the upper surface, the
lower-surface being attached to a resilient layer; and one of a
male and female feature defined in the anchor sheet and located
adjacent an edge of the anchor sheet, the feature being configured
to interlock with the other of male and female feature of a
complementary anchor sheet.
34. The anchor sheet of claim 33, wherein the feature is
keystone-shaped.
35. The anchor sheet of claim 33, wherein the feature is jigsaw
puzzle piece-shaped.
36. An anchor sheet comprising: a first layer of a polypropylene
sheet of between 0.062 inches and 0.50 inches; and a second layer
of polyethylene foam of a density of at least 20 kg/m.sup.3 and of
thickness of between 1/4 inches and 3/8 inches.
37. The anchor sheet of claim 36 in which the anchor sheet provides
for countersunk areas at least along one edge.
Description
FIELD OF THE INVENTION
[0001] This invention concerns improvements to an anchor sheet
having hooks across one side for use under carpets or other
decorative coverings as described, for example in U.S. Pat. Nos.
6,306,477 (Pacione, Oct. 23, 2001), 6,298,624 (Pacione, Oct. 9,
2001), 6,395,362 (Pacione May 23, 2002), and PCT/CA 00/00681
(Pacione et al.), published under WO 00/74544 on Dec. 14, 2000.
This application incorporates by reference the specifications of
these earlier patent documents.
BACKGROUND OF THE INVENTION
[0002] The earlier Pacione cases generally disclose an anchor sheet
which can be supplied in various shapes and sizes, with or without
a pre-attached decorative covering. These earlier cases also
describe how individual sheets can together form a contiguous mass
of anchor sheet to provide a field of hooks which engage loops on
the underside of an overlying flooring, particularly carpet pieces.
Such a contiguous mass can be formed by attaching the anchor sheets
directly together, either by overlapping or abutting or by the use
of attachment devices aided by the bridging of neighbouring sheets
by the overlying covering. Such mass can be free floating or
attached to the floor.
[0003] As discussed in the earlier Pacione cases, the current
inventor has invented an anchor sheet (in some contexts referred to
as a hook plate or a module) which, when installed, acts to tie
decorative covering together as a functional unit and to add mass
and stability to such unit, particularly in the case of a unit
having a flexible decorative covering such as a carpet. The anchor
sheet may be substantially covered over one side with hooks for
anchoring a decorative covering. The anchor sheet itself may be
attached to an underlying substrate, such as a floor or wall, or it
may be loose laid on a floor where the anchor sheet may have
sufficient mass to prevent movement of the anchor sheet.
SUMMARY OF THE INVENTION
[0004] The present invention provides an improved anchor sheet
having desirable characteristics when in place under a floor
covering.
[0005] It is possible, generally even preferred, when using
coverings in combination with the anchor sheet of the present
invention to use a floor covering that includes little or no
cushion layer as is often provided in carpet by a foam layer, e.g.,
as by urethane foam. The benefits of an anchor sheet of the present
invention are most evident when it is used in combination with such
a covering having little or no distinct cushioning layer in the
covering.
[0006] An anchor sheet of the present invention provides an
overlying plastic sheet and an underlying cushioning layer. An
anchor sheet made up of a top plastic layer and underlying cushion
has been generally previously described, as in U.S. Pat. Nos.
6,298,624, 6,306,477, and 6,395,362 and WO 00/74544.
[0007] In a broad aspect, the invention is an anchor sheet made up
of a plastic sheet and an underlying resilient layer secured
thereto. The plastic sheet has a thickness of between 1/16 inches
and 1/4 inches and having a flexural modulus (ASTM D790) of between
700 and 3600 MPa. The resilient layer has a compression force
deflection (ASTM D3574-C) that is within about 30 percent of the
compression force deflection of a low density polyethylene layer
3/8 thick and a density of 30 kg/m.sup.3. A value within about 30
percent of the compression force deflection of the indicated
material can be up to 30 percent more than the value measured for
the indicated material or down to 30 percent less than the value
measured
[0008] When included as part of a carpet installation having an
overlying carpet having no rubber or urethane foam layer, for
example, an anchor sheet of the present invention provides a
desirable "feel" or "give" as a person walks over the installation.
With the present invention, a carpet having little or no internal
resilient layer or cushion can be used, resulting in less stress on
the carpet fibers and primary backing. The anchor sheet can also
provide the required level of sturdiness so that furniture can be
placed on or moved over the installation and is relatively
resistant to puncture, under normal wear. The lower layer includes
a suitable level of resiliency for installation atop, for example,
a concrete floor of a newly constructed office building to suitably
ride over imperfections therein.
[0009] Related to the invention(s) disclosed herein are
invention(s) in the following U.S. provisional patent applications,
all filed concurrently herewith and incorporated by reference:
[0010] U.S. Provisional Patent Application entitled "Carpet tile,
installation, and methods of manufacture and installation thereof".
This application shows coverings that can be used with an anchor
sheet of the present invention; [0011] U.S. Provisional Patent
Application entitled "System and methods of manufacturing
hook-plates". This application shows a method for manufacturing an
upper plastic layer that can be used as the upper portion of the
present invention; [0012] U.S. Provisional Patent Application
entitled "Ultrasonic welding of resilient layers to plates". This
application shows a method for securing a cushioning layer of the
present invention to the upper plastic layer; [0013] U.S.
Provisional Patent Application entitled "Floor covering having a
removable decorative inlay". This application shows a particular
covering arrangement that can be used with the present invention;
and [0014] U.S. Provisional Patent Application entitled "Anchor
sheet positioning and connection system". This application shows
ways and means for connecting anchor sheets to each other.
[0015] In a further aspect of the invention the sheet has a
resilient layer made from low-density polyethylene.
[0016] If polypropylene is used for the anchor sheet and with a
resilient layer made of low-density polyethylene, the preferred
thickness of the anchor sheet is about 0.125 inches. Further
experimentation has shown the preferred size of the anchor sheet
and the preferred way of connecting the anchor sheets together is
as follows. It has been found that one size of anchor sheet of
approximately 24''.times.24'' square (taking into account some
possible geometric variation along the edges, usually the corners,
to accommodate devices for attaching neighboring sheets to each
other) is preferred with an overlap/underlap area provided between
adjacent sheets, so that the sheets overlap to form a planar
surface. However, with a connector disclosed in the above-detailed
application entitled "Anchor sheet positioning and connection
system", no connection of the sheets to the floor, or directly to
each other at the overlap area, is necessarily required.
[0017] Other additional features of the preferred anchor sheet are
additional aspects of the invention disclosed herein and are
described below and outlined in the attached claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention will be further understood from the
following detailed description of an embodiment of the invention,
with reference to the drawings in which:
[0019] FIG. 1 shows an anchor sheet in simplified form with an
underpad according to this invention:
[0020] FIG. 2 shows an anchor sheet in plan view having overlapping
edges in addition to the cutaway portions for the cornerpieces;
[0021] FIG. 3 shows a cornerpiece to be used with certain geometric
shapes of anchor sheets;
[0022] FIG. 4 shows an embodiment with two differently configured
anchor sheets;
[0023] FIG. 4a shows another embodiment with two differently
configured anchor sheets;
[0024] FIG. 4b is a section through line 4b-4b of FIG. 4a;
[0025] FIG. 5 is a section through line 5-5 of FIG. 4;
[0026] FIG. 6 is a section through line 6-6 of FIG. 4; and
[0027] FIG. 7 shows an embodiment of an interlocking anchor
sheet.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0028] Referring to FIG. 1, an anchor sheet 1 is provided. Anchor
sheet 1 is placed on or attached to a surface such as floor (not
shown). In the present embodiment, anchor sheet 1 is in the shape
of a square. Anchor sheet 1 may alternatively be configured in any
shape that can be conveniently abutted with another piece to create
a floor pattern such as, for instance, a rectangle, a hexagon or an
octagon or a mixture thereof. Generally, the preferred shape will
be an equilateral polygon, but a rectangle or any other shape may
also be used as appropriate. Typically, a shape will be chosen
which allows a planar surface to be created out of a single major
piece. Such shape can have a countersink along one edge to receive
an overlapped portion of an adjacent similar sheet. However,
different shapes can be used, having any number of edge areas which
are countersunk from the top surface. Additional sheets can be put
into this area. In FIG. 1, anchor sheet 1 contains a top surface
layer having hooks 4 countersunk area 7 which can be used by an
overlap portion of an adjacent sheet of the same or different shape
or for an attachment piece.
[0029] Anchor sheet 1 may also include a cushion or resilient layer
5, which is attached to a side of anchor sheet 1 opposite to hooks
4. When installed, resilient layer 5 is located between anchor
sheet 1 and the underlying floor. In this configuration, resilient
layer 5 provides resilience to the anchor sheet when a downward
force is applied thereto. Similarly, if an overlayment or cover,
such a decorative covering (not shown), is attached to or supported
by anchor sheet 1, then the decorative covering will be similarly
cushioned. The decorative covering may be a carpet overlaid on top
of the anchor sheet. Resilient layer 5 may also be used to add mass
to anchor sheet 1 to inhibit movement thereof. Furthermore,
resilient layer 5 may be manufactured to have a greater coefficient
of friction with the floor than anchor sheet 1 in order to reduce
movement of resilient layer 5 (and, by connection, anchor sheet 1
and the decorative covering) relative to the floor. However, it
should be emphasized that cushioning is not necessary for anchor
sheet 1 to function, but such cushioning can have at least the
advantages described above, depending on the characteristics of the
overlayment and the intended use of anchor sheet 1.
[0030] The anchor sheet is relatively rigid in the sense that it is
not tape or cloth like. Anchor sheet 1 can have the right degree of
"give", so that a user can experience some cushioning effect from
resilient layer 5 below the anchor sheet, but with some level of
rigidity so that the load of walking is transmitted across a larger
surface and does not "dig" into resilient layer 5. This "give" is a
product of the combination of the "stiffness" common of the anchor
sheet and the "compressibility" of the resilient layer. To achieve
a "feel" it is possible to have a more stiff anchor sheet and a
more compressible resilient layer or it is possible to have a less
stiff anchor sheet and less compressible resilient layer. However,
all of the preferred combinations shown will work, subject to the
application and the personal preference of the user.
[0031] Hooks 4 of top surface layer 3 attach to the loops of an
overlying carpet (not shown). Hooks 4 can be attached to sheet 1 by
any convenient means, but injection molding is preferred. It is
possible for the hook material to be a different plastic or polymer
material, and even applied as a film with adhesive, since hooks 4
may need to be relatively more resilient and flexible than the
anchor sheet 1 itself. In this case, a laminate anchor sheet 1
rather than unitary construction can be used. Hooks 4 have stems 1
mm high and 0.55 mm in diameter with a stem density of
approximately 230 stems per square inch of top surface layer 3. The
ratio of stem height to diameter is preferably about 2:1, and may
be as great as 10:1. The stem diameter may be in the general range
of 0.3 to about 0.9 mm. Stem diameters of as small as 0.1 mm have
been found to be acceptable.
[0032] When the density of hooks 4 is approximately 230 per square
inch, nearest-neighbour hooks are spaced about 1.8 mm from each
other, and are arranged in a grid of equilateral triangles so that
each hook has six nearest neighbours. In this configuration, there
are approximately 128,000 stems on a 24 by 24-inch anchor sheet 1.
Sheets having as many as 330 stems per square inch may be used as
well. While a single anchor sheet 1 may be installed, in the
preferred embodiment, an anchor sheet subfloor comprising two or
more anchor sheets 1 is installed (as illustrated, in part, in FIG.
2).
[0033] As seen in FIG. 1, anchor sheet 1 has a thickness A. The
appropriate thickness A will depend on the intended use of the
anchor sheet, and may vary with the type of overlayment to be used.
The preferred thickness A will generally not be less than 0.062
inches. One preferred thickness A is about 0.125 inches, but the
thickness A may preferably flooring (not shown) is replaced, or
where a thick anchor sheet needs to be used to create a level
surface with an adjacent surface.
[0034] The appropriate thickness of resilient layer 5 may also vary
depending on the intended use of the anchor sheet, and the type of
overlayment to be used. For many uses, the preferred thickness of
resilient layer 5 may be about 0.375 inches. A preferred total
thickness when resilient layer 5 is combined with an anchor sheet
of thickness A, is about 0.5 inches, not including the height of
hooks 4 of anchor sheet 1. When thickness A of anchor sheet 1 is
about 0.125 inches and anchor sheet 1 includes resilient layer 5 of
about 0.375 inches thick, a desirable walkability of the anchor
sheet/resilient layer combination may be achieved.
[0035] In the above-described configuration, the material costs for
the anchor sheet and resilient layer may be generally less than
other configurations. For example, use of a thicker anchor sheet
may increase costs. More material is required to increase the
thickness of the anchor sheet because it is generally more dense
than the resilient layer. Conversely, an increase in the thickness
of the resilient layer is generally less expensive, but, depending
on the magnitude of the increase, the walkability of the anchor
sheet/resilient layer combination may be negatively affected. The
use of the aforementioned thicknesses may also serve to achieve a
level of durability of the anchor sheet/resilient layer combination
without unduly increasing manufacturing costs.
[0036] If the combined thickness of the anchor sheet and resilient
layer is greater than about 0.5 inches, the use of such anchor
sheet combination may be limited in some installations. For
example, a thicker anchor sheet and resilient layer combination may
obstruct or interfere with a door or other nearby feature when the
anchor sheet is installed.
[0037] Referring again to FIG. 1, cutaway from thickness A is a
countersunk area A which circle. When combined with similar
abutting anchor sheets aligned along sides 9 and 11, a 3/4 circular
cut out area is formed. A fourth anchor sheet diagonally opposite
anchor sheet 1 forms a complete circle having a circular cut out
area and could have a "hole" 14, as described below. Typically, the
cut-out area will be such that the width of the anchor sheet at 13
will be approximately half of the total thickness A of the anchor
sheet. However, the width of the anchor sheet at 13 may be other
than approximately half the total thickness A. In addition, there
can be a second area 14 which is cut away from the corner (the apex
of the angle formed by the two sides of the square). This second
area 14 also has a geometric shape (in this example, a 1/4 of a
circle) so that, when combined with other anchor sheets, the anchor
sheet edges are aligned so that their corners meet at the virtual
intersection of the four corners, and a second smaller circle is
formed in the completed anchor sheet structure.
[0038] Thus, a circular cut away area 14 within a second larger
circular cut out area 7 is created when four similar anchor sheets
abut each other, as shown in FIG. 2. A complementary corner piece
or attachment device 31 can then be added which will match the
shape and thickness of the reduced thickness portion and the shape
and thickness of the cutaway area (see FIG. 3). Corner piece 31 can
be attached to area 7 by glue or other permanent attachment, or by
detachable attachment such as pressure sensitive adhesive or a hook
and loop, or post and hole type. Fastening devices such as hook and
loop or a screw or nail may be used to attach the corner pieces to
a floor to hold the anchor sheet to the floor at only a few
discrete points by use of the corner pieces, with or without direct
attachment to the anchor sheets. However, it is not necessary to
attach any part of the anchor sheet 1 or corner piece 31 directly
to the floor. A preferred "snap-fit" attachment system is
described, among others. in the above-detailed application entitled
"Anchor sheet positioning and connection system". With this form of
attachment relative movement between anchor sheets can be achieved,
although the anchor sheets are attached directly to each other. It
will also be appreciated that area 7 can have any shape or size in
relation to the size of the anchor sheet and attachment piece 31
can be correspondingly bigger.
[0039] FIG. 2 shows an arrangement of anchor sheets 1 and corner
pieces 31 where there is a plurality of overlapping anchor sheets
111. In this example, anchor sheets 111 are squares. Except as
noted herein, anchor sheets 1 and 111 have similar characteristics,
and the description of one generally applies to the other (e.g.,
materials used for manufacture). Unlike the embodiment in FIG. 1,
anchor sheets 111 do not abut each other in one plane only. Rather,
anchor sheets 111 have an underlay area 15 in which there is a
lower portion edge 16. Underlay area 15 is indicated in FIG. 2 by a
grid marking, but underlay area 15 is part of anchor sheet 111.
Underlay area 15 is configured to lie under overlap area 19 on an
adjacent sheet 111. Overlap area 19 extends on two sides of each
sheet 111, and underlay area 15 extends on the other two sides.
Overlap area 19 overlaps the underlay area 15 of each sheet 111,
for instance, along an area 20 (the area between the top abutment
edge at the dotted line). Overlap and underlay areas 19 and 15 may
be configured to extend from anchor sheet 111 by a similar amount.
This enables underlay area 15 to generally support overlay area 19.
However, the degree of overlap need not be complete. For example,
overlap area 19 may extend a fraction as far as underlay area 15.
Such unmatched overlap can affect the degree of support provided at
overlap area 20. In an embodiment, each of overlap area 19 and
underlay area 15 may extend from sheet 111 by two inches, and
preferably extend by one inch, to form a generally uniform overlap
thereof in area 20. The thickness of the overlap area 19 may be
approximately half the thickness of thickness A.
[0040] An area of reduced thickness 21 is formed in the general
vicinity of where the apex of underlay edges 15. The cutout is
centered over the area of abutment for instance lower portion edges
16 of anchor sheets 111. The cutout is not centred over the corner
line of abutment 25 created by the overlap edges extending over the
area of overlap 19. In addition to the reduced thickness area 21
(similar to area 7 in FIG. 1) there is a cutaway area 23.
[0041] It is possible to use an embodiment by providing a reduced
thickness area along any edge (or portion of an edge) of a modular
anchor sheet, having a cut away area within the reduced thickness
area to provide a countersink for use with the attachment devices
described. A reduced thickness area surrounding a cut away area may
also be located anywhere in the interior of an anchor sheet for use
of an attachment device at that interior point. However, this is
generally not preferred, unless the attachment device is to be
attached to the floor because an attachment device at an interior
point can obviously not connect two anchor sheets together.
[0042] If an overlapping arrangement is used, the extent of
underlay edges 15 and overlap 19 need not be along more than one
side, nor need it be along an entire side. Overlap may occur at
just a portion of one side enough to permit portions of
co-operating anchor sheets 1 to overlap. Similarly, the particular
shape of such overlapping pieces may be varied as long as the
overlap is sufficient to achieve the functions described
herein.
[0043] In one embodiment, anchor sheets 1 are square, of similar
size and shape, and have sides in the range of 24 to 48 inches,
although anchor sheets outside of this range may also be used.
[0044] Anchor sheets 111 may be made of an extruded or injection
molded material in which the two pieces are thermally bonded so as
to form the overlap 19 and underlay area 15. Sheets 111 may be cut
by a gauge or jig. Anchor sheet modules 111 may be die cut. The
layer of hooks may be thermally bonded to the surface of the top
sheet. Alternatively, the injection-molded using a one- or two-step
or multi-step process mold, using materials such as polypropylene
or polyethylene.
[0045] The overlap 19 and underlay 15 areas of the sheets 111 may
be provided with means for detachable or permanent attachment, or
the underlay areas 15 of an adjacent sheet may simply lie
underneath and support the overlap areas 19 without any form of
attachment. Preferably, however, any attachment provides for
relative movement between adjacent sheets. The snap fit arrangement
described in the above-detailed application entitled "Anchor Sheet
Positioning and Connection System" could be suitable. Possibly, the
sheets 111 may also be made with corresponding registering bumps
and indentations (not shown) in the overlap 19 and underlay 15
portions of sheets 111 to assist in retaining sheets 111 together
and in alignment during installation.
[0046] In cases where hook and loop systems or hooks are provided
for, the hooks may be temporarily covered by a hard slip covering
as discussed in U.S. Pat. No. 6,306,477, or a soft covering as
disclosed in U.S. Pat. No. 4,822,658 to temporarily prevent
premature engagement of the hooks to the loops.
[0047] Anchor sheet 111 may alternatively be configured to work in
conjunction with one or more differently configured anchor sheets.
For example, a first type of anchor sheet (not shown) could be
constructed to have complementary corner pieces (such as 31 in FIG.
3) attached or integrally molded to the corners thereof. A second
complementary anchor sheet, such as anchor sheet 111 would receive
the corner pieces in a similar manner as described for the
preferred embodiment. Alternatively, two or more anchor sheets
could be configured to have an interlocking keystone or jigsaw
puzzle like shape. An example of an interlocking keystone anchor
sheet 111''' is illustrated in FIG. 7. If such an arrangement is
used, then thereof to inhibit separation and bending of adjacent
anchor sheets away from their common plane. However, the keystone
male in portion 41 could be made smaller than the opening so that
some relative movement between the sheets could be possible while
still being interlocked.
[0048] Referring to FIGS. 4 to 6, anchor sheets 111' (shown in
white and light grey) and 111'' (shown in dark grey) are different
yet configured to be complementary to one another. The shading of
sheets 111' and 111'' in FIG. 4 is done merely to distinguish the
two configurations. These anchor sheets are arranged, positioned,
or connected to one another in a similar manner as described for
the preferred embodiment. These anchor sheets differ from the
preferred embodiment in that anchor sheet 111' has only an underlay
areas 15' which co-operate with overlay areas 19'' of anchor sheet
111''. The dashed line in FIG. 4 shows the extent of the underlay
area 15' of anchor sheet 111'. FIGS. 4a and 4b illustrates a
similar arrangement wherein anchor sheet 111''' serves to connect
anchor sheets 111'.
[0049] Referring again to FIG. 1, the thickness A is 1/8 of an
inch, and the thickness of the anchor sheet at 13 is 1/16 of an
inch. (Similarly, the overall thickness of anchor sheet 111 may be
1/8 of an inch, with the thickness of the underlay area 15 being
1/16 of an inch.) The thickness of the resilient layer 5 is in the
range from approximately 1/4 of an inch to 3/8 of an inch,
depending on the desired resiliency and amount of surface traffic.
Hooks 4 of top surface layer 3 have a density that may range from
about 160 to 1200 hooks per square inch, and may be as high as 2000
hooks per square inch. The preferred density is approximately 230
hooks per square inch.
[0050] The preferred materials for anchor sheet 1 and resilient
layer 5 are polypropylene and polyethylene. The preferred plastic
material for anchor sheet 1 is polypropylene, such as ExxonMobil
PP7805 E2 copolymer grade for compounding or injection molding.
Accutuf.RTM. has a melt flow index of 100, a tensile yield strength
of 4100 psi, a flexural modulus of 250.times.10.sup.3 psi. PP7805
E2 has a melt flow index of 80 @ T=230.degree. C., F=2.16 kg), and
a tensile strength at yield of 33 MPa (50 nm/min). Other plastics
may be used such as those sold as STAMYLAN (TM) P 112MN40, with an
ISO 1873 indication of PP-H or other thermoplastic materials.
Stamylan (TM) has a melt flow index of 50 169 T=230.degree. C.,
F=2.16 kg), a flexural modulus of 1900 MPa, proportional strength
of 35 MPa, ultimate strain of greater than 50%, and a density of
910 kg/m.sup.3 and a melting point of approximately 160.degree. C.
Other polypropylenes such as those having lower or higher melt flow
indexes, for example, 80 or 100, may also be used. It will be
appreciated that other materials may also be used in the injection
process, including polyethylene terephthalate, nylon and other
polymers. In general, the plastic from which the sheet is
manufactured has a flexural modulus of between 1200 and 2600 MPa
(ASTM D790), or a flexural modulus of between 1300 and 2500 MPa, or
a flexural modulus of between 1400 and 2400 MPa, or a flexural
modulus of between 1500 and 2300 MPa, or a flexural modulus of
between 1600 and 2200 MPa, or a flexural modulus of between 1700
and 2100 MPa, or a flexural modulus of between 1800 and 2000
MPa.
[0051] In a preferred embodiment, resilient layer 5 is made from
low density polyethylene with a density of approximately 30
kg/m.sup.3. Other foams having a suitable compression force
deflection test may be used, and are of a suitable material such as
polyurethane or rubber. The preferred foam has a compression force
deflection (ASTM D3574-C) which is the same or very near to that of
the disclosed polyethylene foam that is 3/8 inches thick and has a
density of 30 kg/m.sup.3.
[0052] ASTM standards referred to herein are available from ASTM
International. 100 Barr
[0053] ASTM D3574, Test C, is the compression force deflection test
(50% compression) as set out in designation D 3574-01 on Jan. 22,
2003. The value obtained in the test is that set out as the
standard, i.e., 50 mm by 50 mm by 25 mm in thickness.
[0054] Flexural modulus is determined according to ASTM D790 at a
temperature of 23.degree. C.
[0055] In alternative embodiments, anchor sheet 1 is made of thin
polycarbonate or polyester. For thick covering materials such as
stone or ceramic, anchor sheet 1 may be as thick as 1/4 of an inch
or even greater. Thickness may vary depending upon the covering
material and the stability requirements for any covering such as
carpet. It is also possible for anchor sheet 1 to be made of thin
sheet metal, carbon fibres or some form of polymer.
[0056] Anchor sheets 1 may be any size convenient for sale,
transportation or installation, typically in the range of 12 inches
by 12 inches square to 36 inches by 36 inches square. As noted,
anchor sheet 1 is an approximately 24 inches by 24 inches square.
In an alternative embodiment, anchor sheet 1 is an approximately 25
inches by 25 inches square.
[0057] Anchor sheets 1 may be manufactured using some convenient
method such as the injection moulding and coining method disclosed
in the above-detailed patent application entitled "System and
Methods of Manufacturing Hook Plates". The referenced application
discloses that, in order to manufacture an anchor sheet or hook
plate, injection molding is used. The hook plate manufactured by
the molding apparatus (not shown) may be a square that is 24 by 24
inches, and has 1/8 of an inch thickness. Stems integral with the
hook plate are used to form the hooks, and may be 1 mm high and
0.55 mm in diameter. The density of stems may be approximately 230
per square inch, with a distance between stems of 1.8 mm arranged
in a regular triangle, or approximately 128,000 stems on a
plate.
[0058] The polypropylene material is injected into the mold at a
temperature of approximately 280.degree. C. and a pressure of
approximately 150 bar, while the mold is internally cooled to a
temperature of approximately 60.degree. C. Under these constraints,
the injection time is approximately 2 seconds, the holding time is
approximately 12 seconds, the cooling time is approximately 35
seconds, and the ejection time is approximately six seconds, for a
total cycle time of approximately 55 seconds. Due to the large
number of small stems being molded across the plate, it is
important that the work-piece be ejected from the mold before the
shrinkage of the work-piece is sufficient to shear the stems as
they sit in the array of cavities in the mold. In the molding
process of the present description, the total holding and cooling
time is approximately 47 seconds, and it has been found that
letting the hook plate cool for longer than this time results in
shearing of the stems from the rest of the hook plate under the
given pressure conditions for the material. Also, with the large
number of small stems being molded across the plate, it is
important that the hook plate be ejected from the mold at
approximately the same time across the entire work-piece. Air
ejectors may be used for this purpose.
[0059] Once the hook plate is removed from the mold, it is allowed
to passively cool to room temperature. This step is not necessary
if the subsequent coining parameters are adjusted to compensate.
When removed from the mold, the hook plate will have a surface
temperature of approximately 60.degree. C.
[0060] The stems are coined into an array of mushroom-headed hooks
by engaging a heated coining plate onto the tops of the array of
stems, melting (or softening) the tops of the stems and deforming
them into a mushroom-head shape. A generally planar coining plate
may be engaged by lowering it to uniformly apply pressure to the
tops of the stems.
[0061] The coining plate is preferably made of steel, and is heated
electrically. The contact surface of the coining plate is
relatively flat and smooth, having no substantial designed cavities
therein for forming the heads.
[0062] The coining plate is heated above the melting temperature of
the material of array of stems, and is then lowered so that the
coining surface engages the tops of array of stems. This causes the
plastic in tops of array of stems to become molten and deform,
creating an array of mushroom heads or hooks.
[0063] Placed beneath the uncoined plate is a compressible
resilient layer made of any resilient material that is more
resilient and compressible than the material of the work-piece
being coined. While not essential, the resilient layer provides a
cushioning effect underneath the uncoined hook plate. Initially the
downward force of the coining plate onto the stems and the heat
transfer thereto is not sufficient to significantly cause the
stem-heads to deform, as the resilient layer begins to compress,
until the elastic resistance of resilient layer and the heat
transfer are sufficient to alter the shape of the stem heads,
thereby causing the stems to form an array of hooked heads. The
resilient layer may lessen any effect which might be caused by the
coining surface of the coining plate not being parallel with the
stem heads. This causes the stems to form the heads at
substantially the same time, thereby producing generally uniform
hooks for the hook plate.
[0064] Numerous modifications, variations, and adaptations may be
made to the particular embodiments of the invention described above
without departing from the scope of the invention, which is defined
in the following claims.
* * * * *