Information
-
Patent Grant
-
6702330
-
Patent Number
6,702,330
-
Date Filed
Tuesday, June 18, 200222 years ago
-
Date Issued
Tuesday, March 9, 200421 years ago
-
CPC
-
US Classifications
Field of Search
US
- 281 151
- 281 191
- 281 211
- 281 29
- 281 36
- 281 51
-
International Classifications
-
Abstract
The present invention relates to bindings for books, wherein the spine is hidden behind an extension of the cover. Specifically, a piping element is inserted into a recess formed by a doubled-over center section of a cover of the book. Because of the structure of the piping element, the book is capable of laying flat when opened, while hiding the spine and concurrently protecting both the spine and other objects from damage.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to bindings for books. Specifically, by providing a stitched doubled-over center section to form a recess in a cover of the book, and a piping element placed in the recess, the spine of the book may be hidden from view.
2. Background
In conventional book bindings, using round or spiral binding elements, such as metal coils or rings, the binding elements are generally disposed such that they are visible from outside of the book. However, such an arrangement is often objectionable, for aesthetic and other reasons. For example, the binding elements may cause injury or damage to articles with which they may contact, as well as having the potential to become damaged themselves.
Prior attempts to hide the binding elements include U.S. Pat. No. 2,082,423 to Schade, herein incorporated by reference in its entirety. Therein, a coiled wire is hidden by a stitched cover requiring two lines of stitching to maintain the structure of the binding. However, due to the construction of this binding, the resulting product will tend to lean to one side when the book is opened. Thus, when the book is opened, the pages and coil will generate forces preventing the book from laying flat.
It would be desirable to provide a hidden spine for a book, which also permits the book to lie flat, despite forces acting on the spine laterally.
SUMMARY OF THE INVENTION
The present invention relates to hidden spine for books wherein a piping element is inserted into a recess formed by a doubled-over center section of the cover of the book. In particular the book having a hidden spine comprises a cover comprising a front section, a back section and a doubled-over center section, the front section and the back section being connected to or integral with the doubled-over center section; the doubled-over center section comprising a first section and a second section and having a longitudinal axis, the first section comprising a first top surface, a first outer longitudinal edge portion and a first inner longitudinal edge portion, the second section comprising a second top surface, a second outer longitudinal edge portion and a second inner longitudinal edge portion, the first top surface being opposed to the second top surface to form a flange section; a piping element having a longitudinal axis and extending longitudinally along the first and second outer longitudinal edge portions and comprising a stem and a transverse head, wherein at least a portion of the stem is located between the first and second top surfaces and the stem is integral with or attached to the head, the first and second top surfaces are attached to the piping element along an attachment portion of the stem at or adjacent the first and second outer longitudinal edge portions; and at least one page connecting element linked to at least one member of the group consisting of the piping element and the doubled-over center section. Optionally, the first inner longitudinal edge portion is integral with the second inner longitudinal edge portion.
Typically stitching, used to secure the pages to the book, is also used to maintain the piping element in position. In one embodiment, the piping element is in the general shape of a “T” and formed from a resilient structure. Due to the construction, the ends of the T-shape help to maintain the book in a closed position, in addition to ensuring that the book lie flat when opened.
In its method aspects the present invention relates to a method of forming a hidden spine for a book comprising: providing a cover, having a front section and a back section and providing a piping element comprising a stem and a crossbar; folding the cover about the piping element and bending the crossbar such that the cover is in a folded position and the piping is between the front section and the back section and the crossbar is bent away from the stem and a doubled-over center section of the cover is formed; stitching together the cover and the stem while the cover is in the folded position and the crossbar is bent; creating a plurality of holes in at least one member of the group consisting of the doubled-over center section and the stem; passing at least one page connecting element through the plurality of holes. Typically, the stitching penetrates through the stem.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a plan view showing the structure of the hidden spine of a first embodiment of the invention.
FIG. 2
is an end view of the hidden spine of the embodiment of
FIG. 1
with the piping element removed.
FIG. 3
is a view of a cover of the book alone of FIG.
1
.
FIG. 4
is a plan view of the spine of the embodiment of
FIG. 1
with the book in an open position and the piping element removed for clarity.
FIG. 5
is an enlarged view of an end view of section V—V of
FIG. 4
of the piping element of
FIG. 1
that shows typical dimensions and rounded opposed ends.
FIG. 6
is a side view of a second embodiment of the piping element having a tapered end.
FIG. 7
shows a second embodiment of a cover of the present invention.
FIG. 8
shows an embodiment not having aligned holes through the cover of
FIG. 7
, but having holes through the piping element.
FIG. 9
shows an embodiment having aligned holes through both the cover of
FIG. 7 and a
piping element.
FIG. 10
shows an embodiment having a short piping element, relative to a center section of the cover of
FIG. 3
, and having aligned holes only through the cover.
FIG. 11
shows the cover and piping element in a bent position.
DETAILED DESCRIPTION
With reference to
FIG. 1
, a book
1
is provided with a piping element
25
. The piping element
25
is disposed between a front section
7
and a back section
8
of a book cover
3
, in the vicinity of a doubled-over center section
10
(FIG.
2
). Shoulders
12
are located where the front section
7
and back section
8
respectively meet the doubled-over center section
10
. Front section
7
and back section
8
and center section
10
may be integrally formed, as in
FIG. 1
, or front section
7
and back section
8
may be attached to center section
10
at a crease such as a weld (not shown).
The doubled-over center section
10
and has two sections
10
A,
10
B (
FIG. 3
) to form a recess
14
(FIG.
3
). Each section
10
A,
10
B has an outer longitudinal edge portion
11
, an inner longitudinal edge portion
13
(shown as integral edges in FIG.
3
), and a top surface
15
. “Outer” and “inner” for the edges
11
,
13
, respectively, refer to their positions when the book
1
is in a closed position, as for example shown by FIG.
1
. The expression “top” for the surface
15
relates to the position of the surface
15
as shown by FIG.
3
and merely functions as a label for the element.
Through doubled-over center section
10
a plurality of openings
16
(
FIG. 4
) are located. Page connecting elements
20
pass through the plurality of openings
16
. Openings
16
may be pairs of aligned holes through the two parts
10
A,
10
B (
FIG. 2
) of doubled-over center section
10
. Typically, the piping element
25
also has holes
16
A aligned respectively with the holes
16
. Pages
22
are attached to book
1
through page connecting elements
20
. Thus, the piping element
25
and sections
10
A,
10
B reinforce each other to hold connection elements
20
.
The piping element
25
has a “T” shape and comprises a stem
25
A and a transverse head
25
B. In use, the stem
25
A of the piping element
25
is located within recess
14
. Typically, the stem
25
A has sufficient length and has holes
16
A for the page connecting elements
20
to pass through it. Also, typically stitching
37
passes through sections
10
A,
10
B and through the stem
25
A. Thus the stitching forms holes
16
B (
FIG. 4
) in the stem
25
A.
FIG. 5
shows an enlarged view of an end view of section V—V of FIG.
4
and shows typical dimensions of piping element
25
. In
FIG. 5
the dimensions are as follows width “A”={fraction (7/32)} inch; height “L” equals {fraction (13/32)} inch; height “C” equals {fraction (3/128)} inch; height “D” equals {fraction (1/16)} inch; width “E” equals {fraction (3/128)} inch; radius of curvature r
1
equals {fraction (3/64)} inch; and radius of curvature r
2
equals {fraction (9/64)} inch. Typically these dimensions can be varied ±10% or ±30% or more depending, for example, upon the cover used with the piping element
25
.
FIG. 2
shows book
1
in the closed position, i.e., back
8
and front
7
laying in different planes. With book
1
in such a position, the stem
25
A of piping element
25
is located within recess
14
, before the stitching
37
of
FIG. 3
is put into place. In the embodiment shown in
FIG. 2
, piping element
25
has a general “T”-shape, and the transverse head
25
B has two ends
27
and
29
and the stem
25
A has an end
30
. When fully constructed, stem
25
A is inserted into recess
14
, such that it is hidden from view. However, ends
27
and
29
rest adjacent to doubled-over center section
10
of the cover. Ends
27
,
29
may be sharp as shown in
FIG. 2
or rounded as shown in FIG.
5
. The transverse head
25
B of
FIG. 5
may also be known as a crossbar. The colors of the piping element
25
and the cover
3
may be the same or different.
In a second embodiment, a stem
125
has a tapered end
125
A and a transverse head
125
B as shown in FIG.
6
. The tapered end
125
A facilitates simultaneously stamping and die cutting holes
16
,
16
A into the parts
10
A,
10
B and stem
125
.
FIG. 4
shows typical dimensions of piping element
125
. In
FIG. 6
the dimensions are as follows width “X
1
”0.213 inches; width “X
2
” equals 0.020 inches; width “X
3
” equals 0.030 inches; height “Y
1
” equals 0.313 inches; height “Y
2
” equals 0.244 inches; radius of curvature r
3
equals 0.051 inches; and radius of curvature r
4
equals 0.116 inches. Typically these dimensions can be varied ±10% or ±30% or more depending, for example, upon the cover used with the piping element
125
.
Preferably, piping element
25
, and in particular rounded ends
27
and
29
are formed from a material having memory. For example, piping element
25
may include a metal wire, or similar structure, which when ends
27
and
29
are diverted from their natural positions, the internal structure of piping element
25
permits maintaining book
1
either in either an open or closed position. Typically, the material is flexible enough that the ends
27
,
29
can be bent back when the cover front
7
and back
8
are bent to have access to stitch the stem
25
A to the cover
3
(FIG.
10
). However, the material is resilient enough to exert pressure on the shoulders
12
to snugly press against the shoulders (FIG.
1
). Typically, the stitching is sewn close to the transverse head
25
B so that the cover shoulders
12
stay snug to the armpit undersides
23
(
FIG. 5
) of the transverse head
25
B.
Typically the transverse head
25
B of the piping element
25
has an upper convex outer surface
27
A and concave underside surfaces
27
B. Preferably, the radius of curvature r
2
of the upper convex outer surface
27
A is greater than the radius of curvature r
1
of the concave underside surfaces
27
B. This radius relationship encourages a snug fit to the undersides
23
to shoulders
12
.
Typically the material of piping element
25
is a polymer. A typical PVC polymer has a durometer shore A hardness of 60 to 90 or 60 to 70. A typical polymer is virgin extruded polyvinyl chloride having the properties listed on Table 1.
TABLE 1
|
|
P.V.C. (Virgin) EXTRUSIONS
|
Physical Properties Compound
|
|
|
ASTM
|
|
Specific Gravity (±0.2)
1.32
D-792
|
Hardness - Shore A (±3)
90
D-2240
|
Tensile Strength
2760
D-4123
|
(pounds per square inch)
|
Elongation Percent
365
D-412
|
|
1. Specific Gravity - relative density
|
2. Hardness - The durometer based on Shore A is a measure of flexibility
|
and rigidity.
|
3. Tensile Strength - Pounds per square inch that the material will
|
withstand before breaking.
|
4. Elongation - Determines how far the product will stretch before
|
bursting.
|
|
ODOR - Inoffensive
|
TEAR STRENGTH - 250 DPI minimum
|
FADE-O-METER EXPOSURE - Minimum 200 standard FADE-O-
|
METER hours
|
WEATHER-O-METER EXPOSURE - Minimum 200 standard
|
WEATHER-O-METER hours
|
COLD TEST - A 1″ × 6″ × .080″ strip of material shall be first aged 7
|
days at 80° C.-2° C. the 1 day at −40° C.-2° C. The strip shall be bent
|
around a 2 inch diameter mandrel in not more than three seconds without
|
any evidence of breaking, cracking, splitting, etc.
|
|
Other typical polymers include polyolefin, polyurethane, polystryrene, a polymer latex synthetic rubber, such as carboxylated styrene, butadiene copolymer, ethylene propylene diene monomer (EPDM) rubber, or other elastomer. For example, a carboxylated styrene/butadiene copolymer such as BAYPREN latex, available from Bayer, may be employed.
The cover
3
may also be made of a material suitably flexible to bend to facilitate construction, yet rugged enough to be a cover. This facilitates making the entire cover from a single sheet as explained below. However, if desired a cover
103
maybe made of two sheets
107
,
108
, as shown in FIG.
7
. The two sheets have an inner longitudinal edge
If desired, the construction and/or shape of piping element
25
may tend to generate a force to fully open front
7
and back
8
only when front
7
and back
8
are manually passed a particular open threshold apart, such as 30°, 45° or 75°. That is to say, unless front
7
and back
8
, through doubled-over center section
10
, are manipulated to define an angle greater than the predetermined open threshold, piping element
25
maintains book
1
closed. However, when front
7
and back
8
, through doubled-over center section
10
, are manipulated to define an angle greater than the predetermined open threshold, piping element
25
provides a force to assist in opening book
1
and to maintain book
1
in the open position. As such, a user need only separate front
7
and back
8
a small amount, after which, piping element
25
takes over and fully opens book
1
.
FIG. 4
shows a particular embodiment of the invention partially assembled. In particular, piping element
25
has been removed in order to show the general construction of the invention. Although not required by the invention,
FIG. 4
shows a plurality of page connecting elements
20
maintaining pages
22
in book
1
. Each page connecting element
20
passes though one opening
16
, i.e., pair of aligned holes, to hold page
22
inside book
1
. After piping element
25
has been inserted into recess
14
, stitching
32
is added, through doubled-over center section
10
to (1) secure doubled-over center section
10
closed and (2) prevent piping element
25
from exiting recess
14
.
If desired, the two part cover
103
of
FIG. 7
may have sections
110
A,
110
B having a length “LL” which is longer or shorter than the length “L” of stem
125
A of FIG.
6
. For example,
FIG. 8
shows the two part cover
103
employed with a piping element
225
having a stem
225
A having a relatively longer length protruding from the inside edges
113
such that only the stem
225
need have holes
216
A therethrough. In contrast,
FIG. 9
shows the lengths as equal.
If desired, the one part cover
3
is employed with stem
125
A, and sections
10
A,
10
B having a length “LL” which is longer or equal to the length of “L” of stem
125
A.
FIG. 9
shows length “LL” greater than length “L” of stem
325
A of piping element
325
such that only parts
310
A,
310
B need have holes
316
therethrough. In contrast,
FIG. 1
shows the lengths of sections
10
A,
10
B and stem
25
A as equal.
Preferably, stitching
32
is positioned in a line, parallel to the longitudinal axis “LA” of piping element
25
and/or the longitudinal axis of center section
10
shown in FIG.
1
. As such, stitching
32
can actually be located through the center section
10
at or adjacent the shoulder
12
(at or adjacent the joint between front
7
and/or back
8
and doubled-over center section
10
). However, it is within the scope of the invention to position stitching
32
at any location along doubled-over center section
10
between the shoulder
12
and holes
16
,
16
A. Additionally, stitching
32
need not extend completely along doubled-over center section
10
. Stitching
32
assists to hold doubled-over center section
10
closed and piping element
25
in position, and, when book
1
is manipulated into the open position (manually or automatically due to internal forces), stitching
32
keeps doubled-over center section closed and assists to keep book
1
flat against a surface when the book
1
is in an open position.
Stitching
32
may be replaced by another suitable fastener such as staples (not shown) or rivets (not shown).
Straight end
30
of piping element
25
is inserted into recess
14
before stitching
32
is added. Straight end
30
may also assist in maintaining the arrangement of book
1
when in the open position. For example, in one embodiment (not shown), straight end
30
may be provided with a structural element, such as a metal strip along its length, either internal to straight end
30
or fastened to its length, resisting bending of straight end
30
. Therefore, when book
1
is opened, and pages
22
through page connecting elements
20
create a force tending to push and/or pull doubled-over center section
10
towards either front
7
or back
8
, piping element
25
can resist such forces and keep page connecting elements
20
in place.
It must be understood that although page connecting elements
20
are shown in the Figs. as being closed circular wires, the invention is not so limited. For example, in another embodiment not shown, page connecting elements
20
are joined into a single structure, such as a spiral metal coil, passing through each opening
16
, e.g., similar to a coil of a conventional spiral notebook. As long as page connecting elements
20
form a joint between pages
22
and at least one member of the group consisting of stem
25
and doubled-over center section
10
, any shape is sufficient.
The hidden spine of the invention is preferably constructed in the following manner. A cover
3
, having a front section
7
and a back section
8
and a piping element
25
comprising a stem
25
A and a crossbar
25
B, are provided. The cover
3
is folded about the piping element
25
and the crossbar
25
B is bent such that the cover
3
is in a bent or folded position (
FIG. 10
) and the piping element
25
is between the front section
7
and the back section
8
and the crossbar
25
B is bent away from the stem
25
A and a doubled-over center section
10
of the cover
3
is formed. Then, the cover
3
and the stem
25
A are stitched together while the cover
3
is in the folded position and the crossbar
25
B is bent. Then a plurality of holes
16
and/or
16
A are created in at least one member of the group consisting of the doubled-over center section and the stem
25
A. At least one page connecting element
20
, for example a metal wire spiral, is passed through the plurality of holes
16
and/or
16
A. Typically, the stitching
37
penetrates through the stem
25
A and sections
10
A,
10
B.
The holes
16
and/or
16
A can be cut before or after the cover
3
and piping element undergo one or more of the steps of being contacted, bent and stitched together.
If the cover
103
(
FIG. 7
) is formed of two separate pieces
107
,
108
stitched together during construction of the invention, then openings
116
may pass through doubled-over sections
110
A,
110
B of center section
110
and stem
125
(
FIG. 9
) or, in an alternative, openings
216
A pass through only stem
225
(FIG.
8
). The holes can be cut before or after the covers and piping elements of
FIGS. 8 and 9
undergo one or more of the steps of being contacted, bent and stitched together.
The particular order of these steps is not mandatory. For example, it is possible to create doubled-over center section
10
after creating openings
16
,
16
A or pages
22
may be attached to page connecting elements
20
prior to being assembled into the structure of the invention.
It should be apparent that embodiments other than expressly described above come within the spirit and scope of the present invention. Thus, the present invention is not limited by the foregoing description but rather by the claims appended hereto.
Claims
- 1. A book with a hidden spine comprising:a cover comprising a front section, a back section and a doubled-over center section, the front section and the back section being connected to or integral with the doubled-over center section; the doubled-over center section comprising a first section and a second section and having a longitudinal axis, the first section comprising a first top surface, a first outer longitudinal edge portion and a first inner longitudinal edge portion, the second section comprising a second top surface, a second outer longitudinal edge portion and a second inner longitudinal edge portion, the first top surface being opposed to the second top surface to form a flange section; a piping element having a longitudinal axis and extending longitudinally along the first and second outer longitudinal edge portions and comprising a stem and a transverse head, wherein at least a portion of the stem is located between the first and second top surfaces and the stem is integral with or attached to the head, the transverse head extends from the stem transversely relative to the longitudinal axis of the piping element, the first top surface and second top surface are attached to the piping element along an attachment portion of the stem; and at least one page connecting element linked to at least one member of the group consisting of the piping element and the doubled-over center section; optionally the first inner longitudinal edge portion is integral with the second inner longitudinal edge portion.
- 2. The book of claim 1, wherein the attachment portion, at which the first top surface and second top surface are attached to the piping element, is at or adjacent the first and second outer longitudinal edge portions, and the at least one page connecting element is linked to the at least one member of the group consisting of the piping element and the doubled-over center section at a location more distal to the transverse head than is the attachment portion.
- 3. The book of claim 2, wherein the page connecting element is linked to the piping element and the doubled-over center section.
- 4. The book of claim 2, wherein stitching attaches the first and second top surfaces to the piping element along the attachment portion of the stem at or adjacent the first and second outer longitudinal edge portions, and the attachment portion of the stem is close to the transverse head.
- 5. A book with a hidden spine comprising:a cover comprising a front section, a back section and a doubled-over center section, the front section and the back section being connected to or integral with the doubled-over center section; the doubled-over center section comprising a first section and a second section and having a longitudinal axis, the first section comprising a first top surface, a first outer longitudinal edge portion and a first inner longitudinal edge portion, the second section comprising a second top surface, a second outer longitudinal edge portion and a second inner longitudinal edge portion, the first top surface being opposed to the second top surface to form a flange section; a piping element having a longitudinal axis and extending longitudinally along the first and second outer longitudinal edge portions and comprising a stem and a transverse head, wherein at least a portion of the stem is located between the first and second top surfaces and the stem is integral with or attached to the head, the transverse head extends transversely from the stem relative to the longitudinal axis of the piping element, the first top surface and second top surface are attached to the piping element along an attachment portion of the stem; and at least one page connecting element linked to at least one member of the group consisting of the piping element and the doubled-over center section; optionally the first inner longitudinal edge portion is integral with the second inner longitudinal edge portion; wherein the piping element comprises a T-shape, wherein the head is a crossbar and the stem is perpendicularly connected to or integral with the crossbar at approximately the center of the crossbar.
- 6. The book of claim 5, wherein the crossbar has a convex outer surface and has two concave undersides on opposed sides of the stem, each underside of the crossbar has a radius of curvature, the outer surface of the crossbar has a radius of curvature, and respective opposed ends of each underside of the crossbar contact the cover.
- 7. The book of claim 6, wherein the piping element is made of a bendable resilient material having shape memory.
- 8. The book of claim 6, wherein the piping element is made of a bendable resilient polymer having shape memory.
- 9. The book of claim 5, wherein the crossbar has a convex outer surface and two concave undersides on opposed sides of the stem and a radius of curvature of each underside of the crossbar is smaller than a radius of curvature of the outer surface of the crossbar, and respective opposed ends of each underside of the crossbar contact the cover.
- 10. The book of claim 9, wherein a location where the front section meets the doubled-over center section forms a first shoulder and a location where the back section meets the doubled-over center section forms a second shoulder, wherein each respective concave underside of the crossbar contacts a respective said shoulder.
- 11. The book of claim 9, wherein the piping element is made of a bendable resilient material having shape memory and the crossbar contact the cover to exert pressure on the cover.
- 12. The book of claim 1, wherein the cover has a color different from a color of the piping element.
- 13. The book of claim 1, wherein the stem has an end distal to the head and the distal end is tapered.
- 14. The book of claim 1, wherein the at least one connecting element comprises a coil.
- 15. The book of claim 14, wherein the coil is metal.
- 16. The book of claim 14, wherein the doubled-over center section comprises at least one pair of aligned holes, though which the coil passes.
- 17. The book of claim 14, wherein the doubled-over center section comprises a plurality of pairs of aligned holes, and at least one of the circular elements passing though one of a plurality of pairs of aligned holes in the doubled-over center section.
- 18. The book of claim 14, wherein the doubled-over center section comprises a plurality of pairs of aligned holes, and at least one of the circular elements passes through one of a plurality of pairs of aligned holes in the doubled-over center section and passes through a hole of the stem.
- 19. A method of forming a hidden spine for a book comprising:providing a cover, having a front section and a back section and providing a piping element comprising a stem and a crossbar, the crossbar extends transversely from the stem relative to a longitudinal axis of the piping element; folding the cover about the piping element and bending the crossbar such that the cover is in a an inside-out folded position and the piping element is between the front section and the back section and the crossbar is bent away from the stem and a doubled-over center section of the cover is formed; fastening together the cover and the stem while the cover is in the folded position and the crossbar is bent away from the stem; creating a plurality of holes in at least one member of the group consisting of the doubled-over center section and the stem; passing at least one page connecting element through at least one hole of the plurality of holes.
- 20. The method of claim 19, wherein the fastening comprises stitching which penetrates through the stem and the cover.
- 21. The method of claim 20, wherein the stitching attaches the doubled over center section to the piping element along an attachment portion of the stem, wherein the attachment portion of the stem is close to the transverse head.
- 22. The method of claim 21, wherein the piping element is made of a bendable resilient material having shape memory and the piping element comprises a T-shape in an original position, wherein the head is the crossbar and the stem is perpendicularly connected to or integral with the crossbar at approximately the center of the crossbar, wherein the crossbar is bent from the original position to the position wherein the cross-bar is bent away from the stem, and wherein after the stitching the crossbar returns to the original position.
- 23. The method of claim 22, wherein the crossbar has a convex outer surface and has two concave undersides on opposed sides of the stem, each underside of the crossbar has a radius of curvature, the outer surface of the crossbar has a radius of curvature, and respective opposed ends of each underside of the crossbar contact the cover.
- 24. The book of claim 7, wherein stitching attaches the first and second top surfaces to the piping element along the attachment portion of the stem at or adjacent the first and second outer longitudinal edge portions, and the attachment portion of the stem is close to the transverse head.
- 25. The book of claim 8, wherein stitching attaches the first and second top surfaces to the piping element along the attachment portion of the stem at or adjacent the first and second outer longitudinal edge portions, and the attachment portion of the stem is close to the transverse head.
- 26. The book of claim 4, wherein the piping element is made of a bendable resilient material having shape memory.
US Referenced Citations (4)