U.S. patent application number 14/723394 was filed with the patent office on 2015-10-08 for multi-layer structure for ballistic protection.
The applicant listed for this patent is F.LLI CITTERIO. Invention is credited to Filippo CITTERIO, Giorgio Celeste CITTERIO.
Application Number | 20150285596 14/723394 |
Document ID | / |
Family ID | 44786052 |
Filed Date | 2015-10-08 |
United States Patent
Application |
20150285596 |
Kind Code |
A1 |
CITTERIO; Giorgio Celeste ;
et al. |
October 8, 2015 |
MULTI-LAYER STRUCTURE FOR BALLISTIC PROTECTION
Abstract
A ballistic protection is described. The ballistic protection
includes a rigid structure and a flexible structure, co-operating
to dissipate energy associated to an incident bullet impact, the
rigid structure and the flexible structure being separated by at
least a first discontinuity layer. The rigid structure includes at
least a first rigid layer, at least a second rigid layer, and at
least a third layer interposed between the first and the second
rigid layer. The material of the first discontinuity layer and of
the third layer of the rigid structure are selected so that a speed
of propagation of a sound wave through the first discontinuity
layer and the third layer of the rigid structure is less than 50%
of the speed of propagation of a sound wave through fibers of the
first rigid layer. The third layer can have a frame shape extending
along the edges of the ballistic rigid protections, so that
protection is increased along the borders.
Inventors: |
CITTERIO; Giorgio Celeste;
(MONZA, IT) ; CITTERIO; Filippo; (MONZA,
IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
F.LLI CITTERIO |
MONZA |
|
IT |
|
|
Family ID: |
44786052 |
Appl. No.: |
14/723394 |
Filed: |
May 27, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14238337 |
Mar 24, 2014 |
9068802 |
|
|
PCT/IT2011/000295 |
Aug 11, 2011 |
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14723394 |
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Current U.S.
Class: |
89/36.02 |
Current CPC
Class: |
F41H 5/04 20130101; F41H
5/0471 20130101; F41H 5/0457 20130101; F41H 5/0414 20130101; F41H
5/0428 20130101; F41H 5/0442 20130101; F41H 5/0478 20130101 |
International
Class: |
F41H 5/04 20060101
F41H005/04 |
Claims
1. A ballistic protection, including at least one rigid structure
and at least one flexible structure, co-operating to dissipate
energy associated to an incident bullet impact, the at least one
rigid structure and the at least one flexible structure being
separated by at least one first discontinuity layer, the at least
one rigid structure including: at least one first rigid layer
comprising fibers; at least one second rigid layer comprising
fibers; and at least one third layer interposed between the at
least first and the at least second rigid layer; wherein the
material of the at least one third layer of the rigid structure is
selected so that the speed of propagation of a sound wave through
the at least one third layer of the rigid structure is less than
50% of the speed of propagation of a sound wave through the fibers
of the at least one first rigid layer.
2. The ballistic protection of claim 1, wherein the at least one
first rigid layer is a textile element which includes one or more
of the following: UHMW polyethylene, aramidic, copolyaramidic,
polybenzoossazole, polybenzothiazole, liquid crystal, rigid rod
fibers.
3. The ballistic protection of claim 2, wherein the at least one
second rigid layer is a textile element including one or more of
the following: UHMW polyethylene, aramidic, copolyaramidic,
polybenzoossazole, polybenzothiazole, liquid crystal, rigid rod,
glass, carbon fibers.
4. The ballistic protection of claim 3, wherein the at least one
first and at least one second textile elements comprise laminate
textile elements in form of: unidirectional, semi-unidirectional,
bi-axial, multiaxial, or warp and weft structures.
5. The ballistic protection of claim 4, wherein the laminate
textile elements are totally or partially impregnated by one or
more of the following: thermoplastic, thermosetting, elastomeric,
viscous or viscoelastic polymers.
6. The ballistic protection of claim 1 wherein the at least one
third layer of the rigid structure includes a first and a second
part, the first part being fixed to the at least one first rigid
layer and the second part being fixed to the at least one second
rigid layer, the first and the second parts being reversibly
detachable by means of separable fastening means.
7. The ballistic protection of claim 6, wherein the first and the
second parts are the two members of a Velcro fastening device,
wherein one of the two parts is a Velcro hooks member and the other
of the two parts is a Velcro loops member.
8. The ballistic protection of claim 2, wherein the at least one
third layer of the rigid structure includes material selected from
the group consisting of rigid or flexible plastomeric foams,
elastomeric foams, viscoelastic foams, paper, woven fabrics,
non-woven fabrics, felts, honeycomb structures, elastomeric
polymers, plastomeric polymers, viscous or viscoelastic polymers or
mixtures thereof and having a thickness between 0.05 mm and 15
mm.
9. The ballistic protection of claim 8, wherein the at least one
third layer of the rigid structure includes a metallic element,
also in form of metallic foam.
10. The ballistic protection of claim 8, wherein the at least one
third layer of the rigid structure is an element that covers only a
portion of a surface corresponding to a surface of the at least one
first rigid layer.
11. The ballistic protection of claim 10, wherein the at least one
third layer of the rigid structure has a shape substantially of a
frame having an empty space in the middle.
12. The ballistic protection of claim 8, wherein the at least one
flexible structure includes flexible antiballistic fabrics or
flexible antiballistic laminates totally or partially impregnated
by one or more of the following: thermoplastic, thermosetting,
elastomeric, viscous or viscoelastic polymers.
13. The ballistic protection of claim 8, including at least one
ceramic element also embedded in a polymeric structure and situated
outside and before the at least one rigid structure and the at
least one flexible structure with respect to the incident bullet
direction.
14. The ballistic protection of claim 13, further comprising a
discontinuity layer between the at least one ceramic element and
the at least one rigid structure.
15. A ballistic protective article, including the ballistic
protection according to claim 1.
16. The ballistic protection of claim 8, wherein the at least one
first discontinuity layer includes material selected from the group
consisting of rigid or flexible plastomeric foams, elastomeric
foams, viscoelastic foams, paper, woven fabrics, non-woven fabrics,
felts, honeycomb structures, elastomeric polymers, plastomeric
polymers, viscous or viscoelastic polymers or mixtures thereof and
having a thickness between 0.05 mm and 15 mm.
17. The ballistic protection of claim 10, wherein the at least one
third layer of the rigid structure has a shape substantially of a
frame having a space in the middle filled with material.
18. A ballistic protection rigid structure, comprising: a first
rigid textile element including one or more of the following: UHMW
polyethylene, aramidic, copolyaramidic, polybenzoossazole,
polybenzothiazole, liquid crystal, rigid rod fibers; a second rigid
textile element; and a third layer interposed between the first
rigid textile element and the second rigid textile element, wherein
the third layer includes elements made of a material selected from
the group of consisting of rigid or flexible plastomeric foams,
elastomeric foams, viscoelastic foams, paper, woven fabrics,
non-woven fabrics, felts, honeycomb structures, elastomeric
polymers, plastomeric polymers, viscous or viscoelastic polymers or
mixtures thereof; wherein the speed of propagation of a sound wave
through the third layer is less than 50% of the speed of
propagation of a sound wave through the first rigid textile
element.
19. The ballistic protection rigid structure of claim 18, wherein
the third layer has a thickness between 0.05 mm and 15 mm.
20. The ballistic protection rigid structure of claim 18, wherein
the second rigid textile element includes one or more of the
following: UHMW polyethylene, aramidic, copolyaramidic,
polybenzoossazole, polybenzothiazole, liquid crystal, rigid rod,
glass, carbon fibers.
Description
FIELD OF TECHNOLOGY
[0001] The present invention relates to a structure for making
ballistic protections, in particular a multi-layer structure
combining rigid and flexible elements.
BACKGROUND
[0002] Textile flexible structures are known to stop bullet fired
by a gun: they are mainly composed of high tenacity fibers arranged
in different styles as warp/weft fabric, unidirectional fabric,
multiaxial fabric etc.
[0003] These types of protections, also known as body armor, are
mainly used by Local Police Officers.
[0004] Textile flexible structures are not suitable to stop bullet
fired from rifle; in this case the protection can only be given by
hard plates.
[0005] It has been found that a defined combination of soft and
rigid textile structures is suitable to stop also bullets fired by
a rifle. Ceramic layer can be added to the combination if it is
needed to protect from very aggressive Armor Piercing bullets,
These bullets can be used only during war or battle field.
[0006] It is known that a good protection has to combine two
properties: the possibility of stopping the bullet and the
capability of reducing as much as possible the back face
deformation.
[0007] It is obvious that back face is a critical value when the
bullet proof structure protects a person.
[0008] High values of the back face deformation can induce necrosis
and even fatal injuries; more particularly, high values of back
face deformation do not allow the wearer to promptly react to the
attack due to the high shock absorbed by the human body.
[0009] Patent Application IT MI2009A001222 discloses a structure
comprising at least one first and one second textile rigid
elements, which are distinct and co-operate with each other to
dissipate the energy associated with an incident bullet impact.
[0010] The structure above, while providing a good general
protection, still needs some improvements in term of trauma
reduction.
OBJECTS OF THE DISCLOSURE
[0011] It is an object of the present disclosure to overcome at
least some of the problems associated with the prior art.
SUMMARY
[0012] The present disclosure provides a method and system as set
out in the following claims.
[0013] According to one aspect of the present disclosure there is
provided a ballistic protection, including a rigid structure and a
flexible structure, co-operating to dissipate energy associated to
an incident bullet impact, the rigid structure and the flexible
structure being separated by a at least a first discontinuity
layer, the rigid structure including: at least a first rigid layer;
at least a second rigid layer; and at least a third layer (105)
interposed between the first and the second rigid layer; wherein
the material of the first discontinuity layer (109) and of the
third layer of the rigid structure (105) are selected so that the
speed of propagation of a sound wave through the first
discontinuity layer (109) and the third layer of the rigid
structure (105) is less than 50% of the speed of propagation of a
sound wave through the fibers included in the first rigid
layer.
[0014] Advantageously, the rigid structure is placed on the side
facing the direction of the incident bullet.
[0015] In a preferred embodiment of the present invention the first
rigid layer is a textile element which includes one or more of the
following: UHMWPE (also in the form of strips), aramidic,
copolyaramidic, polybenzoossazole, polybenzothiazole, liquid
crystal, rigid rood fibers; while the second rigid layer is a
textile element including one of the following: UHMWPE (also in the
form of strips), aramidic, copolyaramidic, polybenzoossazole,
polybenzothiazole, liquid crystal, rigid rod, glass, carbon fibers
or a mixture thereof. The textile elements can be totally or
partially impregnated by one or more of the following:
thermoplastic, thermosetting, elastomeric, viscous or viscoelastic
polymers. The textile elements of the first and second rigid layers
are laminate elements.
[0016] According to possible embodiments of the present invention,
the fibers of said first and second textile elements can be either
parallel to the fiber of the second textile element or can be
oriented with an angle comprised 0.degree. and 90.degree.(e.g.
45.degree.). Combination of textiles layers based on yarn of
different mechanical characteristic gives particularly advantageous
results
[0017] The present invention allows to realize a ballistic
protection structure with higher stopping power with consistent
reduction of the back face deformation.
[0018] In another aspect of the present invention, the third
element of the rigid structure includes a first and a second part,
the first part being fixed to the first rigid layer and the second
part being fixed to the second rigid layer, the first and the
second parts being reversibly detachable by means of separable
fastening means. The first and the second parts can be for example
the two members of a Velcro fastening device, wherein one of the
two parts is a Velcro hooks member and the other of the two parts
is a Velcro loop member.
[0019] In a further aspect of the present invention, the third
element of the rigid structure and the first discontinuity layer,
are made of a material selected from the group consisting of:
metallic or plastic laminates, composites, rubber, felts,
plastomeric or elastomeric or thermosetting foams, metallic foams,
honeycomb structures, fiber based honeycomb or mixtures thereof,
having a thickness between 0.05 mm and 15 mm.
[0020] In an additional embodiment the third element of the rigid
structure does not cover the whole surface of corresponding to the
first rigid layer. As a particular case it has a shape
substantially of a frame, with an empty area in the middle, so that
the structure is particularly reinforced along the edges. In an
alternative embodiment, the empty area in the middle of the third
element can be filled with e.g. powders or alternatively with the
same material indicated for the discontinuity layers above.
[0021] The flexible structure can include flexible antiballistic
fabrics or flexible antiballistic laminates totally or partially
impregnated by one or more of the following: thermoplastic,
thermosetting, elastomeric, viscous or viscoelastic polymers
[0022] Moreover, the structure includes advantageously also one or
more ceramic elements situated at the front of said textile
elements. This ceramic element can be realized, for example, with
carbide oxides or nitrides (for example alumina, boron carbide,
silicon carbide, boron nitride and silicon nitride) based ceramics.
The ceramic element is advantageously embedded in a polymeric
structure that can include reinforcing fibers like carbon, aramid
or glass. A discontinuity layer can be placed between the ceramic
element and the rigid structure; alternatively the ceramic element
can be in direct contact with the rigid structure
[0023] Combination of the textile layers obtained with yarns having
different mechanical characteristics, in particular different
tensile strength, gives particularly advantageous results.
[0024] The present invention makes it possible to obtain a
ballistic protection element, which is particularly effective for
bullets fired from a gun as well as for bullets fired from a rifle.
In particular the ballistic protection realized with the structure
according to a particular embodiment of the present invention
provides increased protection along the borders which is where the
protection is normally weaker.
[0025] Furthermore, a protective element according to the invention
attains a trauma reduction without compromising the incident
bullets stop capability and, at the same time, allows the
protection weight and cost to be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] These and other advantages, objects and characteristics of
the present invention will be better understood by those skilled in
the art from the following description and from the enclosed
drawings, with reference to non-limiting typical embodiments of the
invention described by way of illustrative examples, and therefore
not to be considered limiting of its scope, in which:
[0027] FIG. 1 is a schematic, vertical section view of a structure
for making ballistic protections according to a possible embodiment
of the present invention;
[0028] FIG. 2 is a schematic exploded view of the structure of FIG.
1.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0029] Reduced to its essential form and with reference to the
figures of the enclosed drawings, a ballistic protection according
to the present invention includes a rigid structure (101, 103, 105)
and a flexible structure 107 which are separated by a discontinuity
layer 109. Advantageously, the rigid structure is placed in front
of the flexible structure, on the side facing the attack with
respect to the direction of the incident bullet.
[0030] The rigid structure includes at least three layers. A first
rigid layer 101 is a textile element adapted for of deforming an
incident bullet and adsorbing part of the energy associated to the
bullet impact: such first textile rigid layer preferably includes
polyethylene fibers, in particular UHMW polyethylene fibers, such
as fibers of the Dyneema.RTM. or Spectra.RTM. type. A second rigid
layer 103 that adsorbs at least part of the residual energy of the
deformed bullet is a textile element including one of the following
fibers: aramidic (e.g. Kevlar.RTM., Twaron.RTM., Heracon.RTM.),
copoly aramidic (e.g. Armos.RTM., Rusar.RTM., SVM.RTM.,
Artec.RTM.), UHMW polyethylene, liquid crystal (e.g. Vectran.RTM.),
rigid rod as M5, polybenzobisoxazole (e.g. Zylone.RTM.) or a
mixture thereof.
[0031] The two textile elements 101 and 103 according to the
present embodiment are not in direct contact with each other: a
third layer 105 is interposed between the two textile elements.
This discontinuity layer has the characteristics that its material
is selected so that the layer offers a higher resistance to the
propagation of a sound wave induced by the bullet, compared to the
resistance to the propagation of shock waves in the first and
second rigid layers.
[0032] The adsorption of energy by the first ballistic structure
which is impacted by the bullet is obtained in part by the breakage
of some fibers and in part by the plasto-elastic deformation of the
fibers included in the structure.
[0033] The speed of adsorption of the energy depends on the speed
of transmission in the fibers; such speed is the speed of
propagation of the sound wave in the fibers and can be calculated
with the following formula:
V= E/N.delta.
(speed V is the square root of the ratio between elastic modulus E
and fiber density .delta.)
[0034] The higher the speed of propagation of sound of the fiber,
the higher the length of fiber and the quantity of fibers which can
adsorb the energy in the time unit.
[0035] In other words, a fiber with a high speed of propagation of
sound is a better ballistic fiber.
[0036] The transfer of energy from the first to the adjacent
ballistic structures is realized by means of a shock wave. If we
interpose between a first and a second rigid element a third layer
which offers a higher resistance to the propagation of a sound wave
the ballistic properties of the whole structure are improved. In
particular the repeated combination of elements showing a high
speed of transmission of the sound wave with elements showing a
reduced speed of transmission of the sound wave significantly
increases the ballistic properties of the whole ballistic
structure.
[0037] The first rigid textile element 101 can be realized with
yarns having tensile strength higher than or equal to 10 g/den,
elongation higher than 1% and modulus higher than 40 GPa. Such
first rigid textile rigid element preferably includes polyethylene
fibers, in particular UHMW polyethylene fibers, such as fibers of
the Dyneema.RTM. or Spectra.RTM. type. The fibers are preferably
impregnated with elastomeric resins, e.g, Kraton.RTM. and then
laminated to realize a continuous sheet with unidirectional
structure, cross plied at 0.degree.)/90.degree..
[0038] Several layers of such structure are then superimposed, also
cross plied and pressed with a pressure between 20 and 250 Bar at a
temperature of about between 110.degree. and 135.degree.. The
resulting product is a monolithic element having a weight typically
comprised between 5 and 100 kg/m.sup.2. The element produced with
the process here described can be flat or shaped.
[0039] The second rigid textile element 103 can be obtained with
yarns having tensile strength higher than or equal to 10 g/den
elongation higher than 1% and modulus higher than 40 GPa. In a
preferred embodiment, the second rigid textile layer aramidic,
copolyaramidic, P.B.O., liquid crystal polymers, solid rod
polymers, glass, asbestos, carbon, polyvinilalcool, polypropylene,
UHMWPE and mixture thereof in form of yarn or tapes.
[0040] The structure of the second rigid textile element comprises
warp and weft, unidirectional, semi-unidirectional, biaxial,
multi-axial, tridimensional textile structures. These textiles
structures are generally impregnated at least partially for example
by one of the following: thermoplastic, thermosetting, elastomeric,
viscous or viscoelastic resin. Examples of these structures are
known as "Goldshield.RTM., Spectrashield.RTM., LFT210, Kevlar
XP.RTM..
[0041] In a preferred embodiment the sound of speed in fiber or
tapes of the second rigid element is at least 10% lower compared to
the sound speed of the fibers of the first rigid element.
[0042] The weight of the second rigid element is between 5% and 65%
when compared to the weight of first rigid element.
[0043] The fibers of the first rigid textile element 101 can be
either parallel to the fibers of the second rigid textile element
103, or oriented at an angle between 0.degree. and 90.degree. with
respect thereto (for example, at 45.degree.).
[0044] Between the first and the second rigid element (101 and 103)
a discontinuity layer 105 is provided. The discontinuity layer can
be made of many different materials and have many different shapes.
For example it can be a metal rigid layer (e.g. aluminum, titanium,
steel) or can be in form of composite like for example glass,
carbon, asbestos, impregnated with thermoplastic or thermosetting
resins, polymeric rigid material like nylon, polycarbonate, rigid
or soft foams, felts, fabrics woven not woven, honey combs,
rubber.
[0045] To reach the purpose of the present invention the third
layer of the rigid structure is selected so that the layer offers a
higher resistance to the propagation of the shockwave. The speed of
sound in this third element must be less than 50% compared to the
speed of sound through the fibers of the first and second rigid
structure.
[0046] The thickness of such layer is comprised between 0.05 mm and
15 m.
[0047] In one preferred embodiment the thickness is comprised
between 1 mm and 6 mm.
[0048] In an alternative embodiment the layer 105 covers only a
portion of the surface of the two rigid elements (101, 103) where
the surface not covered by the layer 105 is at least 5%. In a
preferred embodiment the layer 105 has substantially the shape of a
frame as shown in FIG. 2. In this way the protection along the
edges is increased. This solves one of the drawbacks of the prior
art ballistic protections. Next to the edges the protection against
bullets provided by ballistic protections is normally lower. The
particular shape of the third layer according to an embodiment of
the present invention gives a substantial contribution in
increasing the ballistic performances along the edges, without
excessively increasing the total weight of the protection. The area
in the middle can be left empty (i.e. filled with air) or
alternatively the space could be filled with several materials,
e.g. powders, expanded glass balls, corrugated sheets, foams and
any other already described for the first discontinuity layer 109
and the third layer of the rigid structure 105.
[0049] According to an embodiment of the present invention, the
third layer is made of two parts each one attached to one of the
first and second rigid element. The two parts are arranged to
engage one each other in order to be reversibly
fastened/unfastened. As an example they can be the two members of a
Velcro.RTM. fastening device one being the Velcro.RTM. hooks
member, the other being the Velcro.RTM. loops member. The two parts
hooks and loops can cover only a portion of the surface of the
rigid structure as explained above.
[0050] The flexible structure 107 in a preferred embodiment of the
present invention is represented by unidirectional,
semi-unidirectional biaxial, multiaxial or woven fabrics also in
blend thereof structures. These structures can be not impregnated,
partially impregnated, totally impregnated or stitched
together.
[0051] The impregnation is realized with: thermoplastic,
thermosetting, elastomeric, viscous or viscoelastic polymers or
mixture thereof.
[0052] The count of the fibers is comprised between 50 and 10.000
denier preferably between 290 and 3300 den.
[0053] Advantageously, the mechanical characteristics of the fibers
of the flexible structure 107 are the following: tensile strength
higher than or equal to 20 g/den, elongation greater than 1%, a
modulus higher than 50 GPa
[0054] The discontinuity layer 109 paced between the rigid
structure (101, 103 and 105) and the flexible structure 107 is made
of a material having the same characteristics as the third layer of
the rigid structure 105 described above.
[0055] In a alternative embodiment, requiring an increased
protection against perforation from armour-piercing bullets, in
particular bullets of penetrating type (e.g. 7.62.times.51AP), one
or more ceramic or glass-ceramic elements 111 can be associated to
the above described structure (not shown in FIG. 2).
[0056] Said ceramic elements 111, which can be realized, for
example, from carbide oxides or nitrides based ceramics, can be
monolithic or made of juxtaposed ceramic sub-elements. In a
preferred embodiment of the present invention the at least one
ceramic element is embedded in a polymeric structure.
[0057] Such ceramic elements can be in direct contacts with the
first rigid structure or separated by a discontinuity layer (not
shown neither in FIG. 1 nor in FIG. 2) similar to that already
described for the first discontinuity layer 109 and the third layer
of the rigid structure 105.
[0058] The ceramic element is generally protected by an additional
structure in order to avoid as much as possible fragmentation of
the element being the ceramic very hard but also very fragile.
[0059] The protection is composed of a fabric embedded in rigid
matrices for example a composite layer. The fabric comprises for
example carbon, glass, asbestos, aramidic. This technology is well
known to the person skilled on the art.
[0060] Further combinations are possible depending on the desired
combination of back face deformation and stopping power.
[0061] E.g. in the illustrated examples of the present invention
reference has be made to a rigid structure including two textile
elements (101, 103) and a discontinuity layer (105) between the two
textile elements.
[0062] However it is possible to include plurality of "packages"
composed by two textile elements (101, 103) and the discontinuity
layer 105 and an additional separating layer with the same
characteristics described above for the discontinuity layer
105.
[0063] In any case it is possible to include more than one flexible
structure 107 or additional discontinuity layers 109.
[0064] In practice, in any case, the realization details can vary
in a corresponding way as for single constructive elements
described and illustrated and as for the indicated materials nature
without departing the adopted solution concept and consequently,
remaining within the scope of the present invention.
[0065] It will be appreciated that alterations and modifications
may be made to the above without departing from the scope of the
disclosure. Naturally, in order to satisfy specific requirements, a
person skilled in the art may apply to the solution described above
many modifications and alterations. Particularly, although the
present disclosure has been described with a certain degree of
accuracy with reference to preferred embodiment(s) thereof, it
should be understood that possible omissions, substitutions and
changes the form and details as well as other embodiments are
possible; moreover, it is expressly intended that specific elements
and/or method steps described in connection with any disclosed
embodiment of the disclosure may be incorporated in any other
embodiment as a general matter of design choice.
[0066] For example, similar considerations apply if the components
have different structure or include equivalent units.
* * * * *