The present invention relates to the field of insulating panels. More particularly, it relates to a rigid insulating panel configured to provide high structural integrity and a flexible interlock joint between adjacent panels joined to one another. It also relates to a rigid insulating panel assembly including a plurality of adjacent interconnected insulating panels.
Rigid insulating panels are known in the art for insulating a building structure by creating an insulated barrier to provide a maximum efficiency of heating, ventilating, and air conditioning (HVAC) systems. In order to cover a surface of a building structure, a plurality of insulating panels are usually provided in an edge to edge adjacent configuration, to form an insulating panel assembly, where the panels are juxtaposed at the edges and form a large flat surface. For example and without being limitative, the edge of the rigid insulating panels can be flat, with a shiplap or with a non-interlocking groove to allow the juxtaposition thereof.
Rigid insulating panels commonly found on the market, and manufactured to be used in such insulating panel assembly, however, normally tend to be improperly adapted for use on specific surfaces. For example, when the panels are used on uneven surfaces, the connectors for connecting adjacent panels and/or the core of the panels often break, or spread open, thereby resulting in a breach in the isolation, which is undesirable. For example, such a problem occurs frequently when the insulating panels are used over gravel, crushed stone, or the like, under a concrete floor.
In view of the above, there is a need for improved rigid insulating panels, and insulating panel assemblies which, would be able to overcome or at least minimize some of the above-discussed prior art concerns.
According to a first general aspect, there is provided a rigid insulating panel. The rigid insulating panel comprises an insulating material core with an R-value of at least 2.5 (hr·ft2·° F.)/BTU·in. The insulating material core has opposed first and second surfaces, a pair of spaced-apart longitudinal edges, and a pair of spaced-apart lateral edges extending between the pair of longitudinal edges. At least one of the pair of longitudinal edges and the pair of lateral edges comprises connecting members including a tongue and groove assembly including an inner groove and an outer tongue separated by a substantially S-shaped median wall. The tongue and groove assembly is engageable with the tongue and groove assembly of an adjacent insulating panel to provide a flexible interconnection therebetween. The rigid insulating panel also comprises at least one polymeric-based membrane covering one of the first surface and the second surface of the insulating material core.
In an embodiment, the S-shaped median wall comprises an inflection point positioned at a median of the insulating material core of the rigid insulating panel, between the first and the second surfaces.
In an embodiment, the S-shaped median wall defines consecutive convex and concave sections in the inner groove and the outer tongue with the inflection point being located at the junction of the convex and concave sections.
In an embodiment, the tongue and groove assembly has a length and the insulating material core has a thickness between the first and the second surfaces and the length of the tongue and groove assembly is at maximum ⅓ of the thickness of the insulating material core.
In an embodiment, the outer tongue and the inner groove extend substantially perpendicular to the first surface and the second surface of the insulating material core.
In an embodiment, the at least one polymeric-based membrane comprises a first polymeric-based membrane covering the first surface of the insulating material core and a second polymeric-based membrane covering the second surface of the insulating material core.
In an embodiment, at least one of the at least one polymeric-based membrane is a micro-perforated polymeric-based membrane.
In an embodiment, the at least one polymeric-based membrane is free of continuous discontinuity between a first one of the edges and a second one of the edges, opposed to the first one of the edges.
In an embodiment, the insulating material core is formed of one of shaped expanded polystyrene, extruded polystyrene, polyurethane, polyisocyanurate and phenolic foam.
In an embodiment, a thickness of the rigid insulating panel is between about 0.75 inch and about 6 inches.
In an embodiment, the insulating material core has a compressive strength of between about 8 psi and about 40 psi.
According to another general aspect, there is also provided a rigid insulating panel assembly. The rigid insulating panel assembly comprises at least two rigid insulating panels and each one of the rigid insulating panels comprises an insulating material core having a first surface, an opposed second surface, a pair of spaced-apart longitudinal edges and a pair of spaced-apart lateral edges extending between the pair of longitudinal edges, and at least two connecting members at a respective one of the longitudinal edges and the lateral edges. Each one of the connecting members comprises a median wall separating an inner groove and an outer tongue together defining a tongue and groove assembly. The median wall has an inflection point positioned at a median of the insulating material core. The rigid insulating panel assembly also comprises at least one polymeric-based membrane covering one of the first surface and the second surface of the insulating material core. Adjacent ones of the connecting members of the at least two rigid insulating panels are engageable together with the inflection points allowing flexible interlock between the adjacent ones of the at least two rigid insulating panels.
In an embodiment, the median wall is S-shaped and defines consecutive convex and concave sections in the inner groove and the outer tongue with the inflection point being located at the junction of the convex and concave sections.
In an embodiment, the tongue and groove assembly has a length and the insulating material core has a thickness between the first surface and the second surface and the length of the tongue and groove assembly is at maximum ⅓ of the thickness of the insulating material core.
In an embodiment, the outer tongue and the inner groove extend substantially perpendicular to the first surface and the second surface of the insulating material core.
In an embodiment, the at least one polymeric-based membrane comprises a first polymeric-based membrane covering the first surface of the insulating material core and a second polymeric-based membrane covering the second surface of the insulating material core.
In an embodiment, at least one of the at least one polymeric-based membrane is a micro-perforated polymeric-based membrane.
In an embodiment, the at least one polymeric-based membrane is free of continuous discontinuity between a first one of the edges and a second one of the edges, opposed to the first one of the edges.
In an embodiment, an R-value of the insulating material core of the rigid insulating panel is at least 2.5 (hr·ft2·° F.)/BTU·in.
In an embodiment, the insulating material core is formed of one of shaped expanded polystyrene, extruded polystyrene, polyurethane, polyisocyanurate and phenolic foam.
In an embodiment, a thickness of the at least two rigid insulating panels is between about 0.75 inch and about 6 inches.
In an embodiment, the insulating material core of the at least two rigid insulating panels has a compressive strength of between about 8 psi and about 40 psi.
According to another general aspect there is also provided an assembly method for insulating a concrete surface of a building using a rigid insulating panel assembly as described above. The method comprises the steps of engaging connecting members of the at least two rigid insulating panels substantially perpendicularly to the first surface and the second surfaces of the insulating material core of the at least two rigid insulating panels; and pouring concrete alongside the rigid insulating panel assembly to form the concrete surface of the building.
In an embodiment, the step of pouring concrete alongside the insulating panel assembly to form the concrete surface of the building includes pouring concrete over the insulating panel assembly.
Other objects, advantages and features will become more apparent upon reading the following non-restrictive description of embodiments thereof, given for the purpose of exemplification only, with reference to the accompanying drawings in which:
In the following description, the same numerical references refer to similar elements. The embodiments, geometrical configurations, materials mentioned and/or dimensions shown in the figures or described in the present description are embodiments only, given solely for exemplification purposes.
Moreover, although the embodiments of the rigid insulating panel and corresponding parts thereof consist of certain geometrical configurations as explained and illustrated herein, not all of these components and geometries are essential and thus should not be taken in their restrictive sense. It is to be understood, as also apparent to a person skilled in the art, that other suitable components and cooperation thereinbetween, as well as other suitable geometrical configurations, can be used for the rigid insulating panel, as will be briefly explained herein and as can be easily inferred herefrom by a person skilled in the art. Moreover, it will be appreciated that positional descriptions such as “above”, “below”, “upper”, “lower”, “top”, “bottom”, “left”, “right” and the like should, unless otherwise indicated, be taken in the context of the figures and should not be considered limiting.
Referring generally to
In an embodiment, the insulating material core 11 of the rigid insulating panel 10 has an R-value (a measure of thermal resistance commonly used in the building and construction industry) of at least 2.5 (hr·ft2·° F.)/BTU·in. More precisely, in an embodiment, the insulating material core 11 of the rigid insulating panel 10 has an R-value ranging between 2.5 and 30 (hr·ft2·° F.)/BTU·in. In an embodiment the rigid insulating panel has a thickness of at least about 0.75 inch. More precisely, in an embodiment, the rigid insulating panel has a thickness ranging between about 0.75 inch and 6 inches. In an embodiment, the insulating material core 11 has a density between about 0.8 lb/ft3 and about 2.3 lb/ft3. Moreover, in an embodiment, the insulating material core 11 has a compressive strength between about 8 psi and about 40 psi. More precisely, in an embodiment, the insulating material core 11 has a compressive strength between about 15 psi and about 30 psi.
In the embodiment shown in
The first connecting member 40 includes a first groove 42 and a first tongue 44. The first groove 42 and the first tongue 44 are successive to form a tongue and groove assembly (or male and female member assembly). Similarly, the second connecting member 46 includes a second groove 48 and a second tongue 50, the third connecting member 41 includes a third groove 43 and a third tongue 45 and the fourth connecting member 47 includes a fourth groove 49 and a fourth tongue 51. Each one of the second groove 48 and second tongue 50, the third groove 43 and third tongue 45 and the fourth groove 49 and fourth tongue 51 are also respectively successive to form tongue and groove assemblies.
One skilled in the art will understand that, in an alternative embodiment, the insulating material core 11 can be provided with connecting members along only one, two or three of the longitudinal edges 20, 22 and the lateral edges 24, 26. More particularly, in one embodiment, the insulating material core 11 can be provided with connecting members only along the first longitudinal edge 20 and the second longitudinal edge 22 or along the first lateral edge 24 and the second lateral edge 26. Moreover, in an embodiment, one of the first longitudinal edge 20 and the second longitudinal edge 22 or the first lateral edge 24 and the second lateral edge 26 which does not include connecting members as described above, can rather include complementary abutment lips (not shown).
In an embodiment and as better shown in
In an embodiment, each one of the grooves 42, 43, 48, 49 and the tongues 44, 45, 50, 51 extend substantially perpendicularly to the first surface 30 and the second surface 32 of the rigid insulating panel 10, i.e. the grooves 42, 43, 48, 49 are elongated recesses extending either from the first surface 30 or from the second surface 32 respectively while the tongues 44, 45, 49, 51 are elongated protrusions also extending upwardly from the second surface 32 or the first surface 30 respectively.
The term “substantially perpendicularly” is used herein to indicate that the grooves 42, 43, 48, 49 and the tongues 44, 45, 50, 51 are generally perpendicular to the first and second surfaces 30, 32 of the insulating material core 11, but do not need to be perfectly perpendicular with them. In other words, interlock of two adjacent rigid insulating panels 10 occurs by displacing at least one of the adjacent panels in a direction substantially perpendicular to its first and second surfaces 30, 32 rather than by displacing the adjacent panels laterally towards one another, i.e. along an axis substantially parallel to their first and second surfaces 30, 32.
In the embodiment shown, the first tongue and groove assembly of the first connecting member 40, located along the first longitudinal edge 20, extends downwardly with respect to the first surface 30 of the rigid insulating panel 10, i.e. the first groove 42 is open on the second surface 32. To be engageable with the first tongue and groove assembly of an adjacent one of the rigid insulating panels 10, the second tongue and groove assembly of the second connecting member 46, located along the second longitudinal edge 22 extends upwardly with respect to the first surface 30 of the rigid insulating panel 10, i.e. the groove 48 is open on the first surface 30. Similarly, to be engageable together when adjacent rigid insulating panels 10 are interlocked, the third and fourth tongue and groove assemblies extend in opposed directions. In the embodiment shown, the third tongue and groove assembly of the third connecting member 41, located along the first lateral edge 24, extends downwardly with respect to the first surface 30 of the rigid insulating panel 10. On the opposite, the fourth tongue and groove assembly of the fourth connecting member 47, located along the second lateral edge 26 extends upwardly with respect to the first surface 30 of the rigid insulating panel 10. Thus, the third and fourth grooves 43 and 49 are respectively open on the second surface 32 and the first surface 30.
Thus, when interconnected with an adjacent rigid insulating panel 10, as shown in
In the embodiment shown, the connecting members 40, 41, 46, 47 are configured to provide a flexible interconnection between the engageable ones of the connecting members 40, 41, 46, 47 of adjacent rigid insulating panels 10. Therefore, when adjacent rigid insulating panels 10 are interconnected, a limited arcing movement can occur therebetween, along an arcing axis substantially parallel to the edge 20, 22, 24, 26 including the connecting members 40, 41, 46, 47. In the course of the present description, the term “arcing” is used to refer to a combined movement of flexion of the rigid insulating panels 10 and pivoting of the connecting members 40, 41, 46, 47. One skilled in the art would understand that, arcing can also be understood to refer to only flexion of the rigid insulating panels 10, for example and without being limitative, when a section of one of the connecting members 40, 41, 46, 47 is broken and pivoting no longer occurs. The limited arcing movement of the adjacent rigid insulating panels 10 is allowed either upwardly (wherein the first surfaces 30 are arced towards one another) or downwardly (wherein the second surfaces 32 are arced towards one another). The limited arcing movement of the adjacent rigid insulating panels 10 can occur without breaking the engagement between the rigid insulating panels 10 and without resulting in a breakage of the connecting members 40, 41, 46, 47. In an embodiment, the flexible interconnection between the connecting members 40, 41, 46, 47 results from a combination of the shape of the connecting members 40, 41, 46, 47, and the resiliency of the material thereof.
In an embodiment, the limited arcing movement can reach about 11°. Referring to
In an embodiment and as better shown in
Now referring to
In order to provide the flexible interconnection between the corresponding ones of the connecting members 40, 41, 46 and 47 of adjacent rigid insulating panels 10, each one of the S-shaped median wall 52 of the connecting members 40, 41, 46 and 47 has an inflection point 53. The inflection point 53 is positioned at a median of the insulating material core 11 of the rigid insulating panel 10, i.e. midway between the first surface 30 and the second surface 32 of the insulating material core 11 of the rigid insulating panel 10. The inflection point 53 also corresponds to a point of inflection in the curvature of the median wall 52 and separates the convex section 44a and the concave section 44b of the tongue 44.
The convex section 44a of the tongue 44 is defined by a protuberance at a distal section of the tongue 44, i.e. a section of the tongue 44 distal from the first surface 30 of the insulating material core 11 from which the tongue 44 extends. The concave section 44b of the tongue 44 is defined by a cavity at a proximal section thereof, i.e. a section of the tongue 44 proximal to the first surface 30 of the insulating material core 11 from which the tongue 44 extends. Thus, the tongue 44 is thicker in its distal section than in its proximal section. One skilled in the art will understand that, for the second connecting member 46 and the fourth connecting member 47, where the tongue extends from the second surface 32 of the insulating material core 11, the distal section and the proximal section are defined with regards to the second surface 32 rather than the first surface.
Still referring to
Referring to
One skilled in the art will understand that even though one configuration of the first connecting member 40, the second connecting member 46, the third connecting member 41 and the fourth connecting member 47 is shown in the illustrated embodiment, in an alternative embodiment, the connecting members 40, 41, 46, 47 can present different size, shape, and configuration which also allow a sturdy flexible interconnection therebetween, with the above described inflection point 53 positioned midway between the first surface 30 and the second surface 32 of the rigid insulating panel 10. For example and without being limitative, in an embodiment (not shown), the connecting members 40, 41, 46, 47 can extend discontinuously along the edges 20, 22, 24, 26.
Now referring back to
In an embodiment, the membrane 70 is a film continuously bounded, for example and without being limitative using a thermal roller to perform thermal transfer and/or hot melt glue, to fuse the film with the rigid or semi rigid insulating material core 11, at the at least one of the first surface 30 and the second surface 32, of the insulating material core 11. Such continuous bounding results in a load transfer between the core 11 and the membrane 70 when the rigid insulating panel 10 is under stress, thereby increasing the overall mechanical properties of the rigid insulating panel 10. One skilled in the art will understand that, in alternative embodiments, other bounding techniques and/or methods, such as, and without being limitative, lamination, can be used to continuously join the membrane 70 to the rigid or semi rigid insulating material core 11, at the at least one of the first surface 30 and the second surface 32 thereof.
For example and without being limitative, the membrane 70 may be a polymeric-based membrane, such as a film made of polyester, polyolefin, polypropylene, polyethylene, nylon, foil, polyvinyl chloride, bioplastic or a liquid applied plastic coating, a fiber-based film, such as natural fiber, with a polymeric binder, a polymeric mesh film, or the like. In an embodiment, the membrane is a plastic membrane.
In an embodiment, the thickness of the membrane 70 is negligible in comparison with the thickness “T” of the insulating material core 11.
Still referring to
It will be understood that, in an embodiment, membranes 70 with different properties can also be provided over different sections or surfaces of the rigid insulating panel 10. For example and without being limitative, in an embodiment (not shown), the membrane 70 covering the first surface can be unperforated while the membrane covering the second surface 32 (for instance, the lower surface when the panel is applied horizontally) of the rigid insulating panel 10 can be micro-perforated, or vice-versa. Tests have shown that the use of a micro-perforated membrane 70 to cover the second surface 32 of the rigid insulating panel 10 results in a diminution of the noise when a fracture of the micro-perforated membrane occurs, as well as favoring the flow of liquid and/or vapor therethrough. Moreover, the micro-perforated membrane 70 helps guiding fracture lines, which result from fractures of the micro-perforated membrane and/or the rigid or semi rigid insulating material core 11, longitudinally along the micro-perforations of the membrane.
In an embodiment, a sole membrane 70 covers either the first or the second surfaces 30, 32 of the insulating material core 11. In an embodiment, the membrane covering either the first or the second surfaces 30, 32 of the insulating material core 11 is free of continuous discontinuities, i.e. discontinuities extending from one of the edges 20, 22, 24, 26 to an opposed one of the edges 20, 22, 24, 26.
The rigid insulating panels 10 including the above membrane 70 results in rigid insulating panels 10 with increased flexibility and resistance to rupture thereof. Moreover, the rigid insulating panels 10 including the combination of the above-described membrane 70 and the above-described connecting members 40, 41, 46, 47 results in the insulating panel assembly 80 of adjacent interlocked rigid insulating panels 10 that also has increased flexibility and resistance to rupture.
The results of tests conducted using rigid insulating panels 10 with a rigid insulating material core made of EPS of 1.25 inch thick, a length of about 12 inches and a width of about 3 inches are presented in Table 1 and Table 2 below. Compressive strengths of respectively 16 psi, 20 psi, and 30 psi were used and the tests were conducted according to methods of the standard test method ASTM C-203, using the assemblies shown respectively in
Table 1 below shows results of tests directed to the maximum arcing movement corresponding to the angle “θ” in
Table 2 below shows results of tests directed to a maximum fiber stress (labelled “Max fiber stress” in Table 2), i.e. a maximum force which can be applied on a panel before a rupture of the insulating material core 11 occurs. For each one of the compressive strengths (16 psi, 20 psi, 30 psi), four samples were tested for each of three different membrane configurations: without membrane (labeled “no” in Table 2), with a perforated membrane on the first surface 30 and an unperforated membrane on the second surface 32 (labelled “Upper perforated” in Table 2), and with an unperforated membrane on the first surface 30 and a perforated membrane on the second surface 32 (labelled “Lower perforated” in Table 2). The samples were tested according to method I of the standard test method ASTM C-203, using the assembly shown in
The rigid insulating panel 10 and the rigid insulating panel assembly 80 formed of such adjacent interlocked rigid insulating panels 10 having been described above, an assembly method for forming an insulating barrier for a surface, such as a concrete surface, using the above described rigid insulating panels 10 will now be described. In an embodiment, the surface is a concrete surface of a building, such as, for example and without being limitative, a concrete slab, foundation or wall.
In such a method, at least two rigid insulating panels 10 such as the one described above are provided. The rigid insulating panels 10 are engageable with one another through substantially complementary connecting members 40, 41, 46 or 47, and have a membrane 70 configured to maintain the integrity of the rigid insulating panel 10 in the occurrence of a breakage. In order to form the insulating panel assembly 80, the connecting members 40, 41, 46 or 47 of adjacent rigid insulating panels 10 are engaged with one another to interlock the adjacent rigid insulating panels 10. The engagement is performed by pressing the corresponding connecting members 40, 41, 46 or 47 together substantially perpendicularly to the first surface 30 of the rigid insulating panels 10, for the connecting members 40, 41, 46 or 47 to interlock. Such an engagement results in a flexible interconnection therebetween, as described above.
Concrete can be poured alongside the rigid insulating panel assembly before or after the above-described engagement of the rigid insulating panels 10. In the course of the present application, the term “alongside” is used to describe that the concrete can be poured next to the first surface 30 or the second surface 32 of the rigid insulating panels 10 of the rigid insulating panel assembly, which can be positioned substantially horizontally or vertically. For example and without being limitative, concrete can be poured over (i.e. on top of) the rigid insulating panel assembly positioned substantially horizontally.
In an alternative embodiment, concrete can be poured to form a concrete slab and the rigid insulating panel assembly can be subsequently assembled and rested substantially horizontally over the concrete slab. Moreover, in another alternative embodiment, the rigid insulating panel assembly can be used for insulating foundation wall by pouring the concrete to form foundation walls with the rigid insulating panel assembly being positioned substantially vertically internally or externally therefrom.
One skilled in the art will understand that, therefore, the rigid insulating panel assembly can be used over or under a concrete slab, to provide insulation internally and/or externally of foundation walls, or the like. In an alternative embodiment, the rigid insulating panel assembly can also be used to provide insulation, internally or externally, to walls extending above the ground.
Several alternative embodiments and examples have been described and illustrated herein. The embodiments of the invention described above are intended to be exemplary only. A person skilled in the art would appreciate the features of the individual embodiments, and the possible combinations and variations of the components. A person skilled in the art would further appreciate that any of the embodiments could be provided in any combination with the other embodiments disclosed herein. It is understood that the invention can be embodied in other specific forms without departing from the central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein. Accordingly, while the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the scope of the invention as defined in the appended claims.
This application claims priority under 35USC§ 119(e) of U.S. provisional patent application 61/898,669 filed on Nov. 1, 2013, the specification of which is hereby incorporated by reference.
Number | Name | Date | Kind |
---|---|---|---|
1823039 | Gruner | Sep 1931 | A |
4052831 | Roberts et al. | Oct 1977 | A |
4122203 | Stahl | Oct 1978 | A |
4437287 | Halfaker | Mar 1984 | A |
4530877 | Hadley | Jul 1985 | A |
5133654 | Sheen | Jul 1992 | A |
5220760 | Dimakis | Jun 1993 | A |
5345738 | Dimakis | Sep 1994 | A |
5636489 | Leverrier et al. | Jun 1997 | A |
6018918 | Long, Sr. | Feb 2000 | A |
6263574 | Lubker et al. | Jul 2001 | B1 |
6276104 | Long et al. | Aug 2001 | B1 |
6523324 | Porter | Feb 2003 | B1 |
6599621 | Porter | Jul 2003 | B2 |
6766622 | Thiers | Jul 2004 | B1 |
7168217 | Weber | Jan 2007 | B2 |
7617651 | Grafenauer | Nov 2009 | B2 |
7874118 | Schitter | Jan 2011 | B2 |
7914914 | Tinianov | Mar 2011 | B2 |
7918062 | Chen | Apr 2011 | B2 |
8082717 | Dammers | Dec 2011 | B2 |
20050159057 | Hauber et al. | Jul 2005 | A1 |
20060019568 | Toas et al. | Jan 2006 | A1 |
20060123723 | Weir et al. | Jun 2006 | A1 |
20080016802 | Rheaume | Jan 2008 | A1 |
20080168728 | Scherrer | Jul 2008 | A1 |
20080241440 | Bauer | Oct 2008 | A1 |
20080245007 | McDonald | Oct 2008 | A1 |
20080295450 | Yogev | Dec 2008 | A1 |
20090313935 | Montgomery | Dec 2009 | A1 |
20100101457 | Surace et al. | Apr 2010 | A1 |
20110047908 | Brusman et al. | Mar 2011 | A1 |
20110047912 | Armijo | Mar 2011 | A1 |
20110064901 | Blackburn et al. | Mar 2011 | A1 |
20110197530 | Bahnmiller | Aug 2011 | A1 |
20110214372 | Mullet et al. | Sep 2011 | A1 |
20110258959 | Braun | Oct 2011 | A1 |
20110266088 | Koike et al. | Nov 2011 | A1 |
20120073217 | Wilson et al. | Mar 2012 | A1 |
20120073228 | Fork et al. | Mar 2012 | A1 |
20120180416 | Perra et al. | Jul 2012 | A1 |
20130247502 | Zhang | Sep 2013 | A1 |
20150047282 | Ford | Feb 2015 | A1 |
Number | Date | Country |
---|---|---|
2866109 | Sep 2012 | CA |
10206835 | Sep 2003 | DE |
102010018452 | Oct 2011 | DE |
202011106980 | Nov 2011 | DE |
202011106980 | Nov 2011 | DE |
46256 | Feb 1982 | EP |
0085196 | Aug 1983 | EP |
2585747 | Feb 1987 | FR |
1516552 | Jul 1978 | GB |
2238329 | May 1991 | GB |
885489 | Nov 1981 | SU |
2012001399 | Jan 2012 | WO |
Number | Date | Country | |
---|---|---|---|
20150121799 A1 | May 2015 | US |
Number | Date | Country | |
---|---|---|---|
61898669 | Nov 2013 | US |