Vacuum insulated panels with concave surfaces on the surface layers

An insulating panel and shapes each having an outer, continuous membrane, an internal rigid frame, and an enclosed vacuum space. The outer continuous membrane is made up of a top membrane and a bottom membrane each having a plurality of biaxially curved, concave surface which are loaded in tension when the top or bottom membranes are exposed to ambient atmospheric pressure. Between each biaxially curved, concave surface is an arcuate path through which differential tension loadings on the adjacent biaxially curved, concave surfaces are offset, thereby reducing the structure requirements on the internal rigid frame. A second embodiment has an expansion joint means, the top or bottom membrane which enable the panel to maintain the tension stress loadings on the top and bottom surfaces when thermal contraction or expansion occurs in the top or bottom membranes, a corner shape, an inside corner shape, and a container embodiment are also disclosed herein.

TECHNICAL FIELD 
The present invention relates to insulating panels or other shapes. More 
particularly, this invention relates to vacuum insulating panels or shapes 
used for preserving perishable materials and other goods at optimal 
storage temperatures. 
BACKGROUND ART 
Perishable, temperature-sensitive materials and goods must be stored and 
preserved at optimal storage temperatures. Depending upon the type of 
perishable materials or goods being preserved, the optimal storage 
temperature required inside the storage container may be relatively high 
or low compared to the ambient temperature outside the container. In many 
instances, the materials or goods must be preserved or stored inside the 
container for several days during which time the optimal storage 
temperature must be maintained. 
Conventional insulating containers use foam or other types of insulating 
materials placed between the outer walls of the container and the inside 
insulated space. The amount of heat that is transferred through these 
materials is proportional to the material's thermal conductivity, the 
length of time for exposure, the thickness of the material, and the 
temperature gradient between the material's inside and outer surface. 
Since these materials have relatively moderate thermal conductivity 
properties, the thickness of the material must be increased in order to 
reduce the amount of heat transfer. In the shipping industry, for example, 
where shipping space is often limited, the use of thick, bulky insulating 
material is usually undesirable. 
Therefore, insulating panels or shapes that can efficiently maintain 
optimal storage temperatures for extended time periods and which are 
compact and occupy minimal space are highly desireable. In addition, 
insulating panels or shapes which can be used either separately or placed 
inside a rigid, conventional container are also highly desirable. 
In the insulation field, it is known that a container having a vacuum space 
between its outer and inner surface, can act as an excellent insulator. In 
order to support the enclosed vacuum space, however, the container must 
have a strong rigid structure to support the large pressure loads that 
exist on the container's outer and inner surfaces. In the past, 
cylindrical-shaped containers having an internal vacuum insulating space 
have been used for preserving liquid materials and other goods. These 
containers, typically, have relatively large, outer rigid structures. 
McAllister, (U.S. Pat. No. 4,446,934) discloses a large, self-containing, 
vacuum insulating shipping container having inner and outer wall sections 
with membranes enclosing two structural support frames. The membranes of 
the outer wall section curve inwardly and the membranes of the inner wall 
section curve outwardly with the pressure loads imparted on each set of 
membranes being transmitted into their respective structural support 
frame. The structural support frames are separated by supports. 
Anderson, (U.S. Pat. No. 3,370,740) discloses a double wall, thermal 
insulating evacuated panel having an internal support structure which 
resists collapse of the walls caused by external ambient forces. The 
support structure comprises a series of post-like supports extending 
perpendicular from the inner surface of the walls with tension cables 
extending over the ends of the supports. 
Dinsmore, et al., (U.S. Pat. No. 2,633,264,) discloses a double wall 
thermos unit having an outer and an inner shell with an evacuated space 
created between the shells with no apparent internal support structure. 
The evacuated space may contain dead air space or be evacuated or filled 
with insulating material. 
Schultz, (U.S. Pat. No. 1,337, 278) discloses a vacuum container having 
generally a cylindrical shape with outer and inner walls formed of wood or 
some other rigid material, a vacuum space located between the walls, and 
supporting strips. 
None of these patents disclose a vacuum insulating panel or shape that has 
the features or methods disclosed herein. 
DISCLOSURE OF THE INVENTION 
The invention disclosed herein will be described in the context of the 
shipping or transporting industries. As will be appreciated by those 
skilled in the art, this invention will likely have application in other 
types of industries where insulating devices are used. 
It is a general object of the invention to provide a vacuum insulating 
panel or shape that can be used for shipping or transporting perishable, 
temperature-sensitive materials and other goods at optimal storage 
temperatures. 
It is a general object of the invention to provide a vacuum insulating 
panel that occupies minimal space. 
It is another general object of the invention to provide a vacuum 
insulating panel or shape that can be used either separately or used 
inside a rigid container. 
It is an object of the invention described below to provide a vacuum 
insulating panel having planar top and bottom membrane surfaces and a 
lightweight, rigid frame that provides adequate support to the panel's top 
and bottom membrane surfaces. 
It is a further object of the invention to provide a vacuum insulating 
panel having top and bottom membrane surfaces that can mutually offset 
their respective pressure loadings and thereby minimize the amount of 
structural support needed. 
It is a further object of the invention to provide a vacuum insulating 
panel that can be modified to accommodate different stress loadings and 
temperatures on the panel's top and bottom membrane surfaces. 
It is a still further object of the invention to provide a vacuum 
insulating panel that can be easily modified and used with other like 
vacuum insulating panels to manufacture various corner and container 
insulating shapes having a continuous, enclosed vacuum space and outside 
and inside membrane surfaces which can offset differential pressure 
loadings. 
These and other objects of the invention, which will become apparent, are 
accomplished by the apparatus and methods described herein. 
This invention comprises vacuum insulating shapes that can efficiently 
maintain optimal storage temperatures for preserving perishable, 
temperature-sensitive materials and other goods. In a preferred 
embodiment, the shape is a flat panel having an outer continuous membrane 
which encloses an internal rigid frame and a vacuum space. The continuous 
membrane has a plurality of preformed biaxially curved, concave surfaces 
and arcuate paths between adjacent biaxially curved, concave surfaces 
which can effectively offset differential atmospheric loads presented on 
the panel's adjacent or opposite surfaces. The use of a plurality of 
biaxially curved, concave surfaces on the panel's outer, continuous 
membrane and its ability to offset differential pressure loadings 
significantly reduces the structural requirements on the internal rigid 
frame. Therefore, the rigid frame used to support the outer continuous 
membrane is relatively small compared to the rigid frame structures used 
in conventional vacuum insulated containers. 
In a preferred embodiment, the panel has substantially planar top and 
bottom surfaces, front and rear surfaces, and right and left end surfaces. 
Each surface of the panel is covered with an outer continuous membrane 
made of thin, durable material, such as aluminum, having a uniform 
thickness. In construction, the continuous membrane comprises top and 
bottom membrane sections which are sealed together at their peripheral 
edges along a seam located on the panel's side and end surfaces. A low 
conductive polymer adhesive material, such as a fluoro-carbon film sold by 
E.I. Dupont de Nemours & Co. or silicon sealant material is used between 
the edges to properly seal and attach them together. 
Enclosed within each panel is an internal, continuous vacuum space and a 
lightweight, rigid, relatively small cross-sectional frame made of low 
conductive material, such as fiberglass or an equivalent composite 
material. The rigid frame comprises two identical frame sections, a top 
frame section which supports the top membrane section and a bottom frame 
section which supports the bottom membrane section. Each top and bottom 
frame section is made of parallel rows of beams and cross-members which 
intersect perpendicularly forming a top and bottom planar grid surface, 
respectively. The outer surface of each beam and cross-member is smooth 
and round enabling the adjacent membrane surface to move freely. Support 
columns are formed at the intersection of the beam and cross-member on 
each grid surface and extend centrally into the panel. 
During assembly of the rigid frame structure, the top and bottom grid 
surfaces are oriented parallel to each other, and the ends of the support 
columns are aligned and joined together at a column joint. A thermal break 
having relatively low conductivity properties and a minimal contact 
surface, such as a bead made of glass or some other suitable material, may 
be placed inside the column joint between the adjoining support columns 
ends to reduce conductive heat loss. A planar thermal barrier, made of 
multiple layers of reflective coated polyester film, may be placed 
centrally inside the panel substantially parallel to the panel's top and 
bottom surfaces to further reduce radiation and convection thermal 
transfer through the panel. 
A plurality of preformed, equal size and shape, biaxially curved, concave 
surfaces are manufactured on the outer continuous membrane. The continuous 
membrane encloses the internal rigid frame so that each panel surface has 
a plurality of biaxially curved, concave surfaces. The round, outer 
surfaces of the individual beam and cross-members that make up each grid 
surface are manufactured to match the shape of the inside surface of the 
membrane located between each biaxially curved, concave surface. 
During use, the outside surface of the continuous membrane is exposed to 
ambient atmospheric pressure which loads each individual biaxially curved, 
concave surface in tension. Adjacent biaxially curved, concave surfaces 
are joined together over the round supported surface, known as an arcuate 
path, which distributes the tension stresses on the adjacent biaxially 
curved, concave surfaces equally and oppositely. By using a plurality of 
biaxially curved, concave surfaces joined together over arcuate paths, the 
differential pressure loadings on the panel's membrane on opposite sides 
of the panel are offset which reduces the structural demands placed on the 
panel's rigid frame. The rigid frame, therefore, enclosed in each panel is 
relatively small in cross-section compared to the rigid frames used with 
known vacuum insulated panels. This, in turn, enables the construction of 
an vacuum insulated panel, disclosed herein, having a smaller 
cross-sectional dimension than conventional vacuum insulated panels. 
During construction of the preferred embodiment, the size and shape of each 
biaxially curved, concave surface may be varied. The dimensions of the 
beams and crossmembers of the rigid frame and the curvature of the 
biaxially curved, concave surfaces may be adjusted to utilize different 
materials and different structural loadings. 
A second panel embodiment and three insulating shape embodiments are also 
disclosed having an outer continuous membrane surface and an enclosed 
vacuum space. In the second panel embodiment, the panel has an expansion 
joint means manufactured along one panel surface. The expansion joint 
means comprises an expansion joint arcuate path positioned along the 
surface which enables the panel to maintain the tensile loadings on the 
top and bottom membranes when dimensional changes occur in the top and 
bottom membrane due to thermal contraction or expansion. 
In a corner shape embodiment, a first panel, having a structure similar to 
the first panel embodiment described above, is attached to a second panel. 
The corner shape has a outer, continuous membrane and enclosed vacuum 
space. A corner joint means is used between the panels which provides a 
continuous arcuate path between the two adjoining panel surfaces which 
enable the surface tensile loadings on the adjoining surfaces to be 
offset. In addition, the corner joint means enables the tensile stress 
loadings on each adjoining surface to be maintained when dimensional 
changes occur on each panel's top and bottom membranes due to thermal 
contraction or expansion. 
In still another shape embodiment, the corner shape embodiment described 
above is attached to a third panel to make an inside corner shape having a 
continuous outer membrane surface and an enclosed, continuous vacuum 
space. The third panel is attached to the corner shape embodiment using a 
third corner joint means and a female joint member which interconnects the 
three adjacent corner joint means at the inside corner vertex. Each corner 
joint means provides an arcuate path between two adjoining panel bottom 
surfaces which enables the tensile stress loadings on two bottom surfaces 
to be maintained and offset. Since each bottom surface is joined to an 
adjacent bottom surface, the tensile stress loading on each surface of the 
corner shape is offset. The three corner joint means also enable the 
tensile loadings on the top and bottom membranes on each adjoining panel 
to be maintained when dimensional changes are made on the top or bottom 
membranes due to thermal contraction or expansion. 
In yet another embodiment, a vacuum insulating container shape is disclosed 
having a outer, continuous membrane and an enclosed vacuum space. The 
container shape has four vertical sides surfaces and a horizontal bottom 
surface, each further comprising one or more panel embodiments. Inside 
corner shapes are used at each inside corner site to offset the tensile 
stress loadings on adjacent surfaces. 
Other features of the present invention will become apparent from the 
following detailed description.

BEST MODE FOR CARRYING OUT THE INVENTION 
Referring specifically to the drawings wherein like numerals indicate like 
parts, there is seen in FIGS. 1-7, a rectangular-shaped, vacuum insulating 
panel 15 used for preserving perishable, temperature-sensitive materials 
and other goods. Panel 15 may be manufactured in various widths and 
lengths and in other shapes, and panel 15 may be used for other purposes 
as will be apparent to those skilled in the art. 
As shown generally in FIG. 1, panel 15 has a plurality of biaxially curved, 
concave surfaces 30 located on each planar surface. The biaxially curved, 
concave surfaces 30 may be manufactured with different dimensions and with 
different axial and longitudinal curvatures. The biaxially curved, concave 
surfaces 30, is joined with an adjacent biaxially curved, concave surface 
over an arcuate path 99. Using a plurality of biaxially curved, concave 
surfaces 30 joined together over arcuate paths 99 on each planar surface, 
enables panel 15 to evenly distribute the total pressure loading on each 
planar surface among the biaxially curved, concave surfaces located on 
each panel surface. In addition, panel 15 is able to offset equally and 
oppositely differential pressure loadings on adjacent and opposite planar 
surfaces. 
As shown in FIGS. 1-4, panel 15 has a plurality of substantially planar 
surfaces, numbered and named for reference purposes as top surface 16, a 
bottom surface 17, a right side surface 18, a left side surface 19, a 
front surface 20, and a rear surface 21. In a preferred embodiment, panel 
15 measures approximately 8 inches.times.26 inches.times.38 inches (H x W 
x L). Top and bottom surfaces 16 and 17 each have twelve equal size and 
shape biaxially curved, concave surfaces 30, respectively, each measuring 
approximately 5 inches.times.11 inches (W x L) with an approximate 0.67 
inch curvature deflection. Right and left surfaces 18 and 19 each have 
three equal size and shape biaxially curved, concave surfaces 30, each 
measuring approximately 5 inches.times.11 inches (W x L) with an 
approximate 0.67 inch curvature deflection. Front and rear surfaces 20 and 
21 each have four equal size and shape biaxially curved, concave surfaces 
30, respectively, each measuring 5 inch.times.5 inch (L x W) with an 
approximate 0.67 inch curvature deflection. On each panel surface 16-21, 
the radii of arcuate paths 99 are approximately 1 inch. 
As shown in FIGS. 1-4, panel 15 has an outer continuous membrane 22 
comprising a top membrane section 23 and a bottom membrane 26 section both 
made of strong, durable material, such as aluminum or some other suitable 
material, having a uniform thickness between 0.020 and 0.100 inches. In 
FIG. 4, top membrane 23 and bottom membrane 26 are joined together by 
overlapping their peripheral edges 24 and 27, respectively, and forming a 
continuous, air-tight seam 29 located on right and left side surfaces 18 
and 19 and front and rear surfaces 20 and 21. As seen more clearly in FIG. 
7, a sealant 31, such as a fluorocarbon film, manufactured by E.I Dupont 
de Nemours & Co., or some other suitable sealant material, such as 
silicon, is placed between the overlapping peripheral edges 24 and 27 to 
attach and seal the edges 24 and 27 together. 
As seen in FIGS. 2-4, outer continuous membrane 22 encloses a lightweight, 
rigid frame 33 and a continuous vacuum space 32. Rigid frame 33, is made 
of fiberglass or an equivalent composite material and comprises two 
identical top and bottom frame sections, 34 and 35, respectively. Top 
frame section 34 supports the top membrane 23 and comprises parallel rows 
of beams 36 and cross-members 38 which intersect perpendicularly and form 
a top grid surface 25. Bottom frame section 35 supports the bottom 
membrane 26 and comprises parallel rows of beams 37 and cross-members 39 
which intersect perpendicularly and form a bottom grid surface 28. The 
inner longitudinal surface 36(b) and 37(b) of beams 36 and 37, 
respectively, and the inner longitudinal surface 38(b) and 39(b) of 
cross-members 38 and 39, respectively, are concave outwardly to reduce 
weight. 
When assembling panel 15, opposite biaxially curved, concave surfaces 30 
are positioned between the individual beams and cross-members on the 
supporting top and bottom grid surfaces 25 and 28. Opposite biaxially 
curved, concave surfaces on the right and left side surfaces, 18 and 19 
and front and rear surfaces, 20 and 21, are positioned between the top and 
bottom frame sections, 34 and 35. 
Also as seen in FIGS. 2-4, rigid frame 33 has a plurality of support 
columns 40 and 41 integrally attached to the inside surface of the top and 
bottom frame sections 34 and 35, respectively. Each support column 40 or 
41, as shown in greater detail in FIG. 5, extends centrally into the panel 
15 substantially perpendicular to the top and bottom grid surfaces, 25 and 
28, respectively, from each intersection site of a beam and cross-member. 
Each column 40 and 41 comprises a cylindrical shank 40(a) and 41(a) and an 
end surface 40(b) and 41(b), respectively. During assembly of the rigid 
frame, the top and bottom grid surfaces 25 and 28 are oriented parallel to 
each other. The support columns 40 and 41 are positioned opposite to each 
other, aligned, and then joined together at their ends 40(b) and 41(b) at 
column joint 43. A hollow cylindrical column guide 45 is placed around 
each joint 43 to align and attach the adjoining column ends together. 
FIGS. 5 and 7 show a thermal break and a thermal barrier used inside the 
panel 15 to reduce heat loss. A thermal break having relatively low 
thermal conductive properties and minimal contact surface, such as a bead 
46 made of glass or some other suitable material, is placed between the 
adjoining ends 40(b), 41(b) to reduce thermal conduction through the panel 
15. A continuous, planar thermal barrier 48, made of multiple layers of 
reflective coated polyester film, is placed centrally inside the panel 
substantially parallel to and equal distance from the panel's top and 
bottom surface 16 and 17, respectively, to reduce radiation and convection 
thermal transfer through panel 15. A plurality of holes 49 having 
sufficient diameters are manufactured in the thermal barrier 48 to enable 
support columns 40 and 41 to be joined together. 
During use, ambient atmospheric pressures are presented on adjacent or 
opposite panel surfaces and the biaxially curved, concave surfaces located 
on each surface are loaded primarily in tension. The arcuate paths 99 
between contiguous biaxially curved, concave surfaces transmit the tension 
stresses found on each biaxially curved, concave surface 30 equally and 
oppositely to an adjacent biaxially curved, concave surface. In this 
manner, the tension stresses found on the biaxially curved, concave 
surfaces 30 located on the top membranes 23 are offset equally and 
oppositely with the biaxially curved, concave surfaces located on the 
bottom membrane 26. By sharing the tensile loads of the biaxially curved, 
concave surfaces through arcuate paths, the tensile loads are offset 
resulting in a reduction of the total structural demand on the rigid 
frame. The remaining forces are small and essentially compressive and are 
easy handle by the beams, cross-members, columns of the rigid frame. 
The ability of adjacent biaxially curved, concave surfaces to mutually 
offset their respective tension loadings is shown in FIG. 6 where two 
adjacent biaxially curved, concave surfaces 30 and 30' are supported by 
beam 36 and are exposed to atmospheric pressure A(1) and loaded in tension 
T(1), T(1)', respectively Concave surfaces 30 and 30' are joined together 
over an arcuate path 99 through which their respective tension stress 
loadings, T(1) and T(1)' are offset. The outer contact surface 36(a) of 
beam 36 and cross-member (not shown) is smooth and round and matches the 
shape of the inside surface of arcuate path 99. The section of membrane 
adjacent to arcuate path 99 is freely supported by a beam 36 or 
cross-member (not shown) and therefore, able to move and adjust to minor 
differential tensile loadings. 
FIG. 7 is a partial side view, in section, of front surface 20 and top and 
bottom surface 16 and 17 showing how the tensile stress on opposite panel 
surfaces are transferred to an adjacent surface and offset. The biaxially 
curved, concave surfaces 30 located on the top surface 16 and bottom 
surface 17, are exposed to atmospheric pressures A(1), A(2)' which loads 
each biaxially curved, concave surface essentially in tension T(1) and 
T(2)', respectively. The biaxially curved, concave surface 30 is located 
on front surface 20 with arcuate paths 99 and 99' disposed between the 
biaxially curved, concave surfaces located on top surface 16 and bottom 
surface 17. During use, tensile forces T(1) and T(2) are transferred over 
arcuate paths 99 and 99', respectively, and into the biaxially curved, 
concave surface 30 located on front surface 20, where they are offset. 
The actual tension developed on each biaxially curved, concave surface 30 
is a function of its external dimensions and its axial and longitudinal 
curvatures. By selecting the appropriate curvatures, the external 
dimensions of each biaxially curved, concave surface 30 may be changed 
without changing the biaxially curved, concave surface's tensile loading. 
The overall dimensions and shape of the panel 15 may also be varied by 
adjusting the size of the individual biaxially curved, concave surfaces, 
the number of biaxially curved, concave surfaces on each panel surface, 
the dimensions of the beams and cross-members of the top and bottom frame 
sections, and the radius cf the arcuate paths. 
In another embodiment, panel 15 may be manufactured with an expansion joint 
means 50 manufactured either longitudinally (shown) or transversely across 
one surface. FIGS. 8 and 9 show expansion joint means 50 extending 
longitudinally across bottom surface 17. The purpose of expansion joint 
means 50 is to provide a continuous expansion joint arcuate path 51 on a 
surface of the panel 15 which will maintain the tensile forces on adjacent 
biaxially curved, concave surfaces when dimensional changes are made in 
the top 16 or bottom 17 membranes due to thermal contraction or expansion. 
As shown in FIG. 9, in construction, expansion joint means 50 comprises an 
elongated cylinder body 52, an expansion joint inner membrane 54, two 
expansion joint rigid frame members 55a, 55b, and two expansion joint end 
membranes 56. An expansion joint gap 53 is created between rigid frame 
members 55a and 55b. Cylinder body 52, made of aluminum or some other 
suitable material, has a sufficient length to extend across the bottom 
surface 17. The expansion joint inner membrane 54 and expansion joint end 
membrane 56 are made of the same material used to make the continuous 
membrane 22. 
The expansion joint end membrane 56, shown more clearly in FIG. 10, has a 
central cylindrical portion 56(a) which, during assembly of the expansion 
joint means 50, engages one end of cylindrical body 52 and two adjacent, 
substantially flat, perpendicular sections 56(b) and 56(c) which, during 
assembly, are attached and sealed to end surfaces, 20 and 21. End 
membranes 56 are attached and sealed to panel 15 a similar manner as top 
membrane 23 and bottom membrane 26 are attached and sealed. 
During manufacture of the expansion joint means 50, a plurality of short 
cross members 57 are located in top frame section 34 between beams 36 and 
36' and opposite rigid frame members 55a and 55b. Section 22' of top 
membrane 22 located opposite rigid frame members 55a and 55b may be flat 
or manufactured with a plurality of smaller biaxially curved, concave 
surfaces A cylinder body 52 is disposed through the cylindrical portion 
56(a) of each end membrane 56 and placed inside the central portion of 
expansion joint means 50. Bottom membrane section 26 terminates at ends 
26a and 26b on opposite sides of expansion joint 50. Each edge 26a and 26b 
is looped around an adjacent rigid member 55a or 55b and attached and 
sealed to one edge of expansion joint inner membrane 54. The central 
portion of the expansion joint inner membrane 54 is then positioned inside 
the panel 15 and placed around cylinder body 52 compressing it against 
rigid members 55a and 55b. 
When top surface 16 and bottom surface 17 are exposed to different ambient 
temperatures, thermal contraction and expansion in the top membrane 23 and 
bottom membrane 26, respectively, may occur which changes the tensile 
forces on the biaxially curved, concave surfaces located on top membrane 
23 and bottom membrane 26. Expansion joint means 50 provides an arcuate 
path 51 through which the resultant tensile forces on biaxially curved, 
concave surfaces located on each side of expansion joint means 50 may be 
maintained. When, for example, the bottom membrane 26 is exposed to a 
lower temperature than top membrane 23, the dimension of the bottom 
membrane 26 will be reduced due to thermal contraction causing the 
expansion joint inner membrane 54 to compress against the cylindrical body 
52. This, in turn, forces cylindrical body 52 against rigid frame members 
55a and 55b causing expansion joint gap 53 to widen. The widening of gap 
53 enables cylinder body 52 to move towards bottom surface 17 which 
reduces the length of arcuate path 51. By adjusting the length of the 
arcuate path 51 in this manner, the tensile loadings on adjacent biaxially 
curved concave surfaces located on each side of expansion joint means 50 
may be maintained when the top and bottom surfaces are exposed to 
different temperatures. 
In another embodiment, shown in FIG. 11, a first and second panel 15 and 
15' are joined together using a corner shape means 61 to manufacture a 
corner shape 60 having a outer continuous membrane 22 and a continuous 
vacuum space 32. Corner joint means 61 functions similar to expansion 
joint means 50 by providing a continuous arcuate path 63 between bottom 
surfaces 17 and 17' located on said first and second panels 15 and 15', 
respectively. 
Corner joint means 61 comprises an elongated cylinder body 62, a corner 
joint membrane 65, and two corner joint end membranes 66. FIG. 12 shows 
corner end membrane 66 having a central cylindrical portion 66a, two 
substantially flat perpendicular bottom membrane portions 66(b) and 66(c), 
and a substantially flat outer round end membrane portion 66(d). Corner 
joint membrane 65 and the corner joint end membranes 66 are made of the 
same material as continuous membrane 22. 
During manufacture of the corner shape 60, top frame sections 34 and 34' 
are joined together perpendicularly at outer rigid member 67 located 
opposite to corner joint means 61. Continuous outside membrane 22 
comprising top membrane section 23 and a bottom membrane section 26 each 
having a plurality of biaxially curved, concave surfaces encloses first 
and second panels 15 and 15' and corner joint means 61. A plurality of 
smaller biaxially curved, concave surfaces 69 and 69' are manufactured on 
the two sections of continuous membrane 22 adjacent to outer rigid member 
67 and along top membrane surfaces 23 and 23'. Cylindrical body 62 is 
placed longitudinally across corner joint means 61 inside vacuum space 32 
and adjacent to inner corner joint rigid members 68 and 68'. Each end of 
cylindrical body 62 engages the central cylindrical portion 66a located on 
corner end membranes 66. 
The bottom membranes 26 and 26' located on panels 15 and 15', respectively, 
terminate at edges 26a and 26a', respectively. Edges 26a and 26b are 
looped around inner corner joint rigid member 64 and 64'. Corner joint 
inner membrane 65 has two peripheral edges 65(a) and 65(b) each being 
attached and sealed to edges 26a and 26a' of membranes 26 and 26', 
respectively. The central portion 65a of corner joint inner membrane 65 is 
positioned inside vacuum space 32 and between inner corner joint rigid 
members 68 and 68' and looped around elongated cylinder body 62. Corner 
joint end membranes 66 are attached and sealed to the end surfaces 20 and 
21 to maintain the continuous vacuum 68. 
When exposed to atmospheric pressure, corner joint means 61 operates in the 
same manner as expansion joint means 51 by providing an arcuate path 63 
between adjacent bottom surfaces 17 and 17' located on first and second 
panels 15 and 15'. When thermal expansion or contraction occurs on top 
membranes 16 and 16 or bottom membranes 17, 17', the length of arcuate 
path 63 is increased or decreased which narrows or widens corner joint gap 
69. In this manner, the tensile stress loadings on the adjacent bottom 
membranes 26 and 26' are maintained. 
In another embodiment, shown in FIGS. 13 and 14, a third panel 15" is 
attached to corner shape 60 forming an inside corner shape 70 having an 
outer continuous membrane 22 and a continuous vacuum space (not shown). 
Bottom membranes 26, 26', and 26", of panels 15, 15', and 15", 
respectively, are joined to an adjacent bottom membrane 26, 26', and 26" 
by a corner joint means 61, 61', and 61". A female corner joint connector 
71 is used at the vertex of the inside corner shape 70 to axially align 
and interconnect the corner joint means 61, 61' and 61". Corner joint 
means 61 is used between adjoining panels 15 and 15", corner joint means 
61' is used between adjoining panels 15' and 15", and corner joint means 
61" is used between adjoining panel 15" and 15' which all provide arcuate 
paths between the adjoining surfaces. adjoining bottom surfaces 26, 26' 
and 26". 
As shown in FIG. 14, the top frame sections 34, 34', and 34" are joined 
together to make an internal rigid frame structure. A female joint member 
72 made of similar material as the continuous membrane 22 is positioned at 
the vertex of the adjoining bottom frame sections 35, 35' and 35". Female 
joint member 72, has three cylindrical body guides, 74, 75, and 76 which 
are oriented along the longitudinal axis of each corner joint means 61, 
61', and 61", and three membrane surfaces 77, 78, and 79 which attach to 
the bottom membranes (only bottom membrane 26' shown) and corner joint 
inner membranes (only corner joint inner membrane 65 shown). 
As described above with corner joint 60, the bottom membrane 26, 26' and 
26" of each panel 15, 15' and 15", respectively, are attached to the inner 
membranes of corner joints 60, 60' and 60". A cylindrical body 52 is then 
placed into each corner joint and interconnected with a cylindrical body 
guide located on the female joint member 72. Each corner joint end 
membrane 66 is then attached and sealed to each open end surface of each 
corner joint to maintain the continuous vacuum space as described with 
corner shape 60. In this manner, the tensile stress on adjacent biaxially 
curved, concave surfaces located on the three adjoining bottom membranes 
are maintained. 
A container embodiment 80 of the invention is shown in FIG. 15 having a 
bottom surface 81, two end surfaces 82 and 83, and two side surfaces 84 
and 85. Each surface 81-85 further comprises at least one panel 15, joined 
together using a corner joints means 61 and female joint members 71. 
Expansion joint means 50 may be manufactured along the sides of the 
container 80 for thermal contraction and expansion of the outer continuous 
membrane 90. 
Outer continuous membrane 90 which forms an outer container membrane 
surface 91 and an inner container membrane surface 92. Each outer and 
inner container surface 91 and 92 has a plurality of biaxially curved, 
concave surfaces 30 which are loaded in tension when exposed to ambient 
atmospheric pressure. Between each biaxially curved concave surface 30 on 
each surface 91 and 92 are arcuate paths 99 through which differential 
tension stress loadings on adjacent biaxially curved, concave surfaces may 
be offset. Enclosed by outer continuous membrane 90 is an internal rigid 
frame 89 which supports the each outer and inner container surface 91 and 
92. A continuous vacuum space 87 is enclosed within container 80. 
In compliance with the statute, the invention has been described in 
language more or less specific as to structural features. It is to be 
understood, however, that the invention is not limited to the specific 
features shown since the means of construction herein disclosed describes 
a preferred form of putting the invention into practice. The invention is 
therefore claimed in any of its forms or modifications within the 
legitimate and valid scope of the appended claims properly interpreted in 
accordance with the doctrine of equivalents. 
INDUSTRIAL APPLICABILITY 
Vacuum insulating panels and shapes will find wide spread use in the those 
industries where preserving perishable, temperature-sensitive materials 
and other goods is desired. The vacuum insulating panels and shapes 
disclosed herein will be especially useful in the those industries, such 
as the shipping or cargo industries, to name a few, where perishable, 
temperature-sensitive materials and other goods must be keep efficiently 
at optimal temperatures for sustained time periods.