U.S. patent number 3,699,576 [Application Number 05/052,890] was granted by the patent office on 1972-10-17 for collapsible reflector.
This patent grant is currently assigned to Fairchild Industries, Inc.. Invention is credited to Sigurd Hoyer.
United States Patent |
3,699,576 |
Hoyer |
October 17, 1972 |
COLLAPSIBLE REFLECTOR
Abstract
A collapsible dished paraboloid reflector having an array of
petals that surround and have petals that are rotatably connected
at their inner ends to a reflector hub. The array of petals
comprises a series of substantially spear tip shaped or lanceolate
shaped petals that alternate between semi-hour glass shaped petals.
Substantially wedge shaped petals are located between and have
lateral edges that are rotatably connected in edge to edge
relationship to each lanceolate shaped petal and semi-hour glass
shaped petal. The edges of the petals when viewed from the focal
point of the fully deployed reflector substantially approximates
the parabolic radial curvature of the fully deployed reflector. The
lanceolate shaped petals and the semi-hour glass shaped petals are
of rigid construction lengthwise so that they are not capable of
flexing in a lengthwise direction whereas the wedge shaped petals
are of relatively flexible construction lengthwise so that they are
capable of flexing lengthwise as the reflector assembly is being
deployed or collapsed. The construction of the collapsible
reflector permits it to be collapsed into a compact package and
permits the reflector to be deployed to present a dished rigid
paraboloid shaped surface.
Inventors: |
Hoyer; Sigurd (Rockville,
MD) |
Assignee: |
Fairchild Industries, Inc.
(N/A)
|
Family
ID: |
21980579 |
Appl.
No.: |
05/052,890 |
Filed: |
July 7, 1970 |
Current U.S.
Class: |
342/10;
343/915 |
Current CPC
Class: |
H01Q
15/16 (20130101); H01Q 15/162 (20130101) |
Current International
Class: |
H01Q
15/16 (20060101); H01Q 15/14 (20060101); H01q
015/16 () |
Field of
Search: |
;343/18B,915 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Tubbesing; T. H.
Claims
What is claimed is:
1. A collapsible and deployable reflector comprising:
a reflector hub;
a plurality of petals surrounding said reflector hub and being
adapted to present a dished substantially symetrical reflective
surface upon deployment of said reflector, said petals having
lateral edges that have a curvature when viewed from the focus of
the deployed reflector that substantially approximates the radial
curvature of the surface of the petals of the fully deployed
reflector;
interconnecting means connected to the lateral adjacent edges of
said petals for pivotally connecting said petals together in edge
to edge relationship; and
means connected to said hub and at least some of said petals for
pivotally connecting said petals to said hub.
2. The collapsible and deployable reflector of claim 1 wherein said
plurality of petals comprise petals being of substantially rigid
lengthwise construction and petals being of comparatively flexible
lengthwise construction alternately located between said lengthwise
rigid petals.
3. The collapsible and deployable reflector of claim 2 wherein said
lengthwise rigid petals comprise substantially lanceolate shaped
petals alternating with semi-hour glass shaped petals.
4. The collapsible and deployable reflector of claim 2 including
reinforcing means connected to the back of each of said lengthwise
rigid petals for reinforcing said rigid petals.
5. The collapsible and deployable reflector of claim 4 wherein said
reinforcing means comprises a truss member.
6. The collapsible and deployable reflector of claim 1 including
means operatively connected to at least some of said petals for
collapsing and deploying said petals.
7. The collapsible and deployable reflector of claim 6 wherein said
collapsing and deploying means comprises a hydraulic activating
unit.
8. The collapsible and deployable reflector of claim 1 wherein said
petals are adapted to present a paraboloid and the radial curvature
of the surface of the petals of the fully deployed reflector is
substantially parabolic.
9. The collapsible and deployable reflector of claim 1 wherein said
petals have an electromagnetically reflective wire mesh
surface.
10. The collapsible and deployable reflector of claim 1 wherein
said interconnecting means comprises hinge members.
Description
BACKGROUND OF THE INVENTION
Collapsible reflectors have many uses. Collapsible reflectors are
generally small in size in their collapsed state compared to their
size when fully deployed. This ability to be collapsed into a small
size allows collapsible reflectors to be employed in many
situations where the use of corresponding rigid reflectors would be
impossible. Collapsible reflectors have been used in situations
where it was necessary to transport the reflector in a small
container such as the type that are required to transport and place
a reflector in space. Collapsible reflectors can also be used with
or without containers on trucks, trailers, and other vehicles and
they can also be used on watercraft.
Although there are many uses for collapsible reflectors and there
have been numerous prior designs, most prior art reflectors have
several disadvantages that limit their use. Many prior art
reflectors, particularly those for use in space, lack sufficient
rigidity to be capable of being folded back up once they have been
fully deployed. Another serious disadvantage that many previous
reflector designs possess is a lack of rigidity in the deployed
state. This lack of rigidity has in part been due to a
comparatively low percentage of fixed or rigid structure in the
reflector. This low percentage of rigid structure was required in
prior designs to permit collapsing of the reflector. This lack of
rigidity can result in distortions of the shape of the reflector
when it is deployed which could result in a loss in the performance
and reliability of the reflectors. This lack of rigidity has more
serious consequences in the case of large reflectors that are
designed for use in space. With collapsible reflectors that are to
be used in space, it is highly desirable from the standpoint of
economy and reliability to test the performance of the reflector in
its deployed condition prior to sending it into space.
Unfortunately, previous large surface reflectors designed to retain
their geometric configuration in the zero gravity environment of
space will not retain their shape when subjected to gravitational
forces on earth. This has previously prevented proper performance
and reliability testing of large collapsible reflectors prior to
placing them in space.
SUMMARY OF THE INVENTION
This invention relates to collapsible reflectors and more
particularly to a collapsible reflector that has a rigid dished
reflective surface when it is fully deployed.
It is accordingly an object of the present invention to provide a
collapsible reflector that is capable of presenting a dished
reflective surface that possesses a high degree of rigidity and
resists distortion when the reflector is fully deployed.
It is an object of the present invention to provide a collapsible
reflector that is capable of being collapsed into a compact
package.
It is an object of the present invention to provide a collapsible
reflector that is easy to collapse and deploy.
It is also an object of the present invention to provide a
collapsible reflector that is capable of presenting a large
reflective surface when the collapsible reflector is fully
deployed.
The present invention provides a collapsible and deployable
reflector having a plurality of petals surrounding a hub. The
petals are adapted to present a dished substantially symmetrical
reflective surface upon deployment of the reflector and they have
lateral edges that have a curvature when viewed from the focus of
the deployed reflector that substantially approximates the radial
curvature of the surface of the petals of the fully deployed
reflector. Interconnecting means are provided that are connected to
the lateral adjacent edges of the petals for pivotally connecting
the petals together in edge to edge relationship and means are
connected to the hub and at least some of the petals for pivotally
connecting the petals to the hub.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be hereinafter more fully described with
reference to the accompanying drawings in which:
FIG. 1 is a perspective view of the collapsible reflector of this
invention in the fully deployed state;
FIG. 2 is a perspective view of the collapsible reflector
illustrated in FIG. 1 illustrating the reflector as the reflector
is undergoing deployment or is in the process of being
collapsed;
FIG. 3 is a perspective view of the collapsible reflector
illustrated in FIGS. 1 and 2 when the reflector is in the fully
collapsed state;
FIG. 4 is a plan view of part of the fully deployed collapsible
reflector illustrated in FIG. 1;
FIG. 5 is a cross sectional view of part of the fully deployed
collapsible reflector taken on the line 5--5 of FIG. 4;
FIG. 6 is a view of a portion of the structure illustrated in FIG.
5 showing the edge of the reflector;
FIG. 7 is an enlarged view of part of the deployable reflector
illustrated in FIG. 4 with certain parts broken away to illustrate
the interior construction of the reflector;
FIG. 8 is a sectional view of a lanceolate shaped petal taken on
the line 8--8 of FIG. 7;
FIG. 9 is a sectional view of a lanceolate shaped petal taken on
the line 9--9 of FIG. 7;
FIG. 10 is a sectional view of a wedge shaped petal taken on the
line 10--10 of FIG. 7;
FIG. 11 is a sectional view of a wedge shaped petal taken on the
line 11--11 of FIG. 7;
FIG. 12 is a sectional view of a semi-hour glass shaped petal taken
on the line 12--12 of FIG. 7;
FIG. 13 is a sectional view of a semi-hour glass shaped petal taken
on the line 13--13 in FIG. 7;
FIG. 14 is an enlarged view of part of the collapsible reflector
illustrated in FIG. 2;
FIG. 15 is a sectional view taken on the line 15--15 of FIG. 14;
and
FIG. 16 is a perspective view of the interconnecting means that can
be utilized with the collapsible reflector of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1 the collapsible reflector 10 of the
invention is illustrated in its fully open or deployed
configuration. The reflector 10 comprises an array or plurality of
substantially spear tiped shaped or lanceolate shaped petals 11
that come to a point at each end that are located around and are
pivotally mounted on a centrally located hub 12 by means of
mounting struts 13 that are rigidly connected to the outer
periphery of the hub and whose outer ends are pinned to the inner
ends of the lanceolate shaped petals so that the lanceolate shaped
petals are free to rotate in an upward direction about the pins as
will be described hereinafter in greater detail. The reflector 10
also comprises an array or plurality of semi-hour glass shaped
petals 14 that are located alternately between the lanceolate
shaped petals 11 and are located around and pivotally mounted on
the centrally located hub 12 by means of the mounting struts 13
that are rigidly connected to the outer periphery of the hub and
whose outer ends are pinned to the inner ends of the hour glass
shaped petals in a manner similar to that for the lanceolate shaped
petals. The reflector assembly 10 also comprises an array or
plurality of substantially wedge shaped petals 15 that are located
around the centrally located hub 12 and between each lanceolate
shaped petal 11 and the hour glass shaped petal 14. The hour glass
shaped petals 14 are pivotally connected to the adjacent wedge
shaped petals 15 by interconnecting means 16 that comprise hinge
members that are connected to the lateral adjacent edges of the
hour glass shaped and wedge shaped petals. The lanceolate shaped
petals 11 are pivotally connected to the adjacent wedge shaped
petals 15 by similar interconnecting means 16 that comprise hinge
members that are connected to the lateral adjacent edges of the
lanceolate shaped petals and the wedge shaped petals on the
underside of the reflector 10, as illustrated in FIG. 2. The upper
surfaces of the lanceolate shaped petals 11, hour glass shaped
petals 14, and the wedge shaped petals 15 are appropriately
compound curved or dished slightly so that the fully deployed
reflector 10 presents a reflector having a dished paraboloid that
is substantially symetrical about its axis that passes through the
center of the hub 12 and the focus of the paraboloid that is
suitable for use in reflecting electromagnetic radiation.
In FIG. 2 the reflector 10 is illustrated in its partially
collapsed or partially open configuration. As illustrated in FIG. 2
the lanceolate shaped petals 11 are shown as being rotated upward
and inward about the hub 12 from their positions indicated in FIG.
1 due to the movement of actuating members or arms 17 that form
part of a hydraulic activating unit 18 that is connected to the
underside of the hub and whose outer ends are rotatably connected
to the lower end of support trusses 19 that are rigidly secured to
the back side of the lanceolate shaped petals along the central
axis of the lanceolate shaped petals. The hour glass shaped petals
14 are also shown as being rotated upward and inward about the hub
12 from their positions indicated in FIG. 1 due to the action of
other activating members or arms 17 that form part of the hydraulic
activating unit 18 and whose upper ends are pivotally connected to
the lower ends of support trusses 19 that are rigidly connected to
the back of the hour glass petals along the central axis of the
hour glass petals. The wedge shaped petals 15 that are located
between and pivotally connected in edge to edge relationship to the
adjacent lateral edges of the lanceolate shaped petals 11 and the
hour glass shaped petals 14 by the hinge members 16 on the upper
and lower sides of the reflector have pivoted about the edges of
the lanceolate shaped and hour glass shaped petals when the
reflector assembly is in its partially open or partially closed
configuration. It should be noted that when the reflector assembly
10 is in its partially open or partially closed configuration the
lanceolate shaped petals 11 are located toward the center of the
assembly whereas the hour glass shaped petals 14 are located on the
exterior of the assembly and the hydraulic unit 18 must be properly
programmed to accomplish this to insure proper operation of the
reflector assembly when the assembly is being closed or undergoing
deployment.
The fully collapsed reflector assembly 10 is illustrated in FIG. 3.
In FIG. 3 it can be seen that the hour glass shaped petals 14 have
been rotated upwardly and inwardly by the action of the activating
members 17 of the hydraulic activating unit 18 so that they are
located on the exterior of the assembly 10. The lanceolate shaped
petals 11 have also been rotated upwardly and inwardly by the
action of the activating members 17 of the hydraulic activating
unit 18 so that they are located in the interior of the collapsed
assembly 10. The wedge shaped petals 15 have been forced to pivot
towards each other about the lateral edges of the lanceolate shaped
petals and the hour glass petals 14. Since the wedge shaped petals
15 have pivoted towards each other and the lanceolate shaped petals
11 have pivoted upwardly and inwardly so that they are located on
the interior of the assembly and since the hour glass shaped petals
have pivoted upwardly and inwardly so that they are located on the
exterior of the assembly, the reflector 10 forms a very compact
package when it is in its collapsed state.
As indicated in FIGS. 4 through 6 the curvature A of the lateral
edges of the lanceolate shaped petals 11, the curvature B of the
lateral edges of the semi-hour glass shaped petals 14, and the
curvature C of the lateral edges of the wedge shaped petals 15 when
viewed from the focus or focal point F of the fully deployed
reflector must substantially approximate the radial curvature D of
the surface of the fully deployed reflector when it is viewed in
cross section as illustrated in FIG. 5. In view of this requirement
related to the curvature of the lateral edges of the various
petals, if a lanceolate shaped petal 11 is rotated 90.degree. about
its long axis when in the fully deployed state and its lateral edge
is placed against the corresponding surface of the fully deployed
reflector the edge A will substantially conform to the curvature D
as illustrated in FIG. 6. In a similar manner if the hour glass
shaped petal 14 or the wedge shaped petal 15 is rotated 90.degree.
about its long axis when in the fully deployed configuration and if
their lateral edges were placed against the corresponding surface
of a cross section of the fully deployed reflector 10, the edges B
and C would substantially conform to the curvature D as illustrated
in FIG. 6. This requirement related to the curvature of the petals
is important since this permits the reflector to possess
comparatively rigid petals that provide a rather large relatively
rigid paraboloid reflective surface in the fully deployed state and
yet be capable of being folded into a very compact package. In
order to appreciate the importance of the curvature of the edges of
the petals reference should first be made to FIG. 1 that
illustrates the fully deployed reflector 10. From FIG. 1 it is
apparent that a solid paraboloid is capable of being cut into a
series of lanceolate shaped petals 11, wedge shaped petals 15 and
semi-hour glass shaped petals 14 around a central hub 12 in the
manner illustrated. It is also apparent that if the lateral edges
of these petals are flexibly or rotatably connected the petals can
be folded inwardly as illustrated in FIG. 3 so that one edge of
each wedge shaped petal 15 is pointing toward the center of the
collapsed 10 and the wedge shaped petals form substantially
90.degree. angles with the attached lanceolate shaped petals 11 and
hour glass shaped petals 14 and thus the reflector 10 forms a very
compact assembly in the collapsed configuration. If the edges of
the petals did not substantially correspond to the curvature D of
the deployed reflector assembly then the wedge shaped petals could
not form the 90.degree. relationships with the lanceolate shaped
petals 11 and the hour glass shaped petals 14 since these petals
are connected and when the wedge shaped petals are rotated into the
90.degree. relationship their edges must conform to the radial
curvature of the reflector that the hour glass shaped petals and
the lanceolate shaped petals possess since binding between the
petals or a separation or distortion of the petals would otherwise
tend to occur.
The means for mounting the lanceolate shaped petals 11 and the hour
glass shaped petals 14 to the hub 12 are illustrated in greater
detail in FIG. 5. The mounting means comprises the strut 13 whose
inner end is rigidly connected to the outer edge of the dish shaped
hub 12 and whose outer end is connected to the lower end of the
lanceolate shaped petal 11 by means of the pin 20 so that the
lanceolate shaped petal is free to rotate in an upward direction.
It should be noted that the hub 12 is dished so that it forms a
curvature E when seen in cross section that is an extension of the
radial parabolic curvature D of the rest of the deployed reflector
10. It can also be seen that the activating member or arm 17 of the
activating unit 18 extends outward from the activating unit and has
an outer end that is pivotally connected to the lower end of the
truss member 19 by means of the pin 21. The truss 19 is of rigid
construction and has an upper tubular strut 22 that is bent to
conform to the curvature D' of the underside of the lanceolate
shaped petal 11 which when viewed in cross section has
substantially the same curvature as the upper surface D. The upper
tubular strut 22 is rigidly connected to a lower tubular strut 23
by means of tubular cross or connecting struts 24, 25, 26, 27, 28
and 29, and these cross struts are reinforced by the diagonal
tubular struts 30, 31, 32, 33 and 34 whose ends are respectively
connected to the junctions of the upper strut 22 and the strut 24,
the lower strut 23 and the strut 25; the lower strut 23 and the
strut 25; the upper strut 22 and the strut 26; the upper strut 22
and the strut 26; the lower strut 23 and the strut 27; the lower
strut 23 and the strut 27; the upper strut 22 and the strut 28; the
upper strut 22 and the strut 28; and the lower strut 23 and the
strut 29. The same type of truss construction is used for the
trusses 19 that reinforce the hour glass petals 14.
The construction of the lanceolate shaped petals 11, the hour glass
shaped petals 14 and the wedge shaped petals 15 are illustrated in
greater detail in FIGS. 7 through 13. In FIG. 7 a portion of the
fully deployed reflector assembly is illustrated with the major
portion of a wire mesh electromagnetically reflective screen
covering 35 removed so that the internal construction of the
lanceolate shaped petals 11, the hour glass shaped petals 14 and
the wedge shaped petals 15 is clearly visible. The lanceolate
shaped petal 11 comprises two frame members or struts 36 that are
joined at their ends and are curved so that their outer edges give
the required curvature A when viewed from the focal point of the
fully deployed reflector. These struts are reinforced in a radial
direction by a reinforcing member or strut 37 that extends along
the long central axis of the lanceolate shaped petal and whose ends
are joined to the junction of the ends of the frame members 36.
Reinforcing struts 38, 39 and 40 extend outwardly in a direction
transverse to the long axis of the reinforcing strut 37 and they
are connected to the reinforcing strut and the frame struts 36. A
groove 41 is provided in the lower junction of the frame members 36
that is designed to accept the outer end of one of the mounting
struts 13. The hour glass shaped petal 14 comprises two frame
members or struts 42 that are curved so that their outer edges give
the required curvature B when viewed from the focal point of the
fully deployed reflector assembly 10. These frame members 42 are
connected at their outer ends by an outer frame member 43 that is
slightly curved in an outward direction so that it can form part of
the rim of the fully deployed reflector 10. The frame members 42
are connected at their inner ends by an inner frame member or strut
44 that is curved outwardly slightly. This inner frame member 44
has a slot 45 that is designed to accommodate the outer end of a
mounting strut 13. Located along the central axis of the hour glass
shaped petal 14 is a radial reinforcing member or strut 46 whose
ends are connected to the center of the outer frame member 43 and
the inner frame member 44. Reinforcing struts 47, 48 and 49 are
located in a direction generally transverse to the long axis of the
reinforcing member 46 and the ends of these struts are connected to
the reinforcing member and the frame members 42.
The wedge shaped petal comprises two outer frame members or struts
50 that are connected together at their inner ends to form a point
and are connected at their outer ends by a frame member or strut 51
that is slightly curved in an outward direction so that it can form
part of the rim of the fully deployed reflector assembly 10. The
outer frame members 50 are curved so that their outer edges give
the required curvature C when viewed from the focal point of the
fully deployed reflector. Reinforcing members or struts 52, 53 and
54 extend across the width of the wedge shaped petal and their ends
are connected to outer frame members 50. The wedge shaped petal 15
has no radial reinforcing strut such as the radial reinforcing
strut 37 of the lanceolate shaped petal 11 and the radial
reinforcing strut 46 of the hour glass shaped petal 14 and
consequently the wedge shaped petal is comparatively flexible in a
lengthwise direction whereas the lanceolate shaped petals and the
hour glass petals are of substantially rigid lengthwise
construction and are not flexible in the lengthwise direction in
view of their reinforcing struts.
As illustrated in FIGS. 8 and 9 the reinforcing member 37 of the
lanceolate shaped petal 11 is of substantially uniform thickness
throughout its length and is curved so that its upper surface
corresponds to the curvature D and its lower surface corresponds to
the curvature D' when viewed from the side. The truss 19 is
connected to the lower surface of the reinforcing member 37 to give
the supporting member additional strength and to prevent it from
flexing. It can also be seen that the upper surfaces of the
reinforcing struts 38, 39 and 40 are curved inward or dished so
that the lanceolate shaped petal 11 can form part of a paraboloid
when the reflector assembly is fully deployed. In FIG. 9 as
indicated for one of the reinforcing struts 39, the reinforcing
struts 38, 39 and 40 are thinner at G near the reinforcing member
37 than they are at H near the frame member 36 and thus the
reinforcing struts 38, 39 and 40 can bend or flex and this permits
the lanceolate shaped petal 11 to bend elastically slightly up and
down in a direction that is transverse to the long axis of the
reinforcing member 37 as indicated by the broken lines and the
arrows.
The outer frame member 50, the reinforcing struts 52, 53 and 54,
and the frame member 51 of the wedge shaped petal 15 are also
dished or curved as illustrated in FIGS. 10 and 11 so that when the
wedge shaped petal is covered with wire mesh and viewed in section
from the side it has a curvature D and the surface of the wedge
shaped petal can form a part of a parabolic shaped surface of the
reflector assembly 10 when the reflector assembly is fully
deployed. It should be noted, however, that since the wedge shaped
petal 15 has no radial reinforcing member such as that at 37 in
FIG. 8, the wedge shaped petal is free to flex as indicated by the
arrows and the broken lines so that the underside of the petal when
viewed in cross section from the side it presents the inverted
curvature indicated by D" and the dotted lines that is
substantially equivalent to the curvature D. As illustrated for the
reinforcing member 53 in FIG. 11 the reinforcing members 52, 53 and
54 and the frame member 51 are substantially of uniform thickness
throughout their lengths so that they will not tend to bend in the
manner described previously for the leaf shaped petal and thus the
wedge shaped petal is resistant to bending in a direction
transverse to its long axis.
As illustrated in FIGS. 12 and 13 the frame members 42, the
reinforcing member 46, the reinforcing struts 47, 48, 49, the outer
frame member 43 and the inner frame member 44 of the hour glass
shaped petal 14 are dished or curved so that when the hour glass
petal is viewed in cross section from the side it has a curvature D
and the surface of the hour glass shaped petal can form a part of a
parabolic shaped surface of the reflector assembly when the
reflector assembly is fully deployed. The underside of the
reinforcing member 46 is also connected to the truss 19 to give the
reinforcing member additional strength and to prevent it from
flexing.
In FIG. 13 as indicated for one of the reinforcing struts 48, the
inner frame member 44, the reinforcing struts 47, 48 and 49 and the
outer frame member 43 are thinner at I near the reinforcing member
46 than they are at J near the frame member 42 and thus the inner
frame member 44, the reinforcing struts 47, 48 and 49 and the outer
frame member 43 can bend or flex and this permits the hour glass
shaped petal 14 to bend elastically slightly up and down in a
direction that is transverse to the long axis of the reinforcing
member 46 as indicated by the broken lines and the arrows.
The various frame members and reinforcing struts of the lanceolate
shaped petals 11, the semi-hour glass shaped petals 14 and the
wedge shaped petals 15 may be constructed from various types of
honeycomb materials that are familiar to those skilled in the art.
It will also be appreciated that various types of wire mesh screen
coverings and that reflect electromagnetic radiation that are
familiar in the art can be used to cover the semi-hour glass shaped
petals 11, the hour glass shaped petals 14 and the wedge shaped
petals 15. Generally the selection of the type of screen covering
that is to be used will be governed by the type of electromagnetic
radiation that is to be reflected. In addition, a metalized mylar
sheet covering may be substituted for the wire mesh screen covering
in order to permit the reflector to be used to reflect
electromagnetic radiation in the infrared and visible spectrum.
A portion of the partially deployed or partially collapsed
reflector 10 is illustrated in FIGS. 14 and 15. As illustrated in
FIG. 15 as the reflector is undergoing deployment or being
collapsed the edges of the lanceolate shaped petals 11 bend
inwardly elastically toward the center of the assembly from their
normal positions indicated by the appropriate broken lines and the
edges of the hour glass shaped petals 14 bend elastically outwardly
and away from the center of the assembly and from their normal
positions indicated by the appropriate broken lines. It should also
be appreciated that bending of the lanceolate shaped petals 11 and
the hour glass shaped petals 14 can occur during certain phases of
the deployment or closing of the reflector that is reverse to that
indicated in FIG. 15. This bending of the lanceolate shaped petals
11 and the hour glass shaped petals 14 permits the reflector to be
readily deployed and closed without causing any binding between the
various petals. However, when the reflector assembly is fully
deployed the lanceolate shaped petals 11 and the hour glass shaped
petals 14 have resumed their original shape and are no longer
subject to elastic deformation and thus the reflector has a rigid
reflective surface.
FIG. 16 illustrates in greater detail the type of interconnecting
means 16 that can be utilized with this invention. The
interconnecting means comprise a hinge member 16 that is similar in
construction to the familiar common door hinge and comprises a left
hinge member 55 and a right hinge member 56. The left hinge member
55 has an outer flange 57 that has holes 58 in it for bolts or the
like that can be used to attach the flange to the edge of the
appropriate petal. The flange 57 has a cylindrical projection 59
that is located on its inner edge and this cylindrical projection
has a hole through it along its long axis that is capable of
accepting a pin. The right hinge member 56 also has a flange 60
that has holes 61 in it for bolts or the like that can be used to
attach the flange to the edge of the appropriate petal. The flange
60 has two cylindrical projections 62 located on its inner edge
that are separated to form a gap that accommodates the cylindrical
projection 59. The cylindrical projections 62 have holes in them
along their long cylindrical axis that accept a pin 63 that also
passes through the hole in the cylindrical projection 59 so that
the two hinge members 55 and 56 are rotatably connected to each
other and are free to rotate about the pin.
In order to practice the invention, the collapsible reflector 10 is
assembled in its fully deployed configuration as illustrated in
FIG. 1 on a suitable jig. After the reflector is assembled and
tested the hydraulic unit 18 is activated and this causes the
activating arms 17 whose ends are pivotally connected to the lower
ends of the trusses 19 to push outward and upward against the
trusses that are connected to the backs of the lanceolate shaped
petals 11 and the hour glass petals 14 so that the lanceolate
shaped petals and the hour glass shaped petals are pushed upward
and inwardly toward the center of the assembly. The upward and
inward movement of the lanceolate shaped petals and the hour glass
shaped petals also causes the wedge shaped petals 15 that are
rotatably connected to the lateral edges of the lanceolate shaped
petals 11 and hour glass shaped petals 14 to begin to rotate
towards each other about the edges of the lanceolate shaped petals
as illustrated in FIG. 2. As the lanceolate shaped petals 11 and
the hour glass shaped petals 14 move toward the center of the
assembly they flex in the manner indicated in FIG. 15 so that
binding does not occur between the edges of the petals. As the
lanceolate shaped petals 11 and the hour glass shaped petals 14
begin to move into their final closed positions the wedge shaped
petals 15 are forced to bend backward as illustrated by the broken
lines in FIG. 10 since the lateral edges of the wedge shaped petals
are connected to the edges of the adjacent lateral edges of the
hour glass petals 14 and lanceolate shaped petals 11 and the edges
of the wedge shaped reflector are forced to conform to curvature of
the edges of these lanceolate shaped and hour glass shaped
petals.
If the reflector 10 is to be used in space after the reflector has
been collapsed it is then packaged in a suitable space launching
vehicle and launched into space. When the space launch vehicle is
at the desired location in space the collapsible reflector 10 is
ejected from the launch vehicle and the hydraulic unit 18 is
activated to cause the activating arms 17 to be pulled inward so
that the connected trusses 19 and the attached lanceolate shaped
petals 11 and hour glass shaped petals 14 are pulled outward and
downward as indicated in FIG. 2. As the lanceolate shaped petals 11
and the hour glass shaped petals 14 are pulled outward and downward
this causes the wedge shaped petals 15 that are rotatably connected
to the adjacent lanceolate shaped and hour glass shaped petals to
rotate away from each other about the edges of the lanceolate
shaped petals. As the collapsed reflector assembly 10 is undergoing
deployment the wedge shaped petals 15 are pulled from their
backward bent position illustrated in FIG. 10 to their normal
configuration due to the shape of the lateral edges of the attached
lanceolate shaped petals 11 and hour glass shaped petals 14. It
will be appreciated that as the collapsible reflector 10 is
undergoing deployment the lanceolate shaped petals 11 and the hour
glass shaped petals 14 bend from their bent positions to their
normal positions indicated in dotted lines in FIG. 15. When the
lanceolate shaped petals 11 and the hour glass shaped petals 14
have been pulled to their fully open positions by the action of the
hydraulic unit 18 the connected wedge shaped petals have rotated
almost 90.degree. about their long axis and thus the wedge shaped
petals, the lanceolate shaped petals and the hour glass shaped
petals provide the dished paraboloid illustrated in FIG. 1.
Although the invention has been described in considerable detail
with reference to certain preferred embodiments, it will be
understood that variations and modifications may be made within the
spirit and scope of the invention as defined in the appended
claims.
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