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Claims  |
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What is claimed is:
1. In a stowable portable construction surface of the kind having a
plurality of segment means of essentially identical configuration stacked
along a common axis in overlying relationship for storage in minimum space
and being assembleable into a side by side laterally displaced
relationship to extend over a wide area; the improvement therein which
comprises in combination therewith: translational hinge means: said hinge
means connecting said segment means together serially and responding to
pivotal movement of one of said segment means for causing said one
pivotally moving segment means to move from said stacked position to a
unstacked position in side by side relationship with said adjacent segment
means and axially and laterally displaced from said stacked position.
2. The invention as defined in claim 1 wherein said translational hinge
means comprises a step down hinge.
3. The invention as defined in claim 1 wherein said segment means comprise:
tubular frame means, said frame means defining a hexagon geometry; and a
thin sheet attached to one side of said frame means to provide a
continuous surface.
4. The invention as defined in claim 3 further comprising: a plurality of
RF energy receiving means, said receiving means being attached to and
supported upon said thin sheet of a corresponding one of said segment
means.
5. The invention as defined in claim 1 wherein each of said segment means
includes a panel surface, said surface being of a parabolically curved
segment of a paraboloid.
6. The invention as defined in claim 1, wherein each of said segment means
includes a panel surface, said panel surface being of a flat geometry.
7. The invention as defined in claim 5 wherein said hinge means contains an
axis, said axis being oriented at an angle to said stack axis.
8. The invention as defined in claim 1 wherein said segments are of a
hexagon geometry.
9. The invention as defined in claim 1 wherein said segments comprise a
geometrical shape forming a member of the following class of shapes; a
hexagon, a square, a triangle, a pentagon, a doedecahedron and a circle.
10. A fold out reflector assembly for reflecting electromagnetic energy
comprising:
a plurality of substantially identical panel means including top panel
means, bottom panel means, and intermediate panel means located
intermediate said top and bottom panel means, said panel means having
reflecting surfaces containing six corners;
a plurality of hinge means for connecting said panel means together in a
serial manner for permitting pivotal movement between said panel means
about a hinge axis, each said hinge means comprising a female hinge
portion for connection to one of said panel means and a male hinge portion
for connection to another one of said panel means adjacent to said one
panel means;
each of said intermediate panel means having attached thereto a female
hinge portion associated with a one of said hinge means and a male hinge
portion associated with another one of said hinge means, said hinge
portions being attached at different corners of the associated panel
means;
said hinge means further comprising: step down hinge means responsive to
pivotal movement of one panel means relative to the other hingedly
connected panel means for causing one of said male and female hinge
portions to move axially along the hinge axis relative to said other hinge
portion for permitting a pivoting one of said panel means to which one of
said hinge portions is attached to move between a first position axially
aligned with an adjacent attached panel means to which the other of said
hinge portions is attached and a second position axially and laterally
displaced from said adjacent attached panel means.
11. The invention as defined in claim 10 wherein said step down hinge means
includes:
first cylinder means having an axis;
second cylinder means having an axis;
said first cylinder means being coaxially mounted over said second cylinder
means for relative rotational movement therebetween; said first cylinder
means containing an elongated slot, said slot extending at least partially
around the periphery of said first cylinder means from a first position
along the axis of said cylinder means to a second portion along said axis;
and
said second cylinder means containing radially inwardly directed key means,
said key means being positioned within said slot for travel along the path
defined by the slot.
12. The invention as defined in claim 11, further comprising: a plurality
of latch means, each said latch means being associated with a
corresponding one of said panel means and responsive to the movement of
said corresponding one of said panel means into co-planar abutting
relationship with a serially connected adjacent one of said panel means
for releasably holding said panel means together in said abutting
co-planar relationship.
13. The invention as defined in claim 12 wherein said plurality of panel
means are located in overlying relationship with one another in a stack
with the top panel means located in a first plane and an intermediate
panel means located in a plane underlying said first plane and further
comprising:
means for moving a top most one of said panel means about said hinge means;
indexing means for advancing the position of said stack to said first
plane; and
monitor means responsive to engagement of said latch means for causing said
indexing means to advance said stack to said first plane and initiating
operation of said motor means.
14. In a stowable portable construction surface of the kind having a
plurality of panel means of essentially planar geometry stacked along a
common axis in overlying essentially parallel spaced relationship for
storage in minimum space and assembleable into side by side essentially
co-planar relationship to thereby form a surface having a wide area; the
improvement therein which comprises: step down hinge means, said hinge
means connecting said panel means together serially and responding to
pivotal movement of one of said panel means relative to an attached other
of said panel means for causing said moving panel means to step down from
an initial position overlying said hingedly attached other panel means to
a subsequent position in side by side relationship with said attached
other panel means and laterally and axially displaced from said initial
position.
15. The invention as defined in claim 14 wherein said segments are of
substantially identical size and shape.
16. The invention as defined in claim 15 wherein said shape of said panel
means is a hexagon.
17. The invention as defined in claim 15 wherein said shape of said panel
is a member selected from the following class: a hexagon, a pentagon, a
square, a triangle, a doedecahedron, and a circle.
18. The invention as defined in claim 15 further comprising:
horn means coupled to each of said panel means, said horn means being
pivotally mounted for rotation between a folded position against the
associated panel means to which said horn means is coupled to an upright
position radially outwardly extending from said associated panel means;
said horn containing a forked outer end;
cable means, said cable means being attached at one end to an outermost
panel means and extending through said fork of said horn means associated
with said panel means; said cable means containing a bead means adapted to
engage said fork responsive to said cable being pulled taut, whereby said
cable means may pivot said horn to the upright position and thereby apply
a pivoting force upon said panel means causing said panel means to rotate.
19. The invention as defined in claim 15, further comprising: cable means,
said cable means being attached at one end to an outermost panel means for
rotating said panel means.
20. A fold out construction surface comprising:
a plurality of substantially identical panel means, including top panel
means, bottom panel means, and intermediate panel means located
intermediate said top and bottom panel means;
a plurality of hinge means for connecting said panel means together
serially for pivotal movement therebetween about a hinge axis, each said
hinge means including a male hinge portion for connection to one panel
means and a female hinge portion for connection to another adjacent one of
said panel means, said hinge means further comprising: translational hinge
means responsive to pivotal movement of one panel means relative tot he
connected panel means for causing one of said male and female portions to
move axially along the hinge axis relative to one another to a
predetermined extent for permitting a pivoting one of said panel means to
move into the plane of an adjacent attached one of said panel means.
21. The invention as defined in claim 20 wherein said translational hinge
means comprises:
first hollow cylinder means of a predetermined outer diameter; said first
cylinder means having an axis and containing a first slot and a second
slot;
said first slot extending circumferentially from a first location along the
axis of said cylinder means over an arc of predetermined length and
further extending axially and circumferentially to a second location along
the axis of said cylinder means, said second location being displaced from
said first location;
said second slot extending straight a predetermined distance parallel to
said axis;
second hollow cylinder means having an inner diameter greater than the
outer diameter of said first cylinder means, said second cylinder means
being coaxially mounted over said first cylinder means;
said second cylinder means containing key means, said key means being
radially inwardly extending into said first slot;
third hollow cylinder means having an inner diameter greater than the outer
diameter of said first cylinder means and being mounted side by side and
coaxial with said second cylinder means;
said third cylinder means containing key means, said key means being
radially inwardly extending into said first slot for preventing rotation
of said third cylinder means without interfering with axial movement of
said third cylinder means;
coupling means coupling said third cylinder means to said second cylinder
means for joint axial movement therewith and permitting relative
rotational movement therebetween;
means for connecting said first cylinder means to one of said segment
means; and
means for connecting said second cylinder means to an adjacent one of said
segment means.
22. The invention as defined in claim 21, wherein each of said second
cylinder means and said third cylinder means of said translational hinge
means contain bearing means for reducing friction to relative rotation
between said second and third cylinder means.
23. The invention as defined in claim 20,
wherein each of said panel means is of a hexagonal planar geometry, each of
which contains six corners; and
wherein said translational hinge means comprises: a female hinge portion
and a male hinge portion; and
wherein each of said intermediate panel means has attached thereto a female
hinge portion associated with a given one of said hinge means and a male
hinge portion associated with another one of said hinge means, said hinge
portions being attached at opposed corners of the associated panel means.
24. The invention as defined in claim 21 further comprising:
horn means coupled to each of said panel means, said horn means being
pivotally mounted for rotation between a folded position against the
associated panel means to which said horn means is coupled to an upright
position radially outwardly extending from said associated panel means;
said horn containing a forked outer end;
cable means, said cable means being attached at one end to an outermost
panel means and extending through said fork of said horn means associated
with said panel means; said cable means containing a bead means adapted to
engage said fork responsive to said cable being pulled taut, whereby said
cable means may pivot said horn to the upright position and thereby apply
a pivoting force upon said panel means causing said panel means to rotate.
25. The invention as defined in claim 21, further comprising: cable means,
said cable means being attached at one end to an outermost panel means for
rotating said panel means. |
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Claims |
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Description |
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FIELD OF THE INVENTION
This invention relates to stowable construction surfaces and, more
particularly, relates to a stowable construction surface used to reflect
electromagnetic energy.
BACKGROUND
A surface of simple geometry, such as a frame or flat surface, that covers
a wide area, is found in many applications in daily life: A wall which
acts as a barrier; a billboard or sign, which is used to deliver a
message; a solar panel, which is used to collect the suns rays; an
electromagnetic energy reflector, which serves to reflect light and
microwave energy are examples of known surfaces. Those surfaces are
constructed. They may be assembled as a permanent structure or,
alternatively, as a temporary arrangement to fulfill a temporary need.
Some are prefabricated at one location, moved to a different site, and
then finally assembled. In each of the given examples, devices and
techniques are known which are intended to facilitate the construction of
the surface in a prompt and efficient manner.
Some surfaces are of a complex nature and thus impose greater demands for
skill on the part of the workman who constructs it. In turn, simplified
construction techniques or preassembly lowers the workman's skill
requirements or, alternatively, allows the skilled person to accomplish
the assembly more quickly. Another requirement alluded to previously is
the prefabrication and transportation of the surface. Depending upon its
ultimate size, the surface may be difficult or impossible to transport in
one piece in conventional vehicles. Hence, surfaces of that character are
packaged or folded down into a more compact shape for transportation in
conventional vehicles. The lay person is most likely familiar with
packaging techniques used in connection with the purchase of unassembled
furniture. One may purchase a desk on display at the furniture store. The
one delivered, however, arrives in a flat package, broken down for
convenient transportation, and allows for assembly at home with the
assistance of a screwdriver, screws, and quick fasteners, guided by an
instruction sheet. Those who have tried understand; assembly is not as
easy as it looks.
The demands for portability, easy transportation in compact form and ease
of on-site assembly is especially critical in those surfaces that have
electromagnetic energy reflecting properties and application as
"reflectors", such as those which reflect visible light, infrared and
microwave signals, particularly those reflectors intended for use in or
about space vehicles deployed in the outermost regions of outer space.
Those skilled in space application understand that the size of the
transportation vehicle, such as that vehicle referred to as the "space
shuttle", is limited. The shuttle cannot transport a fully assembled
reflector, such as those used in radiometry, into deployment. Instead the
reflector must be transported in a packed form, as part of an antenna, and
on command is automatically extended and unfolds to cover a wide area.
Both size and weight are limitations in this application and the
limitations imposed must be respected.
Examples of reflectors appear in the patent literature. For additional
background, one may make reference to U.S. Pat. No. 2,471,828 granted May
31, 1949 to Mautner; U.S. Pat. No. 3,354,458 granted Nov. 21, 1967 to
Rottmayer; U.S. Pat. No. 3,617,113 granted Nov. 2, 1971 to Hoyer; U.S.
Pat. No. 3,717,879 granted Feb. 20, 1973 to Ganssle; U.S. Pat. No.
4,115,784 granted Sept. 19, 1978 to Schwerdtfeger et al; U.S. Pat. No.
4,475,323 granted Oct. 9, 1984 to Schwartzberg et al; and to U.S. Pat. No.
4,482,900 granted Nov. 13, 1984 to Bilek et al.
One known type of reflector has many advantages. This is one assembled from
hexagonal or quasi hexagonal segments. One such reflector is described in
an article appearing in Astronautics and Aeronautics December 1977
entitled "An Entry for Large Space Antennas" authored by Messrs. Powell
and Hibbs of the Jet Propulsion Laboratory of Cal Tech. That same article
also suggests using an off axis feed parabolic antenna constructed from
hexagonal segments. Thus a planar array made of hexagonal elements is bent
over from the planar shape slightly through means of struts, trusses
and/or braces to form a parabolic geometry. The antenna covers a wide area
and is composed of many identical regular hexagon shaped panels.
Even if one may easily assemble a large surface on the ground, it is an
altogether different matter doing so in the vacuous region of outer space.
In this instance, the working man, an astronaut, wears a cumbersome space
suit; the person cannot deal in a timely manner to assemble a large
multitude of hexagonal panels for example, on the order of a 50, 100 or
more panels, and the person would quickly tire due to the physical
restraints imposed by the space suit. So far as is known, no large
reflector of that type has been deployed in that application.
An object of the invention, thus, is to provide a new and more easily
assembleable construction surface. It is an additional object of the
invention to provide a stowable construction surface formed of hexagon
shaped panels that is easy to assemble and requires minimal skill and
physical dexterity to do so. A still further object is to provide a
construction surface that is packaged in a compact form and which is
easily assembled into a surface covering a wide area, without the need for
the workman's significant manual intervention and customary skills. It is
a still further object of the invention to provide an improved portable
automatically assembleable reflector that is stowable in and transportable
by existing space vehicles. It is a still additional object of my
invention to provide an electromagnetic energy reflector that may be
easily deployed and constructed in outer space without imposing undue
physical burdens upon the astronaut. Those objects are achieved with the
various structures characteristic of the invention, which are summarized
briefly in the paragraph following.
SUMMARY OF THE INVENTION
In a stowable construction surface structure of the kind having a plurality
of surface segments stacked into a small package for storage and
transportation, which segments are assembleable into a wholly or partially
side by side relationship, either as a final planar or non-planar surface
or frame structure or as an intermediate planar surface structure that is
bent into a non-planar surface configuration, to thereby form a surface
covering a wide area, at least as great in area as the sum of the areas
defined by the individual segments, the improvement characteristic of the
invention comprises: translational hinge means, such as a step-down hinge
means, said hinge means connecting said segments together serially and
responsive to pivotal travel of one of said segments relative to the
hingedly attached other of said segments for causing said moving segment
to move vertically from a position in one plane to the plane containing
the stationary segment.
In a specific aspect of the invention, a step-down hinge means includes a
pair of cylinders, one tall and the other short, mounted coaxially one
over the other, with cylinders of the pair attached to respective adjacent
segments. In that aspect the first cylinder contains an elongated slot
extending at least partially around the periphery of such cylinder and
vertically from a first position along the axis of the cylinder to a
second position there along. The second cylinder contains a radially
inwardly directed key or pin which is positioned within the slot for
travel along the path defined by the slot in the first cylinder. In a more
specific aspect of the invention, the surface of each segment contains
electromagnetic energy reflecting characteristics permitting the surface
to function as a reflector. In a still further aspect of the invention,
struts are included to add support to and bend the surface into a
non-planar surface, such as a parabola. In an alternative form, the hinge
axes are arranged at an angle to the stack axis so as to directly form a
parabolic surface. In a more general aspect, the invention includes a
combination containing a motor and indexing devices to automatically
unstack and deploy the surface structure.
The foregoing objects and advantages of the invention together with the
structure characteristic of the invention, which was only briefly
summarized in the foregoing passage, and the versatility of its
application becomes more apparent to those skilled in the art upon reading
the detailed description of the preferred embodiments of the invention,
which follows in this specification, taken together with the illustrations
thereof presented in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a perspective view of an embodiment of the invention depicted in
stowed form;
FIG. 2 illustrates pictorially in top plan view the embodiment of FIG. 1 in
fully assembled form;
FIG. 2a is a partial section cut away view of the area A--A in FIG. 2 cut
away to show a latch;
FIG. 3 illustrates pictorially a partial view of the hinge assembly used in
the invention drawn to an enlarged scale;
FIGS. 4a through 4d illustrate design details of the hinge of FIG. 3 and
two partial section views of the hinge in initial and final position;
FIGS. 5a through 5i illustrates pictorially various stages of assembly of
the embodiment intermediate that depicted in FIG. 2;
FIGS. 6a through 6g schematically illustrates the dispensing of segments in
an assembly of the embodiment of FIG. 1 and also illustrates schematically
an alternative embodiment containing an additional segment;
FIGS. 7a and 7b shows a modification to the embodiment to provide
additional supports;
FIG. 8 schematically illustrates ancillary apparatus to mechanize the
assembly of the reflector;
FIGS. 9 and 10 illustrate the construction surface employed as a reflector
positioned within a space shuttle vehicle in the packed position and in
position oriented for dispensing of the segments;
FIGS. 11a through 11c illustrate in perspective view an alternative form of
translational hinge used in the embodiment of FIG. 1 as the hinge appears
in stowed position, 120 degrees angular position and in final position,
respectively;
FIG. 11d illustrates a bearing race used in the translational hinge of
FIGS. 11a through 11c;
FIGS. 12a through 12c schematically illustrates the relative positions of
the hinge portions of the hinge of FIG. 11 in each of the angular
positions represented in FIGS. 11a through 11c;
FIG. 13 illustrates in perspective view a phased array antenna that
incorporates the invention as the antenna appears in stowed conditions;
FIG. 14 illustrates the embodiment of FIG. 13 in perspective view in
partially assembled position;
FIG. 15 is a perspective view of still another reflector embodiment as it
appears in stowed form;
FIG. 16 presents the reflector of FIG. 15 in assembled form with certain
portions cut away to show the locations of the translational hinge;
FIGS. 17a through 17f illustrate the sequence of steps in the assembly of
the first two sections of the embodiment of FIG. 15;
FIG. 18 is a perspective view of a translational hinge used in the
embodiment of FIG. 15;
FIG. 19 shows the hinge of FIG. 18 in exploded view;
FIGS. 20a through 20k illustrate another embodiment of the invention which
contains a mechanism for allowing remote dispensing and the steps in the
operation of that mechanism; and
FIGS. 21a through 21e illustrate segments of different geometries that may
be used in the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In accordance with the invention, the construction surface, or as more
specifically characteristic of the disclosed application, reflector 1 is
illustrated in perspective view in its unassembled or stowed forming FIG.
1. This is the condition of the reflector as stored an as stowed for
transport in a minimum size. As shown the reflector contains seven
segments or panels 10, 12, 14, 16, 18, 20 and 22 that are oriented on top
of the other in a spaced parallel overlying relationship, spaced apart
along the assemblies major axis 23. The geometry of the surface of the top
panel in this embodiment is a hexagon of a relatively small thickness and
is essentially flat or planar; and each of the remaining panel sections is
essentially identical in that structure.
A preferred material for the panel is a graphite fiber reinforced epoxy
honeycomb. The surface of each panel section possesses an electromagnetic
energy reflecting characteristic, and is suitably of an aluminum or copper
material or coated with those or other reflective materials, such as
silver. As becomes apparent to those skilled in the art, the panels may be
constructed of any materials which suit the specific purpose to which the
construction surface is applied.
As shown in the figure, a hinge 11 connects panel section 10 to the next
immediate panel section 12. Each of the other panel sections is likewise
connected to the next adjacent panel by a like hinge. Hinge 13 connects
panels 12 and 14; hinge 17 connects panels 16 and 18; and hinge 21
connects panels 20 and 22. The hinges connecting panels 14 and 16, and
panels 18 and 20, are not visible in this FIG. The hinges thus serve to
connect the panel sections in a concatinated chainlike or serial fashion.
Further, the axis of hinges 13, 17 and 23 are coaxial along the same axis
27 and the axes of the two remaining hinges, not visible, are located
along axis 29. Sockets 26, 28 and 30 form the female portion of and prongs
26a, 28a and 30a form the male portion of a latch structure which is
described later in this specification.
FIG. 2 shows the completely assembled reflector in a top plan view. The
seven panels are laid out to form a single large surface with the sides of
adjacent panels in abutment with one another and latched together in that
abutting relationship. Labeling on each panel illustrates the relative
position and degree of rotation relative to panel 10. FIG. 2 also shows
the two additional hinges 15 and 19 connecting panels 14 and 16 and panels
18 and 20, respectively. The panels are arranged in a single plane to form
a constructed surface of a wide area. In this embodiment the constructed
area is an area equal to the sum of the individual surface areas of the
seven panels employed.
FIG. 2a is a cut away view of section A--A in FIG. 2, drawn to an enlarged
scale. This view shows the prong 24a or male end and socket 24 or female
end of a releasable latch that holds panels 10 and 12 together in
assembled position. As visible in FIG. 1, sockets 26, 28 and 30 form the
female portions of the latch for the associated panels. The two additional
sockets and the associated prongs are not visible in the Figures; the
location of each, however, is apparent to those skilled in the art.
The releasable latch holds panel members 10 and 12 in that connected
relationship until one desires to disassemble and store the structure. The
latch formed of plug 24a and socket 24 is of a bayonet type, which is
conventional in the fastener art, and includes a projecting compressible
spring prong which enters a socket, one of which is located in one panel
and the other in the panel that the prior panel abuts. The other latches,
including those formed of sockets 26, 28 and 30, are of identical
structure. Common velcro type fasteners may be used to form a temporary
latched mechanical connection and other alternatives, such as a form of
magnet attached to one panel and an iron bar or "keeper" attached to the
adjacent panel, also provides a releasable latch. If connections of a more
permanent nature are desired, bolts or rivets may be substituted.
Reference is now made to FIG. 3 which illustrates in perspective a portion
of panel sections 10 and 12 and the elements of hinge 11 drawn to an
enlarged scale. A portion of panel member 12 is also cut away at a
location about a hinge portion so as to permit more detailed observation
of its construction. As shown, the hinge contains two parts, a cylindrical
section 31 integrated with a circular washer shaped bottom wall 33 that in
turn is integrally joined to panel 10. The height of cylinder 31 together
with the thickness of wall 33 is such as to be no greater than the overall
thickness of the panel. This portion of the hinge is sometimes referred to
as a male hinge portion. The second portion of the hinge, the female
portion, contains a cylindrical ring like member 34 containing a
cylindrical passage of a diameter slightly larger than the diameter of the
outer wall of cylindrical section 31. As shown, hinge portion 34 is
integrally attached to the associated panel 12 and for convenience, this
portion is of a small height, although cylindrical sections of greater
height may be used as becomes more apparent hereinafter. Two keys or pins
37 and 39 are located on the inside of hinge portion 34 and project
radially inwardly. The upper hinge portion is placed in or over the male
hinge and the keys or pins 37 are inserted into the slot.
As shown, slot 35 extends about the surface of cylinder 31 at the upper end
and detours in an axial direction. The end of the slot is located at a
position along the axis of the hinge that is spaced from the axial
position of the slots starting point and is at the lower end of cylinder
31. Because of the relative circular construction and of the flat surfaces
33 and 34, the two panels can pivot relative to one another to a limited
extent about the hinge axis.
As panel member 10 rotates about the hinge axis relative to panel 12, pins
37 and 39 ride in the slot. Hence, as panel 10 pivots and moves angularly
about the axis, the cam follower action of the slot forces panel 10 also
to shift in position axially. Thus the hinge also translates the panels
pivoting movement into an axial or lateral movement and causes the panel
to move or step down from the spaced planar position above the second
underlying panel, panel 12, to the plane of the underlying panel. Thus the
reference or characterization of the hinge as a translational hinge, more
specifically, a "step-down" hinge is appropriate. An exemplary design for
the hinge is presented in FIGS. 4a through 4d to which reference may be
made.
As illustrated in the schematic view of FIG. 4a, the panel 10 is located in
a position overlying panel 12 and is at that starting position represented
in the partial section view of FIG. 4b, which is taken along the lines
A--A in FIG. 4a. Key 37 is located in the slot in cylinder 31 and for
clarity key 39 is omitted. When panel 10 rotated into the final position,
panel member 10 also moves linearly along the hinge axis to the position
shown in the partial section view of FIG. 4c which is taken along lines
B--B in FIG. 4a, where panels 10 and 12 are shown to be essentially side
by side and co-planar. To achieve that relationship, the slot is designed
as shown in FIG. 4d so that at approximately 120 degrees or so of pivoting
around the axis of the hinge member, the slot descends as a function of
rotational movement to a predetermined distance equal to the thickness of
the panel member, represented as the difference between a1 and a2 in the
figure, and ultimately reaches that final axial position in this
representative design at approximately 240 degrees of rotation, the
furthermost axial position.
Although other slot configurations may be chosen, the arrangement
illustrated permits the panels to rotate away from one another before any
axially movement occurs. This allows the moving one of the panels to clear
the other before the step-down action begins. Any possibility for panel
member 10 to prematurely contact and cause binding with panel member 12 is
thus avoided, insuring smooth assembly of the reflector. This same
relationship holds true for all of the other panels in the construction
surface.
Reference is now made to FIGS. 5a through 5i to illustrate partially and
pictorially the sequence of events in assembling the panel into the final
form previously illustrated in FIG. 2. Initially panel 10 is pulled and
rotated about the axis 11a of hinge 11, moving from the stowed position as
illustrated in FIG. 5a. This may be accomplished by hand grasping and
pulling or by attachment to the panel of a rope or string, not
illustrated, functioning as a tether that is pulled around in a circular
path about the axis of the stack. Panel 10 is angularly rotated as in FIG.
5b and approaching approximately 240 degrees about the hinge axis to
achieve a position as illustrated in FIG. 5c. As shown the axis of panel
10 is laterally displaced in position from the axis of the stack of
remaining panels. At this degree of positional movement, the hinges
step-down action becomes effective and, as shown in FIGS. 5d and 5e, at
approximately 240 degrees of rotation panel 10 has also moved downwardly
along the hinge axis and its side edge 10a travels into the plane of and
into a side by side relationship with panel 12. As the panel attains an
angular rotation of approximately 240 degrees, the side edge of panel 10
abuts the edge of panel 12 and latch 22, symbolically represented, engages
12.
The rotational force applied to panel section 10 is now transmitted through
the attached adjacent panel, panel 12, and that panel is consequently
forced to pivot about the second hinge axis 27. As illustrated in FIG. 5f
panel 12 moves from the normal stowed position off of a position overlying
the surface of and uncovering the underlying surface of the next adjacent
panel, panel 14. After approximately 120 degrees of that rotation, the
panels achieve a relationship illustrated in FIG. 5g.
As rotational movement continues, panel 12 begins to move down along the
axis of the hinge, accompanied by panel 10, and steps down into the plane
of panel 14, continuing the rotational movement until an edge of panel 12
engages an edge of panel 14 and latches as represented at 26 in FIG. 5h.
As the force applied to panel 10 continues, a rotational force is next
coupled to panel 14. In turn panel 14 is forced to pivot about the axis 29
of the associated hinge, hinge 15. Upon completion of the step-down
action, panel 14 as depicted in FIG. 5i engages a side edge of and latches
to panel 16. Continued application of the force to panel 10 continues the
rotation and reorientation of underlying panels as long as there remain
panels in the stack to be dispensed.
For greater clarity, this sequence is symbolically illustrated in FIGS. 6a
through 6f which illustrate formation in the various stages of dispensing
the panel sections from the stack corresponding to the first through sixth
rotation. At FIG. 6h, an eight panel is dispensed, assuming a stack
containing eight panels is used. In as much as the foregoing sequence in
the assembly of the reflector is repetitive, it is not further illustrated
or described.
Thus by simply affixing the bottom one of the stack of panels to a
stationary object, a working man may physically assemble a complete
surface and reflector by simply grasping the first reflector panel or
attaching a string or rope thereto and walking around in essentially a
circle pulling that one panel. The reflector thus constructed may be
propped up on a scaffold or ladder or any like support means to serve as a
reflecting surface in a ground based antenna or, if the surface is shiny,
for reflecting light as part of a light communication or measurement
system, the details of which are not pertinent to the present invention
and are well known to those skilled in those arts.
The reflector can be used in that fashion in an outer space application,
such as an antenna supported within a space shuttle vehicle. In the
crudest form, the astronaut can simply take a rod, such as a hoop stick
and force the panel members to move in rotation, aided in this effort by
the weightlessness in space of the panels. This becomes a simple task. In
effect, the astronaut need only move his arm many times to assemble the
small antenna thus described. Alternatively, the astronaut may attach the
cord or string, as discussed earlier, and pull it around and around,
dispensing panels from the stack. A specific example of the latter
arrangement is described more fully later in this specification.
Although an embodiment containing seven panels is illustrated, the number
of panels employed in any surface is theoretically limitless. However, as
a practical matter the number is limited by available space as well as by
the strength of materials. In ground based applications where gravity has
an effect, it is necessary to prop up the panels and provide extra support
without which the weight of large numbers of panels could cause the hinges
to crack or panel sections to crack, causing the surface assembly to
collapse. This limitation is not one in the structure but is a practical
limit brought about by the strength of materials used. Although the panels
are assembled to form a planar surface in this embodiment, the invention
is not so limited; non-planar surfaces may be formed as is described
elsewhere in this specification.
For a large reflector, the panel thickness is required to be quite thin due
to a limit on the overall height of the stack imposed by space limitations
within the transportation vehicle. In that situation, the edge of the
reflector may be modified to include a rim to improve rigidity. Such a rim
may be formed by struts and braces which can be included on selected
peripheral ones of the panel sections. Reference is made to FIGS. 7a and
7b which show exemplary struts 36 and 38 and the positioning of those
struts. The panels that lie along the edge of the reflector contain
attached struts on the opposite side to that of the reflecting surface.
The struts are folded for storage. They extend, as illustrated in FIG. 7b,
to form a tetrahedron pyramid when released. An attaching brace 40 is
included between the apexes of the tetrahedron pyramids to form a rigid
rim around the reflector.
In alternative forms, the reflector of the invention may comprise many
hundreds if not thousands of panels, subject to the aforecited
limitations, and for that application additional mechanisms are preferably
employed in combination to assist in the surfaces assembly. Thus for
example, an improved combination especially adapted for use in outer space
application through the vehicle of a spacecraft, such as a shuttle or the
like, may take the form illustrated in FIG. 8. FIGS. 9 and 10 illustrate
schematically a space vehicle 41. The reflector panel assembly 42 is shown
stowed in that vehicle as in FIG. 9 and the assembly is raised for
deployment as presented in FIG. 10.
The panels are contained in a cradle and includes a motor mechanism and a
latching indexing mechanism symbolically illustrated in FIG. 8. Once space
vehicle 41 is in low earth orbit, the cargo doors, not illustrated, are
opened. The motor then tilts the stack of panel sections upward at an
angle and the motor commences rotation of the panels. The indexing
mechanism moves up the stack by one panel thickness to release the first
panel from the cradle; the first panel is rotated on a hinge as previously
described in connection with the earlier embodiments to abut the edge of
the underlying panel. The stack of panels is then indexed up the thickness
of the panel in relation to the cradle as the dispensed panels are rotated
about the next hinge. This sequence is repeated until all of the panels
are assembled to form a reflector dish.
One form of indexing mechanism which may be employed in connection with the
invention is symbolically illustrated in FIG. 8. As illustrated the stack
of segments S1 through S8, one of which has been dispensed, are mounted in
a cradle C having a movable platform or base B. The base is mounted upon a
pulley cable arrangement consisting of cable CA, mounted at one end to the
left upper end of the cradle and extending over pulleys P1, P2, and P3.
The other end of the cable is taken up on spool SP. The motor M drives the
take up spool. As motor M operates to turn the spool, the cable is wound
upon the spool causing base B to be raised. The control circuit co
monitors the input from the segment position sensor SE. In response to an
input from the sensor, the controller provides a current to operate the
motor for a predetermined duration, which is a duration sufficient to wind
enough cable upon the spool as causes base B to move vertically by a
distance of one segment thickness. This process continues until all of the
segments are dispensed.
FIGS. 11a through 11c illustrate an alternative construction of the step
down hinge illustrated and described in connection with the preceding
embodiment. The hinge incorporates a ball bearing arrangement between the
cylindrical hinge elements to reduce friction between its parts and,
hence, reduce the amount of torque or force required to pivot one hinge
section relative to the other. FIG. 11d depicts an exemplary bearing race
by means of which the three ball bearings are attached to cylinder 34, the
male hinge portion.
FIGS. 12a through 12c symbolically represent in a linear plane the relative
configuration of the inner bearing race, the outer bearing race of the
hinge and the ball bearing at various angular positions between the male
and female hinge elements. These representations may be considered
together with the illustrations of the hinge presented in FIGS. 11a
through 11c with the hinge elements illustrated in the same relative
angular positions.
As shown in FIG. 11a, the hinge includes a male section containing an arm
32 and an upwardly extending cylinder 34. Cylinder 34 carries a bearing
carrier depicted in FIG. 11d, referred to as the ball spacer, on its outer
peripheral surface. However, the ball bearing spacer and its configuration
is obstructed in this view by the elements of the female hinge portion.
The female hinge portion includes the arm 36 to which is attached a
cylinder 38 which is fitted within a circular opening at the end of arm
36. A bearing race 42 is formed by a groove in the inner cylindrical
surface of cylinder 38. An additional race 42b is partially visible in
this view. The inner wall surface of cylinder 38 includes a third bearing
race not visible in this figure. Each of the races is spaced equi-distant
about the inner periphery of cylinder 38.
Reference may be to FIG. 11c. The inner race, which was not visible in the
view of FIG. 11a, is better illustrated in this figure as element 35. A
portion of the second inner race 35b is also visible in this view. The
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