Design and development of module joint clamping device for application to solar array constructio

Diamond, R. M.

Dubey, M.

English

NASA Technical Reports Server

REPLY TO 
ATTN OF. 
TO : 
FROM: 
SUBJECT : 
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION 
WASIIINGTON, D C 20546 
March 27, 1971 
USI/Scientific & Technical Information Division 
Attention: Miss Winnie M. Morgan 
GP/Office of Assistant General 
Counsel for Patent Matters 
Announcement of NASA-Owned 
U.S. Patents in STAR 
In accordance with the procedures contained in the Code GP 
to Code US1 memorandum on this subject, dated June 8, 1970, 
the attached NASA-owned U.S. patent is being forwarded for 
abstracting and announcement in NASA STAR. 
The following information is provided: 
U.S. Patent No. : 3,330,082 
Corporate Source : Spectrolab 
Supplementary 
Corporate Source 
NASA Patent Case No.: XNP-02341 
Please note that this patent covers an invention made by an 
employee of a NASA contractor. Pursuant to Section 305(a) of 
the National Aeronautics and Space Act, the name of the 
Administrator of NASA appears on the first page of the patent: 
however, the name of the actual inventor (author) appears at 
the heading of Column No. 1 of the Specification, following the 
words-". . . with respect to an invention of. . . ." 
Gayle Parker 
Enclosure : 
Copy of Patent 
https://ntrs.nasa.gov/search.jsp?R=19710012056 2020-03-17T02:49:26+00:00Z
July 11, 1967 JAMES E. WEBB 3,330,082 
Filed Feb. 11, 1965 3 Sheets-Sheet 1 
ADMINISTRATOR OF THE NATIONAL AERONAUTICS 
AND SPACE ADMINISTRATION 
CENTRAL SPAR AND MODULE JOINT 
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July 11, 1967 JAMES E. WEBB 3,330,082 
ADMINISTRATOR OF THE NATIONAL AERONAUTICS 
AND SPACE ADMINISTRATION 
CENTRAL SPAR AND MODULE J O I N T  
Filed Feb. 11, 1965 3 Sheets-Sheet 2 
July 11, 1967 JAMES E. WEBB 3,330,082 
ADMINISTRATOR OF THE NATIONAL AERONAUTICS 
A N D  SPACE ADMINISTRATION 
CENTRAL SPAR AND MODULE 7OINT 
Filed Feb. 11, 1965 3 Sheets-Sheet 3 
I 
3s' 
3,33 nited States Patent Patented July 11, 
1 
3,3 3 0,0 8 2 
CENTRAL SPAR AND MODULE JOINT 
James E. Webb, Administrator of the National Aeronau- 
tics and Space Administration, with respect to an in- 
vention of Michael Dubey and Ronald M. Diamond, 
both of Los Angeles, Calif. 
Filed Feb. 11, 1965, Ber. No. 432,025 
5 Claims. (CL 52-127) 
ABSTRACT OF TNE DISCLOSURE 
This invention relates to a module joint arrangement 
for attaching together, ( 1 )  a hollow central member hav- 
ing a longitudinal axis, and (2)  two members extending 
outwardly from said central member. The extending mem- 
bers contain straps that pass through openings in the sur- 
face of the central member, and that extend into its in- 
terior. Clamp means is carried within the central member 
and engages the straps to clamp them transversely to- 
gether within the central member. The clamp means in- 
cludes a base section and wedge section that are movable 
transversely relative to the axis of the central member to 
clamp onto the straps, and form a secure joint. 
This invention relates to a joint arrangement utilized 
for attaching elements or branches to a central member 
and also relates to clamp means for use in the joint 
arrangement. 
The present invention is particularly adapted for the 
assembly of solar arrays which consist of a central spar 
member to which are connected solar modules. At pres- 
ent, mechanical problems associated with the fabrication 
of such structures are numerous since the solar array must 
extend into space and be firmly supported. Present types 
of fasteners are not satisfactory for this purpose since 
they are directed either to the clamping together of the 
two flat plates or to the attachment together of two flat 
panels which differ in construction from a solar array. 
Basically, the present invention provides a joint arrange- 
ment connecting two oppositely extending members to 
opposite sides of a central spar member. The opposite 
extending members have inner end panels that are com- 
plementary to the surface of the spar member and each 
member has a clamp receiving projection that projects in- 
wardly through an opening in the side of the spar mem- 
ber. The oppositeiy extending members can consist of the 
two modules of a solar panel which is supported by a spar 
consisting of the cylindrical member. The clamp portion 
of the joint arrangement consists of a base section which 
locates the projections from the extending members and 
a tapered section which engages cam surfaces on the pro- 
jections. A bolt connects the two portions together and 
serves to pull the two members together and against the 
supporting spar member. 
It is therefore an object of the present invention to 
provide a joint arrangement for attaching extending mem- 
bers to a central spar member for support thereby. 
Another object of the present invention is to provide a 
clamp for securing two extending members to a central 
spar member with the members projecting to opposite 
sides of the central member. 
Another object of the present invention is to provide a 
joint arrangement for members which are located on 
opposite sides of a hollow cylindrical member and have 
inwardly extending projections which extend through the 
cylindrical member and are pulled towards the center of 
the cylindrical member by clamp means in order to hold 
the members tightly against the cvlindrical member. 
2 
a novel clamp for connecting two oppositely extending 
members to a central spar member. 
These and other objects of the invention not specifically 
set forth above will become readily apparent from the 
5 accompanying description and drawings in which: 
FIGURE 1 is a perspective view of a solar paddle 
which incorporates the present invention and consists of 
a central cylindrical spar member supporting two solar 
modules extending from the spar member; 
FIGURE 2 is a top plan view of the solar paddle of 
lo FIGURE 1 illustrating the construction of each of the 
solar modules; 
FIGURE 3 is a vertical section along line 3-3 of 
FIGURE 2 showing the two portions of the clamp which 
15 serve to pull the solar modules into contact with the cen- 
tral cylindrical member; 
FIGURE 4 is an expanded top plan view similar to 
FIGURE 2 showing the three members of the solar paddle 
construction; 
FIGURE 5 i s  an unassembled view of the clamp along 
line 5-§ of FIGURE 4; and 
FIGURE 6 is an expanded perspective of the clamp. 
Referring to the embodiment of the invention chosen 
for purposes of illustration, a solar paddle PO comprises 
25 two solar modules 11 and 12 which are supported on a 
central cylindrical spar 13. The spar consists of a central 
cylindrical member 14 with solid plugs 15 and 16 fixed in 
opposite ends thereof. The plug 16 is attached by bracket 
17 to a supporting structure 18 so that the paddle ex- 
30 tends outwardly from the structure. Each of the solar 
modules 11 and 12 have top and bottom panels 20 and 21, 
respectively, and outer end panels 22. Also, module 11 
has a curved inner end panel 23 and the module 12 has 
a curved inner end panel 24, both of which are shaped 
35 to conform to the surface curvature of member 14. A 
honeycomb structure 27 is contained within each of the 
solar modules 11 and 12 for internal support and solar 
cells (not shown) are secured to the outside surface of 
the modules. 
The cylindrical member 14 contains, at each of three 
spaced locations, holes 33,34,35 and 36 which are spaced 
apart 90 degrees (see FIGURE 6) .  The inner end panel 
23 of module 11 carries three straps 40, each of which 
projects through one of the openings 34 in the cylindrical 
45 member 14 and the inner end panel 24 of module 12 car- 
ries three straps 41, each of which projects through one 
of the openings 36 in the cylindrical member 14. Each 
of the straps 40 and 41 have opposite sides 43 and 44 con- 
nected by bottom strap 45 and strap 40 has a tapered 
50 end surface 46 while strap 41 has a tapered end surface 
47. 
The clamp means for connecting the modules 11 and 
12 to the central spar 13 consists of a base section 50 
having a flat surface member 51 connected with a tubular 
55 extension 52 and an opening 49 extends through member 
51 and extension 52. Upper wedge section 53 of the 
fastening means consists of arms 54 and 55 extending 
angularly from a central portion 56 toward section 50. 
A projection 57 extends finm portion 56 and the portion 
60 56 and projection 57 contain a threaded opening 58. 
The arms 54 and 55 have wedge surfaces 60 and 61, re- 
spectively, which engage the surfaces 46 and 47, re- 
spectively, when the arms are inserted between the sides 
43 and 44 of the straps 40 and 41 after the straps have 
65 been insereted through openings 34 and 36 in member 
14 (see FIGURE 3 ) .  When the arms 54 and 55 are 
inserted into the straps 40 and 41, the bottom 45 of 
the straps will rest upon the flat surface 51. A bolt 63 
is inserted through opening 49 and threaded into opening 
70 58 so that rotation of the bolt at head 64 will draw the 
sections 50 and 53 together and the wedge surfaces 61 
20 
40 
A further object of the present invention is to provide and 62 acting against the strap cam surfaces 46 and 
3,330,082 
3 
47 will pull modules 13. and 12 toward the central 
cylinder member 14 until the inner side panels 23 and 24 
are tightly held against the cylinder member 14. 
In assembling the fastener means, the clamp sections 
50 and 53 are first inserted into the interior of the cylin- 
drical member 14 until projection 57 is opposite an open- 
ing 33 and projection 52 is opposite opening 35. The 
edge of the inner end surfaces 23 and 24 have semi-circular 
cutouts 33’ and 35’so that when the surfaces 23 and 24 
are drawn tightly against the cylindrical member 14, the 
cutouts define openings for the projections 52 and 57 
above the openings 33 and 35. Thus, the projections 52 
and 57 can extend through the openings 33 and 35 in order 
to attach the clamp sections 50 and 53 to the straps 40 
and 43. and continual access is provided to the head 64 
of the bolt 63. After all the bolts 63 have been tightened 
down, the modules 11 and 12 are firmly secured to the 
central spar 13 along the full length of the spar as illus- 
trated in FIGURES 1-3. During the tightening of the 
bolt, the clamp sections remain centered because of op- 
posite forces on the straps 40 and 49. 
While the invention has been illustrated in connection 
with solar array fabrication, it is obvious that the in- 
vention broadly relates to a joint arrangement for con- 
necting two oppositely extending members to a central 
spar member. Various types of pulling devices could be 
utilized within the spar to pull the extending members 
together and the surfaces of the spar member and end 
surfaces of the extending members which engage each 
other can be of various shapes. Various other modifica- 
tions are contemplated by those skilled in the art without 
departing from the spirit and scope of the invention as 
hereinafter defined by the appended claims. 
What is claimed is: 
1. A joint arrangement comprising: 
a central spar member having a longitudinal axis; 
extending members extending outwardly from said 
central spar member, each member having an end 
panel adjacent said spar member of the same surface 
contour as said spar member; 
strap means projecting outwardly from each of said 
end panel and having tapered cam surfaces thereon; 
a plurality of openings in said spar member to re- 
ceive said (strap means and locate said tapered 
surfaces within the interior of said spar member; 
and 
clamp means located within said spar member and 
positioned transversely to said longitudinal axis of 
said spar member, for engaging said tapered cam 
surfaces and drawing said extending members into 
end engagement with the surface of said spar mem- 
ber, said clamp means including a base section, a 
tightening bolt, and a wedge section, said sections 
being connected together for relative movement trans- 
versely to the axis of said spar member when tighten- 
ing said bolt, said wedge section having wedge sur- 
faces engaging said cam surfaces on said strap 
means, and said base section engaging the bottom 
of said strap means to support said strap means 
while said wedge section is drawn relative to said 
base section to move said cam surfaces into said 
spar member and draw said end panels against said 
spar member. 
2. A joint arrangement as defined in claim 1 where- 
5 in said cam surfaces on said strap means comprises in- 
clined, flat surfaces supported in spaced relationship to 
said end panels, said wedge surfaces having the same 
taper as said cam surfaces and engaging said cam surfaces 
on the sides thereof facing said end panels. 
3. A joint arrangement as defined in claim 1 wherein 
lo said spar member has assembly openings displaced from 
the openings for said strap means, said tightening bolts 
being accessible from the exterior of said spar member 
through said assembly openings. 
4. In a joint arrangement for attaching extending mem- 
bers to a central member having a longitudinal axis, by 
inserting cam means on the ends of said extending mem- 
bers through openings in said central member and clamp- 
ing said cam means on said extending members trans- 
clamp means located within said central member and 
engaging said cam means for drawing said extend- 
ing means into engagement with said central member; 
said clamp means comprising a base section, tightening 
bolt, and a wedge section, said sections connected 
together for relative movement transversely to said 
longitudinal axis of said central member by tighten- 
ing said bolt; 
said wedge section having a wedge surface engaging 
30 said cam means; and 
said base section engaging the bottom of said cam 
means to support said cam means whrile said wedge 
section is drawn transversely relative to said longi- 
tudinal axis of said central member toward said 
base section by said bolt to move said cam means in- 
to said central member and draw said extending 
members against said central member, said wedge 
and base sections applying the sole force on said 
cam means. 
5. In a joint arrangement as defined in claim 4 where- 
in said cam means have cam surfaces that comprise in- 
clined, flat surfaces supported in spaced relationship to 
said extending members, said wedge surfaces having the 
same taper as said cam surfaces and engaging said cam 
45 surfaces on the sides thereof facing said extending mem- 
bers. 
References Cited 
15 
20 versely together inside said central member: 
25 
35 
40 
50 
58 
60 
UNITED STATES PATENTS 
2,582,657 111952 Serner _ _ _ _ _ _ _ _ _ _ _ _  52-584 X 
2,759,574 811956 Miller _ _ _ _ _ _ _ _ _ _ _ _ _  52-720 X 
2,962,133 11/1960 Kivett et al. _ _ _ _ _ _ _ _ _ _  52-580 
3,062,339 11/1962 Geyser _ _ _ _ _ _ _ _  287-189.36 X 
FOREIGN PATENTS 
589,029 12/1959 Canada. 
585,965 311947 Great Britain. 
FRANK L. ABBOTT, Primary Examiner. 
A. C. PERHAM, Assistant Examiner. 


Central spar and module joint Patent

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