Application of movable joints for spacesuits to orthotic and prosthetic devices is discussed. Specifications of the joints, degrees of movement, and details of construction are described. Illustrations of the equipment are provided

Vykukal, H. C.

English

NASA Technical Reports Server

Sptember 1972	 B72-10297 
NASA TECH BRIEF 
Ames Research Center
	 4r 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Space Suit May Have Orthotic Applications 
The joints designed for use in a space suit must re-
main hermetically sealed and be neutrally stable. The 
principle of a rotating pseudoconic (stovepipe) joint 
and the fabrication techniques employed to construct 
the space suit could provide the basis for a variety of 
new orthotic and prosthetic devices. 
Plan	 Elevation 
Seal and bearing friction must be minimal in order 
for the stovepipe joint (figure above) to be acceptable 
and efficient. The deflection torques are directly pro-
portional to friction and the angle at which the diag-
onal bearing is oriented with the longitudinal axis of 
the joint. Additionally, the angle of the diagonal bear-
ing with respect to the longitudinal axis determines 
the range of motion of the joint. For example, a diag-
onal bearing oriented at 400 with the axis joint allows 
for ±100° or a total of 200° of motion. However, 
should the diagonal bearing be allowed to rotate into 
a position where it is at 900 with the plane of motion, 
the joint will become locked because frictional forces 
are at 90° to the bending forces. To prevent this 
locking, stops are placed On the bearing, essentially 
blanking out ±10 * of relative joint segment rotation 
about the lock point. The problem of providing a 
minimum of 150° flexion in the knee and thigh joints,
to permit normal leg mobility, was solved by incorpo-
rating a metal bellows in the lower segment of the 
joints to allow for 90° of motion (or an additional 
600). A cross-section of the seal and bearing configura-
tion developed to meet the above requirements is 
shown in the figure below. Rotary torque of the seal 
and bearing was 45.4 mm-kg (4 in-lb). 
Aluminum Rousing 
Four Point	 Teflon Surface 
Contact Steel
 
Ball Bearing	 Glass Fibers
Suit Structure 
Retainer	 \ Acetal Resin Seal
0-Ring (2 places) 
The nonmovable portions of the suit are made of a 
segmented structure comprised primarily of a tri-
angular-matrix honeycomb glass fiber. To form the 
segments, a triangular matrix defined by polyurethane 
mandrels was covered with a continuous-weave fiber 
cloth and placed over a mold. The cloth was saturated 
with an epoxy resin, and then the mold and matrix 
were placed in a vacuum bag attached to a pump to 
provide uniform pressure over the glass cloth during 
curing. After curing, the mandrels were withdrawn 
and the ends of the triangular cavities were filled to 
provide a uniform bonding surface. Aluminum bear-
ing-and-seal housings and metal bellows were bonded 
to the nonmovable portions of the suit with an epoxy 
resin.
(continued overleaf) 
This document was prepared under the sponsorship of the National
	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States 	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States
	 will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19720000296 2020-03-17T03:28:18+00:00Z
Reference: 
Vykukal, H.C.: Advanced Developments in Hard 
Space Suit Technology. Journal of Engineering for 
Industry, November 1968, page 577. 
Notes: 
1. Athetoid movements of neurologically handicapped 
patients could be minimized by placing the exo-
skeletal joint system on the patient and, with a 
damping system incorporated in the bearing hous-
ings, the large-amplitude motions of the wearer 
could be reduced or totally controlled, thus allow-
ing the patient to become more Self sufficient. 
2. No additional documentation is available. Specific 
questions, however, may be directed to: 
Technology Utilization Officer 
Ames Research Center 
Moffett Field, California 94035 
Reference: B72-10297
Patent status: 
This invention has been patented by NASA (U.S. 
Patent No. 3,636,564). Inquiries concerning nonexclu-
sive or exclusive license for its commercial develop-
ment should be addressed to: 
NASA Patent Counsel 
Mail Code 200-1A 
Ames Research Center 
Moffett Field, California 94035 
Source: Hubert C. Vykukal

Ames Research Center

(ARC-10275) 
B72-10297	 Category 05, 06


Space suit may have orthotic applications

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