Flexible line support assembly

An assembly for supporting a flexible service line between a base structure and an object body mounted to the base structure for movement about lateral and elevation gimbal axes includes lateral and elevation drums fixedly mounted to the body and base structure, respectively, and an arm interconnecting the drums. A spiral groove is defined in the periphery of each drum for receiving looped portions of the flexible line therein. The arm supports a portion of the line extending between its looped portions. Also, the arm is rotatably mounted at its opposite ends to the drums for accommodating relative movement between the body and base structure about the respective gimbal axes. The looped portions of the flexible lines are confined in the grooves on the drums and may expand and contract therein as the body moves relative to the base structure about the gimbal axes.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention broadly relates to devices for supporting a flexible 
line and, more particularly, is concerned with an assembly employing 
spirally-grooved drums for supporting a flexible line against movements 
induced by accelerations and vibrations in a space environment. 
2. Description of the Prior Art 
Large bodies, such as telescopes, antennae and the like, intended for use 
in a space environment usually require that flexible lines, such as fluid 
conduits and electrical cable, be coupled between a base structure and the 
object body while the body is reoriented or steered during operations. For 
example, a large telescope intended for depolyment from the space shuttle 
or other space platform would require such interconnecting lines. 
Ordinarily, the provision of slack in such flexible lines for accommodating 
movement and steering of the object body relative to the base structure 
would entail leaving portions of the flexible lines unsupported which, 
under normal operational vibrations and accelerations, could easily move 
about and cause damage to other equipment as well as disable functioning 
of the reoriented object body. Consequently, a need exists for some 
support arrangement which will continuously confine a flexible line but 
allow sufficient slack therein for accommodating relative movement between 
parts interconnected by the line. 
SUMMARY OF THE INVENTION 
The present invention provides a support assembly designed to satisfy the 
aforementioned needs. The unique feature of the assembly is a pair of 
support drums having deep spiral grooves about the peripheries thereof. 
The grooves in the drums receive and confine looped or wound portions of a 
flexible line while allowing outward expansion and inward contraction 
thereof within the drum grooves so as to provide slack in the line for 
accommodating relative movement of parts interconnected by the line. Thus, 
as an object body is slued or reoriented relative to a base structure, the 
looped portions of the line expand or contract in circumference within the 
deep grooves on the drum peripheries, while the sides of the grooves 
support the slack, looped portions of the line against movements induced 
by accelerations and vibrations. 
Accordingly, the present invention is directed to an assembly for 
supporting a flexible line between a base structure and an object body 
mounted to the base structure for movement about first and second 
orthogonal axes. The assembly includes: (a) a first support drum mounted 
on the base structure and coaxially aligned with the first axis; (b) a 
second support drum mounted on the object body and coaxially aligned with 
the second axis; (c) means defined on each of the first and second support 
drums for receiving looped portions of the flexible line and confining the 
same about the drums such that the lines can expand and contract about the 
drums as the object body moves relative to the base structure about the 
first and second axes; and (d) an arm interconnecting the first and second 
support drums and supporting a portion of the flexible line which 
interconnects the looped portions thereof. In particular, the means 
defined on each of the first and second support drums is in the form of a 
wall which traverses a spiral peripheral path around each drum so as to 
define a spiral groove of sufficient depth to allow the circumference of 
each looped portion of the flexible line to expand outwardly, or contract 
inwardly, within the groove while laterally supported by the drum wall.

DETAILED DESCRIPTION OF THE INVENTION 
Referring now to the drawings, and more particularly to FIGS. 1 and 2, 
there is shown the preferred embodiment of the flexible line support 
assembly of the present invention, being generally designated 10. The 
assembly 10 preferably is used to support a flexible service line 12 which 
interconnects relatively movable parts, such as a base structure 14 of a 
space platform (not shown) and an object body 16 in the form of a 
telescope (a small portion of which is shown). The object body 16 is 
mounted by a gimbal structure 18 (the parts connecting body 16 to 
structure 18 being omitted for sake of clarity) to the base structure 14 
for rotational movement about orthogonally-arranged lateral axis L and 
elevation axis E defined by the gimbal structure 18. The flexible service 
line 12, commonly in the form of electrical cable, fluid conduit and the 
like, must have slack in the portion thereof which extends between the 
base structure 14 and body 16 for accommodating movement of the body with 
respect to the structure about the gimbal axes L, E. 
The flexible line support assembly 10 allows for the provision of slack in 
the flexible line 12. The assembly 10 basically includes a lateral drum 
20, an elevation drum 22 and an arm 24 which interconnects the drums. 
The lateral drum 20 has a hub 26 and a continuous wall 28 (see FIG. 3) 
which traverses a spiral or helical peripheral path around the hub so as 
to define a deep spiral groove 30. Likewise, the elevation drum 22 has a 
hub 32 and a continuous wall 34 which traverses a spiral or helical 
peripheral path around the hub so as to define a deep spiral groove 36. 
The flexible service line 12 has wound or looped portions 38, 40 preformed 
to fit over-sized or loosely within the corresponding grooves 30, 36 on 
the drums 20, 22. The respective grooves 30, 36 are of sufficient depth to 
receive and confine therein the looped line portions 38, 40, while 
allowing outward expansion and inward contraction of the line portions 
within the respective grooves 30, 36. Also, during such expansion and 
contraction, the line is laterally supported within the grooves by the 
respective drum walls 28, 34. If desired, removable confining straps (not 
shown) may be installed across grooves 30 of drums 20, 22 to provide 
additional capability for retaining line 12 therein. 
The lateral drum 20 is stationarily or fixedly mounted on the body 16 by a 
standoff bracket 42 so as to be coaxially aligned with lateral axis L. The 
elevation drum 22 is stationarily or fixedly mounted on the base structure 
14 by another standoff bracket 44 so as to be coaxially aligned with 
elevation axis E. However, the arm 24 at its opposite ends is coupled to 
the lateral and elevation drums 20, 22, respectively, by support brackets 
46, 48 and self-aligning ball bearings 50, 52 for rotation about the 
lateral and elevation axes L, E. The range of movement of the body 16 and 
drum 20 relative to the arm 24 is represented by dash arrow A in FIG. 3, 
while the range of relative movement of arm 24 to the base structure 12 
and drum 22 is represented by dashed arrow B in FIG. 2. In such manner, 
movement of the drums 20, 22 relative to one another is accommodated by 
the arm 24. Also, a hinge 54 is incorporated by the arm 24 which allows it 
to articulate at a location generally intermediate between its opposite 
ends. The hinge augments the ability of the arm to accommodate relative 
motion of the drums. Particularly, the arm 24 is installed and rigged with 
the hinge 54 folded a predetermined displacement which is enough to 
compensate for any relative change of location between opposite ends of 
the arm 24. Such hinge displacement precludes transmission to the gimbal 
structure 18 of any loads induced by such relative location changes during 
gimbal translations. Moreover, the grooves 30, 36 on the drums 20, 22 are 
aligned generally transversely to the respective lateral and elevation 
axes L, E. Therefore, as the looped line portions 38, 40 expand outwardly, 
or contract inwardly, within their respective grooves as the body 16 and 
drum 20 therewith move relative to the base structure and drum 22, the 
looped portions move in planes generally parallel to those in which the 
body moves relative to the base structure about the gimbal axes L, E. 
The looped portions 38, 40 of the flexible service line 12 are maintained 
in their respective positions wound about drums 20, 22 by clamping 
standoffs 56, 58 attached respectively the arm 24 and the base structure 
12. Also, a portion 60 of the flexible service line 12 extending between 
its looped portions 38, 40 is attached to the arm by circular brackets 62, 
64. 
It is readily apparent, therefore, that the flexible line support assembly 
10 accommodates two dimensional movement of the object body 16 relative to 
the base structure 14, that is, movement about lateral and elevation axes 
L, E defined by gimbal structure 18. While it was mentioned that the 
assembly 10 was designed for use in a space environment, it also has broad 
applicability to terrestrial activities. 
It is thought that the flexible line support assembly of the present 
invention and many of its attendant advantages will be understood from the 
foregoing description and it will be apparent that various changes may be 
made in the form, construction and arrangement of the parts thereof 
without departing from the spirit and scope of the invention or 
sacrificing all of its material advantages, the form hereinbefore 
described being merely a preferred or exemplary embodiment thereof.