Note: Descriptions are shown in the official language in which they were submitted.
The present invention relates to a collapsible space
frame~
Collapsible space frames have many uses. They are used
as suE)ports for various structures, including tents and umbrellas.
They may also be used to support such things as reflectors for
light and electromagnetic radiation.
An object of the present invention is to provide an
umbrella-like space frame that may readily be erected by the
manipulation of a single component of the frame and that provides
an interior space entirely free of support members.
According to the present invention there is provided
a collapsible space frame comprising:
a hub with a longitudinal axis;
a plurality of arms;
pivot means mounting the arms on the hub at positions
spaced about the longitudinal axis for pivoting movement of each
arm about a respective tranqverse axis be~ween a collapsed
position extending substantially longitudinally from the hub and a
deployed position projecting substantially radially from the hub;
thruqt means mounted on the hub for axial movement
therealong, the thrust means engaging each arm at a position
radially spaced from the aqsociated transverse axis for applying a
moment to each arm so as to pivot the arm from the collapsed to
the extended position.
With this arrangement, the thruqt means may be advanced
along the hub to pivot the arms from their collapsed to their
extended positions. Where desired, a flexible canopy can be
placed over the space frame so that aq it expands, it extends the
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canopy into a dome-like shape.
It is preferred that the frame arms are resilient ribs
secured at their ends adjacent the hub to rib heads. The heads
are pivoted to the hub and are in turn engaged by the thrust means
as it advances along the hub to extend the frame. The thrust ring
is preferably driven along the hub by an actuator ring threaded
onto a shank of the hub.
In the accompanying drawings, which illustrate an
exemplary embodiment of the invention:
Figure 1 is a perspective view of a frame with a canopy
in an extended condition, the canopy being shown only in part;
Figure 2 is an elevation partially in section, of the
frame in a collapsed condition:
Figure 3 is a view like Figure 3, with the frame in a
collapsed condition, the view being taken along line lII-III of
Figure 4;
Figure 4 is a plan view of the frame in an extended
condition; and
Figure 5 is an exploded view of the components of the
hub.
Referring to the drawings, and particularly to Figure 1,
there is illustrated a space frame 10 consisting of a central hub
12 and a plurality of resilient arms 14 radiating from the hub.
The arms are encompassed by a flexible canopy 16 that is stretched
by the arms into a dome-like shape. The interior of the dome is
entirely open and unobstructed by frame supports.
Figures 2 through 5 illustrate the space frame hub
mechanism in somewhat more detail. The hub consists of a central
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cylindrical spindle 20 with a thread 21 at one end and a radial
flange 22 at the other. The radial flange has a number of radial
slots 24 extending in from the outer peripheral face 25 and an
annular groove 26 in its top face, so that the axial cross section
of the flange is generally L-shaped. An annular notch 28 in the
outer peripheral face 25 surrounds the flange 22 slightly below
its top face.
The arms 14 of the space frame are equal in number to
the radial slots 24 in the spindle flange 22. Each arm 14
consists of a resilient rib 30 projecting from a plate-like head
32. As illustrated in Figure 2, the head 32 has a bevelled upper
face 36 that leads to a rounded nose 38 at the inner uppermost
corner. The heads 32 fit into respective ones of the slots 24 and
are held in place by a pivot wire 34 passing through a bore in
each plate and seated in the annular notch 28 of the flange 22.
The arrangement iB such that each head 32 can pivot between the
collap~ed position illustrated in Figure 2, where the rib is
substantially parallel to the axis of the spindle 20, and an
extended position in which the rounded nose 38 of the head is
pivoted radially inwardly and downwardly and the rib 30 projects
radially from the hub.
A thrust ring 40 is a sliding fit over the spindle 20.
The thrust ring has a generally rectangular cross section, with a
chamfer 42 at the bottom outer edge. The bottom face of the
thrust ring 40 is of sufficient size that it engages the rounded
noses 38 of all of the heads 32 in the collapsed condition of the
frame, as illustrated in Figure 2. Because this contact iR
radially inwards from the pivot wire 34, movement of thrust ring
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40 towards the flange 22 will apply a moment to each head 32
tending to pivot it around the piv~t wire from the collapsed
position (Figure 2) to the extended condition (Figure 3). In the
extencled condition, the chamfer 42 abuts the bevelled face 36 of
each head 32 to provide an end position for the pivoting movement
of the arms.
A thrust washer 44 is positioned on top of the thrust
ring 40 to provide a bearing between the thrust ring and an
actuator 46 consisting of a nut 48 threaded onto the spindle 20
and a hand wheel 50 fixed to the nut. The actuator 46 is retained
in place on the spindle 20 by a spring clip 52 which fits within
groove 51.
To extend the frame from its collapsed condition
illustrated in Figure 2 to its extended condition illustrated in
Figure~ 3 and 4, the hand wheel 50 is rotated to drive the nut 48
and thus the thrust ring 40 along the spindle 20. This rotates
each of the heads 32 about the pivot wire 34 until its bevelled
face 36 comes into abutment with the chamfer 42 on the thrust ring
40. Collapsing the frame is the reverse procedure.
Where the frame is equipped with a canopy, the resilient
ribs stretch the canopy to provide a dome configuration with a
precise shape dictated by the configuration of the canopy. This
extended frame and canopy assembly may be used for such
applications as solar collectors and intensifiers, antennas of
variable shape and temporary lightweight storage units, shelters
etc., depending on the size and characteristics of the canopy.
In the illustrated embodiment, the spindle 20 is shown
with an axial through bore 54 that can be u~ed either for mounting
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the hub 12 on another structure or for the passage of electrical
leads, tubes and the like.
While one embodiment of the present invention has been
desczibed in detail, it is to be understood that other embodiments
are possible without departing from the scope of the invention.
The invention is intended to be limited solely by the scope of the
appended claims.
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