Note: Descriptions are shown in the official language in which they were submitted.
Background of the Invention
.
This invention relates to a strut for use in
snap-together construction sets, and particularly to such
a strut which allows close coupling of the joint elements
of the construction set.
A construction set having multi-faceted joint
elements with openings in each facet, configured to
receive snap fitting clip fasteners located on each end
of the elongate struts for joining a plurality of the
struts into a structure is shown in U.S. Patent 4,129,975.
While construction sets of this type are a great improve-
ment over prior art sets and allow construction of many
structural shapes heretofore not possible, they do
have a shortcoming which forecloses their use in certain
applications. In particular, it is not possible to pro-
vide a short strut to join adjacent joint elementsin close proximity to one another since the clips on the
strut have to be squeezed in order to release them from
the joint elements, and close spacing of the facets of
the respective joint elements does not allow insertion
of the user's finger between them to squeeze the clips.
I Also, if the strut element is to be used as
an axle, in addition to necessarily having to be quite
short in order to reduce its moment arm, it must have means
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allowing it to he rotatably joined to the joint elements.
This combination of features is not provided with the prior
art devices of this class.
Summ-ary of the Invention
The strut of the present invention is used to
interconnect hollow joint elements of the type having
multiple angularly displaced planar facets which contain
elongate joint openings therein. The strut comprises a
pair of clips which extend outwardly from one another in
opposite directions along a common axis. The clip includes
a ~-shaped tip having a width which is slightly less than
the width of the joint openings and an overall transverse
dimension at its base which is slightly greater than the
height o~ the joint openings. Located inwardly adjacent
to the ends of the base are bridge sections which inter-
connect the respective base ends of the tips of opposed clips,
thereby forming the strut into an integral unit. The overall
transverse dimension between the bridge sections is approxi-
mately equal to the height of the joint openings, thereby
forming a step between the tips and the bridge sections.
Accordingly, as a tip of a clip is forced into a joint
opening the clip is deflected inwardly until the ends of
the tip are fully inserted into the opening whereupon
the clip is relaxed to lock it in place in the opening.
In the embodiment illustrated the length of the bridge
sections is quite short and they are separated by trans-
verse extension sections which are configured so that
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the portion of the bridge section remaining on each side
of the extension is slightly larger than the thickness of the
joint element side walls. The extension sections extend out-
wardly of the bridge sect;on past the periphery of the facets
into which the clips are installed so that the bridge sections
can be squeezed together to release the clips from the openings
in the joint elements by application of squeezing pressure on
the extens~on sections.
The bridge sections have arcuate top surfaces so
la that when they are installed into circular joint openings
which are located at each end of the joint element, the strut
can be rotated with respect to the joint element.
Accordingly, it is a principal objective of the
present invention to provide a strut of the class described
which allows very close coupling of adjacent joint elements.
It is a further object of the present invention
to provide such a strut having clips which rotatably engage
with those joint openings which are circular.
The foregoing objectives, features and advantages
2a of the present invention will be more readily understood
upon consideration of the following detailed description of
the invention taken in conjunction with the accompanying
drawings.
Brief Description of the Drawings
FIG. 1 is a perspective view showing a preferred
embodiment of the clip of the present invention.
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FIG. 2 is a side elevational view of the clip of
FIG. 1.
FIG. 3 is a sectional view taken on the line 3-3
in FIG. 2.
FI~. 4 is a side elevational view, partially broken
away, showing the clip installed in a joint element.
FIGS. 5, 6`& 7 are side elevational views, partially
broken awa~, showing the sequence of installing the strut into
two of the joint elements.
F~G. 8 is a plan view of one of the joint elements
with which the strut is used.
Detailed Description of the Invention
.
Referring to the drawings, the strut 10 of the
present invention is uséd to interconnect hollow joint
elements 12 of the type having multiple angularly displaced
planar facets 14, each containing a medial joint opening 16.
The joint elements preferably have 26 facets which are
arranged in a generally spherical pattern. The joint
openings located in the facets preferably are elongate to
2a give maximum strength in a limited facet area.
The strut, best shown in FIG. 1, comprises a
pair of clips 18 which extend outwardly from one another
in opposite directions along a common axis. The clip is
a thin, easily deformable plastic element and includes a
V-shaped tip 20 having a width which is slightly less than
the width of joint opening 16, except for its extremity 21
which taper inwardly. Located in the tip intermediate
its ends, is a short, flat indentation 22.
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As is best shown in FIG. 4, the indentation allows the
clip to be installed into a snap fit interlocking build-
ing blocks 31, having an appropriately sized receptacle.
In the embodiment illustrated the top and bottom of the
tip from indentation 22 outwardly are planar, and from the
indentation inwardly they are arcuate. The base ends of
the tip have an overall transverse dimension which is
slightly greater than the height at the joint openings.
Located inwardly adjacent to each base end of
the tip is a bridge section 24 which interconnects the
respective ends of the tips of opposed clips thereby
forming the strut into an in~egral unit. The bridge
sections have the same width as the tip but the overall
transverse distance between them is approximately equal
to the height of the joint openings thereby forming a
step 25 between each tip and its associated bridge
sections. The top of the bridge sections are arcuate so
that they tightly interfit with the arcuate top and bot-
tom of the joint openings, and the length of the bridge
sections is quite short, preferably positioning adjacent
facets of joint elements interconnected by the strut less
than .25 inches apart.
An extension section 26 extends transversely
from each bridge section to allow squeezing pressure to
be applied between them to allow the clips to be
depressed for removal from the joint openings without
the user's fingers interfering with the joint element.
In the embodiment illustrated the extension
section is an upstanding U-shaped integral medial pro-
trusion of the bridge with an enlarged head 28 at its
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end to facilitate gripping it. Paired tabs 30 located
on the heads are configured to engage with the afore-
mentioned snap type interlocking building blocks 31 as
shown in FIG. 4.
The width of each extension section 26 is
such that the portion of bridge section 24 remaining on
each side of it are slightly longer than the thickness
of the joint element side walls 32, FIG. 4. Therefore,
when the clips of the strut are installed in adjacent
joint elements the respective facets 14 thereof are
closely adjacent to the sides of the extension section.
In operation clip 18 of strut 10 is inserted
into a joint opening 16 of a joint element 12 by placing
the apex of tip 20 into the opening, FIG. 5, and urging
the strut toward the joint element. Accordingly, the
clip is deflected inwardly about the apex of the tip,
FIG. 6, until step 25 passes side wall 32 of the joint
element, and the clip again is free to expand to its
relaxed position with bridge sections 24 located adja-
cent to the top and bottom of the joint openings, FIG. 7.
In this position the strut cannot be separated from the ~-
joint element by merely applying tensile force due to
the engagement of side wall 32 by step 25. To release
the clip, bridge sections 24 are squeezed together to
deflect the tips 20 inwardly and thereby release step
25 from side wall 32.
When joint elements are attached to the clips
at both ends of a strut, the joint elements are closely
adjacent which faciliates building certain types of
structures. Extensions 26, therefore, are used to
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squeeze the bridge sections together for removal of the
strut when the user's finger cannot be inserted between
the joint elements to squeeze the bridge sections directly.
It will be noted that when a clip is installed
in a joint opening 16, the elongate shape of the clip and
opening causes a tight fit therebetween. Therefore, the
clip and joint element are prevented from rotating relative
to one another.
However, if the clip is inserted into one of
the circular openings 16', FIG. 8, located in the end of
the joint eIements, the arcuate surfaces on bridge sections
24 aerve as a bearing surface thereby allowing the strut to
rotate relative to the joint element. Therefore, as shown
in FI~. 7, by placing the clip at one end of a strut into
one of the elongate joint openings of a first joint element,
and placing the clip at the other end of the strut into one
of the circular openings 16l, in the end of a second joint
element, the second joint element is rotatable relative to
the first joint element. Accordingly, the first joint ele-
2Q ment can be incorporated into a structure and the secondjoint element used for example as the hub of a wheel.
The terms and expressions which have been employed
in the foregoing abstract and specifications are used therein
as terms of description and not of limitation, and there is
no intention, in the use of such terms and expressions, of
excluding equivalents of the features shown and described or
portions thereof, it being recognized that the scope of the
invention is defined and limited only by the claims which
follow:
