U.S. patent number RE40,657 [Application Number 10/812,342] was granted by the patent office on 2009-03-10 for pull pin assembly for canopy.
This patent grant is currently assigned to Caravan Canopy International, Inc.. Invention is credited to Dong Tack Suh.
United States Patent |
RE40,657 |
Suh |
March 10, 2009 |
**Please see images for:
( Certificate of Correction ) ** |
Pull pin assembly for canopy
Abstract
A pull pin assembly includes: a first pole having a first hole;
a second pole having a second hole, and sliding in the first pole;
a main body having a central hollow containing the first pole; a
pull pin body extending radially from the central hollow, and
having a space extending into the central hollow; a pull pin,
having a circumferential stop, disposed in the space to move from a
first position extending into the central hollow through the first
hole to a second position outside the central hollow; a pull pin
plug fit into the space and having a hollow containing the pull
pin; and a biasing member biasing the pull pin toward the
.[.second.]. .Iadd.first .Iaddend.position to lock the first and
second poles; wherein the biasing member is disposed to bias the
pull pin between the circumferential stop and the pull pin
plug.
Inventors: |
Suh; Dong Tack (Yong-in,
KR) |
Assignee: |
Caravan Canopy International,
Inc. (La Mirada, CA)
|
Family
ID: |
25340769 |
Appl.
No.: |
10/812,342 |
Filed: |
March 29, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
09863282 |
May 24, 2001 |
06575656 |
Jun 10, 2003 |
|
|
Current U.S.
Class: |
403/109.3;
135/114; 135/131; 135/140; 135/142; 403/109.1; 403/109.6;
403/109.7; 403/109.8; 403/379.5 |
Current CPC
Class: |
E04H
15/46 (20130101); E04H 15/50 (20130101); F16B
7/105 (20130101); Y10T 403/32467 (20150115); Y10T
403/32524 (20150115); Y10T 403/7088 (20150115); Y10T
403/7077 (20150115); Y10T 403/32483 (20150115); Y10T
403/32508 (20150115); Y10T 403/32516 (20150115) |
Current International
Class: |
F16B
7/10 (20060101) |
Field of
Search: |
;403/109.1,109.2,109.3,109.5,109.6,109.7,109.8,378,379.4,379.5
;135/139,140,141,142 ;248/188.5,354.5,407,408,409,423 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
3604497 |
|
Aug 1987 |
|
DE |
|
3841254 |
|
Jun 1990 |
|
DE |
|
26436 |
|
Dec 1923 |
|
FR |
|
8959 |
|
May 1891 |
|
GB |
|
24959 |
|
Nov 1911 |
|
GB |
|
658490 |
|
Oct 1951 |
|
GB |
|
Other References
UK Search Report under Section 17 for Application No. GB0506622.0,
May 6, 2005 (1 page); Combined Search and Examination Report under
Sections 17 & 18(3) for Application No. GB0506622.0, May 11,
2005 (1 page). cited by other .
Combined Search and Examination Report under Section 17 and 18(3)
for Application No. GB0424247.5, Jan. 17, 2005, The Patent Office,
South Wales. cited by other .
International Preliminary Examination Report for PCT/US02/08162,
Nov. 14, 2003. cited by other.
|
Primary Examiner: Ferguson; Michael P
Attorney, Agent or Firm: Christie, Parker & Hale,
LLP
Claims
What is claimed is:
1. A pull pin assembly, comprising: a first rod or pole, having a
first hole and a second notch or hole; a second rod or pole, having
.Iadd.a .Iaddend.third hole, the second rod or pole being slidably
contained within the first rod or pole, so that the first hole is
superimposable on the third hole; a main body, having a central
hollow dimensioned to contain the first rod or pole, and having at
least one resilient tab, the resilient tab being cut out from the
main body and having a boss thereon extending into the central
hollow to engage the second notch or hole of the first rod or pole;
a pull pin body integral with the main body and extending radially
outward from the central hollow, said pin body having a space
therein extending into the central hollow; a pull pin slidably
disposed in the space of the pull pin body to move from a first
position extending into the central hollow through the first hole
to a second position outside of the central hollow; and a biasing
member biasing the pull pin toward the .[.second.]. .Iadd.first
.Iaddend.position to relatively lock the first rod or pole and the
second rod or pole when the first hole is superimposed on the third
hole.
2. A pull pin assembly according to claim 1 further comprising a
pull pin plug fit into the space of the pin body, the pull pin plug
having a hollow dimensioned to slidably contain the pull pin, said
pull pin having a circumferential stop, wherein the biasing member
is disposed to bias the pull pin between the circumferential stop
and the pull pin plug, and wherein the circumferential stop is
dimensioned to prevent the pull pin from passing completely through
the first hole in the .[.second.]. .Iadd.first
.Iaddend.position.
3. A pull pin assembly according to claim 2, wherein said pull pin
comprises a circumferential tongue, wherein said pull pin plug
comprises a radial groove, wherein, the pull pin has a first
engageable position in which the circumferential tongue is movable
in the radial groove, and a second, disengaged position, wherein
the pull pin is .[.radially.]. pulled against a biasing force of
the biasing member to come out of the radial groove and rotated so
that the circumferential tongue is biased against the pull pin
plug.
4. A pull pin assembly according to claim 3, wherein the pull pin
plug is friction fit into the space of the pull pin body.
5. A pull pin assembly according to claim 3, wherein the pull pin
comprises a .[.traverse.]. .Iadd.transverse .Iaddend.hole near a
distal end removed from the central hollow, and further comprising
a pull ring disposed in the transverse hole to prevent the pull pin
from passing completely through the pull pin body.
6. A pull pin assembly according to claim 2, wherein the pull pin
plug is friction fit into the space of the pull pin body.
7. A pull pin assembly according to claim 2, wherein the pull pin
comprises a transverse hole near a distal end removed from the
central hollow, and further comprising a pull ring disposed in the
transverse hole .[.to prevent the pull pin from passing completely
through the pull pin body.]. .
8. A pull pin assembly according to claim 2, wherein said pull pin
plug is countersunk and friction fit into said pull pin body.
9. A pull pin assembly according to claim 1, wherein .[.the.].
.Iadd.a .Iaddend.pull pin plug is friction fit into the space of
the pull pin body.
10. A pull pin assembly according to claim 1, wherein the pull pin
comprises a transverse hole near a distal end removed from the
central hollow, and further comprising a pull ring disposed in the
transverse hole .[.to prevent the pull pin from passing completely
through the pull pin body.]. .
11. A pull pin assembly according to claim 1, wherein the central
hollow, first rod or pole and second rod or pole all have square
cross sections.
12. A pull pin assembly according to claim 1, wherein said main
body further comprises a lip disposed to engage an end of said
first rod or pole.
.[.13. A pull pin assembly, comprising: a first rod or pole, having
a first hole; a second rod or pole, having a second hole, the
second rod or pole being slidably contained within the first rod or
pole, so that the first hole is superimposable on the second hole;
a main body, having a central hollow dimensioned to contain the
first rod or pole; a pull pin body integral with the main body and
extending radially outward from the central hollow, said pin body
having a space therein extending into the central hollow; a pull
pin slidably disposed in the space of the pull pin body to move
from a first position extending into the central hollow through the
first hole to a second position outside of the central hollow, said
pull pin having a circumferential stop; a pull pin plug fit into
the space of the pin body, the pull pin plug having a hollow
dimensioned to slidably contain the pull pin; and a biasing member
biasing the pull pin toward the second position to relatively lock
the first rod or pole and the second rod or pole when the first
hole is superimposed on the second hole; wherein the biasing member
is disposed to bias the pull pin between the circumferential stop
and the pull pin plug, and wherein the circumferential stop is
dimensioned to prevent the pull pin from passing completely through
the first hole in the second position..].
.[.14. A pull pin assembly according to claim 13, wherein said pull
pin comprises a circumferential tongue, wherein said pull pin plug
comprises a radial groove, wherein, the pull pin has a first
engageable position in which the circumferential tongue is movable
in the radial groove, and a second, disengaged position, wherein
the pull pin is radially pulled against a biasing force of the
biasing member to come out of the radial groove and rotated so that
the circumferential tongue is biased against the pull pin
plug..].
.Iadd.15. A pull pin assembly according to claim 1 wherein the
first rod or pole comprises an end and the main body extends around
the end of the first rod or pole..Iaddend.
.Iadd.16. A pull pin assembly according to claim 2 wherein the
circumferential stop is dimensioned to prevent more than a
predetermined length of the pull pin from extending into the
central hollow in the first position..Iaddend.
.Iadd.17. A pull pin assembly, comprising: a first rod or pole,
having a first hole; a second rod or pole, having a second hole,
the second rod or pole being slidably contained within the first
rod or pole, so that the first hole is superimposable on the second
hole; a main body, having a central hollow dimensioned to contain
the first rod or pole; a pull pin body integral with the main body
and extending radially outward from the central hollow, said pin
body having a space therein extending into the central hollow; a
pull pin slidably disposed in the space of the pull pin body to
move from a first position extending into the central hollow
through the first hole to a second position outside of the central
hollow, said pull pin having a circumferential stop; a pull pin
plug fit into the space of the pin body, the pull pin plug having a
hollow dimensioned to slidably contain the pull pin; and a biasing
member biasing the pull pin toward the first position to relatively
lock the first rod or pole and the second rod or pole when the
first hole is superimposed on the second hole; wherein the biasing
member is disposed to bias the pull pin between the circumferential
stop and the pull pin plug, and wherein the circumferential stop is
dimensioned to prevent the pull pin from passing completely through
the first hole in the first position, and wherein the main body
comprises at least one resilient tab having a boss thereon
extending into the central hollow to engage a second notch or hole
of the first rod or pole..Iaddend.
.Iadd.18. A pull pin assembly, comprising: a first rod or pole,
having a first hole; a second rod or pole, having a second hole,
the second rod or pole being slidably contained within the first
rod or pole, so that the first hole is superimposable on the second
hole; a main body having a central hollow dimensioned to contain
the first rod or pole; a pull pin body adjacent to the main body
and extending outward from the central hollow, said pin body having
a space therein extending into the central hollow; a pull pin
disposed in the space of the pull pin body to move from a first
position extending into the second hole to a second position not
extending into the second hole; and a biasing member biasing the
pull pin toward the first position to relatively lock the first rod
or pole and the second rod or pole when the first hole is
superimposed on the second hole, wherein the main body is fixed
against movement along the first rod or pole when the pull pin is
in the second position, wherein the first rod or pole further
comprises a third notch or hole and wherein the main body is fixed
against movement along the first rod or pole in the second position
by a boss extending between the main body and the first rod or
pole, and wherein the boss is formed on a resilient tab on the main
body, the boss extending into the central hollow to engage the
third notch or hole of the first rod or pole..Iaddend.
.Iadd.19. A pull pin assembly according to claim 18 wherein
resilient tab is cut out from the main body..Iaddend.
.Iadd.20. A pull pin assembly, comprising: a first rod or pole,
having a first hole; a second rod or pole, having a second hole,
the second rod or pole being slidably contained within the first
rod or pole, so that the first hole is superimposable on the second
hole; a main body, having a central hollow dimensioned to contain
the first rod or pole; a pull pin body adjacent to the main body
and extending outward from the central hollow, said pin body having
a space therein extending into the central hollow; a pull pin
disposed in the space of the pull pin body to move from a first
position extending into the second hole to a second position not
extending into the second hole, said pull pin having a
circumferential stop; a pull pin plug having a hollow dimensioned
to slidably contain the pull pin; and a biasing member biasing the
pull pin toward the first position to relatively lock the first rod
or pole and the second rod or pole when the first hole is
superimposed on the second hole; wherein the biasing member is
disposed to bias the pull pin between the circumferential stop and
the pull pin plug, and wherein the circumferential stop is
dimensioned to prevent more than a predetermined length of the pull
pin from extending into the central hollow in the first position,
wherein the main body is fixed against movement along the first rod
or pole when the pull pin is in the second position, wherein the
main body is fixed against movement along the first rod or pole by
a boss extending between the main body and the first rod or pole,
and wherein the first rod or pole further comprises a third notch
or hole and wherein the boss is formed on a resilient tab, the boss
extending into the central hollow to engage the third notch or hole
of the first rod or pole..Iaddend.
.Iadd.21. A pull pin assembly according to claim 20, wherein the
resilient tab is cut out from the main body..Iaddend.
.Iadd.22. A pull pin assembly, comprising: a first rod or pole,
having a first hole, a second notch or hole, a third notch or hole
and an end; a second rod or pole having a fourth hole, the second
rod or pole being slidably contained within the first rod or pole,
so that the first hole is superimposable on the fourth hole; a main
body, having a first wall and a central hollow dimensioned to
contain the first rod or pole, the main body extending around the
end of the first rod or pole and having an opening on the first
wall leading into the central hollow, the main body further having
two resilient tabs, the resilient tabs being cut out from
substantially opposite sides of the main body and having bosses
therein, each boss extending into the central hollow to engage a
different one of the second notch or hole and the third notch or
hole and to fix the main body against movement along the first rod
or pole; a pull pin body integral with the main body and extending
from the first wall away from the central hollow and surrounding an
area of the first wall containing the opening, such that the
surrounded area forms a ledge; a pull pin plug disposed in the pull
pin body, the pull pin plug having a central opening and a surface
facing the central hollow; a pull pin extending through the central
opening of the pull pin plug to move from a first position
extending into the fourth hole to a second position not extending
into the fourth hole, said pull pin having a circumferential stop;
and a biasing member disposed between the circumferential stop and
the surface of the pull pin plug facing the central hollow, the
biasing member biasing the pull pin toward the first position to
relatively lock the first rod or pole and the second rod or pole
when the first hole is superimposed on the fourth hole, wherein the
ledge is dimensioned to abut the circumferential stop such that no
more than a predetermined length of the pull pin can extend into
the central hollow in the first position..Iaddend.
Description
FIELD OF THE INVENTION
The present invention relates to a pull pin assembly, particularly
to a pull pin assembly for a portable canopy. More particularly,
the present invention relates to a pull pin assembly that is easy
to produce, assemble, and use.
BACKGROUND OF THE INVENTION
Portable canopies are known which fold out, and expand or telescope
from a compact, storage state to an expanded, folded out and
erected state. Such canopies have wide application, for example,
for various recreational uses, and as temporary shelters. Such
canopies also have wide application for commercial uses, such as
temporary sales booths or display booths for conventions, fairs,
and the like.
One such typical canopy is shown in FIG. 1. In the FIG. 1, canopy
10 comprises a frame 4, on which a canopy cover 5 and side panels 6
and 7 are draped. The frame 4 comprises a roof of expandable
scissor-like members 9, four supporting telescoping corner uprights
8, and two side rails 3. The supporting corner uprights 8 further
comprise telescoping poles or rods 11 and 12, and a locking means
1, for locking the poles or rods 11 and 12 in a desired expanded
position. The locking means for locking poles or rods 11 and 12 in
the erected, expanded position have traditionally been difficult to
assemble and mount, unnecessarily complicated, and often
unreliable.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a
locking means, particularly one for a portable canopy, which is
easy to assemble, easy to mount, uncomplicated and reliable.
In accordance with the present invention there is provided a pull
pin assembly comprising: a first rod or pole, having a first hole
and a second notch or hole, and a second rod or pole, having third
hole, the second rod or pole being slidably contained within the
first rod or pole, so that the first hole is superimposable on the
second hole. A main body is provided having a central hollow
dimensioned to contain the first rod or pole, and having at least
one resilient tab, the resilient tab being cut out from the main
body and having a boss thereon extending into the central hollow to
engage the second notch or hole of the first rod or pole. A pull
pin body is provided integral with the main body and extending
radially outward from the central hollow, the pin body having a
space therein extending into the central hollow. A pull pin is
slidably disposed in the space of the pull pin body to move from a
first position extending into the central hollow through the first
hole to a second position outside of the central hollow. A biasing
member biases the pull pin toward the .[.second.]. .Iadd.first
.Iaddend.position to relatively lock the first rod or pole and the
second rod or pole when the first hole is superimposed on the
second hole.
The pull pin assembly according to the present invention preferably
further comprises a pull pin plug fit into the space of the pin
body, the pull pin plug having a hollow dimensioned to slidably
contain the pull pin, the pull pin also having a circumferential
stop, wherein the biasing member is disposed to bias the pull pin
between the circumferential stop and the pull pin plug, and wherein
the circumferential stop is dimensioned to prevent the pull pin
from passing completely through the first hole in the second
position.
In a further embodiment, the pull pin comprises a circumferential
tongue, wherein said pull pin plug comprises a radial groove,
wherein, the pull pin has a first engageable position in which the
circumferential tongue is movable in the radial groove, and a
second, disengaged position, wherein the pull pin is radially
pulled against a biasing force of the biasing member to come out of
the radial groove and rotated so that the circumferential tongue is
biased against the pull pin plug.
The pull pin plug is friction fit into the space of the pull pin
body. In a still further embodiment, the pull pin comprises a
radial hole near a distal end removed from the central hollow, and
further comprising a pull ring disposed in the radial hole to
prevent the pull pin from passing completely through the pull pin
body.
The central hollow, first rod or pole and second rod or pole all
preferably have square cross sections. The main body preferably
further comprises a lip disposed to engage .[.and.]. .Iadd.an
.Iaddend.end of said first rod or pole. The pull pin plug is
preferably countersunk and friction fit into the pull pin body.
In a still further embodiment, the present invention provides a
pull pin assembly, comprising: a rod or pole, having a hole; and a
main body, having a central hollow dimensioned to contain the rod
or pole. A pull pin body is preferably provided integral with the
main body and extending radially outward from the central hollow,
the pin body having a space therein extending into the central
hollow. A pull pin is slidably disposed in the space of the pull
pin body to move from a first position extending into the central
hollow through the first hole to a second position outside of the
central hollow, the pull pin having a circumferential stop. A pull
pin plug is fit into the space of the pin body, the pull pin plug
having a hollow dimensioned to slidably contain the pull pin. A
biasing member is provided biasing the pull pin toward the
.[.second.]. .Iadd.first .Iaddend.position to relatively lock the
first rod or pole and the second rod or pole when the first hole is
superimposed on the second hole. In this .[.embedment.].
.Iadd.embodiment.Iaddend., the biasing member is disposed to bias
the pull pin between the circumferential stop and the pull pin
plug, and wherein the circumferential stop is dimensioned to
prevent the pull pin from passing completely through the first hole
in the second position. Preferably, the pull pin comprises a
circumferential tongue, wherein the pull pin plug comprises a
radial groove, wherein, the pull pin has a first engageable
position in which the circumferential tongue is movable in the
radial groove, and a second, disengaged position, wherein the pull
pin is radially pulled against a biasing force of the biasing
member to come out of the radial groove and rotated so that the
circumferential tongue is biased against the pull pin plug.
Further objects, features and advantages of the present invention
will become apparent from the Detailed Description of Preferred
Embodiments, which follows, when considered together with the
attached Figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a typical, portable canopy, such as one in which the
present invention may be applied.
FIG. 2 is a partially cut-away, perspective view of a pull pin
assembly according to a preferred embodiment of the present
invention.
FIG. 3 is a cross section of the pull pin assembly of .Iadd.one
embodiment of .Iaddend.the present invention.
FIG. 4 is a further cross section of the pull pin assembly of the
.[.present invention.]. .Iadd.embodiment shown in FIG.
3.Iaddend..
FIG. 5 is .[.yet another.]. .Iadd.a .Iaddend.cross section of the
pull pin assembly .[.of the present invention.]. .Iadd.of FIG. 4
.Iaddend.taken .[.alone.]. .Iadd.along .Iaddend.the line I--I .[.in
FIG. 4.]. .
FIG. 6 is a top view cross section of the pull pin assembly of
.[.the present invention.]. .Iadd.FIG. 3.Iaddend..
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The pull pin assembly of the present invention will now be
described, with reference to the drawings and in relation to
certain preferred embodiments. In the Figs., like parts are
referred to with like reference numerals.
FIG. 2 shows a preferred embodiment of the pull pin assembly 20 of
the present invention. Main body 21 is fit over an end of pole 12
of an upright 8 of portable canopy 10 .Iadd.(as shown in FIG.
1).Iaddend.. .[.A.]. .Iadd.As shown in FIGS. 2 and 6, a
.Iaddend.resilient tab 26 is cut out from main body 21 by slots 28,
and a boss 27 on tab 26 engages a hole 60 to fix the main body 21
to the assembly .Iadd.20.Iaddend.. In this manner, the main body
can be easily fixed to pole 12 without the necessity of special
tools or adhesives. While the body 21 is also preferably friction
fit to pole 12, tab 26 and boss 27 ensure that the main body 21 is
securely fit to pole 12, without the necessity for precise
tolerances. While only one tab 26 is visible in FIG. 2, the
preferred embodiment has a corresponding, symmetrically-arranged
second tab 26 on a side of pole .[.11.]. .Iadd.12 .Iaddend.not seen
in the FIG. 2. A second boss 27 fit into second hole 60 is shown in
FIG. 6. The number.Iadd., .Iaddend.size, and dimensions of
resilient tabs 26 can be varied, however.
A pull pin body 22, integral with main body 21 extends radially
outward from main body 21. A pull pin 24 is slidably contained in
the pull pin body 22. At a distal end of pull pin 24 is a pull ring
25 fitted through a transverse hole 34 .Iadd.(shown in FIG. 3)
.Iaddend.at the distal end of pin 24. As .Iadd.shown in FIG. 3 and
as .Iaddend.will be discussed further below, pulling pull pin 24
from a first position in which the pin extends through two
superimposed holes 36, 37 into a central hollow 62 of the assembly
to a second position outside of the hollow, release pole 11 from
pole 12 so as to allow relative movement of poles 11, 12 in the
direction of the double headed arrow of FIG. 3. In the present
embodiment, poles 11 and 12 have a square cross section.
FIG. 3 shows a cross section of the assembly according to .Iadd.one
embodiment of .Iaddend.the present invention. In FIG. 3, pull pin
24 is shown in the second position, outside of central hollow 62.
As discussed above, pull pin 24 is slidably contained inside pull
pin body 22 within a space 30 and a hole 51 in plug 23. Plug 23 is
countersunk and preferably friction fit into pull pin body 22
.Iadd.(shown in FIG. 5) .Iaddend.to maintain its position. A spring
32 serves as a biasing member to bias the pull pin 24 toward the
first position in which the pull pin 24 extends into the central
space 62. Spring 32 acts between an inner space 39 of plug 23 and a
circumferential stop 31 of pull pin 24. A hole 35 is provided at
the end of space 30 closest to the central hollow 62. The hole 35
is surrounded by a circumferential ledge 38 having a circumference
substantially the same as space 30. In FIG. 3, hole 35 is
superimposed on likewise superimposed holes 36 and 37 of poles 12
and 11, respectively. Also shown in FIG. 3, is lip 40 of main body
21. Lip 40 serves not only to protect the end of pole 12 from
damage, but also to guide pole 11 as it slides in and out of pole
12 in a telescopic manner to extend and collapse upright 8.
FIG. 4 shows a cross section identical to .Iadd.the embodiment
shown in .Iaddend.FIG. 3, except that pull pin 24 is in the first
position, extending through holes 35, 36, 37 into central hollow
62, thus locking poles 11 and 12 together. FIG. 4 also shows that
circumferential stop 31 also serves to prevent more than a
predetermined length of pull pin 24 from extending past hole 35, by
abutting against circumferential ledge 38.
FIG. 5 shows a cross section along line I--I in FIG. 4. As shown in
FIG. 5, a tongue 33 is provided on the outer circumference of pull
pin 24. Tongue 33 slides within a groove 50 provided in hole 51 of
plug 23. As shown in FIG. 2, when the pull pin 24 is moved from the
first position to the second position, tongue 33 comes out of
groove 50 allowing pull pin 24 to be rotated from position A to
position B .Iadd.(as shown in FIG. 2).Iaddend.. In position B, the
groove is biased toward an outer surface of plug 23 and the pin is
held by friction in the second position. In this locked, second
position, the poles 11 and 12 are, of course, free to move relative
to one another and the upright 8 can be extended or collapsed, as
described. Pull pin 24 is moved from position B to position A by
pulling pull pin 24, by means of pull ring 25, slightly outward
against the biasing force of spring 32, rotating pull pin 24 by
means of ring 25, positioning tongue 33 at an entrance to groove 50
and releasing pull ring 25 so that pull pin 24 once again moves
toward the first position by the biasing force of spring 33. Also
shown in FIG. 2 are several holes 37, each of which can be
superimposed on holes 35 and 36, so that, when the pull pin is
moved back through holes 35, 36, 37 to the first position, poles 11
and 12 are once again relatively locked together as shown, for
example, in FIG. 4.
As shown in FIG. 5, groove 50 is provided on opposite sides of hole
51 in plug 23. Groove 50 may also be provided on only one side of
hole 51. More than one groove 50 can also be provided, if desired.
It is further possible to leave out the function represented by
tongue 33 and groove 50 so that pull pin 24 rotates freely within
hole 51, in cases where it is not necessary for the pull pin 24 to
be lockable in the second position.
FIG. 6 is a top view cross-section showing the pin 24 in the first,
locked position. In the embodiment described above, as can be seen
for example in FIG. 6, poles 11, 12, central space 62 and inner
wall 61 of main body 21 that defines central space 62 are all
square in cross section. Other functional shapes are possible
however. Triangular, rectangular, hexagonal, octagonal, circular,
oval and other useful geometric cross sections also fall within the
scope of the present invention.
While the present invention has been described in terms of certain
preferred embodiments, one of ordinary skill in the art of the
invention will recognize that additions, deletions, substitutions,
modifications and improvements can be made while remaining within
the scope and spirit of the invention as defined by the attached
claims.
* * * * *