Note: Descriptions are shown in the official language in which they were submitted.
6~L8 .~1103
TITLE: ~ ~
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VERTICALLY ADJUSTA~LE SUPPORT LEG
5BACKGROUND OF THE :[NVENTION
Field of the Invention
The present invention relakes generally to a leg for
supporting a structure, and more particularly to a
support leg that is adjustable in the vertical
direction to easily adju~t the height of the structure
being supported.
The support leg can be used to support, for example, a
table or multiple shelves. The number of legs needed
to support such structure can ~ary from one, two,
three, four, or more, depending on the size, design,
and shape of the s~ructure and its environment.
One aspect of the present in~ention makes use of a
mounting assembly of the type disclosed U.S. Patent No.
3 1 523, 508 (Ma~low). The mounting assembly in that
patent is used in conjunction with an adjustable
shelving system comprisiny a formed-wire shelf
component having a frustoconically shaped collar at
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each corner for receiving a support post. Each collar
tapers outwardly toward its lower extremity when viewed
in normal use. Generally cylindrical support posts,
each having a plurality of uniformly spaced annular
5 grooves formed in its outer surface, are secured to the
shelf by the mounting assembly. Each mounting assembly
comprises at least two separate mounting members which
are joined about and at least partially surround the
support post to define a unitary sleeve having an
10 complementary frustoconically shaped outer surface.
Thus, the mounting sleeve is thickes~ at its bottom .-
portion than at its top. The sleeves are sized to fit
snugly wichin the shelf collars. An annular rib formed
on an insicLe surface of each sleeve is sized to engage
15 the annular groove formed on the ~upport post. t
_scription of the Prior Art
Vertically adjustable legs for supporting various types
of structures have been known for many years. For
example, U.S. Patent No. 2,705,119 (Ingwer) discloses a
pipe support stand that is adjustable in the vertical
direction. An inner column having a series of spaced
annular grooves is supported within a hollow outer
pipe. Steel balls are supported in holes in the outer
pipe by a ring and serve to secure the inner column by
engaging one of the annular grooves. The steel balls
are released from the engaged annular groove by sliding
the ring to allow the inner column to be vertically
adjusted. When the inner column is set at the desired
height the ring i9 manipulated to bias the steel balls
into engagement with another annular groove.
Another prior art example is provided in a footrest
mounsi~g assembly disclosed in U.S. Patent No.
3,458,234 (Bates). This patent discloses a
compressible plastic sleeve that i9 disposed around a
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vertical tube for supporting a seat. The outer face of
the sleeve is tapered to have a wider lower end and
slidably carries thereon an annular collar with a
similar tapering or frustoconical shape. The collar
forms the central part of a footrest that is supported
on ~he tube by compressing the sleeve around the tube.
To adjust the height of the footrest, the collar is
lifted slightly to release tne compressive force on the
sleeve, and both the sleeve and collar can be moved up
or down the tube to the desired height.
While systems such as ~ose discussed above are known,
further improvements in vertically adju~table support
legs are desirable.
SUMM~RY OF THE INVENTION
It is an ob;ect o~ the present invention to provide a
vertically adjustable support leg that improves upon
supporting legs known in the art. It i9 another object
of the present invention to provide improvements that
utilize a relatively simple and uncomplicated structure
that provides significant strength, reliability and
load-supporting capability.
It is still another object of the pres2nt invention to
provide a vertically adjustable support leg that is
readily adju~ted with minimal ef~ort, without tools,
and provides high ~trength, stability and rigidity.
It is yet another object of the preRent invention to
provide a simple and economical means for providing a
vertically adjustable supporting leg that can support
substantial loads.
In accordance with one aspect of the invention, the
vertically adjustable supporting leg comprises an outer
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shaft having an axial opening at one end, and an inner
shaft shaped to fit telescopically within the axial
opening of the outer shaft. A sleeve is mounted about
the inner shaft for securing the inner shaft within the
axial opening of the outer shaft and can include
engaging means for engaging the inner shaft. -
In accordance with another aspect of the inven.ion, the
sleeve is comprised oE two mounting members with a
frustoconically shapecl outer surface. The axial
opening in the first leg has a complementary-shaped
frustoconical surface f~r radially compressing the
sleeve about the inner shaft and securing the inner
shaft within the outer shaft.
In accordance with still another aspect of the
invention, a supporting leg comprises a first leg
having a first diameter and an axial opening at one
end, a second leg having a seconcl diameter smaller than
the first diameter and insertable telescopically into
the axial opening, and a sleeve nnountable at different
heights on the second leg for securing the second leg
within the axial opening of the iirst leg.
These and other objects, aspects, features and
advantages of the present invention will become
apparent from the following detailed description of the
preferred embodiment taken in conjunction with the
accompanying drawings.
~RIEF DESCRIPTION OF THE DRAWINGS
Figure 1 i9 a vertical cross-sectional view of the
vertically adjustable support leg in an assembled state
in accordance with the present invention; and
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Figure 2 is a perspective view, partially in vertical
cross-section, of the elements comprising the
vertically adjustable support leg in an unassembled
state in accordance with the present invention. t
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For convenience, the support leg of the present
invention will be described in this specification and
set forth in the concluding claims as if it is in a
vertical attitude.
A vertically adjustable support leg 10 in accordance
with the subject invention is shown in Figure 1. The
support leg comprises a first leg section, or outer
shaft, 12 and a second leg section, or inner shaft, 14
insertable telescopically into an axial opening 16 in
the bottom of the outer shaft.
The outer shaft is preferably circular in cross-section
and includes a plurality of spaced annular grooves 18
provided on its outer sur~ace. The top end of the
outer shaft extends upwardly to support, for example, a
table top or the outer sha~t can support one or more
structures such a~ shelves in the manner described, for
example, in U.S. Patent No. 3,523,508 (Maslow), which
is incorporated herein by reference.
The axial opening 16 of the outer shaft, as best seen
in Figure 2, is designed to recei~e the upper end of
the inner shaft 14. This axial opening, described in
detail below, may be formed integrally with the outer
shaft or may be formed as a separate insert member as
shown in the Figures, which i5 received in the lower
end of the outer shaft. A lower portion of the axial
opening 16 has a frustoconically shaped, or tapered,
surface 20 with a widest opening 22 at the bottom end
of the outer shaft. The upper portion of the axial
opening is sized slightly larger than the outer
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dlameter of the inner shaft. The portion of the outer
shaf~ 12 that extends above the axial opening can be
hollow to reduce the weight and cost of the supporting
leg.
The inner shaft 14 is also preferably cylindrical,
hollow and includes, at leas~ at its upper end, a
series of preferably regularly spaced annular grooves
24.
The inner shaft 14 is formed to be telescopically
inserted into the axial opening 16 of the outer shaft
12 and secured therein by ~ mounting assembly, or
sleeve, 30~ As best seen in Figure 2, the sleeve 30 is
comprised of two separate, complementary sleeve mernbers
32 and 34, each formed with a cylindrical inner surface
and an annular interior rib 31 for engaging any one of
the annular grooves 24 on the outer surface of inner
shaft 14. Each assembled sleeve 30 has a downwardly,
outwardly fru~toconically shaped exterior surface 40.
The frustoconical shape of the surface of the sleeve 30
is seen in Figure 1 to generally correspond to or
complement the frustoconical inner surface 20 of the
axial opening in the outer shaft 12.
The vertical edges of each sleeve are formed with a
respective tongue 36 and 38 groove arrangement. The
tongue and groove of each sleeve member complement the
same arrangement on the other sleeve member. Further,
each sleeve member 32 and 34, in cross ~ection extends
around in inner shaft by more than 180 degree~, thereby
to embrace the shaft.
Thu~ ~he sleeve member~ may be as~embled around the
35 inner shaft to define the unitary sleeve 30 that tapers ~.
outwardly toward its lower extreme when viewed in
normal use, that is, it i9 thicker at its bottom than
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at its top. The sleeve may be secured to the inner
shaft 14 at increment positions by engagement of the
ribs 31 in one of the grooves 24, with the a tapered
exterior mating surface 40 prepared to engage the
frustoconical surface 20 of the axial opening.
The outer shaft and inner shaft can be made of metal or
plastic, and the sleeve is preferably made of a plastic
polymeric material. Additionally, while described as
cylindrical, the shafts may have other cross-sectional
shapes without departirg from the teaching of the
subject invention. Sti11 further, the sleeve 30 may be
formed a~ a one piece member or as two portions hinged
toyether, ~or example, by a "living-hinge."
To assemble the supporting leg, the sleeve members are
placed about the inner shaft 14 such that the annular
rib 31 formed by their assembly on their inside surface
engages a groove 24 on the inner shaft at the desired
height. The inner shaft with the sleeve mounted
thereon i9 then inserted into the axial opening until
the sleeve firmly grips the inne!r shaft by virtue of a
compressing force supplied by engaging the
frustoconical surfaces 20 of the axial opening and
complementary surface 40 of the sleeve. Thi~
arrangement is shown best in Figure 1.
The load from the outer shaft and, when the supporting
leg is positioned for use, the supported structure
produces a wedging action between the tapered exterior
ma~ing surface 40 of the sleeve and the frustoconically
surface 20 in the axial opening. The wedging action
provides a radially inwardly directed force to bring
the sleeve 30 into a locking relation with the inner
shaft 14, and an outwardly directed force is exerted by
the sleeve on the surface 20 in the axial opening to
secure the inner shaft within the outer shaft. As the
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load supported by the leg increases, both the radially
inwardly directed force and the outwardly directed
force increase.
To adjust vertically the height of the leg, the outer
shaft and the inner shaft are forced axially in
opposite directions relative to each other to relieve
the wedging force and al.low the inner shaft and sleeve
to be withdrawn from the axial opening of the outer
shaft. The sleeve can be repositioned to engage a
different groove on the inner shaft and then inserted
back into the axial ope.~ing of the outer shaft as
discussed above.
:L5 As shown in Figure 1, an adjustable foot pad 26 can be
threadedly engaged with the bottom of th~ inner shaft
14 in conventional fashion to permit minor height
adjustment of the supporting leg, independent of the
gross adjustment provided by the locking sleeve-axial
opening configuration of the present invention.
An optional removable locking ring 42, shown in phantom
view in Figure 1, or comparable locking means can be
provided to secure the sleeve within the axial opening
and prevent the inner and outer shafts from relative
axial movement in opposite directions. In this manner,
the assembled structure can be lifted off the ground
without the possibility of the inner shaft sliding out
of the outer shaft.
Accordingly, it will be appreciated that the present
invention pro~ides a novel supporting leg that can
easily and reliably be adjusted in the vertical
direction to change the length of the leg. The tapered
35 sleeve can be removably mounted at different heights on i~
the inner shaft and then secured by a wedging action
when the inner shaft is in~erted into the tapered axial
i 9 i~
opening of the outer shaft. For these and other
reasons described above in detail, the present
invention provides substantial improvements over known
vertically adjustable supporting legs.
Although a specific embodiment of the present invention
has been described above in detail, it will be
understood that this clescription is merely for purposes
of illustration. Various modifications of and
equivalent structures corresponding to the disclosed
aspects of the preferred embodiment in addition to
those described above may be made by those skilled in
the art without departins from the spirit of the
present invention which is defined in the following
claims, the scope of which is to be accorded the
broadest interpretation so as to encompass ~uch
modifications and equivalent structures.
