U.S. patent number 3,891,334 [Application Number 05/401,017] was granted by the patent office on 1975-06-24 for cross brace interlock.
This patent grant is currently assigned to Buildex Incorporated. Invention is credited to Frank Loikitz.
United States Patent |
3,891,334 |
Loikitz |
June 24, 1975 |
Cross brace interlock
Abstract
A coupling between a vertical tubular leg and a horizontal
tubular brace includes an expander member bolted to the leg and
projecting radially outwardly and having an elongated transverse
cross section with diametrically opposite cylindrically convex
faces. An expansion collar having a bore of oval shape rotatably
engages the expander member and has longitudinal and
circumferential slots delineating opposing expansion fingers. The
brace slideably engages the expansion collar which is rotated by a
hand tool to cam expand the fingers into tight locking engagement
with the brace inside face.
Inventors: |
Loikitz; Frank (Middletown,
NJ) |
Assignee: |
Buildex Incorporated
(Huntington, NY)
|
Family
ID: |
23585925 |
Appl.
No.: |
05/401,017 |
Filed: |
September 26, 1973 |
Current U.S.
Class: |
403/234;
403/192 |
Current CPC
Class: |
F16B
7/0446 (20130101) |
Current International
Class: |
F16B
7/04 (20060101); F16b 007/04 () |
Field of
Search: |
;403/234,237,230,192,187,199,297,350 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schroeder; Werner H.
Attorney, Agent or Firm: Wolder & Gross
Claims
I claim:
1. A structural assembly comprising a first structural member, a
coupling member mounted on and projecting from said first
structural member and including an axially extending expander
section of non-circular transverse cross section and an expansion
collar engaging said expander section and having a non-circular
bore with a minor transverse dimension less than the major
transverse dimension of said expander section and being expandable
and contractable in response to angular variation between said
expander section and expansion collar, and a second structural
member having a bore axially slideably engaging said collar, said
collar being rotatable relative to said expander member between a
collar contracted condition with the major axis of said expander
section and said collar bore coinciding permitting relative axial
movement between said coupling member and said second structural
member and a collar expanded condition locking said second
structural member to said coupling member with the major axes of
said collar bore and said expander section being relatively
angularly offset.
2. The structural assembly of claim 1 wherein said collar has a
pair of diametrically opposed longitudinally extending slots formed
therein extending to the outer end thereof to define a pair of
opposite expandable fingers.
3. The structural assembly of claim 2 wherein said collar has
formed therein peripheral slots extending from the inner ends of
said longitudinal slots in a common direction to points short of
the respective opposite longitudinal slots.
4. The structural assembly of claim 3 wherein each of said
peripheral slots terminates in a short forwardly extending
longitudinal slot.
5. The structural assembly of claim 2 wherein said collar bore is
of oval transverse cross section with its major axis extending
between said longitudinal slots.
6. The structural assembly of claim 5 wherein said expander section
has peripherally cylindrical convex diametrically opposed end faces
spaced along the major axis thereof.
7. The structural assembly of claim 5 wherein the outer face of
said collar is of circular cylindrical configuration when said
collar is in its unstressed condition and said second structural
member bore is of circular cylindrical configuration.
8. The structural assembly of claim 2 including a circular
cylindrical head integrally formed at the base of said expander
section and having a peripherally extending groove formed therein,
the inner portion of said collar being of circular transverse cross
section and rotatably engaging said head, and a follower pin
projecting from said collar inner portion into sliding engagement
with said groove.
9. The structural assembly of claim 8 wherein said collar inner
portion has a tool receiving recess formed in its outer face.
10. The structural assembly of claim 1 wherein said first
structural member comprises a tube and including an internally
threaded sleeve affixed to and projecting radially through an
opening in said tube, said expander member having an axial bore and
a concave cylindrical face at its inner end matingly engageing the
outer face of said tube, and a bolt extending through said expander
member bolt and engaging said threaded sleeve to lock said coupling
member to said tube.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to improvements in frame
construction and it relates more particularly to an improved
coupling device for rigidly interconnecting vertical frames, legs
and horizontal brace members.
Many support structures are in the form of rigid frames which
include vertical legs and horizontal brace members interconnecting
the legs. Typical of such structures are the supporting
substructures of tables, counters, platforms, cabinets and the
like. Such structures should be rigid, of light weight and provide
a minimum of hinderance to access to the space delineated by the
substructure. A conventional expedient is to weld horizontal cross
brace members between the vertical legs. However, such practice
possesses numerous drawbacks and disadvantages. The on site
assembly of such structures is highly time consuming resulting in
products of non-uniform and often inferior quality, requires highly
skilled labor, close tolerances are difficult and often impossible
to attain and it otherwise leaves much to be desired. Moreover,
these same drawbacks apply even in the factory assembly of such
structures, and in addition, the shipping, handling and storing of
the assembled structures are diffucult and expensive. Not only is
the welding procedure difficult, but the welds must often be ground
and polished for sanitary and visual appearing reasons.
SUMMARY OF THE INVENTION
It is a principal object of the present invention to provide an
improved frame structure.
Another object of the present invention is to provide an improved
structural member connection.
Still another object of the present invention is to provide an
improved rigid coupling between angulary related structural
members.
A further object of the present invention is to provide an improved
coupling device for interconnecting vertical tubular legs and
horizontal tubular cross braces which is assembled and locked with
a leg and brace by means of a simple hand tool.
Still a further object of the present invention is to provide a
device of the above nature characterized by its reliability,
ruggedness, simplicity, great versatility and adaptability and the
ease, rapidity and convenience of application.
The above and other objects of the present invention will become
apparent from a reading of the following description taken in
conjunction with the accompanying drawing which illustrates a
preferred embodiment thereof.
In a sense, the present invention contemplates the provision of an
assembly of first and second structural members by a coupling
member mounted on the first structural member and including an
axially extending expander section of non-circular cross section
and an expansion collar rotatably engaging the expander section and
having a non-circular bore with a minor transverse dimension less
than the major transverse dimension of the expander section, the
second structural member having a bore slideably engaging the
collar when the collar is in its contracted condition with the
major axes of the expander section and collar coinciding. By
turning the collar on the expander section, the collar is expanded
into firm locking engagement with the section structural member
thereby providing a rigid connection between the structural
members.
In the preferred form of the assembly, the structural members are
tubular the first defining a support leg and the second a cross
brace. The expander section is mounted in the leg by an axial bolt
and is of elongated transverse cross section with opposite curved
end faces. The expansion collar is provided with diametrically
exposed longitudinal slots extending to its free outer edge and
joined at their inner ends by circumferentially extending slots to
delineate a pair of opposite expansion fingers. In its unstressed
state the collar outer face is of circular transverse cross section
and its bore is of oval transverse cross section with its major
axis extending between the longitudinal slots. The base of the
collar is enlarged and provided with a hand tool receiving
recess.
The improved coupling device and the assembly effected thereby are
reliable, rugged and simple and are of great versatility and
adaptability.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded front elevational view of the improved
coupling device and the associated leg structural member shown
partially in section;
FIG. 2 is a front elevational view, partially in section, of the
assembled coupling member and structural members;
FIG. 3 is a sectional view taken along line 3--3 of FIG. 2;
FIG. 4 is a sectional view taken along line 4--4 in FIG. 2;
FIG. 5 is a view similar to FIG. 4 but with the coupling shown in a
locked condition;
FIG. 6 is a sectional view taken along line 6--6 in FIG. 2; and
FIG. 7 is a perspective view of a table employing the improved
structural assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing which illustrates a preferred
embodiment of the present invention as applied, by way of example,
to a table or counter structure 10, the reference numeral 11
generally designates the table support frame which includes a
horizontal rectangular top panel 12. Depending from the corners of
top panel 12 and secured to the underface thereof are vertical
tubular legs 13. The lower portions of adjacent legs 13 are
interconnected by horizontal tubular brace members 14 whose ends
are rigidly connected to corresponding legs 13 by means of coupling
devices 16 constructed in accordance with the present
invention.
The coupling device 16 primarily includes an expander section 17
and an expansion collar 18 and fastening means for connecting the
expander section 17 to a tubular leg 13. The expander section 17 is
integrally formed of metal and consists of an inner base portion
19, an intermediate bearing portion 26, and an outer and expander
portion 21, a longitudinal axil bore 22 being formed in the
expander section 17.
The inner base portion 19 is of cylindrical configuration and has a
concave cylindrical face 23 mating the outer face of leg member 13,
the bore 22 having an enlarged counterbore 24 at the rear face 23.
The intermediate bearing portion 20 is likewise of circular
cylindrical configuration coaxial with the base portion 19 and of
smaller diameter, being delineated from the base portion by a
peripheral shoulder 26. Projecting axially outwardly from bearing
portion 20 is the relatively longitudinally elongated expander
portion 21 which has diametrically opposite parallel longitudinally
extending side faces 27 and diametrically opposite longitudinally
extending convexly curved end faces not extending radially beyond
the plane of the peripherial face of intermediate section 20 and
preferably substantially coincident therewith at the medial
longitudinal sections of the faces 28 whose longitudinal borders
are spaced shortly inwardly of such plane. The forward edges of
expander portion 21 are beveled as at 29. A peripherally extending
channel or groove 30 is formed in the outer face of intermediate
portion 20.
The expansion collar 18 surrounds the expander portions 20 and 21
and is rotatably supported by and coaxial with expander member 17
and includes an enlarged base portion 32 which rotatably engages
bearing portion 20 and a forwardly projecting expansion portion 33
integrally formed with base portion 32. A follower pin 34 is fixed
in a radial bore in collar base portion 32 and slideably engages
channel 30 to permit rotation of expansion collar 18 in expander
section 17 while preventing their relative axial movement. Also
formed in the collar base 32 is a tool receiving radial bore 36.
The expansion portion 33 in its unstressed state has a circular
cylindrical outside face of lesser diameter than that of base
portion 32 and delineated therefrom by a peripheral shoulder
37.
The bore 38 is collar base portion 32 and the immediately adjacent
part of expansion portion 33 is circular whereas the bore of the
remainder of expansion portion 33 is oval or ecliptical with the
dimension along its major axes being approximately equal to or
slightly greater than that of expander portion 27 and the dimension
along its minor axis being less than that along the major axis of
expander portion 27. The leading edge of expansion portion 38 is
beveled as at 39.
A pair of diametrically opposite longitudinal slots 40 are formed
in collar expansion portion 33 at opposite ends of the major axis
of bore 38 and extends from the free edge of expansion portion 33
to points short of the base portion 32. Extending from the inner
end of each longitudinal slot 40, counter clockwise, as viewed in
FIGS. 4 and 5, to points short of the opposite slots 40 are
circumferentially extending slots 41 which terminate in short
forwardly extending slots 42. The slot 40, 41 and 42 delineate a
pair of opposite arcuate expansion fingers on wings 43 whose medial
longitudinal sections are of greater thickness than the outer
parallel longitudinal edges thereof, the fingers 43 tapering
inwardly from its medial longitudinal axis to the opposite
longitudinal edges the inner faces of the fingers 43 defining cam
surfaces.
An internally threaded bushing or sleeve 44 engages an opening in
leg 13 and projects radially inwardly and is firmly anchored to the
wall of leg 13 by axially spaced peripheral flanges or lips
embracing the border of the opening in the known manner. The
expander section 17 is affixed to a leg 13 by an allen head bolt 46
extending through bore 22 and engaging the threaded anchor bushing
44. The end face 23 of base portion 19 embraces the outer face of
leg 13 with the outwardly projecting portion of bushing 44 nesting
in the counterbore 24.
In connecting a tubular brace member 14 to the leg 13 by means of
the coupling device 16 a corresponding end of the brace member 14
is axially slipped into engagement with the expansion collar 18 and
slid to bring its end edge into abutment with the peripheral
shoulder 37 on expansion collar 33. Thereafter, a suitable lever
tool such as a rod 47 or the pin of a suitable spanner wrench is
inserted into the tool receiving bore 36, as shown in FIG. 4, and
the expansion collar 18 forcibly turned with a predetermined
torque, as shown in FIG. 5. With the turning of expansion collar 18
relative to expander member 17 which is maintained stationary by
reason of its attachment and relationships to leg 13 the inner
faces of the thicker portions of the opposite fingers 43 which
faces define cam surfaces are engaged by corresponding curved end
faces 28 of expander portion 21 to expand or spread the fingers 43
outwardly into a tight wedging engagement with the inside face of
the brace member 14 whereby to effect a locked rigid connection
between the leg and brace members.
The degree of rotation of expansion collar 18 relative to the
expansion section 17 is limited by the length of channel 30. The
same procedure is followed in connection with each of the brace
members 14 between each corresponding pair of legs 13. If desired,
the brace and leg may be disconnected by rotating the collar 18 in
an opposite direction to bring the major axes of expander portion
21 and bore 28 into coincidence whereby fingers 43 contract to
release the brace member 14 for axial sliding out of engagement
with expansion collar 18.
While there has been described and illustrated a preferred
embodiment of the present invention it is apparent that numerous
alterations, omissions and additions may be made without departing
from the spirit thereof.
* * * * *