U.S. patent number 3,675,957 [Application Number 05/018,071] was granted by the patent office on 1972-07-11 for locking connection for supporting grid systems.
This patent grant is currently assigned to Flangeklamp Corporation. Invention is credited to Earl Abbott, Robert Paul Lickliter, John F. Reeves.
United States Patent |
3,675,957 |
Lickliter , et al. |
July 11, 1972 |
LOCKING CONNECTION FOR SUPPORTING GRID SYSTEMS
Abstract
A first support member having a web with a slot therein and a
second support member having a web upstanding from a pair of
laterally extending support flanges and a locking connector formed
integral with the web and extending axially therefrom for insertion
in the slot. The connector has a locking tab engageable behind one
side of the first support member web. The second support member has
an offset end portion forming a continuation of the support flanges
and adapted to overlie the first support member support flanges.
The offset portion is provided with a transverse edge engageable
with the other side of the first support member web to provide a
rigid connection between the first and second support members. The
offset portion has a thickness less than one-half the thickness of
the support flanges with which it is integrally formed.
Inventors: |
Lickliter; Robert Paul
(Hamburg, NY), Abbott; Earl (Hamburg, NY), Reeves; John
F. (Tonawanda, NY) |
Assignee: |
Flangeklamp Corporation
(Buffalo, NY)
|
Family
ID: |
26690696 |
Appl.
No.: |
05/018,071 |
Filed: |
March 10, 1970 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
806977 |
Mar 13, 1969 |
3584904 |
|
|
|
Current U.S.
Class: |
403/252; 52/667;
52/664; 403/219 |
Current CPC
Class: |
E04B
9/122 (20130101); F16B 7/00 (20130101); Y10T
403/70 (20150115); F16B 2200/20 (20180801); Y10T
403/447 (20150115) |
Current International
Class: |
E04B
9/06 (20060101); F16B 7/00 (20060101); E04B
9/12 (20060101); E16b 021/08 (); E04b 001/38 () |
Field of
Search: |
;52/665,667,484,475,664
;287/189.36A |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Perham; Alfred C.
Parent Case Text
CROSS-REFERENCE TO A RELATED APPLICATION
This application is a continuation-in-part of Application Ser. No.
806,977, filed Mar. 13, 1969 on a Locking Connection for Supporting
Grid Systems now U.S. Pat. No. 3,584,904.
Claims
What is claimed is:
1. A locking connection for supporting grid systems and the like
comprising a first support member having flanges and a web
upstanding therefrom provided with a slot; a second support member
having flanges and a web upstanding therefrom provided with a
locking connector extending axially therefrom and insertable
through said slot; said locking connector having a portion engaging
one side of said first support member web; said second support
member having an end portion forming a continuation of said support
flanges thereof and having a terminal edge below said locking
connector portion engaging the other side of said first support
member web; said locking connector having a stop shoulder above
said locking connector portion engaging said other side of said
first support member web above said end portion terminal edge and
substantially vertically aligned therewith.
2. A locking connection according to claim 1 wherein said end
portion has a thickness substantially less than the thickness of
said flanges of said second support member.
3. A locking connection according to claim 1 wherein said end
portion has a thickness less than one-half the thickness of said
flanges of said second support member.
4. A locking connection according to claim 1 wherein said end
portion has a thickness no greater than one-half the thickness of
said flanges of said second support member.
5. A locking connection according to claim 1 wherein said end
portion is offset and overlies a flange of the first support
member.
6. A locking connection according to claim 1 wherein the spacing
between said end portion terminal edge and said locking connector
portion is substantially the thickness of said first support member
web.
7. A locking connection according to claim 1 wherein said locking
connector is provided with a bead along one longitudinal edge
thereof, said bead having a tapered edge inclined toward the free
end of said bead.
8. A locking connection according to claim 7 wherein said bead is
provided with a slot at the end remote from said free end.
9. A locking connection according to claim 1 wherein the spacing
between said end portion terminal edge and said locking connector
portion is substantially the thickness of said first support member
web; said end portion being offset and adapted to overlie a flange
of the first support member; said end portion having a thickness
substantially less than the thickness of said flanges of said
second support member; a tapered bead along the outer longitudinal
edge of said locking connector inclined toward the free end of said
locking connector; the other end of said bead terminating in a
slot.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to structural connector elements
and, more particularly, to rigid locking connections between
support members used in supporting grid systems.
While not limited thereto, the present invention is particularly
adapted for use in ceiling tile supporting grid systems of the type
comprising a plurality of parallel spaced main grid members and
cross grid members extending transversely between the main grid
members and having end portions insertable through said main grid
members and interlocking therewith.
Prior to the invention claimed and disclosed in application Ser.
No. 806,977, these intersecting grid members often were provided
with locking connectors having slots, notches or hooks intended to
lock the grid members in place. Others employed short, resilient
fingers stuck out from the body of the connector forming an opening
so that the fingers could be cammed into the opening when inserted
through a slot of a transversely extending main grid member and
snapped into locking engagement behind the web portion of the main
grid member when passed through the slot. Still others utilized
separable locking connectors fixed to the end portions of the grid
members. These locking connectors possessed certain disadvantages
in that they often were relatively complicated or expensive, or
excessive clearance was realized between the interlocking parts
thereby effecting a loose and unsatisfactory connection between the
grid members.
The invention claimed and disclosed in Application Ser. No. 806,977
obviated these disadvantages encountered in prior known locking
connectors by forming locking connectors of a unitary, one-piece
construction having a tab extending axially outwardly of the
connector and reversely bent into a reinforced recess in the
connector body to form a resilient locking member adapted to snap
into firm locking engagement behind one side of the main grid
support web to form a tight and rigid connection. However, to
maintain the intersecting grid members in right angular relation,
the tile supporting flanges of the cross grid terminated
sufficiently inwardly of the locking connector member in an axial
direction to accommodate the coplanar tile supporting flanges of
the main grid member and abut the same with a tight fit. It can be
appreciated that in such a connection, the width of the main grid
member tile supporting flanges must be maintained within close
tolerances to provide a tight, flush fit with the recessed ends of
the cross grid member tile supporting flanges. Since these flanges
are roll formed, the problem of maintaining accurate close
tolerances is compounded and meticulous and diligent quality
control must be exercised to maintain such flanges within these
close tolerances. It is desirable, therefore, to eliminate the
problem of maintaining the width of the tile supporting flanges
within such close tolerances.
It has been proposed to offset the cross member of tile supporting
flanges so as to rest upon the main grid member tile supporting
flanges in the assembled relation. However, this poses a problem
because the thickness of the reversely bent flanges causes the
tiles to be tilted and inclined on the supporting flanges. This not
only presents an uneven and irregular ceiling surface having sound
and heat conducting openings therein, but detracts considerably
from the decor of the ceiling surface.
SUMMARY OF THE INVENTION
The primary object of the present invention is to provide a locking
connection between intersecting grid members retaining the
advantages found in the locking connector of Ser. No. 806,977
without requiring the maintaining of close tolerances in roll
forming the main grid flanges.
The improved connection of the present invention is characterized
by the provision of an offset portion located at opposite ends of a
cross grid member having a flat edge engageable with the web
portion of the intersecting main grid member. The offset portion
has a thickness of less than one-half the thickness of the tile
supporting flanges to minimize the tilting disposition of the tiles
on the supporting flanges of the intersecting support flanges. The
flat terminal edge of the offset portion is spaced from the cross
grid member locking connector substantially the thickness of the
main grid member web portion secured therebetween.
The foregoing and other objects, advantages and characterizing
features of the present invention will become clearly apparent from
the ensuing detailed description of an illustrative embodiment
thereof, taken together with the accompanying drawings wherein like
reference characters denote like parts throughout the various
views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary, perspective view of intersecting grid
members incorporating the rigid locking connection of this
invention;
FIG. 2 is a view similar to FIG. 1, but with the members
disassembled;
FIG. 3 is a side elevational view, on an enlarged scale, of a
supporting grid member incorporating the offset tile supporting
flanges of this invention, being broken away for ease of
illustration;
FIG. 4 is an enlarged, fragmentary, horizontal sectional view of
the assembled members taken about on line 4--4 of FIG. 1;
FIG. 5 is a fragmentary, vertical sectional view thereof taken
about on line 5--5 of FIG. 1;
FIG. 6 is a fragmentary, vertical sectional view thereof on a
further enlarged scale, taken about on line 6--6 of FIG. 4;
FIG. 7 is a view similar to FIG. 6 but with the locking connectors
removed; and
FIG. 8 is a fragmentary side elevational view of the offset
supporting flange.
DETAILED DESCRIPTION OF THE PREFERRED FORM
Referring now in detail to the illustrative embodiment shown in the
drawings, FIG. 1 shows a ceiling tile supporting grid system
incorporating locking connectors of the present invention and
comprising a main T support member, generally designated 10,
detachable connected to a pair of cross T support members,
generally designated 12. The main T member 10 can be conveniently
fabricated from a single piece of any suitable material, preferably
an inexpensive, lightweight metal such as soft steel for example,
and is formed to provide a generally vertical web portion 14
upstanding from laterally projecting, tile supporting flanges 16 on
opposite sides thereof and surmounted by a generally box-shaped,
longitudinally extending, reinforcing member 18.
Web 14 is provided at spaced intervals with rectangular, normally
vertical slots 20 for reception of the locking connectors of cross
T members 12, only one such slot being illustrated. Slots 20 are
generally H-shaped, being formed with downwardly and upwardly
projecting tabs 22 and 24, respectively, at the top and bottom of
the slot (FIG. 7) which serve as partitions or separators between
the two cross T members 12 in the assembled joint.
Cross T members 12 can be similarly fabricated from a single piece
of any suitable material, such as soft steel by way of example, and
formed to provide a normally vertical web portion 26 upstanding
from laterally projecting, tile supporting flanges 28 and
surmounted by a generally flat, longitudinally extending,
reinforcing member 30. It should be appreciated that reinforcing
members 18 and 30 can take various shapes in transverse
cross-section, such as a flat horizontal strip, a reinforced flat
vertical edge having a thickness approximately twice that of the
web portion, or a curved or rounded bulb shape, as desired.
Cross T members 12 are provided at their opposite ends with locking
connectors, generally designated 40, extending from said opposite
ends of each cross T member 12 and formed integral therewith. It
should be noted that connectors 40 at opposite ends of cross T
member 12 are offset and oriented in opposite lateral directions.
As shown in FIG. 3, connectors 40 each include a tongue, generally
designated 42, laterally offset from web 26 and projecting axially
beyond the end of cross T member 12. A mechanical reinforcement is
provided for each connector in the form of a channel 44 having a
web body 46 and opposed longitudinally extending beads 48 and 50
defining a recess 52 therebetween. The leading edges of beads 48
and 50 are rounded, as shown at 60 and 62, to facilitate insertion
of connector 40 into slot 20 of main T member web portion 14. To
further facilitate continued insertion of connector 40 into slot
20, bead 50 is slightly tapered at its upper edge 51 longitudinally
toward the leading edge thereof as shown in FIG. 3. Beads 48 and 50
are curved in transverse cross section so that the opposite sides
thereof engage the sides of slot 20 and tabs 22, 24 to form a tight
connection and prevent rotation of twisting of connector 40 within
slot 20, as shown in FIG. 6. A small slot 53 is formed at the rear
end of bead 50 for engaging the upper edge defining the slot
portion between tab 22 and the side of slot 20 as will hereinafter
become apparent.
A tab 54 initially extending axially beyond channel 44 and forming
a continuation of web body 46 terminates in a generally flat edge
56. Tab 54 is bent back toward web body 46 with flat edge 56
adapted to engage behind main T member web portion 14 for locking
engagement therewith in the assembled relation, as shown in FIG. 4.
Tab 54 is partially disposed within recess 52 of channel 44 and is
slightly inclined outwardly away from recess 52 and rearwardly
toward web portion 26. Tab 54 is resiliently yieldable into recess
52, being held against complete collapse into recess 52 by means of
a projection or stop 58 protruding from web body 56 toward tab 54.
The material of connector 40 including tab 54 is relatively soft
and ductile. However, stop 58 prevents tab 54 from being completely
forced into recess 52 and taking a permanent set therein, thereby
insuring an outwardly sloping disposition of tab 54 when assembled.
Accordingly, tab 54 can be repeatedly installed, disconnected, and
subjected to impact forces during handling an assembly without
being sufficiently damaged to destroy its useful life.
A second channel member or elongated embossment 66 is disposed
above channel 44 and oriented generally parallel thereto.
Embossment 66 is provided with a web body 68 recessed laterally in
the opposite direction from web body 46 of the adjacent channel 44
and forms an upward continuation of a portion of bead 50.
Embossment 66 has a forward edge forming a stop shoulder 70
abutting web portion 14 of main T member 10 in the assembled
relation. Embossment 66 extends inwardly of web portion 26 and
tapers toward web portion 26 into which it finally merges. This
embossment 66 not only provides a mechanical reinforcement for
tongue 42 but also prevents lateral deflection of such tongue in
the assembled connecting joint.
A significant feature of this invention is the provision of an
offset portion 72 on the distal end of tile supporting flanges 28
adapted to overlie and rest on the tile supporting flanges 16 of
main T support member 10. Offset portion 72 is less than one-half
the thickness of flanges 28 and is offset upwardly to lie in a
common plane with the upper folded portion of flanges 28 so as to
present a substantially continuous coplanar surface as shown in
FIG. 8. Cross T member 12 is fabricated from a suitable flat,
one-piece blank with flanges 28 consisting of reversely bent
portions 74 and 76 contiguously disposed and shaped by roll
forming. Thus the thickness of flanges 28 is at least twice the
thickness of the original blank or the summation of the thicknesses
of portions 74, 76 and the inherent spaces or voids therebetween.
Since offset portion 72 is a continuation of the underlying portion
74, its thickness is the same as said portion 74 or less than
one-half the composite thickness of flanges 28. Offset portion 72
is formed by prenotching and then removing sections of material
from opposite sides of the blank at the opposite ends thereof prior
to the flange forming operation. After the flange forming
operation, portion 72 is offset from the plane of portion 74 to the
plane of portion 76 in a suitable press forming operation.
Offset portion 72 terminates in a flat terminal edge 78 which can
have rounded corners and is adapted to abut and fully engage
thereacross with web portion 14 of main T member 10. The spacing
between edge 78 of offset portion 72 and the edge 56 of locking tab
54 is substantially the thickness of web portion 14 thereby
insuring a rigid connection between main T member 10 and cross
member 12 in the interlocking relation without any lateral rocking
movement therebetween.
When assembling the grid system, connectors 40 are inserted into
slots 20. In the illustrated joint, connectors 40 from the adjacent
ends of aligned cross T members 12 extend side by side through web
portion 14 of main T member 10, as shown in FIG. 4. Stop tabs 22
and 24 are vertically aligned, and divide each slot into a
connected pair of slot portions, allowing connectors 40 to be
inserted into each slot 20 from opposite sides of main T member web
portion 14.
As each connector 40 is linearly inserted into its side of slot 20,
tab 54 bears against the main T member web portion 14 defining that
side of slot 20 and is cammed out of the way, into recess 52,
permitting tab 54 to pass through slot 20. The resiliency of tab 54
permits deflection by such camming action. The forward end portion
of tongue 42 is confined between tabs 22, 24 and the side of slot
20. During such tab insertion, offset portion 72 rides on the upper
surfaces of flange 16 of main T member 10. Further insertion of
connection 40 causes tab 54 to pass beyond web portion 14, allowing
the resiliently displaced tab 54, urged by stop 58, to snap
laterally outwardly from recess 52 to the locking position shown in
FIGS. 4 and 5. Tab 54 is thereby positioned behind web portion 14
with tab edge 56 in locking engagement thereagainst, preventing
withdrawal of connector 40 from slot 20 and holding the associated
cross T member 12 connected to main T member 10. Because of the
relatively long length of tab 54 as opposed to the short,
struck-out fingers known in the prior art, tab 54 is cammed
inwardly only slightly during insertion whereby upon outward urging
thereof only a small, tolerable clearance exists between edge 56
and web portion 14, of negligible effect in achieving a tight
assembled connection. In this locked position, terminal edge 78 of
offset portion 72 engages against web portion 14 along with
shoulder 70, to block further insertion of connector 40. The
spacing between edge 78 of offset portion 72 and edge 56 of tab 54,
is substantially the thickness of web portion 14 to insure a rigid
connection between the intersecting T members 10 and 12 and
maintain them in right angular relation.
As offset portion 72 of cross T member 12 rides on the upper
surfaces of flange 16 of main T member 10 during the linear
insertion of each connector 40 into its side of slot 20, connector
40 is urged upwardly against the upper edge of slot 20. The tapered
edge 51 of bead 50 compensates for this and permits easier
insertion of connector 40 into slot 20. Further insertion of
connector 40 causes bead 50 to pass beyond slot 20 and slot 53 is
advanced into registry with slot 20. The upward force exerted by
offset portion 72 urges the bottom of slot 53 into engagement with
the top edge of slot 20 to provide a second locking engagement
between main T member web portion 14 and the rear end of bead 50
insuring that the associated cross T member 12 is positively held
connected to main T member 10.
It should be appreciated that in forming grid members, the web
portion is not always in perfect alignment along its entire length,
i.e. it is not always centered true with respect to the edges of
the grid member flanges. However, since the longitudinal or
lengthwise spacing between edge 56 of tab 54 and edge 78 of offset
portion 72 is constant in the present invention, a tight connection
between T members 10 and 12 is insured regardless of the
off-centered orientation of web portion 14 of main T member 10.
Connector 40 of the other cross T member 12 is inserted through the
other side of slot 20 in the same manner from the opposite side of
main T member 10 to form a rigid joint. Web portions 26 of both
cross T members 12 on opposite sides of main T member lie in a
generally common plane. The engagement of edges 78 with web 14
maintains the intersecting members 10 and 12 in right angular
relation, and together with shoulder 70 prevents vertical rocking
of the cross T members.
In order to disconnect the grid member, bead 50 is depressed and
tab 54 is resiliently displaced into recess 52 either by hand or
with an appropriate tool to move edge 56 from behind main T member
web portion 14. Tabs 54 face outwardly, as shown in FIG. 4, and are
accessible for this purpose. With bead 50 and tab 54 depressed,
connector 40 is easily withdrawn from slot 20 thereby disconnecting
cross T member 12 from main T member 10.
From the foregoing, it is apparent that the objects of the present
invention have been fully accomplished. By providing the cross
support member with an integral offset portion having a transverse
terminal edge adapted to engage the main support member web portion
and spaced from the abutting edge of the locking connector
substantially the thickness of each web portion, a strong, rigid
joint is effected between the transversely extending support
members. Moreover, the spacing between such transverse edge and the
locking connector edge can be relatively easily maintained within
close tolerances, as can the spacing between shoulder 70 and edge
56 thereby eliminating the much more difficult problem of
maintaining close tolerances on the tile supporting flange width.
Since the thickness of such offset portion is less than one-half
the thickness of the tile supporting flanges, the difference in
elevation is negligible in achieving a substantially continuous
ceiling surface. Also, the urging of the bottom edge of slot 53
against the top edge of slot 20 by offset portion 72 provides a
second locking engagement between the rear end of bead 50 and the
main support member web portion 14 to further prevent withdrawal of
connector 40 form slot 20.
A preferred embodiment of this invention having been disclosed in
detail, it is to be understood that this has been done by way of
illustration only.
* * * * *