US 3746379 A
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United States Patent [191- Sauer July 17, 1973 LOCKING CONNECTION FOR SUPPORTING GRID SYSTEMS  Inventor: Gale E. Sauer, Williamsville, N.Y.
 Assignee: Flangeklamp Corporation, Buffalo,
221 Filed: Sept. 9,1971
21 Appl.No.: 178,893
 [1.8. CI 287/189.36 A, 52/667, 52/DIG. 5  Inn-Cl Fl6b 7/22  Field of Search 287/l89.36 R;
52/664, 665, 667, DIG. 5
 References Cited UNITED STATES PATENTS 3,367,695 2/1968 Haertel et al. 287/l89.36 A
9/197l Rousey 287/l89.36 A 7/1972 Lickliter et al. 287/l89.36 A
Primary Examiner-David J. Williamowsky Assistant Exnminerwayne L. Shedd A ttorney- Conrad Christel and Edwin T. Bean, J r.
57 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 resiliently yieldable locking finger struck out fromthe body of the connector and bent along a fold line inclined relative to the longitudinal axis of the connector.
7 Claims, 6 Drawing Figures PAIENIED JUL l 7 I973 sum 2 0r 2 III-l J in In mi'al III:
Gale E. S uQr ATTORNEY 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 paral- I lel main grid members and cross grid members extending transversely between the main grid members and having end portions insertable through said main grid members in interlocking relation thereto.
Various types of locking connectors have been proposed for these cross grid member end portions in an effort to provide a strong, rigid tile supporting grid construction. In some instances, resilient fingers have been struck out laterally from the body of the connector and bent along a vertical fold line to present a vertical abutting edge, spaced rearwardly of the fold line and adapted to engage behind the web of the main grid member. While such locking finger have been satisfactory for many purposes, they possess certain disadvantages. For example, the entire lateral surface of the finger bears against the side wall defining the slot during insertion of the connector. Also, these connectors are generally formed of a soft, ductile sheet metal whereby after being assembled and disconnected several times the finger tends to take a permanent set toward its associated opening thereby minimizing if not destroying its usefulness. Moreover, since such fingers are bent about vertical fold lines located forwardly of the web engaging edge, the' disposition of the latter may vary after being worked resulting in a nonuniform or excessive clearance between such edge and the web of the main grid member.
SUMMARY OF THE INVENTION Accordingly, a primary object of the present invention is to provide an improved locking connection for supporting grid systems and the like of increaseddurability and dependability,which slip-fits into assembled relation easily, by hand, with a simple, straight line motion, and which accommodates expansion of grid members subjected to elevated temperatures.
Another object of this invention is to provide the foregoing in a locking connector for supporting grid systems and the like having a snap locking finger automatically operable upon slip fitting the connector into place.
The improved connection of the present invention is characterized by the provision of a first support memher having a slot in its web for receiving a locking connector extending from and formed integral with a second support member, the connector having a locking finger struck out of the web of the connector and bent along a fold line extending at an angle of approximately 45 to the longitudinal axis of the connector to optimize the resiliency of the locking finger. The finger has a locking edge, the lower portion of which engages behind the web of the first member upon slip fitting the connector into place. A stop tab is provided on the connectorfor engagment with the other side of the first member web when the connector is locked in place and is yieldable to permit further insertion of the connector through the slot upon expansion.
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 side elevational view of a supporting grid member incorporating locking connectors of this in-' vention, being broken away for ease of illustration;
FIG. 2 is a fragmentary, horizontal sectional view, on an enlarged scale, of the assembled grid members taken about on line 22 of FIG. 4;
FIG. 3 is a fragmentary view, partly in elevation and partly in vertical section, on the same enlarged scale, taken about on line 3--3 of FIG. 2;
FIG. 4 is a fragmentary, perspective view, on a reduced scale, of intersecting grid members shown in assembled relation;
FIG. 5 is a fragmentary, vertical! sectional view, on a further enlarged scale, taken about on line 5-5 of FIG. 3; and I FIG. 6 is a view similar to FIG. 5 but with the cross T locking connectors removed from the main T slot.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Referring now in detail to, the drawings, there is from a single piece of any suitable material, preferably 1 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-s'haped, longitudinally extending, reinforcing bead 18.
Web portion 14 is provided at spaced intervals, therealong with rectangular, normally vertical slots 20 (FIG. 6) for the reception of the locking connectors of cross T members 12, only one such slot being illustrated. Slots 20 are generally I-I-shaped, being formed with downwardly and upwardly projecting tabs 22 and 24, respectively, at the top and bottom of the slot (FIG.
6) in spaced centered relation to the opposite sides thereof, which tabs 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 asingle piece of any suitable material, such as soft steel byway 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 box-shaped, longitudinally extending, reinforcing bead 30. It should be appreciated that reinforcing beads 18 and 30 can take various shapes in transversecross-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.
Flanges 28 are formed by bending the sheet material transversely with respect to web portion 26 to form an outwardly extending overlying portion 32 of flanges 28, the material then being bent back upon itself to form an underlying portion 34 of flange 28, and finally being bent upwardly and reversely on itself on the opposite side of web portion 26 to form a second overlying portion 36 that terminates adjacent the edge of flange 28, reinforcing the latter. As shown in FIGS. 2 and 3, overlying portions 32 and 36 terminate inwardly of the opposite ends of web portion 26 and the underlying portion 34 projects axially beyond each end of web portion 26. Each portion 34 terminates in an upwardly offset lip 38 joined to portion 34 by an inclined shoulder 40. Lips 38 at the opposite ends of cross T support member 12 are adapted to overlie and rest on tile supporting flanges 16 of main T support members under normal conditions in the assembled relation and shoulders 40 act as cams causing cross T support members l2 to override flanges 16 during expansion, as will be described in greater detail hereafter.
Cross T support members 12 are provided at their opposite ends with locking connectors, generally designated 42, extending axially outwardly from said opposite ends of each cross T member 12 so as to project longitudinally therefrom and formed integral therewith. Connectors 42 at opposite ends of each cross T member 12 are slightly offset from web portion 26 in opposite lateral directions, as clearly evident in FIG. 3. Connectors 42 each include a tongue, generally designated 44, projecting axially beyond the ends of cross T member 12, and each tongue 44 is channel shaped in cross section and comprises a recessed web body 46 and opposed longitudinally extending edges 48 and 50. The channeled configuration of tongues 44 serves to mechanically reinforce, them and adds rigidity thereto. The leading ends of edges 48 and 50 are rounded, as shown at 52 and 54 in FIG. 1, to facilitate insertion of tongue 44 into slot of main T web 14. Edges 48 and 50 are offset from the plane of web body 46 a distance such that the outer surfaces thereof engage the sides of slot 20 when web 46 engages tabs 22, 24 thereby to form a tight connection and prevent rotation or twisting of tongue 44 within slot 20, asshown in FIG. 5.
Tongues 44 are formed with'a tab 56 projecting upwardly from upper edge 48 and providing a stop shoulder abutting web portion 14 of main T support member 10 above slot 20 in the assembled relation. The portion of edge 48 rearwardly of tab 56 is recessed as shown at 57 and extends rearwardly into web portion 26, merging into the lower portion of an elongated embossment 58 which is formed in web portion 26 adjacent the end thereof and oriented generally parallel to tongue 44. Embossment 58 is provided with a central, recessed portion 60 offset laterally in the opposite direction from web body 46 of the channeled tongue 44, and only provides a mechanical reinforcement for tongue 44 but also prevents lateraly deflection of such tongue in the assembled joint.
Web body 46 of channeled tongue 44 is provided with a spring finger 64 struck out therefrom and having a web engaging edge 66 for locking engagment behind the web portion 14 of main T support member 10 on the opposite side thereof from tab 56. The spacing between edge 66 of finger 64 and the leading edge of tab 56 is substantially the thickness of web portion 14 of main T support member 10, thereby insuring a rigid connection between main T member 10 and cross T member 12 in assembled, interlocking relation.
It is a particular feature of this invention that finger 64 is formed by bending along a fold line 68 extending at an angle of approximately 45 relative to the longitudinal axis of tongue 44. This provides a longer spring hinge line and renders finger 64 more resilient than would be the case if finger 64 where bent along a vertical fold line. The is particularly significant when it is realized that the material of cross T support member 12, including finger 64, often is relatively soft and ductile and has a tendency to take a permanent set. Beading finger 64 along a diagonal or inclined fold line, and thereby elongating its spring hinge, increases its resiliency or springiness and counteracts the tendency thereof to take a permanent set which is more likely to occur with fingers bent along vertical lines. Accordingly, finger 64 will repeatedly spring laterally outwardly after being depressed into its associated opening 70 thereby prolonging the useful life of cross T support member 12 and enabling it to be used many times.
When assembling the grid system, connectors 42 are insertedinto slots 20. In the illustrated joint, connectors 42 from the adjacent ends of aligned cross T support members 12 extend side by side through web portion 14 of main T member 10, as shown in FIG. 2. Stop tabs 22 and 24 are vertically aligned, and divide each slot into a connected pair of slot portions, allowing connectors 42 to be inserted into each slot 20 from opposite sides of main T member web portion 14.
As each connector 42 is linearly inserted into its side of slot 20, only the lower edge of finger 64 bears against the main T support member web portion defining that side of slot 20 and finger 64 is cammed out of the way, toward its associated opening 70, permitting finger 64 to pass through slot 20. The resiliency of finger 64 permits deflection by such camming action. The forward end portion of tongue 44 is confined between tabs 22, 24 and the side of slot 20. Further insertion of connector 42 causes finger 64 to pass beyond web portion 14, allowing the resiliently displaced finger 64 to snap laterally outwardly away from opening 70 to the locking position shown in FIGS. 2 and 3. Finger 64 is thereby positioned behind web portion 14 with finger edge 66 in locking engagement thereagainst, preventing with- .drawal of connector 42 from slot 20 and holding the associated cross T member 12 connected to main T member 10. In this locked position, offset lip 38 engages against and seats on flange 16 of main T support member 10. Also, upwardly extending tab 56 engages the side of web portion 14 opposite finger 64 to block further insertion of connector 42. The spacing between edge 66 of finger 64 and the leading edge of tab 56 is substantially no greater than the thickness of web portion 14 to insure a rigid connection between the intersecting T support members 10 and 12 and maintain them in a right angular relation. Connector 42 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 10 lie in a generally common plane.
In order to disconnect cross T support member 12, finger 64 is resiliently displaced into its associate opening 70 either by hand or with an appropriate tool to move edge 66 from its blocking position behind web portion 14 of main T member 10. Fingers 64 face outwardly, as shown in FIG. 2, and are accessible for this purpose. With finger 64 depressed, connector 42 is easily withdrawn from slot 20 thereby disconnecting cross T member 12 .from main T member 10.
Thus, under normal environmental conditions, tongue 44 provides a rigid and strong, snap type connection which is easily assembled, by a simple linear insertion of the connector through the slot and which is easily disconnected. Tongues 44 are confined to their respective sides of the slot, and have sliding clearance therein at their outer ends. Under elevated temperatures the grid members seek to expand, and will buckle unless such expansion can be absorbed by the grid system. In the present invention, any such expansion is accomodated, and buckling avoided, as follows:
Shoulder stops or tabs 56 abut web portion 14 of main T support member when connector 42 is in place in the normal assembled relation. Under abnormally elevated temperatures cross T support member 12 expands longitudinally and develops sufficient force to drive tongues 44 further into slot 20, shearing and/or twisting tabs 56 in the process. Cross T support member 12 can now expand with shoulder 40 camming portion 34 of flange 28 onto flange l6 and tongue 44 being carried further through slot 20. The recessed portion 57 of upper edge 48 behind tab 56 permits such upward movement of tongue 44 as it is carried further through slot. 20.
Accordingly, cross T support members 12 can expand toward main T support member 10, to prevent buckling and collapse of the grid system under abnormally elevated temperatures, such as occur during a fire. In such an expanded condition, tongue 44remains inserted in slot to maintain a strong connection keeping the fire retarding ceiling intact.
From the foregoing, it is apparent that the objects of the present invention have been fully accomplished. As
a a result of this invention, an improved locking connector, formed integral with the web portion of a support member, is provided for effecting a strong, rigid joint between transversely extending support members. The locking connector is in the form of an offset tongue having a channel shaped configuration for resisting lateral deflection generated in the assembled joint and is provided with a locking finger struck out from the recessed portion of the channeled tongue for locking engagement behind the web portion of the main T support member. The locking finger is bent along an angularly, diagonally oriented fold line, whereby the resilier'icy imparted to such finger is greater than would be realized if the finger were bent about a horizontal or vertical fold line. This added resiliency tends to prevent the locking finger from being permanently deformed into its depressed position whereby the connector and, consequently, the cross T support me'mber, can be reused many times. Moreover, due to the angular outward disposition of the locking finger, only a small portion of the outer lateral surface thereof along the lower edge bears against the side wall of the slot during relative sliding movement 'therebetween therebyreducing friction therebetween and rendering the connector eas' ier to insert through such slot. in addition, when fabricating'the connector, the distance between the locking edge of the finger and the leading edge of the tab can be easily controlled to insure a rigid connection between the main grid member and the cross grid member in the assembled relation.
A single embodiment of this invention having been disclosed in detail, it is to be understood that this has been done by way of illustration only.
1. A locking connection for supporting grid systems and the like comprising a first support member having a flange and a web upstanding therefrom, said web being provided with a slot; a second support member having a flange and a web upstanding therefrom, said second member web being provided with a locking connector extending axially therefrom and insertable through said slot; said locking connector having opposite marginal edges and a first portion projecting from one of said marginal edges and engaging one side of said first support member web; said locking connector having a resiliently yieldable second portion yieldably camming against an edge of said slot upon insertion therethrough and snapping back to engage against the side of said first support member web opposite said first locking connector portion; said first portion being yieldable to accommodate further insertion of said connector through saidslot upon expansion of said second support member; saidone marginal edge having a recess adjacent said first portion to permit movement of said connector in a direction generally normal to the longitudinal axis thereof during said further insertion of said connector through said slot; said resiliently'yieldable portion being bent about a fold line disposed at an acute angle to the longitudinal axis of said second support member.
2. A locking connection according to claim 1 wherein said fold line is disposed at an angle of approximately 45 to the longitudinal axis of said second support member. i
3. A locking connection according to claim 1 wherein said first mentioned connector portion comprises a tab.
4. A locking connection according to claim 3 wherein said resiliently yieldable portion has an edge adapted to engage against said opposite side of said first support member web, said edge being spaced from said tab a distance approximating the thickness of said first support member web.
5. A locking connection according to claim 1 wherein said resiliently yieldable portion has substantially only a line contact frictional engagement with said edge of said slot upon insertion therethrough.
6. A locking connection according to claim I wherein said second support member has an end portion forming, a continuation of said support flange thereof and of a thicknesssubstantially less than said flange thicknesses.
7. A locking connection according to claim 6 wherein said end portion is offset and adapted to oversupport member.
lie a flange of said first a: is t e a