US3187856A - Acoustical ceiling suspension fastening system - Google Patents

Description

ACOUSTIGAL CEILING SUSPENSION FASTENING SYSTEM Filed May 1, 1961 M. L. LYDARD June 8, 1965 2 Sheets-Sheet 1 llill M. L. LYDARD 3,187,856

ACOUSTICAL CEILING SUSPENSION FASTENING SYSTEM June 8, 1965 ZSheets-Sheet 2 Filed May 1, 1961 FIG. IO

United States Patent 3,187,856 ACOUSTICAL CEILING SUSPENSIGN FASTENING SYSTEM Martin L. Lydard, Ellicott City, Md., assignor to Eastern Products Corporation, Baltimore, Md, a corporation Maryland Filed May 1, 1961, Ser. No. 1%,794 8 (Ilaims. (Cl. 189-66) The present invention relates to ceiling constructions and more particularly to suspended ceiling constructions in which a metallic grid system is suspended from primary ceiling members and is used to support acoustical tiles and other ceiling panels.

In recent years it has been common in the construction of new buildings and in the renovation of old build ings to employ suspended ceilings in which acoustical tiles or other types of ceiling panels are supported by flanged beams, usually made of steel or aluminum. In most such systems the flanged beams are arranged in a rectangular grid system with long parallel beams, called main runners, being joined at suitable intervals by transverse parallel beams, called cross-Ts, In some systems the bottom flange of the metal beams forms a part of the visible ceiling surface, while in others the metal beams are not visible after the ceiling panels are installed.

In acoustical ceiling systems in which main runners and cross-Ts are arranged into a rectangular grid, it is important that the attachment of the cross-Ts to the main runners afford substantial stability and rigidity. It is also desirable that attachment of the cross-T's to the main runners be effected with as little labor as possible and preferably without the use of tools. It is also desirable that the cross-Ts be readily removable although it is important that accidental disengagement of the cross-Ts from the main runners be prevented.

In accordance with the foregoing, it has been a principal object of the invention to provide a novel and improved suspension fastening system for acoustical ceilings.

More particularly, it has been an object of the invention to provide a fastening system in which the cross-Ts may be easily attached to the main runners and which, when so attached, afiord a grid system having excellent stability and rigidity characteristics.

Another object of the invention has been the provision of a fastening system in which the cross-Ts may be installed and locked to the main runners without the use of tools.

Another object of the invention has been the provision of a fastening system in which cross-Ts are readily removable but in which accidental disengagement of the cross-Ts from the main runners is avoided.

A further object of the invention has been the provision of a fastening system in which the cross-Ts may all be identical.

Other and further objects, features. and advantages of the invention will appear more fully from the following description of the invention taken in connection with the appended drawings, in which:

FIG. 1 is a fragmentary perspective view of a suspended ceiling grid system embodying the invention;

FIG. 2 is a fragmentary side elevational view of a typical main runner for use in the system of the invention;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a side elevational view of a cross-T constructed in accordance with the invention;

FIG. 5 is an end elevational view of the cross-T of FIG. 4;

FIG. 6 is a side elevational view of a hook latch embodying the invention and adapted for attachment to one end of the cross-T of FIG. 4;

FIG. 7 is a top plan view of the hook latch of FIG. 6;

FIG. 8 is an end elevational view of the hook latch of FIG. 6;

FIG. 9 is an elevational view, partly in cross section showing an assembled cross-T and hook latch in position to be locked to a main runner;

FIG. 10 is a view similar to FIG. 9 with the hook latch locked to the main runner; and

FIG. 11 is a perspective view, partly exploded, showing one cross-T and hook latch assembled to one side of a main runner and another cross-T and hook latch positioned to be brought into engagement with the other side of the main runner.

Referring now to the drawings, and more particularly to FIG. 1, the grid system may comprise a series of parallel main runners, as shown at 20, 21 and 22 and a series of parallel cross-Ts disposed at right angles to the main runners and spaced at regular intervals. Cross- Ts are shown at 23, 24, 25, 26, 27, 28, 29 and 30. Typically, the main runners will be suspended from roof trusses or other primary members by wires or other means well known in the art. The main runners will usually be relatively long, 12 feet being a typical length, and main runners will be spliced together end to end to span the ceiling space. The cross-Ts will usually be spaced along the main runners at regular intervals, e.g., 2 or 4 feet, and, typically, will be 2 or 4 feet long, providing grid openings of a size to accommodate the acoustical tiles or other panels to be supported on the main runner and cross-T flanges.

A main runner is illustrated in detail in FIGS. 2 and 3 and comprises an upstanding web 31 formed from vertical portions 32 and 33 joined at the top by a rounded rib 34. The vertical portions 32 and 33 terminate, respectively, in horizontal ceiling panel supporting flanges 35 and 36. The main runner in cross section is essentially shaped as an inverted T and may be rolled or otherwise formed from a single sheet of metal. In the case of aluminum, the main runner will preferably be extruded and the web 31 will be formed of a single thickness of metal. A decorative flange cover 37 caps flanges 35 and 36 to provide an attractive under-surface which is desirable in installations where the under-surface of the main runner forms a visible part of the installed ceiling.

At suitable axial intervals, the main runner web 3-1 is provided with vertically elongated cross-T attaching holes or routes," as shown at 38 in FIG. 2. The axial spacing between adjacent cross-T attaching routes may be selected as desired to accommodate various grid structures, but, typically, this axial spacing might be 12 inches center to center.

The route 38 is located generally in the lower half of web 31 and has vertical side walls 39 and 40. The side wall 39 terminates in inclined walls 41 and 42, while the side wall 40 terminates in inclined walls 43 and 44. The walls 41-4-4 might, for example, be inclined at an angle to the vertical of 15. The walls 41-44 meet short hori zontal walls 45, 46, 47 and 43, respectively. The walls and 47 are joined by a semicircular wall 49, while the walls 42 and 44 are joined by a semicircular wall 56. Typically, the overall vertical height of the rcute bs might be 0.515 inch, while the spacing between Walls 39 and 40 might be inch. The vertical height of each of the Walls 41-44 might be 0.060 inch. Surfaces 46 and 48 might be vertically spaced from the upper surfaces of areasse 3 flanges 35 and 36 by 0.161 inch. It should be understood that the foregoing and other dimensions set forth herein are given solely by way of example and are not intended to limit the invention.

Round holes 51 and 52 may be provided adjacent each route for convenient attachment of main runner supporting wires, as is well known in the art.

As shown in FIGS. 4 and 5, the cross-Ts are also shaped with an inverted T cross section and have a vertical web 53 formed from vertical portions 54 and 55 joined by a rounded rib 56 and terminating, respectively, in horizontal ceiling panel supporting flanges 57 and 58 capped by a decorative flange cover 59.

The cross-T may have a central route 6% for attachment of a bridging T, as is well known. For convenience of illustration, the cross-T is broken off at 61 and 62, although the overall axial length thereof might be 2 or 4 feet.- Generally, the cross-T height will be somewhat less than the main runner height, and the cross-T may be made of lighter gauge metal.

The two ends of the cross-T are identical and each comprises -a vertical shoulder 63 formed by the axial ends of the flanges 57 and 58 and by the rear of a notch in the end of the cross-T web. The ends also comprise a horizontal shoulder 64, an inclined shoulder 65, a horizontal shoulder 66, a vertical shoulder 67, a horizontal shoulder 68, and a vertical shoulder 69, all formed in the web -3, and an inclined shoulder 70 formed in rounded rib 56. An elongated open-topped slot 7-1 is formed adjacent each end of the cross-T by removal of that portion of rounded rib 56 between vertical shoulders 72 and 73.

Shoulders 72 and 73 might be located axially and 2 /2 .lower half of the web adjacent each end of the cross-T and located axially outwardly a short distance from the respective shoulders 73. A round hole 75 is provided adjacent each end of the cross-T. The holes 75 are formed about a center located above a respective shoulder 64 and axially inwardly of a respective shoulder 67.

A hook latch, as illustrated in FIGS. 6, 7 and 8, is at- .tached to each end of each cross-T for releasable locking attachment of the cross-Ts to the main runners, The hook latch may be formed from a single sheet of metal and comprises a flat body portion 76 having a rivet-receiving hole 77 near the forward edge thereof. The body portion 76 is adapted .to be connected to a cross-T web by means of a rivet or other suit-able fastener acting in hole 77 and in cross-T hole 75. This attachment permits the hook latch to be pivoted about the center line of the rivet-receiving holes with the body portion 76 in sliding contact-with the adjacent cross-T web surface 54 or 55.

. The hook latch body 76 has an inclined bottom surface 78 and an inclined upper surface 79. The surface 79 terminates at its forward end in a horizontal surface 80, which in turn terminates in a forwardly projecting nose 81 having a hook-latching surface formed by a shoulder 82 projecting upwardly at a slight rearward incline, e.g., 11 with respect to the vertical from surface 80. As best shown in FIG. 7, nose 8% is displaced laterally slightlywith respect to body portion 76. The upper end of shoulder 82 meets a horizontal surface 83, which in turn meets an inclined surface 84. The inclined surface 84 joins a rounded surface 85, which in turn meets an inclined surface 86 .to complete the nose 81.

The forward lower end of the hook latch is formed with sidewardly extending legs 87 and 88 located on opposite sides of the body 7-6. Upper edge 89 of leg 87 is joined to surface86 by .a rounded surface 90 in the forward edge of the body portion 76. The upper edge 91 of leg 88 is inclined upwardly from side edge 92 thereof and joins leg 87 at an intermediate height. The bottom of leg 87 is formed by a horizontal foot surface 93 which meets a slightly concave surface 94 which extends into 3 leg 88 and meets a horizontal foot surface 95 at the bottom side edge of leg 88.

The lower rear edge of body portion 76 is provided with a sidewardly extending lug 96 having an outer side edge Q7 inclined inwardly from the top to the bottom of lug 96. The lug 96 extends sidewa-rds from body portion 76 in the same direction as leg 88.

The rear upper edge of body portion 76 is provided with a sidewardly extending horizontal flange 98, The outer edge of flange 98 is provided with a slot 99 from the center of which projects a downwardly and outwardly extending finger 1%. A slot 101 may be provided in body portion 76 to facilitate forming of flange 98. The flange 98 extends sidewards from body portion 76 in the same direction as leg 88.

The hook latch of FIGS. 68 is intended to be installed on the left side of the cross-T web, considering right and left as determined by looking axially along the cross- T from the center toward the end in question. The hook latches on both ends of each cross-T could .be identical. However, as will be explained below, added stability and rigidity are achieved by making the hook latch on one end of each cross-T a left-hand hook latch, as in FIGS. 68, and making the hook latch on the other end of each cross- T a right-hand hook latch. By a right-hand hook latch is meant a hook latch intended to be installed on the right side of the cross-T web. A right-hand hook latch is essentially a mirror image of the hook latch of FIGS. 6-8, i.e., those elements projecting to one side of body portion 76 in left-hand hook latch of FIGS. 6-8

project on the opposite side in a right-hand hook latch.

By using a right-hand hook latch on one end of a cross-T and a left-hand hook latch on the other end thereof, the hook latches are both installed on the same web surface, which might be either the surface 54- on the surface 55 of the cross-T of FIGS. 4 and 5. Assuming a left-hand hook latch to be installed on the left end of the cross-T in FIG. 4 and a right-hand hook latch to be installed on the right end thereof, both hook latches would be installed against the surface 54 of web 53.

Referring to FIG. 1, the hook latches 23B, 2413, 25A, 26A, 27B, 28B, 29A and 36A are left-hand, while hook latches 25B, 26B, 27A and 28A are right-hand. It will be evident from FIG. 1 that the hook latches on adjacent ends of two cross-Ts abutting corresponding points on opposite sides of a main runner should both be of either the right-hand or left-hand type. Thus, after cross-T 25 is installed between main runners 20 and 21 with its"right-hand hook latch engaging main runner 21, cross-T 27 should be installed with its righthand hook latch engaging main runner 2.1. Since the cross-Ts will normally be shipped with all right-hand hook latches at the same end of the shipping box, this will involve turning one of the cross-Ts end for end before installation. i i

The assembled relationship of the hook latches to the cross-Ts and the assembled relationship of cross-Ts to the main runners are best illustrated in FIGS. 9-ll. In these figures the hook'latches are shown as'the righthand type but the same reference numerals are used as in FIGS. 6-8. in FIGS. 9-1l the main runner is designated 102, while the cross-Ts are designated N3 and 104. The hook latches for cross-Ts 103 and 164 are designated 165 and 166, respectively.

The cross-T 103 is shown fully attached to main runner 102 in FIGS. 10 and 11. In this condition, the shoulder 63 formed by the ends of the cross-T flanges 57 and 58 abut against the adjacent outer edge of main runner flange 35; abutment actually will be against cap covering 37 if the latter is used. The bottom surfaces of the flanges are flush, providing the desired smooth ceiling surface. The lower edge of the cross-T for- Ward edge is in the form of a notch which permits shoulder 64 to rest on the adjacent main runner flange.

The forwardly projecting nose of web 53 formed by shoulder 69 abuts against the adjacent surface of main runner web 31. Nose 81 of hook latch 105 projects through the upper right-hand side of route 38 in main runner web 31, and the upper edge of shoulder 82 of nose 81 contacts the opposite surface of web 31 from that contacted by nose 69. The point of contact of shoulder 82 and web 31 is slightly above the top surface of route 38 but below nose 69. The shoulder 82 in contacting web 31 causes a squeezing or gripping action which produces a tight contact betweenshoulder 82 and web 31, between nose 69 and web 31, between shoulder 64 and flange 35, and between shoulder 63 and flange 35. These tight contacts alford substantial stability and rigidity in a vertical plane. The contact between shoulder 63 and flange 35 also affords substantial stability of rigidity in a horizontal plane which is enhanced by contact of feet 93 and 95 of legs 87 and 88 with axially spaced areas on the upper surface of main runner flange 35. It will be observed that legs 87 and 88 are parallel to main runner web 31 but are laterally spaced therefrom. This lateral spacing aids in affording the stability and rigidity in a vertical plane.

Lug 96 of hook latch 105 projects into slot 74 in cross-T web 53, and contact between the upper surface of lug 96 and the top surface of slot 74 prevents the hook latch from pivoting about its rivet 107 in a clockwise direction (FIG. Lug 96 is prevented from leaving slot 74 by contact between finger 100 and the adjacent surface of web 53. The lateral spacing between the upper end of finger 100 and web 53 should be sufficient to permit some lateral motion of lug 96 but not suflicient for the lug 96 to accidentally lose contact with the upper surface of slot 74.

Installation of the cross-T to the main runner may be effected as shown for the cross-T 103 in FIG. 9 and for the cross-T 104 in FIG. 10. The cross-T hook latch initially is in a pivoted position with the bottom of lug 96 resting on the bottom Wall of slot 71 in web 53. Pivoting of the hook latch substantially beyond this position is prevented by contact between leg 88 and shoulder 65. The cross-T is brought into close proximity with the main runner with nose 81 of the hook latch inserted through the beam route 38. This insertion is through one side of the beam route for cross-T 103 and through the other side for cross-T 104. In each case the hook latch will be inserted in the right half of the beam route as viewed axially toward the main runner web. Nose 69 is brought into contact with web 31 and feet 93 and 95 are brought into contact with the adjacent main runner flange.

The rear of the cross-T hook latch is then sprung outwardly away from the cross-T web, as by exerting a lateral force on the finger 100. Since the edge 97 of lung 95 is inclined, the bottom edge of lug 96 is shorter than the top surface. This shorter lug buttom edge facilitates outward springing of the hook latch. Gnce thebottom edge ofthe lug 96 is clear of the top edge of the cross-T web, the rear of the cross-T hook latch is pivoted downwardly, as by exerting a force on the top surface of flange 98. When the top edge of lug 96 clears the top surface of slot 74, the lug 96 will spring inwardly into the slot 74, bringing the hook latch into close contact with the cross-T web.

As the rear of the hook latch is being pivoted downwardly, the nose 81 is being pivoted upwardly, bringing the shoulder 82 into tight contact with the main runner web. It is desirable that substantial manual force be required to pivot completely the hook latch so that tight contact with the main runner will be assured.

The leg 87 extends axially along the main runner flange away from the route 38. However, the leg 87 extends past that portion of the route 38 to be occupied by the opposite cross-T, e.g., the cross-T 104. The height of leg 88 is kept small so that the leg 88 will not obstruct the route portion to be occupied by the opposite cross-T.

By offsetting hook latch nose 81 slightly to the side, as best shown in FIG. 7, a substantial axial separation may be made between the main runner web areas contacted by the noses 81 of opposing cross-T hook latches, this separation being that provided by the surface 49 (FIG. 2). Nevertheless, nose ends 69 of opposing cross- Ts contact identical areas on opposite sides of the main web.

As mentioned previously, it is desirable that the cross- T hook latches at each end of a cross-T be on the same side of the cross-T. The reason for this is that with this arrangement the cross-T may be disposed exactly perpendicular to the main runners, affording a grid structure of greater rigidity than if the cross-Ts were disposed at a slight angle other than 90. Such angular disposition would be required if the hook latch on one end of a cross- T were on the opposite side of the cross-T web from the hook latch at the other end.

Disassembly of the cross-T from the main runner may be effected by forcing the rear end of the cross-T hook latch outwardly of the cross-T web until the top edge of lug 96 clears the upper surface of slot 74. The rear end of the hook latch is then pivoted upwardly, freeing the shoulder 82 from the main runner web and at the same time freeing shoulder 69 from the main runner Web and shoulder 63 and feet 93 and 95 from the main runner flange. In a fully installed grid system, a slight flexing of the main runner and/or cross-T would be needed to free completely the first end of the cross-T. To prevent accidental disengagement of lug 95 from slot 74, it is desirable that the force required to efiect this disengagement be considerable and hence disassembly may require the use of a screwdriver or like tool to force the lug 96 out of slot 74. However, provision of the inclined edge 97 on lug 96 permits assembly of the cross-T to the main runner without the use of tools, since it is easier to urge the rear end of the hook latch outwardly by exerting a downward force on flange 93 than to force the rear end outwardly by lateral motion only. And during assembly the lower edge of the lug 96 will clear the web 53 without interference from finger 100, since the latter will initially be pivoted to a point above the web 43, as shown in FIG. 9.

While the invention has been described in connection with a specific embodiment thereof and in a specific use, various modifications thereof will occur to those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

1. In a suspended ceiling grid structure having a main runner and transverse cross-T positioned parallel to each other .at opposite sides of the main runner, said main runner having an axially extending upstanding web and a pair of axially extending flanges projecting horizontally from the main runner web, said main runner web having a plurality of axially spaced apertures located at an intermediate height in said main runner web, the im provement comprising: said cross-Ts each having an axially extending upstanding web and a pair of axially extending flanges projecting horizontally from the cross- T web but terminating axially inwardly of the forward end of the cross-T Web by a distance substantially equal to the width of a main runner flange, a first shoulder forming the forward end of each cross-T web at the end of the latter facing said main runner and located so as to be in contact with the adjacent main runner web above the top of one of said main runner apertures when the forward edge of the corresponding cross-T flange is aligned with and in contact with the outside edge of the adjacent main runner flange, said cross-T webs each having a closed sided aperture located inwardly of each forward end thereof, and a pair of hook latching elements each attached to a respective cross-T web adjacent the forward end thereof, said attachment of said hook latching elements of said cross-T webs permitting pivoting of said hook latching elements in a substantially vertical plane between an unlatched position and a latched position,

each hook latching element comprising a flat body portion disposed so as to be in slidable contact with one cross-T web surface, a locking lug projecting laterally from said body portion and arranged to enter the adjacent cross-T Web aperture when said hook latching element is pivoted to said latched position thereof, a forwardly extending nose adapted to enter said one main runner, aperture when said cross-T is aligned with said one main runner aperture and having an upwardly extending second shoulder arranged to contact the opposite surface of said main runner web above the top of said one main runner aperture when said hook latching element is pivoted to said latched position thereof, a pair of legs projecting laterally in opposite directions from said body portion and each having a foot surface arranged to contact the upper surface of the adjacent main runner flange and a flange extension projecting laterally from said body portion and arranged to contact the opposite cross-T web surface when said hook latching element is pivoted to said latched position thereof thereby to prevent accidental disengagement of said lug from said cross-T web aperture.

2. In a suspended ceiling grid structure having a main runner and transverse cross-Ts positioned parallel to each other .at opposite sides of the main runner, said main runner having an axially extending upstanding web and a pair of axially extending flanges projecting horizontally from the base of the main runner web, said main runner web having a plurality of axially spaced apertures located at an intermediate height in said main runner web, the improvement comprising: said cross-Ts each having an axially extending upstanding web and a pair of axially extending flanges projecting horizontally from the base of the cross-T web but terminating axially inwardly of the forward end of the cross-T web by a distance substan tially equal to the width of a main runner flange, a vertical shoulder forming the forward end of each cross-T web at the end of the latter facing said main runner and located so as to be in contact with the adjacent main runner web above the top of one of said main runner apertures when the forward edge of the corresponding cross-T flange is aligned with and in contact with the outside edge of the adjacent main runner flange, said cross-T webs each having a closed sided aperture located inwardly of each forward end thereof, and a pair of hook latching elements each attached to a respective cross-T web adjacent the for-ward end thereof, said attachment of said hook latching elements to said cross-T webs permitting pivoting of said hook latching elements in a substantially vertical plane between an unlatched position and a latched position, each hook latching element comprising a flat body portion disposed so as to be in slidable contact with one cross-T web surface, a locking lug projecting laterally from said body portion and arranged to enter the adjacent cross-T web aperture when said hook latching element is pivoted to said latch position thereof, a forwardly extending nose adapted to enter one side of said one main runneraperture when said cross-T is aligned with said one main runner aperture and having an upwardly extending shoulder arranged to contact the opposite surface of said main runner web above the top of said one main runneraperture when said hook latching element is pivoted to said latched position thereof, a pair of legs projecting laterally in opposite directions from said bodyportion and each having a foot surface arranged to contact the upper surface of the adjacent main runner flange outwardly of the main runner Web and a flange extension projecting laterally from said body portion and arranged to surmount the cross-T web andcontact the opposite cross-T web surface when said hook latching element deliberate withdrawal of said lug from said cross-T web aperture therebytto permit said hook latching element to be pivoted to said unlatched position thereof in which said upwardly extending shoulder is free of the adjacent main runner web surface and said cross-T may be disengaged from said main runner.

3. The combination set forth in claim 2 in which the hook latching elements attached to said forward ends of said cross-T webs are substantially mirror images of each other.

4. The combination set forth in claim 2 in which the hook latching element leg extending axially across the other side of said one main runner aperture has a top edge located below the bottom edge of said other side of said one main runner aperture.

5. The combination set forth in claim 2 in which said lug has an outer edge inclined so that the upper edge of said lug is substantially longer than the lower edge of said lug.

6. The combination set forth in claim 2 in which said upwardly extending shoulder of said hook latching element nose is inclined to limit contact between said upwardly extending shoulder and said opposite surface of said main runner web to an area adjacent the upper end of said upwardly extending shoulder.

7. In a suspended ceiling grid structure having a main runner and transverse cross-Ts positioned parallel to each other at opposite sides of the main runner, said main runner having an axially extending upstanding web and a pair of axially extending flanges projecting horizontally from the base of the main runner web, said main runner web having a plurality of axially spaced apertures located at an intermediate height in said web, the improvement comprising: said cross-Ts each having an axially extending upstanding web and a pair of axially extending flanges projecting horizontally from the base of the cross-T web but terminating axially inwardly of the forward end of the cross-T web by a distance substantially equal to the width of a main runner flange, a vertical shoulder forming the forward end of each cross-T web at the end of the latter facing said main runner and located so as to be in contact with the adjacent main runner web above the top of one of said main runner apertures when the forward edge of the corresponding cross-T flange is aligned with and in contact with the outside edge of the adjacent main runner flange, said cross-T webs each having a rectangular aperture located at an intermediate height and inwardly of the forward end thereof, the forward ends of said cross-T webs each having a notch in the lower edge thereof forming a horizontal shoulder arranged to contact the upper surface of the adjacent main runner flange when the forward edge of said cross-T flange is aligned with and in contact with the outside edge of said adjacent main runner flange, and a pair of hook latching elements each attached to a respective cross'T Web adjacent the forward end thereof, said attachment of said hook latching elements to said cross-T webs permitting pivoting of said hook latching elements in a substantially vertical plane between an unlatched position and a latched position, each hook latching element comprising a flat body portion disposed as to be in slidable contact with the cross-T Web surface, a locking lug projecting laterally from said body portion and arranged to enter the adjacent cross-T web aperture when said hook latching element is pivoted to said latched position thereof, said locking lug having a horizontal upper edge, a horizontal lower edge shorter than said upper edge and an inclined forward edge joining said upper and lower edges thereof, said lower edge of said locking lug being arranged to rest on an upper edge of said cross-T web when said hook latching element is in said unlatched position thereof, a forwardly extending nose adapted to enter one side of said one main runner aperture when said cross-T is aligned with said one main runner aperture and having an upwardly extending shoulder arranged to contact the opposite main runner web surface above the top of said one main runner aperture when said hook latching element is pivoted to said latched position thereof, said nose being offset in the direction of said one side of said one main runner aperture, a pair of legs projecting laterally in opposite directions from said body portion and each having a foot surface arranged to contact the upper surface of the adjacent main runner flange outwardly of the main runner web, and a flange extension projecting laterally from said body portion and arranged to surmount the cross-T web and contact the opposite cross-T web surface when said hook latching element is pivoted to said latched position thereof thereby to prevent accidental disengagement of said lug from said cross-T web aperture, said contact between said flange extension and said opposite surface of said cross-T Web permitting deliberate withdrawal of said lug from said cross-T web aperture thereby to permit said hook latching element to be pivoted to said unlatched position thereof in which said upwardly extending shoulder is free of the adjacent main runner web surface and said cross-T may be disengaged from said main runner.

8. In a suspended ceiling grid structure having a main runner and transverse cross-Ts positioned parallel to each other at opposite sides of the main runner, said main runner having an axially extending upstanding web and a pair of axially extending flanges projecting horizontally from the main runner web, said main runner web having an aperture located at an intermediate height in said web, the improvement comprising: said cross-Ts each having an axially extending upstanding web and a pair of axially extending flanges projecting horizontally from the cross-T web but terminating axially inwardly of the forward end of the cross-T web by a distance substantially equal to the width of a main runner flange, a nose surface forming the forward end of each cross-T web at the end of the latter facing said main runner and located so as to be in contact with the adjacent main runner web when the forward edge of the corresponding cross-T flange is aligned with and in contact with the outside edge of the adjacent main runner flange, said cross-T webs each having a closed sided aperture located inwardly of each forward end thereof, and a pair of hook latching elements each attached to a respective cross-T web adjacent the forward end thereof, said attachment of said hook latching elements to said cross-T webs permitting pivoting of said hook latching elements in a substantially vertical plane between an unlatched position and a latched position, each hook latching element comprising a body portion disposed so as to be in contact with the cross-T web surface, a locking lug projecting laterally from said body portion and arranged to enter the adjacent cross-T web aperture when said hook latching element is pivoted to said latched position thereof, a forwardly extending nose adapted to enter said main runner aperture when said cross-T is aligned with said main runner aperture and having an upwardly extending shoulder arranged to contact the opposite main runner web surface above the top of said main runner aperture when said hook latching element is pivoted to said latched position thereof, and a leg projecting from said body portion and having a foot surface arranged to contact an upper surface of a flange of the adjacent main runner.

References Cited by the Examiner UNITED STATES PATENTS RICHARD W. COOKE, JR., Primary Examiner.

6/63 Purdy .189--36

Claims (1)

1. IN A SUSPENDED CEILING GRID STRUCTURE HAVING A MAIN RUNNER AND TRANSVERSE CROSS-T POSITIONED PARALLEL TO EACH OTHER AT OPPOSITE SIDES OF THE MAIN RUNNER, SAID MAIN RUNNER HAVING AN AXIALLY EXTENDING UPSTANDING WEB AND A PAIR OF AXIALLY EXTENDING FLANGES PROJECTING HORIZONTALLY FROM THE MAIN RUNNER WEB, SAID MAIN RUNNER WEB HAVING A PLURALITY OF AXIALLY SPACED APERTURES LOCATED AT AN INTERMEDIATE HEIGHT IN SAID MAIN RUNNER WEB, THE IMPROVEMENT COMPRISING: SAID CROSS-T''S EACH HAVING AN AXIALLY EXTENDING UPSTANDING WEB AND A PAIR OF AXIALLY EXTENDING FLANGES PROJECTING HORIZONTALLY FROM THE CROSST WEB BUT TERMINATING AXIALLY INWARDLY OF THE FORWARD END OF THE CROSS-T WEB BY A DISTANCE SUBSTANTIALLY EQUAL TO THE WIDTH OF A MAIN RUNNER AND LOCATED SO AS TO FORMING THE FOWARD END OF EACH CROSS-T WEB AT THE END OF THE LATTER FACING SAID MAIN RUNNER AND LOCATED SO AS TO BE IN CONTACT WITH THE ADJACENT MAIN RUNNER WEB ABOVE THE TOP OF ONE OF SAID MAIN RUNNER APERTURES WHEN THE FORWARD EDGE OF THE CORRESPONDING CROSS-T FLANGE IS ALINGED WITH AND IN CONTACT WITH THE OUTSIDE EDGE OF THE ADJACENT MAIN RUNNER FLANGE, SAID CROSS-T WEBS EACH HAVING A CLOSED SIDED APERTURE LOCATED INWARDLY OF EACH FORWARD END THEREOF, AND A PAIR OF HOOK LATCHING ELEMENTS EACH ATTACHED TO A RESPECTIVE CROSS-T WEB ADJACENT THE FORWARD END THEREOF, SAID ATTACHMENT OF SAID HOOK LATCHING ELEMENTS OF SAID CROSS-T WEBS PERMITTING PIVOTING OF SAID HOOK LATCHING ELEMENTS IN A SUBSTANTIALLY VERTICAL PLANE BETWEEN AN UNLATCHED POSITION AND A LATCHED POSITION, EACH HOOK LATCHING ELEMENT COMPRISING A FLAT BODY PORTION DISPOSED SO AS TO BE IN SLIDABLE CONTACT WITH ONE CROSS-T WEB APERTURE WHEN SAID HOOK LATCHING ELEMENT FROM SAID BODY PORTION AND ARRANGED TO ENTER THE ADJACENT CROSS-T WEB APERTURE WHEN SAID HOOK LATCHING ELEMENT IS PIVOTED TO SAID LATCHED POSITION THEREOF, A FORWARDLY EXTENDING NOSE ADAPTED TO ENTER SAID ONE MAIN RUNNER APERTURE WHEN SAID CROSS-T IS ALIGNED WITH SAID ONE MAIN RUNNER APERTURE AND HAVING AN UPWARDLY EXTENDING SECOND SHOULDER ARRANGED TO CONTACT THE OPPOSITE SURFACE OF SAID MAIN RUNNER WEB ABOVE THE TOP OF SAID ONE MAIN RUNNER APERTURE WHEN SAID HOOK LATCHING ELEMENT IS PIVOTED TO SAID LATCHED POSITION THEREOF, A PAIR OF LEGS PROJECTING LATERALLY IN OPPOSITE DIRECTIONS FROM SAID BODY PORTION AND EACH HAVING A FOOT SURFACE ARRANGED TO CONTACT THE UPPER SURFACE OF THE ADJACENT MAIN RUNNER FLANGE AND A FLANGE EXTENSION PROJECTING LATERALLY FROM SAID BODY PORTION AND ARRANGED TO CONTACT THE OPPOSITE CROSS-T WEB SURFACE WHEN SAID HOOK LATCHING ELEMENT IS PIVOTED TO SAID LATCHED POSITION THEREOF THEREBY TO PREVENT ACCIDENTAL DISENGAGEMENT OF SAID LUG FROM SAID CROSS-T WEB APERTURE.

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