US3859770A

US3859770A - Suspension system

Info

Publication number: US3859770A
Application number: US324737A
Authority: US
Inventors: Harry A Chambers; John C Tillman
Original assignee: TRW Inc
Current assignee: Northrop Grumman Space and Mission Systems Corp
Priority date: 1973-01-18
Filing date: 1973-01-18
Publication date: 1975-01-14
Anticipated expiration: 1992-01-14

Abstract

A method and apparatus for suspending an acoustical ceiling from an overhead structure are provided. The overhead structure comprises a structural steel member and a metal deck on which concrete is poured, with a layer of fireproofing material covering the entire lower surface of the metal structure. A cleaning tool on an extension handle is used to scrape away a circular portion of the fireproofing layer and also to remove paint or galvanizing on the metal surface underneath. A unique stud is provided with a supporting wire centrally attached by a loop extending through a hole in a middle portion, the stud preferably having two weldable ends. A ferrule is placed around the upper end of the stud which is then welded to the exposed metal surface by a special welding tool which includes a long extension, that enables the operator to stand on the floor while welding. The ferrule can be left in place to provide a degree of fireproofing in place of the removed portion of the layer. Consequently, no additional fireproofing material usually need be applied after the stud is welded. A supporting grid for acoustical panels or tiles is then suitably attached to the lower ends of the wires to complete the suspension system.

Description

United States Patent [191 Chambers et a1.

[ SUSPENSION SYSTEM [75] Inventors: Harry A. Chambers, Amherst; John C. Tillman, Hudson, both of Ohio [73] Assignee: TRW Inc., Cleveland, Ohio [22] Filed: Jan. 18, 1973 [21] Appl. No.: 324,737

[52] US. Cl 52/741, 52/127, 52/484, 52/486, 52/758 B [51] Int. Cl E04b 5/52, E04b 5/62 [58] Field of Search 52/334, 336, 664, 618, 52/741, 484, 758 B, 486

[56] References Cited UNITED STATES PATENTS 1,865,284 6/1932 Smith 52/758 B 3,032,833 5/1962 52/484 3,102,610 9/1963 52/484 X 3,102,611 9/1963 Mole 52/484 X 3,197,926 8/1965 Shumaker 52/484 X 3,267,624 8/1966 Wozwiak et a1. 52/486 X 3,333,387 8/1967 Deakins 52/484 X 3,523,395 8/1970 Rutter et a1 85/7 FOREIGN PATENTS OR APPLICATIONS 1,104,351 2/1968 Great Britain 52/484 1,340,294 9/1963 France 1,313,158 11/1962 France 52/486 OTHER PUBLICATIONS Nelson Electric Arc Stud Welder, page 4A, 5A, 6C, 8C,11C, 5/1948.

[ Jan. 14, 1975 Nelson Stud Welding, 4 pages, 10/1959.

Primary Examiner-Ernest R. Purser Assistant Examiner-Leslie A. Biraun Attorney, Agent, or Firm-Allen D. Gutchess, Jr.

[57] ABSTRACT A method and apparatus for suspending an acoustical ceiling from an overhead structure are provided. The overhead structure comprises a structural steel member and a metal deck on which concrete is poured, with a layer of fireproofing material covering the entire lower surface of the metal structure. A cleaning tool on an extension handle is used to scrape away a circular portion of the fireproofing layer and also to remove paint or galvanizing on the metal surface underneath. A unique stud is provided with a supporting wire centrally attached by a loop extending through a hole in a middle portion, the stud preferably having two weldable ends. A ferrule is placed around the upper end of the stud which is then welded to the exposed metal surface by a special welding tool which includes a long extension, that enables the operator to stand on the floor while welding. The ferrule can be left in place to provide a degree of fireproofing in place of the removed portion of the layer. Consequently, no additional fireproofing material usually need be applied after the stud is welded. A supporting grid for acoustical panels or tiles is then suitably at tached to the lower ends of the wires to complete the suspension system.

5 Claims, 9 Drawing Figures SUSPENSION SYSTEM This invention relates to a suspension system for an acoustical ceiling, and to a method and apparatus for suspending an acoustical ceiling, and to a weldable stud for same.

It is common practice, particularly in commercial buildings, to suspend acoustical tiles or panels as a false ceiling a distance below the structural ceiling of the building, Such suspended ceilings not only provide an acoustical effect for the room but the lower ceilings establish a more modern and finished appearance, and provide space thereabove for piping, wiring, etc. Further, the acoustical ceilings can be installed relatively rapidly and do not require painters, plasterers, or other skilled craftsmen for the installation.

The present invention provides an improved acoustical ceiling suspension system and a method and apparatus for suspending a supporting grid from a ceiling structure. The invention further provides a unique weldable stud for use in the system.

In accordance with the invention, a cleaning tool having a circular scraper at an end thereof is used to remove a small, circular area of the fireproofing layer commonly sprayed on or otherwise applied to the steel structural members and the metal deck of the structural ceiling of the building. This leaves a small exposed metal surface from which paint or galvanizing can also be removed by the tool.

A wire is attached to a stud and a ferrule is placed around a weldable end of the stud. The stud is then welded to the exposed metal surface by a welding tool equipped with an extension, with the ferrule being left in place to provide fire protection for the metal in place of the removed portion of the fireproofing layer. With the ferrule remaining in place, it usually is not necessary to spray or otherwise apply the material over the structure again. The acoustical panel grid system is then suitably attached to the lower ends of the wires and the panels assembled therewith.

The stud used to affix the wire to the metal surface preferably has two weldable ends so that it is not necessary for the workman to specially orient the stud in the chuck of the welding tool. The stud has a central hole through which a loop of the wire extends, with the loop of the wire being long enough to exceed the distance from the hole to both of the weldable ends of the stud, when studs having two such ends are used. This enables the wire to hang freely from the stud and not be interfered with by the stud. This also enables either end of the stud to be positioned upwardly for being welded to the metal surface.

The suspension system according to the invention has a number of advantages. The wires can be affixed to the overhead structure at the same time the acoustical tile ceiling is to be installed, so that one team of installers can install the entire ceiling and suspension system in one trip. The wires can be affixed to the ceiling struc ture at any desired position so that all of the hanger wires will be in the proper positions and be useable. The suspension system can also be installed significantly faster than other systems heretofore employed. Further, there is no possibility of the studs penetrating the metal structure and perhaps interfering with electrical wiring in integral raceways in the metal deck.

It is, therefore, a principal object of the invention to provide an improved method and apparatus for suspending acoustical ceilings from an overhead structure.

Another object of the invention is to provide a weldable stud, with a wire centrally attached, for use in suspending members from overhead structures.

A further object of the invention is to provide an improved method and apparatus for suspending a grid system for acoustical panels from an overhead structure more quickly and at the same time that the acoustical panels are to be installed.

Yet another object of the invention is to provide a suspension system for an acoustical ceiling in which a supporting grid is suspended by weldable studs having wires attached at central portions thereof, and with ferrules surrounding the studs adjacent the exposed overhead surfaces to which the studs are welded.

Many other objects and advantages of the invention will be apparent from the following detailed description of a preferred embodiment thereof, reference being made to the accompanying drawings, in which:

FIG. 1 is a view in perspective of an interior of a building with an overhead metal deck on which is a layer of asbestos or the like, and a cleaning tool in place to remove a circular portion of the asbestos layer and expose the metal surface of the deck;

FIG. 2 is a fragmentary view in elevation of the cleaning tool of FIG. 1;

FIG. 3 is an end view of the cleaning tool;

FIG. 4 is a view in perspective of the structure of FIG. 1 but with welding apparatus in welding position in place of the cleaning tool;

FIG. 5 is an enlarged, fragmentary view in longitudinal cross section taken through the welding end of the welding apparatus of FIG. 4;

FIG. 6 is a fragmentary end view of the welding apparatus of FIG. 5;

FIG. 7 is a view in cross section taken along the lines 7-7 of FIG. 5;

FIG. 8 is a view in perspective ofa weldable stud used in the suspension system and a fragmentary portion of a wire connected thereto; and

FIG. 9 is a view in perspective, with an upper portion in section, of the suspension system completed and with an acoustical panel in place.

Referring particularly to FIG. 1, a commercial building in which the invention is to be embodied is indicated at 12 and includes a floor 14, a wall 16, and an overhead structure 18. The overhead structure 18 includes structural members or beams 20 and a metal deck 22 on which is poured concrete 24 and below which is applied a layer 26 of refractory or insulating material, such as asbestos or the like, to provide fireproofing for the structure. The layer 26 can be sprayed on the lower surfaces or can be in the form of panels which are adhered to the surfaces, for example. The building 12 is ready to receive a suspended acoustical ceiling which is suspended from the overhead structure 18. The suspended ceiling provides acoustical deadening for the room, improves the appearance thereof by providing a decorative, lower ceiling, and provides space between the suspended ceiling and the overhead structure 18 for pipes, conduits, etc.

To suspend a ceiling from the overhead structure 18, a cleaning tool 28 is first employed to remove a circular portion of the layer 26 and to expose a portion of the lower metal surface of the deck 2.2. Referring to FIGS. 2 and 3, the tool 28 includes a cup-shaped member 30 having a serrated, annular edge 32. Within the member 30 is a transverse blade 34 extending from a hub 36. The cup 30 is affixed to a tubular handle extension 38, the lower end of which is affixed to a transverse handle 40 which can be manipulated by a workman or installer to rotate the handle extension 38 and the cup-shaped member 30. This removes an annular portion of the layer 26. The hub 36 of the blade 34 is affixed by a pin 42 to a rod-like, inner handle extension 44 which extends completely through the tubular extension 38 and the transverse handle 40 to a knob 46 affixed thereto. The knob 46 can be pushed and rotated to rotate the blade 34 and remove the portion of the layer 26 within the annular portion cleaned by the serrated edge 32 of the member 30. The cleaning tool 28 not only removes a portion of the layer 26 but can also remove paint or galvanizing from the exposed surface of the metal deck 22.

With a portion of the refractory layer 26 removed to expose the metal surface, an extension 48 of a stud welding tool 50 is moved into a welding position as shown in FIG. 4, aligned with the exposed metal surface. In this position, a stud 52 embodying the invention is moved into engagement with an exposed metal surface 54 (FIG. of the deck 22, with the operator or installer standing on the floor 14.

Referring particularly to FIG. 8, the stud 52 includes a main body 56 of rectangular shape in transverse cross section with a width about three times, and preferably about two to four times, the thickness. In a preferred form, the body 56 has two weldable ends 58 and 60, neither of which employ separate bodies of flux in the embodiment shown, but can do so, as is known in the art. If the transverse area of the stud does not exceed the transverse area of a quarter-inch stud, no flux is ordinarily needed. Each of the weldable ends has a point 62 with edges 64 and 66 tapering back therefrom to longitudinal side edges 68 and 70. The edges 64 and 66, as shown, each slope at an angle of 12 /2 to a plane perpendicular to the longitudinal extent of the stud. This angle can vary from to ,however. The stud 52 has means for connecting a wire thereto, with the means shown being an opening 72 in a central portion of the stud body 56. A loop 74 formed in a wire 76 extends through the opening 72 to pivotally connect the wire 76 to the stud 52. The length of the loop 74 is sufficient to exceed the distance from the opening 72 to either of the weldable ends 58 and 60. This enables the wire to pivot freely when the stud 52 is welded to the deck 22 and also enables either of the

ends

58 and 60 to be welded to the deck 22, without special orientation by the installer. The wire 76 can be of any suitable length and is usually provided in 4 foot or 6 foot lengths, depending upon the installation.

The welding tool 50 is basically of a known design and welds the stud 52 to the surface 54 by means of a substantially conventional stud welding technique. In such technique, the stud and a ferrule are placed against the surface and the stud is withdrawn as an electrical potential is established between the stud and surface, to form a pilot arc. Subsequently, a heavier, welding arc is established between the two with the welding are preferably being maintained until the stud is plunged back against the surface. Pools of molten metal are formed by the welding arc on both the stud and the surface to form a solid weld therebetween. A welding tool of this type can be similar to that disclosed which extends from the tool 50 to the operating end of the extension 48.

Referring particularly to FIGS. 5 and 6, a welding foot 82 is affixed by a plate 84 to the end of the supporting member 78 of the extension 48. The foot 82, of insulating material, has a bore or recess 86 in which a ferrule holder or hollow member 88 is affixed by fasteners 90. The ferrule holder 88 is of a generally tubular shape but with an elongate opening 92 extending the length thereof and located to correspond with a large notch or elongate opening 94 in the bore 86. Thus, the

openings

92 and 94 can accommodate the wire 76 connected to the stud 52 and extending outwardly and downwardly therefrom.

The long chuck leg has a tapered socket 96 at the end thereof for a chuck 98. The chuck 98 includes an outer body 100 having a tapered, enlarged end 102 frictionally received in the tapered socket 96, and a tubular forward portion 104 forming an elongate cylindrical chamber 106. An inner body 108 has a solid, cylindrical rear portion 110 and forward, resilient, bifurcated fingers 112. The fingers 112 have shoulders 114, as shown in FIG. 7, which receive an end of the stud 52 with the body 56 of the stud held between the fingers 112. The end of the body 56 below the wire 96 must be of sufficient length to be properly engaged and positioned by the chuck 98. For this reason, the hole 72 for the wire 76 is placed in the middle portion of the stud. The tubular portion 104 of the outer body 100 also can help to position the stud 52 perpendicularly to the deck surface 54. The inner body 108 isheld in the cylindrical chamber 106 by a cap screw 116 which enables the inner body 108 to be quickly removed and replaced, as needed. The chuck fingers tend to arc with the stud from time to time, causing gradual disintegration of the fingers and necessitating their replacement. Replacement is relatively inexpensive when only the inner body 108 having the fingers 112 can be replaced.

When the stud 52 is placed in the chuck 98, a ceramic ferrule 118 is placed in the end of the ferrule holder 88, being frictionally received therein. The ferrule 118 includes a shoulder 120 which abuts the end of the holder 88 to position the ferrule perpendicular to the travel of the stud. The ferrule 118 also has four generally radially-extending passages 122 which communicate with a rectangular recess 124 therein. The recess 124 contains the weld metal when the stud is welded to the workpiece, as is known in the art. When the stud is welded to the workpiece, the ferrule 118 can be left in place so as to cover the surface 54 and thereby often eliminate the necessity of reapplying the material for the layer 26 after the studs are welded.

After the studs are welded in place, suitable tile or panel supporting members, such as one indicated at 126 in FIG. 9, are suitably affixed to the wires 76. As shown, the member 126 has a rib 128 in which can be formed a plurality of openings 130. The wires 76 are extended through the openings 130 and twisted back for the desired support. After the grid system formed by the supporting members 126 is in place, acoustical panels or tiles 132 can be moved into position and supported on the members 126 to complete the overall suspension assembly.

Various modifications of the above-described embodiments of the invention will be apparent to those skilled in the art, and it is to be understood that such modifications can be made without departing from the scope of the invention, if they are within the spirit and the tenor of the accompanying claims.

We claim:

1. A method of suspending an acoustical ceiling from an overhead structure, said method comprising attaching wires to weldable studs, placing each stud in a chuck of a stud welding tool, with the wire extending outwardly to one side of the stud in front of the chuck, placing the end of the stud in contact with the overhead structure, subsequently welding the studs to the overhead structure in selected positions, attaching portions of the supporting members to the lower ends of said wires to support said members in a common plane below said overhead structure, and placing acoustical panels on said supporting members.

2. A method according to claim 1 characterized further by cleaning circular areas of the overhead structure prior to welding the studs thereto, and placing ferrules around said studs prior to welding the studs to the circular areas of the overhead structure, with each ferrule having a diameter slightly smaller than that of the corresponding circular area, and leaving the ferrules in place after welding the studs to the overhead structure.

3. A method according to claim 1 characterized fur ther by placing a ferrule around the end of the stud in front of the wire, engaging the ferrule in the end of a ferrule holder around the chuck, and positioning the wire through an elongate opening in the ferrule holder prior to welding the stud to the overhead structure,

4. A method of suspending ceiling panels from an overhead metal structure, said method comprising cleaning circular areas of the overhead structure prior to welding studs thereto by engaging each of the areas by means of a blade and rotating the blade while standing on the floor therebelow, attaching wires to weldable studs, placing ferrules around the studs prior to welding the studs, subsequently welding the studs to the circular areas of the overhead metal structure with the wires already attached thereto and while continuing to stand on the floor, attaching portions of supporting members to the lower ends of said wires to support said members in a common plane below said overhead metal structure and above the floor, and placing ceiling panels on said supporting members.

5. A method according to claim 4 characterized by leaving the ferrules in place after welding the studs to the overhead structure to enable said ferrules to substantially cover any otherwise exposed portions of the

Claims

3. A method according to claim 1 characterized further by placing a ferrule around the end of the stud in front of the wire, engaging the ferrule in the end of a ferrule holder around the chuck, and positioning the wire through an elongate opening in the ferrule holder prior to welding the stud to the overhead structure.

5. A method according to claim 4 characterized by leaving the ferrules in place after welding the studs to the overhead structure to enable said ferrules to substantially cover any otherwise exposed portions of the cleaned areas.