Title:
STEEL DECK INSERT
United States Patent 3769774
Abstract:
An elongate bolt having a head at its upper end and a threaded lower end is mounted through a corrugated sheet steel member of a steel floor deck. The threaded lower end comprises a stud formation which carries an elongate nut which provides a downwardly opening interior threaded socket. The bolt is mounted in a hole drilled in the horizontal portion of the corrugated sheet steel member and is held in place by the resilient splayed fingers of a ring engaging the bolt below the sheet of steel and a helical spring backed against a shoulder of the bolt and engaging the upper surface of the corrugated sheet of steel through a large washer. When concrete is poured on the upper surface of the sheet steel member and set, it will embed the upper portion of the bolt. Prior to pouring, however, the upper portion of the bolt is yieldable by reason of the helical spring but recoverable to a position perpendicular to the plane of the sheet steel member.
US Patent References:
/3616591.html
Bahr - November 1971 - 3616591
SCREW ANCHOR
Kapajek - January 1970 - 3487746
Structural fasteners
Hall, Jr. - March 1968 - 3372523
Hanger
Waite - December 1931 - 1837930
Fastener
Ritzel - October 1945 - 2387468
/3616591.html
Bahr - November 1971 - 3616591
SCREW ANCHOR
Kapajek - January 1970 - 3487746
Structural fasteners
Hall, Jr. - March 1968 - 3372523
Hanger
Waite - December 1931 - 1837930
Fastener
Ritzel - October 1945 - 2387468
Application Number:
05/266387
Publication Date:
11/06/1973
Filing Date:
06/26/1972
View Patent Images:
Export Citation:
Assignee:
International Telephone and Telegraph Corporation (New York, NY)
Primary Class:
Other Classes:
248/58, 411/544, 52/39, 411/970, 411/340
International Classes:
E04B1/41; E04B9/18; F16L3/14; E04B1/41
Field of Search:
52/698,699,700,703,705,335,27,39,334-336 248/56,317,17,58 287/2.92C 85/1H,80,75,70,71,5R 151/44.75
Primary Examiner:
Abbott, Frank L.
Assistant Examiner:
Friedman, Carl D.
Parent Case Data:
CROSS REFERENCE TO A RELATED APPLICATION.
A related application was filed in the name of Hiroshi Imai on June 18- 1971, Ser. No. 154,324, and was assigned to the same assignee as the present application.
Claims:
What is desired to secure by Letters Patent of the United States is
1. In a hanger insert for installation in steel decking and which includes an elongate bolt having a body with a head at its upper end and its bottom end being threaded, a helical spring coaxial with the body, upper stop means on the body engaging the upper end of the spring, nut and finger means engaging the bottom end of the bolt, and including upwardly diverging fingers, and a washer between the bottom of the spring and the upper ends of the fingers with the lower end of the spring engaged against the top of the washer, the insert adapted to be pushed through a hole in the steel decking nut and finger means first so that the fingers contract while passing through the hole and spring back after passing to engage against the bottom of the steel decking, the spring being under some compression against the top of the washer to bias the insert in erect position; the invention herein which comprises: said stop means comprising an annular shoulder on said body of a diameter larger than the diameter of the helical spring at its upper end.
2. The invention as claimed in claim 1 in which the spring is conical and its lower end has a diameter substantially larger than the diameter of said upper end, but smaller than the diameter of said washer.
3. The invention as claimed in claim 1 in which said nut and finger means comprise a sleevelike member of resilient sheet metal having a lower ring and integral splayed fingers connected to the ring and spaced circumferentially and a nut independent of said sleevelike member engaging said threaded bottom end and backing up said ring and providing means to enable a structural member to be connected to said bolt bottom end.
4. The invention as claimed in claim 1 in which the head is offset.
5. The invention as claimed in claim 1 in which the head is non-circular.
6. The invention as claimed in claim 5 in which the head is offset.
7. In a hanger insert for installation in steel decking and which includes an elongate bolt having a body with a head at its upper end and its bottom end being threaded, a helical spring coaxial with the body, upper stop means on the body engaging the upper end of the spring, nut and finger means engaging the bottom end of the bolt, and including upwardly diverging fingers, and a washer between the bottom of the spring and the upper ends of the fingers with the lower end of the spring engaged against the top of the washer, the insert adapted to be pushed through a hole in the steel decking nut and finger means first so that the fingers contract while passing through the hole and spring back after passing to engage against the bottom of the steel decking, the spring being under some compression against the top of the washer to bias the insert in erect position; the invention herein which comprises: said nut and finger means comprising a sleevelike member of resilient sheet metal having a lower ring and integral splayed fingers connected to the ring and spaced circumferentially and a nut independent of said sleevelike member engaging said threaded bottom end and backing up said ring and providing means to enable a structural member to be connected to said bolt bottom end.
8. The invention as claimed in claim 7 in which the helical spring is conical, the upper end being of smaller diameter and engaging said stop means, the lower diameter being of substantially larger diameter than the upper end and engaging the top of the washer, the washer being of larger diameter than the diameter of said lower end of said spring.
9. The invention as claimed in claim 7 in which the head is offset.
10. The invention as claimed in claim 7 in which the head is non-circular.
11. The invention as claimed in claim 10 in which the head is offset.
1. In a hanger insert for installation in steel decking and which includes an elongate bolt having a body with a head at its upper end and its bottom end being threaded, a helical spring coaxial with the body, upper stop means on the body engaging the upper end of the spring, nut and finger means engaging the bottom end of the bolt, and including upwardly diverging fingers, and a washer between the bottom of the spring and the upper ends of the fingers with the lower end of the spring engaged against the top of the washer, the insert adapted to be pushed through a hole in the steel decking nut and finger means first so that the fingers contract while passing through the hole and spring back after passing to engage against the bottom of the steel decking, the spring being under some compression against the top of the washer to bias the insert in erect position; the invention herein which comprises: said stop means comprising an annular shoulder on said body of a diameter larger than the diameter of the helical spring at its upper end.
2. The invention as claimed in claim 1 in which the spring is conical and its lower end has a diameter substantially larger than the diameter of said upper end, but smaller than the diameter of said washer.
3. The invention as claimed in claim 1 in which said nut and finger means comprise a sleevelike member of resilient sheet metal having a lower ring and integral splayed fingers connected to the ring and spaced circumferentially and a nut independent of said sleevelike member engaging said threaded bottom end and backing up said ring and providing means to enable a structural member to be connected to said bolt bottom end.
4. The invention as claimed in claim 1 in which the head is offset.
5. The invention as claimed in claim 1 in which the head is non-circular.
6. The invention as claimed in claim 5 in which the head is offset.
7. In a hanger insert for installation in steel decking and which includes an elongate bolt having a body with a head at its upper end and its bottom end being threaded, a helical spring coaxial with the body, upper stop means on the body engaging the upper end of the spring, nut and finger means engaging the bottom end of the bolt, and including upwardly diverging fingers, and a washer between the bottom of the spring and the upper ends of the fingers with the lower end of the spring engaged against the top of the washer, the insert adapted to be pushed through a hole in the steel decking nut and finger means first so that the fingers contract while passing through the hole and spring back after passing to engage against the bottom of the steel decking, the spring being under some compression against the top of the washer to bias the insert in erect position; the invention herein which comprises: said nut and finger means comprising a sleevelike member of resilient sheet metal having a lower ring and integral splayed fingers connected to the ring and spaced circumferentially and a nut independent of said sleevelike member engaging said threaded bottom end and backing up said ring and providing means to enable a structural member to be connected to said bolt bottom end.
8. The invention as claimed in claim 7 in which the helical spring is conical, the upper end being of smaller diameter and engaging said stop means, the lower diameter being of substantially larger diameter than the upper end and engaging the top of the washer, the washer being of larger diameter than the diameter of said lower end of said spring.
9. The invention as claimed in claim 7 in which the head is offset.
10. The invention as claimed in claim 7 in which the head is non-circular.
11. The invention as claimed in claim 10 in which the head is offset.
Description:
BACKGROUND OF THE INVENTION
The invention herein is concerned with apparatus which is intended to be installed in the deck of a building during the construction thereof to provide depending hangers below the deck. For example, through the use of the hanger inserts of the invention, one may support pipes and conduits, automatic sprinkler apparatus, electrical fixtures, and any other apparatus which would normally be depending from a ceiling as well as supports for false ceilings and the like.
Deck construction or decking is a type of construction which is extensively used for forming the floors of large steel frame buildings of multiple stories. The floor of one level is defined on the upper surface of a given deck while the true ceiling of the lower level is defined by the lower surface of the same deck.
Although there are several types of deck construction in use today in the construction of large buildings, one of the most important of these is the steel floor deck due to its presently increased use in large steel frame buildings of multiple stories.
Fluted or corrugated sheet steel is utilized as a floor base and filled with a substantial layer of concrete poured in situ. Utility service conduits are laid in suitable formations of the sheet steel member prior to pouring concrete upon the upper surface of the member. There may be outlets for these conduits on the upper surfaces of the concrete layer which are prelocated in the concrete or otherwise identified to be used at a later time. The bottom of this layer of concrete is in intimate contact with the steel base whose underside is exposed below as the true ceiling for the lower level. The resulting deck structure is strong and substantially fireproof.
In the planning of a building, structures to be supported from the bottom of the deck are best located and inserts installed in the sheet steel prior to pouring the concrete. The only alternative is to attempt to effect the installation from below after the concrete has set. This is a difficult and expensive technique. One must first cut or drill through the layer of steel and then use some form of concrete anchor.
The invention contemplates a type of hanger insert which obviates some problems arising in any attempt to provide hanger inserts for pre-installation.
First, the insert must be simple and strong so that it can be installed effectively and easily. Also, it must be economical and result in a strong installation below the deck after the concrete has set.
Secondly, the insert must not readily be pulled out or permanently bent over prior to the pouring of the concrete. This is important because until the concrete has been fully poured, workmen may step on the inserts, accidentally kick them, or structures to be preset into the concrete may be moved against the inserts. The latter structures might be utility conduits or reinforcing rods.
Certain problems in connection with such hanger inserts are solved by the invention as will be seen.
One hanger insert available commercially has a construction substantially as described but is not economical to manufacture. The upper helical spring is prevented from riding up the bolt by lateral stop members that must be formed by an operation in addition to the manufacturing process of making the bolt. There is a nut structure at the bottom of the bolt that comprises a cylindrical metal bushing having a threaded interior molded into a plastic bushing the upper end of which extends beyond the metal bushing and is segmented axially to provide a plurality of circumferentially spaced fingers which diverge upwardly. The resilience of the fingers enables them to contract as the nut structure is pushed downwardly through a hole in the metal decking with the bolt bottom and then spread after passing through. The fingers engage the bottom surface of the metal decking and are yieldably held in position by the compressed resilience of the upper helical spring.
The nut structure described is expensive to manufacture because it has to be made out of plastic moulded around the threaded metal bushing and then segmented.
The invention provides simple stop means for the upper spring formed during the manufacture of the bolt itself. It also contemplates two parts in place of the above described nut structure, both of which are simple to manufacture and hence more economical while also being more effective in operation. One part is a ring of resilient metal having integral fingers formed by simple production techniques and the other part is a simple cylindrical nut readily formed on a screw machine.
The head of the prior hanger insert is axially symmetrical and hence likely to be twisted loose out of the set concrete as the bolt is subjected to torque during attachment of a structural member to the bottom thereof. The invention provides an offset head to prevent this. In addition the head may also be non-circular for the same purpose.
Another feature of the invention is the use of a conical or frusto-conical spring giving a broader base and providing a higher degree of stability to aid the bolt in recovering to vertical position after having been rocked laterally.
SUMMARY OF THE INVENTION
The hanger insert of the invention comprises an elongate structure including a bolt which is yieldably mounted above a corrugated sheet steel member with its bottom end protruding through a hole in the sheet member and having means for securing structural members depending from the bolt below the corrugated sheet steel member. After installation the upper structure is embedded in concrete poured on the upper surface of the steel member.
The hanger insert comprises a boltlike member having an elongate cylindrical body, an offset and/or non-circular head at its upper end and a threaded lower end. An annular shoulder is formed in the body between its ends by having the lower portion of the body of reduced diameter. A conical helical spring has its smaller diameter engaged against the shoulder and its lower diameter engaged against a washer under compression. A metal ring having splayed resilient fingers has the fingers engaged against the bottom of the washer and held in place by a cylindrical nut threaded to the bottom end of the boltlike member.
The insert is installed by pushing the nut and ring through the hole from the top of the sheet steel member, compressing the helical spring until the contracted fingers slip through the hole and snap outwardly below the bottom of the sheet steel member. The washer remains on top and the insert is yieldably mounted, clamped in place onto the sheet steel member between the washer and the fingers.
The nut provides means for securement of structural members after the upper part of the insert has been embedded in concrete.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a steel deck insert according to the invention including a portion of a steel floor deck plate, a false ceiling member and a ceiling support bolt;
FIG. 2 is a front elevational view of the assembled steel deck insert constructed according to the invention;
FIG. 3 is a side elevational view, partly in section illustrating the steel deck insert installed in the steel floor deck;
FIG. 4 is a fragmentary sectional view taken through a portion of a corrugated steel floor deck illustrating two hanger inserts installed therein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As previously explained, the steel deck or hanger insert of the invention is designed to be installed in decking of the type which involves poured concrete prior to the pouring of the concrete so that the setting of the concrete will permanently anchor the insert in the deck.
Considering for a moment FIG. 4, there is illustrated a portion of a steel floor deck comprising a sheet steel member 10 having a layer of concrete 11 of substantial thickness above the same and in intimate contact therewith.
The details of the hanger insert of the invention are shown in FIGS. 1 to 3 wherein the hanger insert is designated generally by the reference character 12 and is shown partially above and partially below the sheet steel member 10.
The insert comprises an elongate boltlike member 13 having an upper cylindrical body portion 14 and a lower cylindrical body portion 16. The upper cylindrical body portion 14 is of a diameter slightly greater than the diameter of the lower body portion 16. The lower part 18 of the lower body portion 16 is threaded so that a cylindrical nut 20 may be fastened to the lower body portion 16.
The upper end of the upper portion 14 has a relatively large head 22 integral therewith. The head 22 is preferably offset relative to the bolt 13 for reasons which will be set forth hereinafter. It may also be non-circular.
The insert further comprises a helical spring 24 of frusto-conical configuration the smaller -- in the drawing upper -- diameter thereof being somewhat larger than the diameter of the lower body portion 16 but smaller than the diameter of the upper body portion 14. Thus, the spring 24 is capable of readily sliding over the lower portion 16 but in moving upwardly is stopped by the shoulder 26 which is the beginning of the larger diameter section. This shoulder is easily and economically formed during the machining of the bolt member 13 to serve as stop means for spring 24.
The insert is also provided with a washer 28 having a central circular opening of a diameter enabling the washer to slide over the lower portion 16 of the bolt member 13. The larger -- in the drawing lower -- diameter of the helical spring 24 is smaller than the diameter of the washer 28 but provides a stable base for the spring to bias the bolt upright at all times.
A sleevelike member 30 is provided to secure the bolt member to the sheet steel member 10. The member 30 is best illustrated in FIG. 1 and is formed from thin resilient sheet metal. It has a bottom ring portion 32 with a plurality of circumferentially spaced flared fingers 34 integral therewith.
The insert is further provided with the bushing or cylindrical steel nut 20 which may be somewhat elongate. The upper part of the nut 20 is intended to be connected to the threaded end 18 of the bolt 13. The lower part of the nut 20 serves as a socket for threading therein a bolt 38 or other structural member. The particular bolt 38 has a threaded upper end 40 and a head 42. The bolt 38 with its head 42, as indicated in FIGS. 1 and 4, may be employed to carry a sheet member forming part of a false ceiling 44 or any other structural member.
The hanger insert may be assembled by the manufacturer in the condition shown in FIG. 4 with all parts as shown, the spring 24 being somewhat compressed against the upper surface of the washer 28.
In installing the insert, first a hole is drilled in the sheet steel member 10 as shown at 46, this hole being of a diameter slightly larger than the diameter of the ring 32 of the sleeve member 30. Subsequently the assembly is pushed through the hole 46 from the top of the sheet metal 10. In pushing the insert through the hole the spring 24 is first compressed and the fingers 34 must be constricted. They spring outwardly when the upper ends have passed downwardly through the hole 46.
As seen in FIG. 3 the insert is now resiliently clamped in position, the flared fingers 34 engaging the sheet metal member 10 from below and the washer under the force of the spring 24 engaging same from above. The pressure applied by the spring 24 is readily adjusted by taking up or releasing the structural member 20. The bolt 13 resists force tending to rock same laterally.
After the insert has been assembled as shown in FIG. 3 it is capable of being rocked or otherwise moved to a certain extent by workmen kicking or stepping one the same, and it will recover to its vertical position perpendicular to the plane of the sheet steel member 10. When the concrete is poured around the same, it will become permanently embedded as indicated in FIG. 4.
The head 22 of the bolt member 13 is offset. Expressed otherwise, the center of the head 22 is not aligned with the axis of the bolt member 13. It may alternately or additionally be non-circular. The purpose of the offsetting and/or non-circular features is to impede the likelihood of rotational motion of the head 22 within the hardened concrete 11 when torque is applied to the bottom of the bolt member 13.
FIG. 4 illustrates the corrugated steel sheet member 10 with two steel inserts installed so as to be embedded in the concrete. The bolt 40 is fastened to the first insert. The head 42 of the bolt 40 is shown engaged below a hole in the sheet member of a false ceiling 44. A pipe hanger or other fixture may be secured as shown at 50 to the second hanger insert.
As noted the sleeve member 30 and the nut 20 replace the combined plastic and metal structure described as prior art. The economy of these components is obvious since the sleeve member 30 may be formed of resilient sheet metal by stamping, forming, drawing and the like while the nut 20 is the most elemental type of screw machine product. Further, the sheet metal fingers 34 are stronger and more resilient than plastic. The bottom end of the nut 20 may be externally threaded to provide a stud attachment, if desired.
Modification of the invention may be made without departing from the spirit or scope of the same as defined in the appended claims.
The invention herein is concerned with apparatus which is intended to be installed in the deck of a building during the construction thereof to provide depending hangers below the deck. For example, through the use of the hanger inserts of the invention, one may support pipes and conduits, automatic sprinkler apparatus, electrical fixtures, and any other apparatus which would normally be depending from a ceiling as well as supports for false ceilings and the like.
Deck construction or decking is a type of construction which is extensively used for forming the floors of large steel frame buildings of multiple stories. The floor of one level is defined on the upper surface of a given deck while the true ceiling of the lower level is defined by the lower surface of the same deck.
Although there are several types of deck construction in use today in the construction of large buildings, one of the most important of these is the steel floor deck due to its presently increased use in large steel frame buildings of multiple stories.
Fluted or corrugated sheet steel is utilized as a floor base and filled with a substantial layer of concrete poured in situ. Utility service conduits are laid in suitable formations of the sheet steel member prior to pouring concrete upon the upper surface of the member. There may be outlets for these conduits on the upper surfaces of the concrete layer which are prelocated in the concrete or otherwise identified to be used at a later time. The bottom of this layer of concrete is in intimate contact with the steel base whose underside is exposed below as the true ceiling for the lower level. The resulting deck structure is strong and substantially fireproof.
In the planning of a building, structures to be supported from the bottom of the deck are best located and inserts installed in the sheet steel prior to pouring the concrete. The only alternative is to attempt to effect the installation from below after the concrete has set. This is a difficult and expensive technique. One must first cut or drill through the layer of steel and then use some form of concrete anchor.
The invention contemplates a type of hanger insert which obviates some problems arising in any attempt to provide hanger inserts for pre-installation.
First, the insert must be simple and strong so that it can be installed effectively and easily. Also, it must be economical and result in a strong installation below the deck after the concrete has set.
Secondly, the insert must not readily be pulled out or permanently bent over prior to the pouring of the concrete. This is important because until the concrete has been fully poured, workmen may step on the inserts, accidentally kick them, or structures to be preset into the concrete may be moved against the inserts. The latter structures might be utility conduits or reinforcing rods.
Certain problems in connection with such hanger inserts are solved by the invention as will be seen.
One hanger insert available commercially has a construction substantially as described but is not economical to manufacture. The upper helical spring is prevented from riding up the bolt by lateral stop members that must be formed by an operation in addition to the manufacturing process of making the bolt. There is a nut structure at the bottom of the bolt that comprises a cylindrical metal bushing having a threaded interior molded into a plastic bushing the upper end of which extends beyond the metal bushing and is segmented axially to provide a plurality of circumferentially spaced fingers which diverge upwardly. The resilience of the fingers enables them to contract as the nut structure is pushed downwardly through a hole in the metal decking with the bolt bottom and then spread after passing through. The fingers engage the bottom surface of the metal decking and are yieldably held in position by the compressed resilience of the upper helical spring.
The nut structure described is expensive to manufacture because it has to be made out of plastic moulded around the threaded metal bushing and then segmented.
The invention provides simple stop means for the upper spring formed during the manufacture of the bolt itself. It also contemplates two parts in place of the above described nut structure, both of which are simple to manufacture and hence more economical while also being more effective in operation. One part is a ring of resilient metal having integral fingers formed by simple production techniques and the other part is a simple cylindrical nut readily formed on a screw machine.
The head of the prior hanger insert is axially symmetrical and hence likely to be twisted loose out of the set concrete as the bolt is subjected to torque during attachment of a structural member to the bottom thereof. The invention provides an offset head to prevent this. In addition the head may also be non-circular for the same purpose.
Another feature of the invention is the use of a conical or frusto-conical spring giving a broader base and providing a higher degree of stability to aid the bolt in recovering to vertical position after having been rocked laterally.
SUMMARY OF THE INVENTION
The hanger insert of the invention comprises an elongate structure including a bolt which is yieldably mounted above a corrugated sheet steel member with its bottom end protruding through a hole in the sheet member and having means for securing structural members depending from the bolt below the corrugated sheet steel member. After installation the upper structure is embedded in concrete poured on the upper surface of the steel member.
The hanger insert comprises a boltlike member having an elongate cylindrical body, an offset and/or non-circular head at its upper end and a threaded lower end. An annular shoulder is formed in the body between its ends by having the lower portion of the body of reduced diameter. A conical helical spring has its smaller diameter engaged against the shoulder and its lower diameter engaged against a washer under compression. A metal ring having splayed resilient fingers has the fingers engaged against the bottom of the washer and held in place by a cylindrical nut threaded to the bottom end of the boltlike member.
The insert is installed by pushing the nut and ring through the hole from the top of the sheet steel member, compressing the helical spring until the contracted fingers slip through the hole and snap outwardly below the bottom of the sheet steel member. The washer remains on top and the insert is yieldably mounted, clamped in place onto the sheet steel member between the washer and the fingers.
The nut provides means for securement of structural members after the upper part of the insert has been embedded in concrete.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a steel deck insert according to the invention including a portion of a steel floor deck plate, a false ceiling member and a ceiling support bolt;
FIG. 2 is a front elevational view of the assembled steel deck insert constructed according to the invention;
FIG. 3 is a side elevational view, partly in section illustrating the steel deck insert installed in the steel floor deck;
FIG. 4 is a fragmentary sectional view taken through a portion of a corrugated steel floor deck illustrating two hanger inserts installed therein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As previously explained, the steel deck or hanger insert of the invention is designed to be installed in decking of the type which involves poured concrete prior to the pouring of the concrete so that the setting of the concrete will permanently anchor the insert in the deck.
Considering for a moment FIG. 4, there is illustrated a portion of a steel floor deck comprising a sheet steel member 10 having a layer of concrete 11 of substantial thickness above the same and in intimate contact therewith.
The details of the hanger insert of the invention are shown in FIGS. 1 to 3 wherein the hanger insert is designated generally by the reference character 12 and is shown partially above and partially below the sheet steel member 10.
The insert comprises an elongate boltlike member 13 having an upper cylindrical body portion 14 and a lower cylindrical body portion 16. The upper cylindrical body portion 14 is of a diameter slightly greater than the diameter of the lower body portion 16. The lower part 18 of the lower body portion 16 is threaded so that a cylindrical nut 20 may be fastened to the lower body portion 16.
The upper end of the upper portion 14 has a relatively large head 22 integral therewith. The head 22 is preferably offset relative to the bolt 13 for reasons which will be set forth hereinafter. It may also be non-circular.
The insert further comprises a helical spring 24 of frusto-conical configuration the smaller -- in the drawing upper -- diameter thereof being somewhat larger than the diameter of the lower body portion 16 but smaller than the diameter of the upper body portion 14. Thus, the spring 24 is capable of readily sliding over the lower portion 16 but in moving upwardly is stopped by the shoulder 26 which is the beginning of the larger diameter section. This shoulder is easily and economically formed during the machining of the bolt member 13 to serve as stop means for spring 24.
The insert is also provided with a washer 28 having a central circular opening of a diameter enabling the washer to slide over the lower portion 16 of the bolt member 13. The larger -- in the drawing lower -- diameter of the helical spring 24 is smaller than the diameter of the washer 28 but provides a stable base for the spring to bias the bolt upright at all times.
A sleevelike member 30 is provided to secure the bolt member to the sheet steel member 10. The member 30 is best illustrated in FIG. 1 and is formed from thin resilient sheet metal. It has a bottom ring portion 32 with a plurality of circumferentially spaced flared fingers 34 integral therewith.
The insert is further provided with the bushing or cylindrical steel nut 20 which may be somewhat elongate. The upper part of the nut 20 is intended to be connected to the threaded end 18 of the bolt 13. The lower part of the nut 20 serves as a socket for threading therein a bolt 38 or other structural member. The particular bolt 38 has a threaded upper end 40 and a head 42. The bolt 38 with its head 42, as indicated in FIGS. 1 and 4, may be employed to carry a sheet member forming part of a false ceiling 44 or any other structural member.
The hanger insert may be assembled by the manufacturer in the condition shown in FIG. 4 with all parts as shown, the spring 24 being somewhat compressed against the upper surface of the washer 28.
In installing the insert, first a hole is drilled in the sheet steel member 10 as shown at 46, this hole being of a diameter slightly larger than the diameter of the ring 32 of the sleeve member 30. Subsequently the assembly is pushed through the hole 46 from the top of the sheet metal 10. In pushing the insert through the hole the spring 24 is first compressed and the fingers 34 must be constricted. They spring outwardly when the upper ends have passed downwardly through the hole 46.
As seen in FIG. 3 the insert is now resiliently clamped in position, the flared fingers 34 engaging the sheet metal member 10 from below and the washer under the force of the spring 24 engaging same from above. The pressure applied by the spring 24 is readily adjusted by taking up or releasing the structural member 20. The bolt 13 resists force tending to rock same laterally.
After the insert has been assembled as shown in FIG. 3 it is capable of being rocked or otherwise moved to a certain extent by workmen kicking or stepping one the same, and it will recover to its vertical position perpendicular to the plane of the sheet steel member 10. When the concrete is poured around the same, it will become permanently embedded as indicated in FIG. 4.
The head 22 of the bolt member 13 is offset. Expressed otherwise, the center of the head 22 is not aligned with the axis of the bolt member 13. It may alternately or additionally be non-circular. The purpose of the offsetting and/or non-circular features is to impede the likelihood of rotational motion of the head 22 within the hardened concrete 11 when torque is applied to the bottom of the bolt member 13.
FIG. 4 illustrates the corrugated steel sheet member 10 with two steel inserts installed so as to be embedded in the concrete. The bolt 40 is fastened to the first insert. The head 42 of the bolt 40 is shown engaged below a hole in the sheet member of a false ceiling 44. A pipe hanger or other fixture may be secured as shown at 50 to the second hanger insert.
As noted the sleeve member 30 and the nut 20 replace the combined plastic and metal structure described as prior art. The economy of these components is obvious since the sleeve member 30 may be formed of resilient sheet metal by stamping, forming, drawing and the like while the nut 20 is the most elemental type of screw machine product. Further, the sheet metal fingers 34 are stronger and more resilient than plastic. The bottom end of the nut 20 may be externally threaded to provide a stud attachment, if desired.
Modification of the invention may be made without departing from the spirit or scope of the same as defined in the appended claims.