US3686819A
Expired / Lapsed
US
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Structural chord members for joist construction
Assignee: Individual
•
Filing: 1970-01-14
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Granted: 1972-08-29
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Expires: 1990-01-14
Abstract
Abstract A new structural chord member is provided from which joists can readily be formed of different sizes and capabilities. Each chord member has a cross section represented by two modified Z-section members disposed with their top flanges coplanar and their chord webs inclined toward one another, the junctions between the chord webs and the bottom flanges being spaced apart for insertion of joist web members to form the joist member. Each chord member is provided with compositing shear projections extending from its top flanges alternatively away from or toward the chord member interior. A particular joist construction comprises two spaced hollow chord members connected by a plurality of joist web members, the upper chord member being filled with high strength cementitious material to apply preloading tension to the lower chord member and increase the moment of inertia of the joist.
Inventors
- 👤 Archibald H Atkinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:40
CPC Classifications
E; E04; E04B; E04B5/00; E04B5/16; E04B5/17; E04B5/23; E04B5/29; E04C; E04C3/00; E04C3/02; E04C3/04; E04C3/08; E04C3/09; E04C3/29; E04C3/293; E04C3/294; E04C2003/0486; E04C2003/0491
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
146 words
A structural chord member adapted for the fabrication of joists therefrom comprising a pair of connected, opposed modified Z-section members, each member having a longitudinal shear projection, a top flange rigidly connected to the shear projection along a respective top member junction, a bottom flange and a chord web connecting the said top and bottom flanges, wherein the top flanges of the two members extend toward one another and are rigidly connected to one another at said top member junctions, wherein the chord webs are inclined toward one another from the top flange toward the bottom flange to provide a corresponding chord member cross-section of decreasing width, wherein the bottom junctions of each chord web with its respective bottom flange are spaced from one another for the insertion therebetween of a joist web member, and wherein the said shear projections project transversely to the top flanges.
Claim 2
Dependent Claim
146 words
A structural chord member adapted for the fabrication of joists therefrom comprising a pair of connected, opposed modified Z-section members, each member having a longitudinal shear projection, a top flange rigidly connected to the shear projection along a respective top member junction, a bottom flange and a chord web connecting the said top and bottom flanges, wherein the top flanges of the two members extend toward one another and are rigidly connected to one another at said top member junctions, wherein the chord webs are inclined toward one another from the top flange toward the bottom flange to provide a corresponding chord member cross-section of decreasing width, wherein the bottom junctions of each chord web with its respective bottom flange are spaced from one another for the insertion therebetween of a joist web member, and wherein the said shear projections project transversely to the top flanges.
Claim 3
Dependent Claim
38 words
The invention as claimed in claim 1, wherein each Z-section member is rolled from sheet steel material to have the said top and bottom flanges, the said chord web and the said shear projection integral with one another.
Claim 4
Dependent Claim
33 words
The invention as claimed in claim 1, wherein each said shear projection projects at about 60* to the respective top flange and the two projections are inclined at about 60* to one another.
Claim 5
Dependent Claim
25 words
The invention as claimed in claim 1, wherein the shear projections project from the said top member junctions into the interior of the chord member.
Claim 6
Dependent Claim
26 words
The invention as claimed in claim 1, wherein the shear projections project from the said top member junctions away from the interior of the chord member.
Claim 7
Dependent Claim
61 words
The invention as claimed in claim 1, and comprising two spaced structural chord members disposed spaced apart with their bottom flanges facing one another, and a plurality of joist web members each inserted at each end between the two bottom flanges of the corresponding chord member and fastened to the chord members to connect them and thereby form a joist member.
Claim 8
Dependent Claim
74 words
The invention as claimed in claim 1, and comprising two spaced structural chord members disposed spaced apart with their bottom flanges facing one another, and a plurality of joist web members connecting the chord members to form a joist, and wherein the upper chord member only is filled with a high strength cementitious material to apply corresponding tensional stress to the lower chord member and to increase the moment of inertia of the joist.
Claim 9
Dependent Claim
96 words
The invention as claimed in claim 1, and comprising two spaced structural chord members disposed spaced apart with their bottom flanges facing one another, and a plurality of joist web members connecting the chord members to form a joist member, wherein the upper chord member only is filled with a high strength cementitious material to apply corresponding tensional stress to the lower chord member and to increase the moment of inertia of the joist, and wherein the upper chord member has the respective shear projections projecting into its interior to be enclosed by the cementitious material.
Claim 10
Dependent Claim
104 words
The invention as claimed in claim 1, and comprising two spaced structural chord members disposed spaced apart with their bottom flanges facing one another, and a plurality of joist web members each inserted at each end between the two bottom flanges of the corresponding chord member and fastened to the chord members to connect them and thereby form a joist member, wherein the upper chord member has the shear projections projecting from the top flanges away from the interior of the chord member, and the lower chord member has the shear projections projecting from the top flanges into the interior of the chord member.
Claim 11
Dependent Claim
110 words
A structural chord member for the fabrication of joists therefrom comprising a top flange, two bottom flanges and two chord webs each connecting the said top flange and a respective bottom flange, wherein the chord webs are inclined toward one another from the top flange toward the bottom flange to provide a corresponding chord member cross-section of decreasing width, wherein the bottom junctions of each chord web with its respective bottom flange are spaced from one another for the insertion thErebetween of a joist web member, the member also comprising a shear projection rigidly connected to the top flange and constituted by a closed loop of material extending longitudinally thereof.
Claim 12
Dependent Claim
110 words
A structural chord member for the fabrication of joists therefrom comprising a top flange, two bottom flanges and two chord webs each connecting the said top flange and a respective bottom flange, wherein the chord webs are inclined toward one another from the top flange toward the bottom flange to provide a corresponding chord member cross-section of decreasing width, wherein the bottom junctions of each chord web with its respective bottom flange are spaced from one another for the insertion thErebetween of a joist web member, the member also comprising a shear projection rigidly connected to the top flange and constituted by a closed loop of material extending longitudinally thereof.
Claim 13
Dependent Claim
46 words
The invention as claimed in claim 10, wherein the said closed loop shear projection is constituted by a portion of the sheet steel material rolled to the form of a loop, the top flange, bottom flanges, chord web and projection all being integral with one another.
Claim 14
Dependent Claim
34 words
The invention as claimed in claim 10, wherein the junctions of the said closed loop projection with the top flange are disposed immediately adjacent to one another and are joined directly to one another.
Claim 15
Dependent Claim
61 words
The invention as claimed in claim 10, and comprising two spaced structural chord members disposed spaced apart with their bottom flanges facing one another, and a plurality of joist web members each inserted at each end between the two bottom flanges of the corresponding chord member and fastened to the chord members to connect them and thereby form a joist member.
Claim 16
Dependent Claim
73 words
The invention as claimed in claim 10, and comprising two spaced structural chord members disposed spaced apart with their bottom flanges facing one another, and a plurality of joist web members connecting the chord members to form a joist, wherein the upper chord member only is filled with a high strength cementitious material to apply corresponding tensional stress to the lower chord member and to increase the moment of inertia of the joist.
Claim 17
Dependent Claim
36 words
The invention as claimed in claim 1, wherein the upper chord member is provided with at least one respective shear projection rigidly fastened thereto and projecting into its interior to be enclosed by the cementitious material.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |