US1160546A - Disk strain-insulator. - Google Patents
Disk strain-insulator. Download PDFInfo
- Publication number
- US1160546A US1160546A US73998913A US1913739989A US1160546A US 1160546 A US1160546 A US 1160546A US 73998913 A US73998913 A US 73998913A US 1913739989 A US1913739989 A US 1913739989A US 1160546 A US1160546 A US 1160546A
- Authority
- US
- United States
- Prior art keywords
- web
- ridges
- ridge
- portions
- insulator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B17/00—Insulators or insulating bodies characterised by their form
- H01B17/02—Suspension insulators; Strain insulators
- H01B17/12—Special features of strain insulators
Definitions
- Patented NOV. 16, 1915 Patented NOV. 16, 1915.
- This invention relates to strain insulators, and particularly to those of the disk type.
- a particular object of the'present invention is to provide a new and improved 1nsulator of this type wherein the irregularities of surface, for providing water sheds and for otherwise increasing the insulating value of the disk without increasing the size of the disk, are arranged in such manner that they are amply supported from the Y body without material increase in the thickness of the intervening web portions of the 20 disk beyond what would bel required for resistance against puncture.
- a further object is to provide a structure as above, which comprises ridges formed on the surface of thedisk so shaped that a materially greater proportion of the strength of the ridges themselves, than is found in the ordinary concentric-ridges, is employed to reinforce the web portions.
- a further object is to provide a disk with ridges so shaped as to comprise relatively straight legs running tangent to the center of the disk, and forming angles, whereby the strength of the ridges is employed for reinforcing intermediate web portions.
- a further object is to provide a disk with ridges on its opposite surfaces, and to shape the ridges in such manner that portions thereof upon the respective surfaces will lie in intersecting planes for lending added strength to the structure.
- a further object is to provide an insulator comprisinga body portion and an annular flange extending therefrom having ridges on its surface, to provide a conductor projecting from the body portion, havinga greater width in one diametrical direction than in another, and to form the ridges upon the surface of thedisk to encircle the body so that portions ofthe ridges in the line of the greatest diametrical width of the conductor are spaced a relatively greater distance from the body than are portions of the ridges in the line of less diametrical width of the conductor, whereby to preventlocalized disJ charges.
- a further object is to provide a structure as above, which is simple in design, which comprises a minimum of material, and which is therefore cheap to manufacture, but is nevertheless thoroughly substantial andembodies maximum eliiciency, both as to its insulating qualities and as to its mechanical strength, for a given sized disk.
- Figure l is a top plan view of an insulator constructed in accordance with the principles of this invention
- Fig. 2 is a transverse sectional view partly in elevation, said section being taken substantially on the plane of line 2-2 of Fig. l
- Fig. 3 is a view similar to Fig. 2, but illustrating a modification.V
- the numeral 1 indicates what may be termed the body portion of the insulator, which portion is preferably of a more or less elongated cylindrical shape adapted for receiving the strain members illustrated at 2 and 3.
- the strain members illustrated each comprise Aa short bolt having an eye as 4 at its outer end, and having its inner end formed as a head 5 as clearly disclosed in Fig. 2.
- the inner ends. of the two strain members are spaced apart and the material of the body fills the intervening space for effectuallv insulating the members from each other.
- strain members as comprising simple bolts having heads spaced apart and molded within the body l in axial alinement
- said strain members may of course take any other form described for increasing the mechanical strength of the structure in resisting strains placed upon the strain members, or for increasing the insulatingvvalue of the structure.
- ridges Formed upon the upper surface of the web 6 is plurality of ridges designated as 7, S and 9. These ridges encircle the body portion l, but they are not circular as has been heretofore customan. Each of them comprise four substantially straight legs joined by angles forming' a square, the square or ridge 7 being smallest and nearest the body l, the sanare or 8 being larger and spaced ea'uidistant from all sides of the square or ridge 7, and thesquare or ridge 9 being ⁇ ccessively larger and surrounding the ridge S. rEhe legs of the squares may be slightl,7 boived, if desired, as indicated in the ridge 9. is many squares or ridges may be employed as desired for lai'ger insulators, or more or less of the squares or ridges may be" twisted-,fed ⁇ upon a given sized insulator.
- the ridge or square 9 here is preferably arranged a circular ridge or flange l0 formed substantially concentricy to the body l and adapted to cooperate with a simila-r ridge formed upon the opposite surface ofthe iveb'tc form an annular groove ll encircling tlie periphery ofthe ii'eb.
- rllhe ridges upon the 'two surfaces of the web may be arrangedY directly opposite'each other, but they are preferably arranged so that the straight legs of those on one surface stand' in longitudinal planes int'ersected by thelongitudinal planes of those on the other surface for lending added s'rength to the structure.
- insulators having their ridges forming. a square ligure. as iliustrated, the squares of one surface are turned substantially i5@ relatively to the squares of the other surface, as shown by the dotted line in Fig.
- Vvvrlhe strain members@l and 3 are "preferably arranged so that the diameter ofgreat# est measurement lies in a plane extending toward opposite angles of the squares upon the respective surfaces of theweb so that the relatively projecting portions of a given strain member will be properly spaced from a given ridge. The tendency of localized discharges between the strain n embers is thus minimized. This is especially true where the ridges upon the opposite surfaces are arranged in intersecting planes as shown in Fig. 1 for the reason that in such a structure the strain members are likewise rotated relatively to each other.
- All ridges upon the two surfaces of the web may project outward from the surface of the web for a uniform distance, and the body 1 may project from the surfaces of the web for a like distance, and aiso the thickness of the web itself may be uniform throughout, if desired. It is, however, apparent that these various proportions may be altered within the scope of the invention,
- Fig. 3 also there is illustrated a groove as 12 formed in some of the ridges.
- These grooves. where employed, are formed at the apeX of the ridges and preferably extend throughout the length of the ridge. They serve to further increase the surface extent of the structure and to form positive paths for conducting away such moisture as happens to flow to the apex of the ridge. They prevent themoisture from flowing directly across the ridge.
- insulator ⁇ comprising a web of insulating material formed with a plurality of ridges on each of its two opposite surfaces, each of said ridges having portions of its length lying relatively nearer the center of the web than other portions of the ridges, and the portions of the ridges of one surface of the web which lie farthest from the center of the web, being disposed to overlie portions of the ridges on the other surface of the web which lie nearest the enter of the web, whereby to reinforce the web.
- An insulator comprising a web of insulatinow material, a conductor disposed upon one sur ,ce of said web, said conductor having a part projecting relatively farther from the center of said web than other parts of said conductor, and a ridge upstanding upon the mentioned surface of the web surrounding said conductor, said ridge having a por ⁇ tion intermediate .its length spaced farther from the center of said web than portions at other points in the length of the ridge, and the portion of the ridge which is spaced farther from the center of the web being radially opposite that portion of the conductor which lies farthest from the' center of the web, for the purpose described.
- An insulator comprising a web of insulating material, ridges formed upon the opposite surfaces of said web.
- the ridge upon one surface of said web being shaped to form a poly-sided figure
- the ridge upon the other surface of the web also being shaped te form a poly-sided figure
- the polysided figures on said two surfaces being disposed so that each of the sides of one of said figures overlie one of the sides of the other ligure, and said overlying sides extending in angular relation to each other, substantially described.
- An insulator comprising a web of insulating material, ridges formed upon each of the opposite surfaces of said web, said ridges each being' formed into a relatively straight portion and a. relatively angular portion, and the relatively angular portion of the ridge on one surface being disposed to overlie the relatively straight portion of the ridge on the other surface, whereby to reinforce the web.
- An insulator comprising a web portion, pair of ridges outstanding upon one surface of said web spaced apart, a ridge outstanding from the opposite surface of said web having portions spaced apart in the length thereof overlying each of said first ridges, so as to reinforce said first ridges, and all of said ridges extending in a direction entirely surrounding the central portion of the web.
- An insulator comprising a web portion, a pair of ridges outstanding upon one surface of: saidv web, spaced apart, and a ridge outstanding upon theopposite surface of said Web having a portion intermediate its length overlying one of said first ridges, and having portions. in its length at opposite sides of said intermediate portion eX tending along the surface of said- Web in diverging relation and overlying the other of said first ridges, so as to reinforce said first ridges.
- nv insulator Comprising a memberl of insulating materialhavinga conductor part at one surface thereof, said conductor part having a portion projecting'laterally from the main body thereof, and a ridge former upon the mentioned surface of the insulating materialv surrounding said conductor part, said ridge-having a portion intermediate its length spaced farther from the main body of thel conductor part than portions at other points in the length of the ridge, and the portion ofthe ridge which is spacer farther from theinain body of the Conductor part being radially opposite that portion of the Conductor part which projects farthest from the body thereof.V
Landscapes
- Insulators (AREA)
Description
L. STEINBERGER.
DISK STRAIN INSULATOR.
Patented NOV. 16, 1915.
, INVENTOH UNITED STATES PATENT OFFICE;
LUIS STEINBERGER, OF BROOKLYN, NEW YORK.
DISK STRAIN-INSULATOR.
Application filed January 3, 1913.
To all whom 'it may concern Be it known that I, LOUIS STEINBERGER, residing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Disk Strain-Insulators, of which the following is aspecification.
This invention relates to strain insulators, and particularly to those of the disk type.
A particular object of the'present invention is to provide a new and improved 1nsulator of this type wherein the irregularities of surface, for providing water sheds and for otherwise increasing the insulating value of the disk without increasing the size of the disk, are arranged in such manner that they are amply supported from the Y body without material increase in the thickness of the intervening web portions of the 20 disk beyond what would bel required for resistance against puncture.
A further object is to provide a structure as above, which comprises ridges formed on the surface of thedisk so shaped that a materially greater proportion of the strength of the ridges themselves, than is found in the ordinary concentric-ridges, is employed to reinforce the web portions. l
A further object is to provide a disk with ridges so shaped as to comprise relatively straight legs running tangent to the center of the disk, and forming angles, whereby the strength of the ridges is employed for reinforcing intermediate web portions.
v A further object is to provide a disk with ridges on its opposite surfaces, and to shape the ridges in such manner that portions thereof upon the respective surfaces will lie in intersecting planes for lending added strength to the structure.
A further object is to provide an insulator comprisinga body portion and an annular flange extending therefrom having ridges on its surface, to provide a conductor projecting from the body portion, havinga greater width in one diametrical direction than in another, and to form the ridges upon the surface of thedisk to encircle the body so that portions ofthe ridges in the line of the greatest diametrical width of the conductor are spaced a relatively greater distance from the body than are portions of the ridges in the line of less diametrical width of the conductor, whereby to preventlocalized disJ charges. A
Specification of Letters atent.
Patented Nov. 16, 1915.
Serial No. 739,989.
A further object is to provide a structure as above, which is simple in design, which comprises a minimum of material, and which is therefore cheap to manufacture, but is nevertheless thoroughly substantial andembodies maximum eliiciency, both as to its insulating qualities and as to its mechanical strength, for a given sized disk.
Other objects and aims of the invention, more or less specific than those referred to above, will be in part obvious and in part pointed out in the course of the following description of the elements, combinations, arrangements of parts and applications of principles, constituting the invention; and the scope of protection contemplated will be indicated in the appended claims.
In the accompanying drawings which are to be taken as a part of this specification, and in which I have shown a merely preferred form of embodiment of the invention: Figure l is a top plan view of an insulator constructed in accordance with the principles of this invention; Fig. 2 is a transverse sectional view partly in elevation, said section being taken substantially on the plane of line 2-2 of Fig. l; and Fig. 3 is a view similar to Fig. 2, but illustrating a modification.V
Y Referring to the drawings for a more detailed description of the structure illustrated, the numeral 1 indicates what may be termed the body portion of the insulator, which portion is preferably of a more or less elongated cylindrical shape adapted for receiving the strain members illustrated at 2 and 3.
The strain members illustrated each comprise Aa short bolt having an eye as 4 at its outer end, and having its inner end formed as a head 5 as clearly disclosed in Fig. 2. The inner ends. of the two strain members are spaced apart and the material of the body fills the intervening space for effectuallv insulating the members from each other.
It will be understood, that though I have shown and described the strain members as comprising simple bolts having heads spaced apart and molded within the body l in axial alinement, said strain members may of course take any other form described for increasing the mechanical strength of the structure in resisting strains placed upon the strain members, or for increasing the insulatingvvalue of the structure.
trat/ed generally by the reference numeral 6, l Y-."ll be hereinafter referred to as the cointrises a ivall or annular 'flange tially uniform thickness. springing from the body l. pr ferably about inidiay betiveen the enf s of the body, and serving, in addition to its insulating quality, as a continuous bond betiveen` the system of reinforcing ribs or ridges noiv to be described.
Formed upon the upper surface of the web 6 is plurality of ridges designated as 7, S and 9. These ridges encircle the body portion l, but they are not circular as has been heretofore customan. Each of them comprise four substantially straight legs joined by angles forming' a square, the square or ridge 7 being smallest and nearest the body l, the sanare or 8 being larger and spaced ea'uidistant from all sides of the square or ridge 7, and thesquare or ridge 9 being` ccessively larger and surrounding the ridge S. rEhe legs of the squares may be slightl,7 boived, if desired, as indicated in the ridge 9. is many squares or ridges may be employed as desired for lai'ger insulators, or more or less of the squares or ridges may be" emploi-,fed` upon a given sized insulator.
lt Will be noted that the intermediate portion of the length of each ofthe straight legs of thesquares7 is relatively nearer the body lV than are the ends of the legs or the angles connecting the legs together. rllhe legs ofthe squares stand tangent tocircles drawn concentric ivith the body l, andthe result is that forces tending to fracture the Web, especially such forces as may beexerted against the upper or lower surface ofthe iveb, would need to contend5 with thereinforcingvalue afforded by the fact that the intermediate portions of the legs, standing as they do close to the body l, are quite rig# idly supported from the body l, only a short expanse of the web portionv 6 intervening, as along a line ilsin Fig.' l, the short eX- panse of iveb obviously affords materially greater strength than vwould a longer eX- panse such as appears'betiveen the bodyv l and the end portions of the legs) and the opposite end portion of the legs therefore afford substantial kbraces extending across the surface of the vweb to a considerablek distance from the body l, so as to provide an effectual reinforcement for the outer por'- tions of the web.
A line, as l, drawn concentric to the center or the body l, and intersecting one ofthe angles of a squareivill approach or intersect,
according to the distance between the ridges,
the next outer ridge intermediate the' length of the legs of said next' outer ridge; rlhis outer ridge is therefore effectue,llyreinforced from theinn'er ridge. T he natural tendency of the Web to break' along'a' hnesubstantia'lly" ie disk portion of the structure is illus-` greater than that of circular ridges. rlhe spaced individual square figures illusti ted,
however, are at this time thought to be preferable.
leyond the ridge or square 9 here is preferably arranged a circular ridge or flange l0 formed substantially concentricy to the body l and adapted to cooperate with a simila-r ridge formed upon the opposite surface ofthe iveb'tc form an annular groove ll encircling tlie periphery ofthe ii'eb.
The opposite surface of the iveb is provided with ridges 'i3 in all respects the counterpart of those just described.
rllhe ridges upon the 'two surfaces of the web may be arrangedY directly opposite'each other, but they are preferably arranged so that the straight legs of those on one surface stand' in longitudinal planes int'ersected by thelongitudinal planes of those on the other surface for lending added s'rength to the structure. ln insulators having their ridges forming. a square ligure. as iliustrated, the squares of one surface are turned substantially i5@ relatively to the squares of the other surface, as shown by the dotted line in Fig. l., so that the ridges of one surface lap the ridges on the other surface in angular relation.v The intermediate portions of the sQuares upon one surface are supported and reinforced' by. the lapping angular portions ofthe squares upon the other surface of the web.v
' The substantially parallel legs of adjacent squares upon one surface deline a straight line of Weahness longitudinally between them, as for instance along lines X- and iT-Y of Fig. l. lllhese lines are etl'ectually reinforced however, not only by the adjacent portions, as lo, of the other legs of the squares, but especially by the angular portions,l as 16, of the squares upon the other surface of the web. Tdeference to Fig. l shows that these portions l@ form angular reinforcing` parts practically extending betu'een and connecting the intermediate por-- tions of the legs, and this is true in every in stance with wrespect to both sides of the web.
Vvvrlhe strain members@l and 3 are "preferably arranged so that the diameter ofgreat# est measurement lies in a plane extending toward opposite angles of the squares upon the respective surfaces of theweb so that the relatively proiecting portions of a given strain member will be properly spaced from a given ridge. The tendency of localized discharges between the strain n embers is thus minimized. This is especially true where the ridges upon the opposite surfaces are arranged in intersecting planes as shown in Fig. 1 for the reason that in such a structure the strain members are likewise rotated relatively to each other.
All ridges upon the two surfaces of the web may project outward from the surface of the web for a uniform distance, and the body 1 may proiect from the surfaces of the web for a like distance, and aiso the thickness of the web itself may be uniform throughout, if desired. It is, however, apparent that these various proportions may be altered within the scope of the invention,
for instance, asv shown in the modification Fig. 3 wherein the body l projects for a slight distance lrevond the plane of the outer edges of the ridges, and wherein the thick-- ness of the web is slightly greater nearer the Vbody l and gradually decreasing in thickness toward its periphery. The tendency to puncture of the web nearest the bodv 1 is, of course, greater tha at points further spaced from the body. The difference in thickness of the web, as shown in Fig. 3. may be calculated so as to compensate for the difference in tendency to puncture. For the same reason the degree of prominence' of each of the ridges, that is the distance they project from the surface of the web. may be successively reduced as shown in Fig. 3. This figure also indicates the outer circular ridge 10 as being sufliciently wide to effectively' protect the intermediate ridges. The outer lateral edges of the ridges 10 are in the plane substantially the same as the plane of the corresponding edges of the innermost ridge.
1n Fig. 3 also there is illustrated a groove as 12 formed in some of the ridges. These grooves. where employed, are formed at the apeX of the ridges and preferably extend throughout the length of the ridge. They serve to further increase the surface extent of the structure and to form positive paths for conducting away such moisture as happens to flow to the apex of the ridge. They prevent themoisture from flowing directly across the ridge.
As many changes could be made in this construction without departing from the scope of the following claims, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative only and not in a limiting sense.
Having thus described my invention what 1 claim as new and desire to secure by Letters Patent, is
in insulator` comprising a web of insulating material formed with a plurality of ridges on each of its two opposite surfaces, each of said ridges having portions of its length lying relatively nearer the center of the web than other portions of the ridges, and the portions of the ridges of one surface of the web which lie farthest from the center of the web, being disposed to overlie portions of the ridges on the other surface of the web which lie nearest the enter of the web, whereby to reinforce the web.
2. An insulator, comprising a web of insulatinow material, a conductor disposed upon one sur ,ce of said web, said conductor having a part projecting relatively farther from the center of said web than other parts of said conductor, and a ridge upstanding upon the mentioned surface of the web surrounding said conductor, said ridge having a por` tion intermediate .its length spaced farther from the center of said web than portions at other points in the length of the ridge, and the portion of the ridge which is spaced farther from the center of the web being radially opposite that portion of the conductor which lies farthest from the' center of the web, for the purpose described.
8. An insulator, comprising a web of insulating material, ridges formed upon the opposite surfaces of said web. the ridge upon one surface of said web being shaped to form a poly-sided figure, the ridge upon the other surface of the web also being shaped te form a poly-sided figure, and the polysided figures on said two surfaces being disposed so that each of the sides of one of said figures overlie one of the sides of the other ligure, and said overlying sides extending in angular relation to each other, substantially described.
il. An insulator, comprising a web of insulating material, ridges formed upon each of the opposite surfaces of said web, said ridges each being' formed into a relatively straight portion and a. relatively angular portion, and the relatively angular portion of the ridge on one surface being disposed to overlie the relatively straight portion of the ridge on the other surface, whereby to reinforce the web.
5. An insulator, comprising a web portion, pair of ridges outstanding upon one surface of said web spaced apart, a ridge outstanding from the opposite surface of said web having portions spaced apart in the length thereof overlying each of said first ridges, so as to reinforce said first ridges, and all of said ridges extending in a direction entirely surrounding the central portion of the web.
' 6. An insulator, comprising a web portion, a pair of ridges outstanding upon one surface of: saidv web, spaced apart, and a ridge outstanding upon theopposite surface of said Web having a portion intermediate its length overlying one of said first ridges, and having portions. in its length at opposite sides of said intermediate portion eX tending along the surface of said- Web in diverging relation and overlying the other of said first ridges, so as to reinforce said first ridges.
7. nv insulator Comprising a memberl of insulating materialhavinga conductor part at one surface thereof, said conductor part having a portion projecting'laterally from the main body thereof, and a ridge former upon the mentioned surface of the insulating materialv surrounding said conductor part, said ridge-having a portion intermediate its length spaced farther from the main body of thel conductor part than portions at other points in the length of the ridge, and the portion ofthe ridge which is spacer farther from theinain body of the Conductor part being radially opposite that portion of the Conductor part which projects farthest from the body thereof.V
ln testimony whereof, allix iny signature in the presence of two Witnesses.
LOUS STENBERGER.
lVitnesses L'. Gnssronn Hnnnnn, NATHALIE THOMPSON.
Copies of'this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US73998913A US1160546A (en) | 1913-01-03 | 1913-01-03 | Disk strain-insulator. |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US73998913A US1160546A (en) | 1913-01-03 | 1913-01-03 | Disk strain-insulator. |
Publications (1)
Publication Number | Publication Date |
---|---|
US1160546A true US1160546A (en) | 1915-11-16 |
Family
ID=3228586
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US73998913A Expired - Lifetime US1160546A (en) | 1913-01-03 | 1913-01-03 | Disk strain-insulator. |
Country Status (1)
Country | Link |
---|---|
US (1) | US1160546A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2756271A (en) * | 1950-08-08 | 1956-07-24 | Lansdale Nipple Company | Fitting for insulator assemblies and method |
US6606426B2 (en) | 2000-11-03 | 2003-08-12 | Herzel Laor | Piezoelectric and electromagnetic actuators for beam alignment and systems and methods using the same |
-
1913
- 1913-01-03 US US73998913A patent/US1160546A/en not_active Expired - Lifetime
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2756271A (en) * | 1950-08-08 | 1956-07-24 | Lansdale Nipple Company | Fitting for insulator assemblies and method |
US6606426B2 (en) | 2000-11-03 | 2003-08-12 | Herzel Laor | Piezoelectric and electromagnetic actuators for beam alignment and systems and methods using the same |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US1160546A (en) | Disk strain-insulator. | |
US887284A (en) | Culvert. | |
US1164477A (en) | Deformed bar for reinforced concrete construction. | |
US678605A (en) | Culvert. | |
US706194A (en) | Insulator. | |
US1232539A (en) | Rake. | |
US1533019A (en) | Guy coupler for masts | |
US619555A (en) | Telegraph-insulator | |
US1223909A (en) | Disk strain-insulator. | |
US1251013A (en) | Insulator-joint. | |
US900379A (en) | Reinforcing-bar. | |
US845938A (en) | Concrete metal construction. | |
US906479A (en) | Concrete reinforcement. | |
US724329A (en) | Insulator. | |
US1458754A (en) | Insulator | |
USD35759S (en) | Design for a vessel | |
USD29550S (en) | Design for a post-socket | |
USD29532S (en) | Design for a paper-weight | |
US787160A (en) | Packing-washer. | |
US550612A (en) | Oscar iiammerstein | |
US904370A (en) | Disk strain-insulator. | |
USD35672S (en) | Design for an egg-case filler | |
US1143527A (en) | Concrete construction. | |
US1230545A (en) | Reinforced wooden structure. | |
US870129A (en) | Reinforcing-bar for concrete structures. |