US1021429A

US1021429A - Reinforced concrete.

Info

Publication number: US1021429A
Application number: US48518109A
Authority: US
Inventors: William Fry Scott
Original assignee: Individual
Current assignee: Individual
Priority date: 1909-03-23
Filing date: 1909-03-23
Publication date: 1912-03-26
Anticipated expiration: 1929-03-26

Description

W. F. SCOTT. REINFOROED GONORETE.

APPLIOATION PILED uume, 1909.

1,021,429. A i Patented Mar.26, 1912.

I I C,

0/ af C INVENTO A TTbRNE Y UNITED STA ENT OFFICE WILLIAM FRY SCOTT; OF TORONTO, ONTARIO, CANADA.

REINFORCED CONCRETE.

Specification of Letters Patent.

Application filed March 23, 1909. Serial No. 485,181.

strength with a minimum of reinforcing metal and the utmost Simplicity of coni shoe to prevent slipping of the tension rein :Eorcing member in the concrete and are also* struction; I attain this result by a Construction which may be briefly described as follows:

A tension member is embedded` in the tension side of the beam and the ends of the member are connected with plates each of large face area'relative to the cross-sectional area of the tension member and each arranged and set so as to act efiectively as a preferably arranged and set to receive and transmit to the tension member a large proportion of any thrust which may arise due i (i to arching of the concrete. The plates are bowed in' form with the concave face directed toward the center of the beam and the ends of the bows toward the tension and compression sides of the beam. Each end of the tension member is connected to one of the bowed plates, preferably in the manner ?p hereinafter described and illustrated.

' Figure 1 is a longitudinal vertical section of a reinforced concrete beam constructed in accordance with my invention. Fig. 2

is a cross-section of same showing a single plate. p i a double plate. Fig 4 a longitudinal vertical section showing a slight modification I of the arrangement shown 'in Figil'. Fig;

5 is .a horizontal section of a reinforced concrete beam showing a bowed' plate having its ends 'directed toward the sides of the beam. F ig. 6 is a vertical longitudinal section of the beam, showing 'the parts which are shown in plan in Fig. 5. Fig. 7 is a perspective detail illustrating the preferred shape of the plates and the method of connecting them to the tension member.

'In the drawings like\ letters of reference Fig.' 3 is a similar view showing indicate corresponding parts in the difierent figures.- 4

Referring particularly to Fig. 15 A is a, beam of concrete or similar material, B a tension reinforcing member and C plates forming shoes for the ends of the same, which plates are located at the ends of the beam above the supports DL Patented Mar. 26, 1912.

The tension member B is preferably 7 formed of a plurality of rods a b, as shown in Fig. 1. Near the ends of the beam the rods separate and form the forked ends c, d,

which are connected to the ends of the plates C, as hereinafter described, These plates i are bowed in form: that is they'are so bent or shaped as to 'partly inclose a portion of the concrete in the beam. The concave face of the plate is directed toward the center of the beam. The endsof the bows may lie i in the direction of the sides of the beam, as shown in Figs. 5 and 6, but preferably lie in the direction of the compression and tension sides of the beam, as' shown in Fig. 1. e

These plates, it will be seen, are also of large face area relative to the cross-sectional area of the tension member.

I prefer that the plates shall be so ar ranged and disposed as to receive and transmit to the tension member a large propori I tion of any thrust which may arise due to arching in` the concrete. The lines of thrust due to such arching are indicated in Fig. 1, and from this figure it will be seen to what extent they are received by the plates and i by them transmitted to the tension member.

I' am aware that shoes have'heretofore been'connected to the ends of the tension members, which shoes were located at the ends of the beam and above the supports, but such shoes have not usually been plates and have not 'been constructed so as to take,

off the pull of the tension member with the use of a minimum weight of metal 'in the shoe. i I have found that the bond stress in beam reinforcements is very much less thanis com monly supposed hence the need for a large plate. i i

A large fiat plate is not thebest adapted to develop the full strength of the tension member with the use of the least amount of material in the plate, as such a plate must be made very stifl and this Construction demands the use of a considerable 'amount of material to take care of the bending stresses on the plate. By using the bowed form, however, I give the plates the shape which they would tend to assume under the stresses to which they are subject. When thus shaped they partly inclose a mass of concrete over which the tension of the plate is distributed instead of being concentrated at the ends of the plate as it would be in the case of a fiexible non-bowed plate.

To secure lightness with strength and convenience in shipping in a knocked-down condition the plates C are preferably formed of sheetmetal, and are normally in an unflexed condition, and I provide means, preferably detachable, whereby they may be connected to the forked end a (Z of the tension member in the fiexed position shown. From Figs. l, 2, 3 and 7 these connections will be understood.

The forked end c is bent to form the hook e and bent again to form the teat f which is directed substantially parallel to the main portion c of the fork. Two holes g h are formed in the plate C near its upper end, and the hook e is passed through the hole g and the teat fits into the hole h. This gives a stiff detachable connection between the plate and the forked end c which will enable the plate to be fiexed to the position shown, slots z' shown in Fig. 7 extending part way toward the middle of the plate, enabling the parts of the plate to be separately fiexed and connected to the tension members with ease whereas the fiexing of the entire plate at once might be very diflicult.

A detachable connection is formed between the end d and the plate in the following manner: A hole or slot 2' is formed at the lower end of the plate which slot enables the plate to be straddled over the end ri, as shown, between the nuts j which are threaded on the end d and may be tightened up to securely hold the plate in place. In Fig. 3 I show both a hole and a slot.

l Vhen the tension member is formed of two rods, as shown in Fig. 1, they are preferably tied together by means of ties 76 where they fork at each end. Instead of forming the tension member of two or more independent rods, I may form the central portion of the tension member of a single rod B, as shown in Fig. 4, the ends of which are connected to a bridle E formed as shown in Fig. 4:, the ends of thebridles being connected to the ends of the shoes in any suitable Inanner.

It will also be found that by the Constructions I have described the full value of the tensional strength of the tension member can be developed as all creeping of the tension member in the concrete is absolutely prevented owing to the great face area of the plates and their shape arrangement and postioning in the beam.

My: Construction is further of especial Value where the loading is adjacent to the ends of the beam where with ordinary constructions the safe adhesion value between the concrete and the tension member may easily be exceeded, resulting in the stripping of the concrete incasing the short end of the tension member, and the consequent failure of the beam.

What I claim as my invention is:

l. A concrete beam provided with a metallic reinforcement comprising a longitudinal tension member having forked ends and bowed tension plates, of large width and face area relative to the cross sectional area of the longitudinal member, connecting the ends of the forks and having their concave faces directed toward the center of the beam, whereby tensional strains are transmitted through said plates as a continuation of the longitudinal tension member.

2. A concrete beam provided with a metallic reinforcement comprising a longitudinal tension member having forked ends and bowed tension plates, of large width and face area relative to the cross sectional area of the longitudinal member, connecting the ends of the forks and set with their ends toward the tension and compression sides of the beam and their concave faces directed toward the center of the beam, whereby tensional strains are transmitted through said plates as a continuation of the longitudinal tension member.

3. A concrete beam provided with a metallic reinforcement comprising a longitudinal tension member formed of two rods haV- ing their ends spread apart to form V-shaped forks, and bowed tension plates, of large width and face area relative to the cross sectional area of the longitudinal member, connecting the ends of the forks and having their concave faces directed toward the center of the beam, whereby tensional strains are transmitted through said plates as a continuaton of the longitudinal tension member.

4. In a metallic reinforcement for concrete beams the combinaton of a longitudinal metal tension member having forked ends; fleXible metal anchor plates connecting the ends of the forks and secured thereto in a fleXed or bowed position with their concave faces directed toward the center of the beam, whereby tensional strains are transmitted through said plates as a continuation of the longitudinal tension member.

5. In a metal reinforcement for concrete beams the -combination of a metal tension member having forked ends; stiff fiexible bowed metal plates for the ends of the tension member; a stif detachable connection between one end of each plate and one of the'end forks of the tension member which connection is adapted to enable the plate to be fleXed; and means securing the other end of the plate to the other forked ends in said flexed and boWed position With the concave face of the bow toward the center of the beam. a

6. *In a metal reinforcement for eoncrete beams the combination of a metal tension member having forked ends; a fiexible boWed metal plate for each end of the tension member; a detachable hook connection between one end of the shoe and one of the end forks of the tension member adapted to form a stifi connection to enable the'plate to be fieXed; and means connecting the plate to the other orked end in said fleXed or bowed position With the concave face of the bow toward the center of the beam.

7. In a metal reinforcement for concrete beams the combination of a metal tension member having forked ends; a hook formed on one of said ends; and a teat on the hook; a fiexible metal plate having two holes formed near one edge the said hook passing copies of this patent may be obtained for five cents each, by addressig the Commissioner of Patents;

a flexible metal plate having two` holes formed near one edge, the said hook passing through one of said holes from the back and lying against the front of the plate and the teat enteringthe other hole from the front of the plate; and means securing the other end of the plate to the other forked end of the tension member, comprising a threaded end on saidforked end passing through the I plzte and a nut screWed on said threaded en 9. In a metal reinforcement for concrete beans the combination of a fiexible metal piate slotted from each end part Way toward the m'iddle to permit of the parts of the plate formed thereby being separately fieXed and a plurality of metal tension members detachably Secured to the ends ofone of the parts of the plate.

10. In a metal reinforcement beams the combination of a flexible bowed metal plate slotted from each end part Way toward the middle to permit of the parts of the plate 'being separately fleXed and a -plurality of metal tension members each detachably secured to the ends of one of the parts of the plate.

Toronto this 17th day of March, 1909.

WILLIAM FRY SCOTT.

Signed in the presence of- J. EDW. MAYBEE',

F. -W. MCKENDRICK.

Washington, D. G."

for concrete