Steel Rod Straining Device

Abstract

A steel rod straining device has a pair of strain applying members, one having a right handed threaded tubular part thereon and the other having a left handed threaded tubular part thereon. A steel rod extends between the strain applying members, one end of the rod having right handed threads thereon threaded into the right handed threaded tubular part on one of the strain applying members and the other end of the rod having left handed threads thereon threaded into the left handed threaded tubular part on the other of the strain applying members. The strain applying members can be attached to the framework of a structure in which the steel rods are to be used as reinforcing rods.

Description

This invention relates to a steel rod straining device. More specifically, this invention relates to an apparatus for straining the reinforcing steel rods used in buildings and other structures.

A commonly employed device for straining reinforcing rods in buildings, for example in prefabricated houses, has consisted of a pair of steel rods the outer ends of which are welded to a receiving plate and the inner ends of which are threaded into a turnbuckle. This commonly employed device is costly due to the relatively high cost of the turnbuckle.

It is an object of the present invention to provide an apparatus for straining steel rods which does not require a turnbuckle, which has a good straining effect, the construction of which is simple and which is manufactured easily.

An apparatus according to the present invention is illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a front view of a steel rod straining device according to the present invention;

FIG. 2 is a partial view, on an enlarged scale of the device of FIG. 1;

FIG. 3 is a transverse section taken on line 3 -- 3 of FIG. 2; and

FIG. 4 is a transverse section taken on line 4 -- 4 of FIG. 2

Referring now to the drawings, a pair of strain applying members 10 and 10' of a steel plate have longitudinally extending slots 12 and 12' therein. Extending across the slots at the inner ends thereof are semicircular parts 11 and 11' which are integral with the plates. Key-hole shaped openings 13 and 13' are provided at the outer ends of the members, the smaller parts 14 and 14' of which extend outwardly from the larger parts. Semicircular elements 15 and 15' are positioned face to face with semicircular parts 11 and 11' and have the same shape as semicircular parts 11 and 11'. The semicircular parts 11 and 11' and 15 and 15' are fastened by rivets or the like through flat portions 16 and 16' and 17 and 17', respectively, to form tubular parts 18 and 18' at the inner ends of members 10 and 10'. Right-handed threads are cut inside tubular part 18 of strain applying member 10, and left-handed threads are cut inside tubular part 18' of strain applying member 10'. A steel reinforcing rod 19 is provided with connecting part 22 in the shape of a spanner with parallel flat faces at about half-way between the ends of the steel rod 19. One end of the rod is provided with right-handed threads 20 and the other end of the steel rod 19 is provided with left-handed threads 21. Frame members or pillars of a building or like structure are shown at 23 and 23' and projections 24 and 24' are provided on the building or the structure.

As shown in the figures, said right-handed threads 20 and said left-handed threads 21 are threaded into said tubular parts 18 and 18' having the right-handed threads and and left-handed threads on the inner surface thereof on said pair of straining applying members 10 and 10', respectively.

The thus constructed straining device can be attached to projections 24 and 24' on the frame or pillar 23 and 23' of buildings or like structures by placing the larger parts of said key-hole like openings 13 and 13' at the outer ends of said strain applying plates 10 and 10' over said projections. Said steel rod 19 is rotated and the two ends are caused to move into said slots 12 and 12' in said straining applying members 10 and 10' due to the opposite directions of said right-handed threads 20 and said left-handed threads 21, resulting in drawing said strain applying members 10 and 10' toward each other. This action reinforces the strain between said projections 24 and 24' on said pillars 23 and 23'.

If it is necessary that the strain on said steel rod 19 and the pair of straining applying members 10 and 10' be released, this can easily be done by rotating said steel rod 19 in the opposite direction to that for producing straining.

From the foregoing explanation, the action of the steel rod straining device of the present invention can be clearly understood.

In the present invention, the pair of straining applying members 10 and 10' can be manufactured on a large scale by a pressing operation, and accordingly, the cost of manufacturing said members 10 and 10' is low. Because the semicircular parts 11 and 11' formed at the inner end of said members 10 and 10' are at the inner ends of said slots 12 and 12' and during the straining action of said straining device the ends of said steel rod 19, move along the grooves 10 and 10' toward the outside ends thereof during rotation of said steel rod 19, there are no obstructions to the movement of the rod and accordingly the steel rod straining device of the present invention can be handled more easily than the conventional device using a turnbuckle. In addition, the steel rod straining device of the present invention can apply a larger amount of strain and it eliminates the use of a comparatively expensive turnbuckle.

It will be understood that many changes can be made without changing the scope of the present invention. If it is desired, said tubular parts 18 and 18' can be formed by welding the opposed faces of the parts 16 and 16' and 17 and 17', or said semicircular parts 15 and 15' can be replaced with internally threaded tubular parts mounted firmly on members 10 and 10' by a method as welding.

It is thought that the invention and its advantages will be understood from the foregoing description and it is apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing its material advantages, the form hereinbefore described and illustrated in the drawings being merely a preferred embodiment thereof.

Claims

I claim:

1. A steel reinforcing rod device comprising a pair of strain applying members, each strain applying member being comprised of an elongated flat steel plate having a keyhole shaped opening at one end thereof and an elongated slot extending from a position adjacent said keyhole opening toward the other end of said elongated plate, said other end of said plate being bent in a semi-cylindrical shape and being provided with screw threads, a corresponding semi-cylindrically shaped member having screw threads thereon positioned adjacent said semi-cylindrical portion of said plate and being riveted thereto thereby forming a tubular member having an internal screw thread, the tubular member on one of said strain applying members having a right handed screw thread and the tubular member on the other of said strain applying members having a left handed screw thread, a steel rod extending between said strain applying members, one end of said rod having right handed threads thereon and being threaded into said right handed threaded tubular member on said one of said strain applying members and the other end of said rod having left handed threads thereon and being threaded into the left handed threaded tubular member on said other of said strain applying members, said ends of said rod extending through said tubular members into said elongated slots, and a flat portion positioned at an intermediate portion of said steel rod and adapted to be engaged with a tool for turning said rod.