US3788120A

US3788120A - Apparatus for hot-stretching steel wire and cable

Info

Publication number: US3788120A
Application number: US00278323A
Authority: US
Inventors: K Takeo; T Katsumata; A Hijikata
Original assignee: Sumitomo Electric Industries Ltd
Current assignee: Sumitomo Electric Industries Ltd
Priority date: 1971-08-07
Filing date: 1972-08-07
Publication date: 1974-01-29
Anticipated expiration: 1991-01-29
Also published as: JPS5140296Y2; JPS4826233U

Abstract

A pair of spaced caterpillars along a moving direction of steel wire or steel cable to be stretched, comprises a pair of chainrollers which compressively contact each other and rotate in opposite directions. A heating apparatus is disposed between the caterpillars and a cooling apparatus is also disposed at another position between the caterpillars. One caterpillar is disposed forwardly of the other caterpillar in the moving direction of the steel wire or cable and driven at a higher velocity than that of the other caterpillar so that a predetermined tension is applied on the moving steel wire or cable between the caterpillars. Each chain-roller of the pair includes holder members which are provided in facing relation to and urged, under liquid pressure, against those of the other chain-roller. Each of the holder members has an upper part holding the steel wire or steel cable and a lower part connected to the chain-roller, the parts being formed of metal, and the upper part is supported by the lower part through a resilient plate.

Description

United States Patent n91 Takeo et al.

[ APPARATUS FOR HOT-STRETCHING STEEL WIRE AND CABLE [75] inventors: Keinosuke Takeo, Osaki; Tomoaki Katsumata; Akimitsu Hijikata, both of ltami, all of Japan 73] Assignee: Sumitomo Electric Industries, Ltd.,

Osaka, Japan [22] Filed: Aug. 7, 1972 [21] Appl. N0.: 278,323

[30] Foreign Application Priority Data Aug. 7, 1971 Japan 46/70839 [52] US. Cl 72/342, 72/17, 72/378,

[51] Int. Cl B2lf 9/00 [58] Field of Search.... 140/2; 72/17, 287, 342, 378; 266/3; 226/172, 186

[ Jan. 29, 1974 3,469,829 9/1969 Fujita et al 140/2 P imqryNEmmm H Q U a se Zinn and Macpeak 5 7 1 ABSTRACT A pair of spaced caterpillars along a moving direction of steel wire or steel cable to be stretched, comprises a pair of chain-rollers which compressively contact each other and rotate in opposite directions. A heating apparatus is disposed between the caterpillars and a cooling apparatus is also disposed at another position between the caterpillars. One caterpillar is disposed forwardly of the other caterpillar in the moving direction of the steel wire or cable and driven at a higher velocity than that of the other caterpillar so that a predetermined tension is applied on the moving steel wire or cable between the caterpillars. Each chain-roller of the pair includes holder members which are provided in facing relation to and urged, under liquid pressure, against those of the other chain-roller. Each of the holder members has an upper part holding the steel wire or steel cable and a lower part connected to the chain-roller, the parts being formed of metal, and the upper part is supported by the lower part through a resilient plate.

2 Claims, 3 Drawing Figures APPARATUS FOR HOT-STRETCI-IING STEEL WIRE AND CABLE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus of manufacturing at least one steel wire or steel cable having a small relaxation, particularly steel wire or steel cable suitable to be used as steel tendons in prestressed concrete, by means of hot-stretching thereof.

2. Description of the Prior Art As to such stretching apparatus, an apparatus has been known which is disclosed in Japanese Patent Publication No. 27704/1970, in which a pair of caterpillar assemblies, each of which is constituted by a pair of chain-rollers contacting each other under pressure and rotating in opposite directions are spaced along a moving steel wire or steel cable and a plurality of holding members are provided on each of the chain-rollers and urged against those provided on the opposite chainroller by fluid pressure to hold the steel wire or steel cable therebetween and to move it so that the steel wire or steel cable is stretched. In such apparatus, in general, the steel wire or steel cable is stretched between the caterpillars by changing the rotational velocities of the caterpillars.

However, since the steel wire or steel cable to be processed in such apparatus is stretched at the input and output sides of the. respective caterpillars, slippage of the steel wire or steel cable may be encountered. In the above-mentioned conventional apparatus, since the holding member for holding the steel wire or steel cable is a solid structure of metal, the possibility of the slippage of the steel wire or steel cable is even larger and if it occurs the shoes are defaced and the steel wire or steel cable is damaged, resulting in the defect that good stretching can not be performed. On the other hand, when the holding members themselves are formed of rubber in order to eliminate such slippage, the holding force is necessarily lowered resulting in the same defect.

A primary object of the present invention is to provide a stretcher apparatus for hot-stretching steel wire or steel cable which can hot-stretch the steel wire or steel cable with a uniform tension load applied on the steel wire or steel'cable to be processed by preventing the moving steel wire or steel cable from slipping.

Another object of the present invention is to provide a hot-stretching apparatus for steel wire or steel cable which can apply a substantially constant tension load on the steel wire or steel cable to be processed and hotstretch it uniformly by readily controlling the tension on the moving steel wire or steel cable.

Another object of the present invention is to provide an installation which is simple in construction and easy in operation and by which steel wire or steel cable of uniform quality with small relaxation can be manufacthe wire or cable with exerting thereon a uniform tension load.

The present invention resides in a hot stretching apparatus comprising a pair of spaced caterpillars located along the moving direction of steel wire or steel cable to be stretched, each including at least one pair of chain-rollers which are in compressive contact with each other and rotated in opposite directions. A heating apparatus is disposed at a position between the caterpillars and a cooling apparatus is also disposed at an- 7 other position between the caterpillars. One caterpillar tured by applying a desired substantially constant tension load on the steel wire or steel cable to be processed and hot-stretching the wire or cable.

SUMMARY OF THE INVENTION The present invention provides an installation which is easily operable and has simple construction, for manufacturing steel wire or steel cable having small relaxation and uniform quality by preventing the slippage of the moving steel wire or steel cable and hot-stretching is disposed forwardly of the other caterpillar in the moving direction of the steel wire or steel cable and driven at a higher velocity than that of the other caterpillar so that a predetermined tension is applied on the moving steel wire or cable between the caterpillars. The invention is characterized by each chain-roller of the pair including holder members which are provided in facing relation to and urged, under liquid pressure, againstthose of the other chain-roller, and that each of the holder members has an upper part holding the steel wire or cable and a lower part physically connected to the chain-roller, the parts being formed of metal, and that the upper part is supported by the lower part through resilient plates.

The above and other objects and features of the present invention will be fully understood by reading the description of the present invention with reference to the attached drawings, which illustrate an embodiment of the present invention although the present invention is not limited to such embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view of an embodiment of a hot-stretching apparatus of steel wire and steel cable, according to the present invention;

FIG. 2 is an enlarged front view of a portion of the embodiment in FIG. 1, and

FIG. 3 is an enlarged side view of a portion of the embodiment in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the embodiment shown in the drawings, it includes caterpillar assemblies 2 and 3, each comprising a pair of chain-rollers provided at spaced positions along a moving direction of steel wire or cable 1 as shown in FIG. 1. The caterpillar 3 is disposed forwardly of the caterpillar 2 and is driven so that it rotates in direction shown by arrows at higher velocity than the caterpillar 2 by the order of 1-1.2 percent by a suitable driving device. The driving device may be separate electric motors so that both caterpillars can simultaneously be controlled or may be a single motor in which the caterpillars may be driven simultaneously through transmission mechanisms. The respective caterpillars 2 and 3 have endless chain-rollers 4 and 4' which are disposed respectively, in over and under fashion, with compressive pressure urging them into contact with each other and are rotated in opposite directions. On the chain-rollers 4 and 4' thus disposed, a plurality of

holder members

12 and 12 are provided respectively as shown in FIG. 2 and the holder members on one chain roller are in facing relation to the holder members on the other chain roller with a slight gap therebetween.

Each of the holder members 12' provided on the lower chain-roller 4 has a metal upper part provided with a V-shaped holding groove 16 for holding the steel wire or cable 1 on the upper surface thereof and a metal plate secured at one surface to the upper part 15 by means of bolts 18, the other surface of the metal plate 20 being bonded to a rubber like resilient plate 17, as shown in FIG. 3. The lower surface of the resilient plate 17 is bonded to another metal plate 21 which is bolted to a lower metal part 14 by means of bolts 18'. The lower metal part 14 is welded to a chain 11' of the chain-roller 4 so that the holding member 12 is rotated with the rotation of a roller 13' of the chain roller 4'.

Although the upper metal part 15 and the lower metal part 14 of the holding member 12 may be bonded directly to the resilient plate 17, it is economical and efficient to bolt the upper part 15 and the lower part 14 to the

metal plates

20 and 21 by means of the

bolts

18 and 18, respectively, as described and to bond the

metal plates

20 and 21 to the opposite surfaces of the resilient plate 17, because the provision of the holding member is facilitated by so doing and the upper part 15 which requires precise machining and the lower part 14 welded to the chain 11 can be reused by unfastening the

bolts

18 and 18 and exchanging only the resilient plate 17 and the

metal plates

20 and 21 even when the resilient plate 17 is fatigued.

The holder members 12 provided on the upper chain roller 4 are constructed in similar manner to the lower holding members 12. Above the roller 13 of the upper chain roller 4, a plurality of horizontally spaced liquid pressure cylinders (not shown) are provided each of which cooperates with three or four pairs of holder members 12 and 12' through a guide rail 19 to urge the members toward each other. However, any number of the holder member pairs to be actuated by one liquid pressure cylinder and any number of the liquid pressure cylinders may be used.

According to the apparatus thus constructed, since the upper parts 15 of the

holding members

12 and 12 which hold the steel wire or steel cable 1 and the lower parts 14 secured to the chain rollers 4 and 4' are formed of metal and the upper parts 15 are supported through the rubber-like resilient plates 17 by the metal lower parts 14, the resilient plates 17 intermediate between the holder members 12 and 12', even when the stretching of the steel wire or cable 1 is gradually increased from the input to the output of the caterpillar 2 and from the output to the input of the caterpillar 3, are deformed slippingly in response to such increases in elongation, and thus the upper parts 15 follow the steel wire or cable 1, resulting in no slippage between the cable 1 and the upper parts 15 which hold the cable directly and in uniform holding of the cable 1 by the

plural holder members

12 and 12 through liquid pressure. In addition to this, two or more steel wires can simultaneously be stretched by forming two or more holding grooves on the respective wire holding surfaces of the metal upper parts 15 which are supported by the rubber-like resilient plates 17 provided between the holder members 12 and 12'.

Returning to FIG. 1, a numeral 5 shows a support roller positioned between the caterpillars 2 and 3 and, between the support roller 5 and the caterpillar 2, a pressure roller 6 is provided. The function of the pressure roller 6 is to detect the tension strength applied on the steel wire 1 between the caterpillars 2 and 3. The load or pressure exerted by the pressure roller 6 may be about one fifth to one seventh of the total tension and, consequently, a means for producing such load is sufficiently to be small sized one. The load to be exerted on the steel wire 1 by the pressure roller 6 may be applied by a weight hanging from the roller 6 or a strong plate spring. However, it will be described a case where the load is applied by an oil pressure cylinder 7 as shown.

The detection and the regulation of tension on the moving steel wire or cable is generally performed by shifting the pressure roller 6 within the stroke range of vthe cylinder 7 and, if the roller shift is out of the range,

the regulation thereof becomes possible by changing the difference in velocity between the caterpillars 2 and 3 by using an automatic control device 8.

The same object of the present invention may be achieved without the pressure roller 6 by fixing the velocity difference between the caterpillars 2 and 3 after the difference, that is, the standing tension condition of the steel wire or steel cable is determined by these regulation devices.

Numeral 9 shows a heating device which is provided between the pressure roller 5 and the caterpillar 3 and functions to heat the steel wire to 300400 C. As the heating method, high frequency induction heating, electric resistance heating or a hot-air, heating etc. may be used as desired. A conventional cooling device such as spray 10 is provided between the heating device 9 and the caterpillar 3 and functions to cool the steel wire 1 heated by the heater 9. In this case the steel wire 1 is merely in contact with the support roller 5 and the pressure roller 6.

In this manner, the steel wire 1 is permanently stretched between the caterpillars 2 and 3 and the relaxation properties of the wire is improved.

Thus, the apparatus according to the present invention is simple in construction and unexpensive in installation and, by the apparatus the regulation of tension is facilitated. For the steel cable, it is easy to unload the same when the joints pass through the apparatus.

As described hereinbefore, the present invention has an advantage that the steel wire or cable can be stretched with uniform load because of the special construction of the chain-rollers of the caterpillars of the hot-stretching apparatus for steel wire or cablewhich prevents the moving steel wire or cable from slipping and of the provision of the pressure roller which is simple in construction and can desirably regulate the urging pressure on the steel wire or cable and thus the tension on the wire or cable.

What is claimed is:

1. In an apparatus for hot stretching steel wire comprising: a pair of longitudinally spaced caterpillar assemblies located with a space therebetween along the path of movement of a steel wire to be stretched, each caterpillar assembly including a pair of chain-rollers which compressively contact each other and rotate in opposite directions, a heating device disposed longitudinally at a position between the caterpillar assemblies, one caterpillar assembly disposed forwardly of the other caterpillar assembly in the moving direction of the steel wire and being driven at a higher velocity than that of the other caterpillar assembly so that a predetermined, high tension is applied to the moving steel wire between the caterpillar assemblies sufficient to effect stretching of said wire, the improvement wherein: each said wire relative to said first parts which grip the wire on either side thereof.

2. The apparatus for hot stretching for steel wire and cable as set forth in claim 1, further comprising a pressure roller and a support roller provided longitudinally between said other caterpillar assembly and the heating device and contacting said wire or cable with said pressure roller including means for regulating the tension exerted on the steel wire being processed.

Claims

1. In an apparatus for hot stretching steel wire comprising: a pair of longitudinally spaced caterpillar assemblies located with a space therebetween along the path of movement of a steel wire to be stretched, each caterpillar assembly including a pair of chain-rollers which compressively contact each other and rotate in opposite directions, a heating device disposed longitudinally at a position between the caterpillar assemblies, one caterpillar assembly disposed forwardly of the other caterpillar assembly in the moving direction of the steel wire and being driven at a higher velocity than that of the other caterpillar assembly so that a predetermined, high tension is applied to the moving steel wire between the caterpillar assemblies sufficient to effect stretching of said wire, the improvement wherein: each longitudinally aligned chain roller of the pair includes a plurality of holder members in facing relation to and urged under liquid pressure against those of the opposite chain roller, each of said holder members having a first part frictionally gripping opposite sides of the steel wire and a second part connected to the chain roller, said parts being formed of metal, and said first parts being fixed to said second parts respectively through resilient plates which permit relative shifting between first and second parts in the direction of wire travel under applied tension but which prevents Slippage of said wire relative to said first parts which grip the wire on either side thereof.