Reinforcing Bar Tying Tool

Abstract

It includes a driving load detecting device which detects a driving load amount of a tie wire cutting mechanism, and a tie wire feeding amount control device which controls a feeding amount of the tie wire in a subsequent tying operation in accordance with the detected driving load amount. If the driving load amount when cutting the tie wire is equal to or less than a cutting determination reference value, the tie wire is fed by a normal feeding amount with a predetermined amount being added thereto in the subsequent tying operation to compensate the tie wire feeding amount, whereby a tip end of the tie wire is fed to a position which is same as the position in the normal state. The subsequent tying cycle is executed normally even if the tip end of the biding wire is failed to be clamped due to the failure of the feeding operation of the tie wire and the tie wire is pulled excessively.

Description

TECHNICAL FIELD[0001]The present invention relates a reinforcing bar tying tool.BACKGROUND ART[0002]An electric reinforcing bar tying tool is widely used as means for saving labor and for improving efficiency in a reinforcing bar tying work. For example, Japanese Patent No. 3496463 discloses an electric reinforcing bar tying tool including a tie wire feeding mechanism which feeds a tie wire wound around a reel so as to wind it around reinforcing bars, a tie wire cutting mechanism which cuts a rear end of a tie wire loop wound around the reinforcing bars so as to separate it from the succeeding tie wire, and a tie wire twisting mechanism which twists the tie wire loop to tie the reinforcing bars, in which, when a trigger lever is pulled, one cycle operation from the feeding of the tie wire to the twisting of the tie wire and the tying of the reinforcing bars can be executed in quite a short time.[0003]Further, such as JP-A-2003-267307, JP-A-2004-142813, JP-A-2004-142814 disclose an e...

AI Technical Summary

Benefits of technology

[0009]According to the above configuration, in a case where the tie wire twisting mechanism fails to clamp the tie wire after feeding the tie wire so that the tie wire is pulled back to a position backward from an initial position passing through the tie wire cutting mechanism, a load increase due to a shearing resistance does not appear at the time of the cutting operation. Thus, it is recognized that the tie wire is pulled back to the position backward from the predetermined initial position, and the feeding amount is increased than the normal tie wire feeding amount when starting the subsequent tying operation. Therefore, the shortage of the feeding length of the tie wire is compensated so that the tie wire is fed out to a position where the tie wire twisting mechanism can clamp the tie wire, whereby a normal tying operation is made possible.

[0010]According to one or more embodiments of the invention, the reinforcing bar tying tool monitors the driving load amount in a cutting step after the pulling step of tie wire to determine whether the cutting operation is carried out or not, and controls the subsequent tie wire feeding amount in accordance with the determination result. In a case where the clamping of the tip end portion of the tie wire is failed so that the tie wire is pulled back to the position backward from the predetermined initial position, the feeding amount is increased than the normal tie wire feeding amount when starting of the subsequent tying operation. Thus, the shortage of the feeding length of the tie wire in the subsequent tying operation is compensated, whereby a work for manually adjusting a position of the tie wire becomes unnecessary so that a degradation of working efficiency due to an interruption of the tying operation or due to a restoration work can be prevented.

Problems solved by technology

However, there is a case where the tie wire is not placed between clamps of the tie wire twisting mechanism for some reasons such as an excessive curvature of the tie wire or an abnormality of the feeding, so that the tie wire cannot be clamped.

Because a feeding amount of the tie wire is controlled to be constant in a reinforcing bar tying tool, when the tip end of the tie wire is moved backward than a regular position, a feeding length of the tie wire becomes insufficient in a subsequent tying cycle, whereby a tying operation cannot be performed like the preceding tying cycle which has been failed.

Thus, in such a case, the tying operation is interrupted and trouble some works are required such as manually feeding the tip end of the tie wire to the regular position and setting the tie wire again.

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