Cutting apparatus and method

Abstract

In a cutting apparatus a rotating carousel conveys caps made of synthetic plastic material to a fixed blade having the shape of a circumferential arc. The caps are rotated about themselves by spindles. The blade cuts an annular weakening line to form the tamperproof ring of the cap. The carousel has an emitter and a laser receiver that cooperate to detect the presence or absence of the cutting edge of the fixed blade. The apparatus ensures good cutting quality.

Description

BACKGROUND OF THE INVENTION[0001]The invention relates to a cutting apparatus and method, in particular for cutting or engraving plastics or metal (for example aluminium or steel), more in particular to make a weakening line in caps made of plastics.[0002]Specifically, but not exclusively, the invention can be used to produce caps made of plastics for closing containers, in particular for making the preferential weakening or fracturing line that is used to define a tamperproof device intended to indicate the first opening of the cap.[0003]Making the preferential breaking line of a tamperproof ring in caps made of plastics by cutting apparatuses that comprise a carousel that has a series of movable spindles that are able to rotate around their axis is known. In use, the caps to be cut engage in the spindles and are thus rolled on a fixed sector that carries a blade that is suitably shaped according to the type of cut that it is desired to perform. The fixed sector can be positioned e...

AI Technical Summary

Benefits of technology

[0014]One object of the invention is to provide a cutting apparatus in which the good quality of the cutting operation performed is assured.

[0015]Another object is to provide a cutting method in which the good quality of the cut operation is ensured.

[0016]One advantage is to make an apparatus and / or a cutting method available for making the weakening line in caps made of plastics with relatively high productivity.

[0018]A further advantage is to reduce the risk of rejects in the production of caps made of plastics provided with a tamperproof device.

Problems solved by technology

One of the problems of the known apparatuses of this type consists of the fact that the cutting blade is subject to wear during use and can accidentally splinter or break, with consequent deterioration in the quality of the caps produced, such that the correct operation of the tamperproof device is no longer ensured.

This problem is particularly relevant in the case of a machining process that occurs continuously and in line with other apparatuses.

This solution nevertheless has the following drawback: for example, if average production speed is 60,000 caps an hour and the sampling period is one hour, if insufficient quality is detected in the sample of caps all the 60,000 caps produced in the hour preceding the sampling have to be rejected because correct operation of the tamperproof device would not be guaranteed.

The reflected beam may or may not be intercepted by the receiver, which produces a significant signal of the state of damage of the blade.

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