Boots – shoes – and leggings
Patent
1982-05-21
1985-04-16
Ruggiero, Joseph
Boots, shoes, and leggings
364167, 364185, 371 20, 371 49, G06F 1546, G05B 2302
Patent
active
045119759
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a numerical control machine tool, and more particularly to improvements in signal transmitting and receiving equipment which performs transmission and reception of signals regarding M, S and T functions between a numerical controller and a machine tool.
Equipping a numerical controller (hereinafter referred to as an NC apparatus) with M, S, and T functions so as to improve its performance as an NC machine tool has heretofore been known. The M function is one that performs ON-OFF control for starting and stopping the rotation of a spindle, turning ON and OFF of a coolant and so forth in accordance with commands stored on a command tape. The S and T functions are those for similarly controlling the number of revolutions of the spindle and controlling the tool selection in accordance with commands stored on the command tape. These functions are performed by sending out signals regarding the M, S and T functions as relay contact signals to the machine tool and controlling its heavy current circuits.
The M, S and T functions serve to effect principal control of the machine tool and the control operations have to be carried out accurately because an erroneous operation would produce serious trouble, such as a breakdown of the machine tool or damage to an expensive workpiece. However, since data transfer between the NC apparatus and the machine tool is usually effected by parallel transfer which does not involve parallel-serial conversion and is high in transfer rate, and since a number of transmission lines and relays corresponding in number thereto are used, there are some occasions when a faulty signal is sent out owing to breakage of the transmission line or a breakdown of the relay. In such a case, according to a conventional arrangement, the faulty signal may be applied as it is to a heavy current circuit on the side of the machine tool to cause an erroneous operation. That is to say, in a prior art NC machine tool, such as for instance the one shown in FIG. 1, a code sending circuit 10, by which numeric codes following address characters M, S and T indicating the kinds of functions are transmitted in parallel via transmission lines l.sub.1 to l.sub.n having connected thereto relay circuits (not shown), is provided for each function on the side of the NC apparatus. A code signal sent out from the code sending circuit is received and decoded following a strobe signal sb in a decoding circuit 11 provided on the side of the machine tool, and the decoded signal is applied to the heavy current circuit of the machine tool. Accordingly, even if a wrong code is transmitted and received due to, for example, breakage of a transmission line l.sub.1 to l.sub.n or breakdown of a relay, since no error detecting means is provided on the receiving side, the machine tool operates following the wrong code.
SUMMARY OF THE INVENTION
The present invention is intended to overcome such a defect of the prior art and has for its object to ensure the operations of the M, S and T functions, thereby to prevent accidents resulting from malfunctioning. According to the machine tool of the present invention, a numeric code sent from an NC apparatus to the side of the machine tool is added or combined with a redundant signal for checking its validity, and the machine tool is operated only when it is decided, based on the added signal on the side of the machine tool, that the received code is valid. With such an arrangement, even if a parallel transmission system using many signal lines is employed, it is possible to offer an NC machine tool which is capable of preventing erroneous operations related to the M, S and T functions and hence the NC machine tool is of high reliability.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the arrangement of signal transmitting and receiving equipment in a conventional NC machine tool; and
FIG. 2 is a block diagram illustrating the principal part of an embodiment of signal transmitting and receiving equipment of the NC m
REFERENCES:
patent: 4118771 (1978-10-01), Pomella et al.
patent: 4229804 (1980-10-01), Kobayashi et al.
patent: 4291388 (1981-09-01), Ecker, Jr. et al.
patent: 4328448 (1982-05-01), Berenberg et al.
Kawamura Hideaki
Miyata Mitsuto
Nagamine Tsuyoshi
Nozawa Ryoichiro
Fanuc Ltd
Ruggiero Joseph
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