GB2132233A - Time sequence monitoring and control system for controlling the operation of a circular knitting machine - Google Patents

Abstract

The present invention relates to processing and evaluation of signals from monitoring devices (11, 12, 21, 22) connected to a microcomputer (3) for controlling the operation steps of a circular knitting machine for manufacturing hosiery and similar goods. The present invention secures the reliability of the machine operation and the time of response to failures in such manner, that both quick-acting monitors (11, 12) and stable monitors (21, 22) are connected to a multiplexor (4) which is interconnected to the microcomputer (3), the quick-acting monitors (11, 12) being moreover connected directly to the interrupt input INT of the microcomputer (3). The quick-acting monitors may be responsive to needle failure, the stable monitors to oil and air pressure. Thread tension and run-out monitors are also provided. The type of fault is signalled at (5). <IMAGE>

Description

SPECIFICATION Time sequence monitoring and control system for contolling the operation of a circular knitting machine The present invention relates to a time sequence monitoring and control system for controlling the operation of a circular knitting machine.

It is known that in small diameter circular knitting machines various monitoring devices are used, as thread run-out monitors, thread tension monitors, rubber thread monitors, needle and sinker monitors, oil monitors, air pressure monitors etc. These monitors connect either directly, or via separator diodes the coils of monitoring relays to earth potential, thus closing the electric circuit, the relay is attracted and forms with its contact a self-retainment. By a further contact, the electric circuit of the auxiliary relay is opened which by its release causes the interuption of feeding the coils of the electric driving motor contactors. The active operation of the most important monitors is indicated by light signals, or possibly by bulbs fed via diode rectifiers.The actual switching of the monitors is secured either directly by the contact of the monitor or by the contact of the monitoring relay.

The purpose of the present invention consists in removing from the circuit the above mentioned feeding circuits, relay circuits, signalling circuits, separating circuits etc. in a machine provided with a microcomputer for controlling the operation steps of the machine.

According to the invention there is provided a time sequence monitoring and control system for controlling the operation of a circular knitting machine, comprising a plurality of quick-acting monitors and a plurality of stable monitors adapted to monitor various machine parameters, said monitors being connected to a microcomputer via a multiplexor and said quickacting monitors being further connected to the interrupt input of the microcomputer via diodes, and said microcomputer being programmed to send a control signal to a control element of the machine in response to signals from said monitors.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing.

A known single cylinder circular knitting machine for manufacturing hosiery goods is provided with quick-acting monitors i.e. a needle butt monitor 11, a needle latch monitor 12, and stable monitors, i.e. an oil monitor 2, and an air pressure monitor 22, and further thread run-out monitors and thread tension monitors (not represented). The quick-acting monitors 11 and 12 are connected via diodes 2 to the interrupt input INT of a microcomputer 3 and also to the inputs of a multiplexor 4. The stable monitors 21 and 22 are connected to multiplexor 4. Multiplexor 4 is in turn connected to a microcomputer 3, which is connected on one hand to a display 5 and further to a control element 6 of the machine.

The microcomputer 3 checks, during its operation, the states of signals of all monitors ii, 12, 21, 22 in time sequence, by switching multiplexor 4. Upon detecting an active state of monitor 11, 12, 21, 22, its evaluation and processing is performed by microcomputer 3, and a command is issued for the control element 6 of the machine. Simultaneously, the type of the active, failure signalling monitor is signalled by an agreed character. It is possible that during checking the monitors, the time of the active signal from the quick-acting monitor 11, or 12 is shorter than the time of the checking signal. In this case, due to the fact that the signal is directed to interrupt input INT directly, it is processed also by microcomputer 3, which issues a command for machine stoppage.

The advantage of the circuit according to the present invention consists in that by connecting the monitors via multiplexor 4, the delicate inputs of the microcomputer are separated from the monitors, which might be the source of damaging of the microcomputer. By the circuit according to the present invention, the structure of the electric box of the machine is also simplified, the lifetime of the display is longer and also the resistance against vibrations. The electronic circuits reduce substantially the time of response of the machine to the failure. By the microcomputer program, it is possible to secure the elimination of failure signals at the monitor inputs, thus reducing the consumption of electric power.

1. A time sequence monitoring and control system for controlling the operation of a circular knitting machine, comprising a plurality of quickacting monitors and a plurality of stable monitors adapted to monitor various machine parameters, said monitors being connected to a microcomputer via a multiplexor and said quickacting monitors being further connected to the interrupt input of the microcomputer via diodes, and said microcomputer being programmed to send a control signal to a control element of the machine in response to signals from said monitors.

2. A time sequence monitoring and control system according to claim 1, further comprising display means.

3. A time sequence monitoring and control system substantially as hereinbefore described with reference to the accompanying drawing.

4. A circular knitting machine for manufacturing hosiery and the like comprising a time sequence monitoring and control system according to any preceding claim.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Time sequence monitoring and control system for contolling the operation of a circular knitting machine The present invention relates to a time sequence monitoring and control system for controlling the operation of a circular knitting machine. It is known that in small diameter circular knitting machines various monitoring devices are used, as thread run-out monitors, thread tension monitors, rubber thread monitors, needle and sinker monitors, oil monitors, air pressure monitors etc. These monitors connect either directly, or via separator diodes the coils of monitoring relays to earth potential, thus closing the electric circuit, the relay is attracted and forms with its contact a self-retainment. By a further contact, the electric circuit of the auxiliary relay is opened which by its release causes the interuption of feeding the coils of the electric driving motor contactors. The active operation of the most important monitors is indicated by light signals, or possibly by bulbs fed via diode rectifiers.The actual switching of the monitors is secured either directly by the contact of the monitor or by the contact of the monitoring relay. The purpose of the present invention consists in removing from the circuit the above mentioned feeding circuits, relay circuits, signalling circuits, separating circuits etc. in a machine provided with a microcomputer for controlling the operation steps of the machine. According to the invention there is provided a time sequence monitoring and control system for controlling the operation of a circular knitting machine, comprising a plurality of quick-acting monitors and a plurality of stable monitors adapted to monitor various machine parameters, said monitors being connected to a microcomputer via a multiplexor and said quickacting monitors being further connected to the interrupt input of the microcomputer via diodes, and said microcomputer being programmed to send a control signal to a control element of the machine in response to signals from said monitors. An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing. A known single cylinder circular knitting machine for manufacturing hosiery goods is provided with quick-acting monitors i.e. a needle butt monitor 11, a needle latch monitor 12, and stable monitors, i.e. an oil monitor 2, and an air pressure monitor 22, and further thread run-out monitors and thread tension monitors (not represented). The quick-acting monitors 11 and 12 are connected via diodes 2 to the interrupt input INT of a microcomputer 3 and also to the inputs of a multiplexor 4. The stable monitors 21 and 22 are connected to multiplexor 4. Multiplexor 4 is in turn connected to a microcomputer 3, which is connected on one hand to a display 5 and further to a control element 6 of the machine. The microcomputer 3 checks, during its operation, the states of signals of all monitors ii, 12, 21, 22 in time sequence, by switching multiplexor 4. Upon detecting an active state of monitor 11, 12, 21, 22, its evaluation and processing is performed by microcomputer 3, and a command is issued for the control element 6 of the machine. Simultaneously, the type of the active, failure signalling monitor is signalled by an agreed character. It is possible that during checking the monitors, the time of the active signal from the quick-acting monitor 11, or 12 is shorter than the time of the checking signal. In this case, due to the fact that the signal is directed to interrupt input INT directly, it is processed also by microcomputer 3, which issues a command for machine stoppage. The advantage of the circuit according to the present invention consists in that by connecting the monitors via multiplexor 4, the delicate inputs of the microcomputer are separated from the monitors, which might be the source of damaging of the microcomputer. By the circuit according to the present invention, the structure of the electric box of the machine is also simplified, the lifetime of the display is longer and also the resistance against vibrations. The electronic circuits reduce substantially the time of response of the machine to the failure. By the microcomputer program, it is possible to secure the elimination of failure signals at the monitor inputs, thus reducing the consumption of electric power. CLAIMS

1. A time sequence monitoring and control system for controlling the operation of a circular knitting machine, comprising a plurality of quickacting monitors and a plurality of stable monitors adapted to monitor various machine parameters, said monitors being connected to a microcomputer via a multiplexor and said quickacting monitors being further connected to the interrupt input of the microcomputer via diodes, and said microcomputer being programmed to send a control signal to a control element of the machine in response to signals from said monitors.

2. A time sequence monitoring and control system according to claim 1, further comprising display means.

3. A time sequence monitoring and control system substantially as hereinbefore described with reference to the accompanying drawing.

4. A circular knitting machine for manufacturing hosiery and the like comprising a time sequence monitoring and control system according to any preceding claim.