GB1598119A - Flat knitting machines - Google Patents

Abstract

There is provided a multiplex circuit (6), which according to the movement of the carriage, transmits signals to the needle-selection systems, in order to bring about the knitting of a knitted article with a pattern when control signals from a memory arrive at the multiplex circuit. In such a device, a variation in the working width from one row to the next should be simple and take place over the entire width of the bed of the flat knitting machine, without limit switches having to be mechanically adjusted. The change in the setting should also be as simple as possible. For this purpose, the memory is designed as a working memory (12) having storage locations which are assigned to the needles of the flat knitting machine over the entire width of the bed and in which the entire working width is stored. <IMAGE>

Description

(54) IMPROVEMENTS IN OR RELATING TO FLAT KNITTING MACHINES (71) We, H. STOLL GMBH & CO., a company of the Federal Republic of Germany of Stollweg 1, 7410 Reutlingen, Federal Republic of Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a device for de determining the operating width of a flat knitting machine.

One such device is known from DT-AS 21 20 892. In this known device the control circuit is constituted by an AND-gate link (64, Figure 2) having an input (at 16) at which signals representing patterning information are applied, and another input to which control signals are applied, thereby controlling the knitting procedure, only when the carriage is within a preset operating width.

These signals are triggered by limit switches (202, 202'; of in the text column 5, lines 22 to 29 and column 8, lines 4 to line 29) which are arranged in the bed of the flat knitting machine. They control a flip-flop (67) which is connected to a memory (39, 40) which-in dependence on control pulses (at 41)-can be transmitted to marginal needles which are additional to the operating width defined by the limit switches.

The variation of the marginal needles is however extremely limited in this device.

Having regard to a predetermined position of the limit switches a certain increase, but no reduction, is only possible within narrow limits prescribed by the aforesaid memory.

Larger variations are not possible; they can only be varied from one stroke to the next by adjusting the limit switches. A manual adjustment of the limit switches of this nature is moreover extremely troublesome.

Devices to be introduced into the cambox and having a mechanical action for adding and withdrawing needles are so structured that simultaneous use of jacquard devices for defining a pattern is not possible; special devices have therefore to be used for defining the pattern, and these only allow a limited type of pattern form; further they involve the disadvantage that the pattern cannot be catered for generally over the complete length of travel of the carriage independently of the momentary operating width. The preselection of the operating width by the jacquard cards would mean that to use the same pattern for different working zones different complete sets of jacquard cards would have to be provided. The outlay for this is comparably large.

The present invention provides a device for controlling the operating width of a flat knitting machine comprising a control circuit operable responsively to reception of control signals from a memory to transmit pattern data signals to a needle selector system of the machine in synchronism with the movement of the machine carriage, and wherein the memory is an operating memory which has respective storage locations associated with the needles of the flat knitting machine over the complete width of the machine bed, and the full operating width of the machine is determined by stored information in the memory.

The starting width is set by the initial programming of the operating memory, the storage location of the same associated with each needle position are interrogated in succession during each passage of the carriage and the contents are used to constitute con trcl signals which are transmitted to the control circuit. For example within the operating width the storage locations contain logic 1 signals; in this event the control circuit passes pattern data to the flat knitting machine. Outside the operating width the storage locations contain logic 0 signals; in this event the control circuit is blocked so that no pattern data is transmitted to the flat knitting machine and there is no knitting.

The content of an operating memory therefore determines the operating width independent of the pattern data over the complete width of the bed of the flat knitting machine.

If the operating width is to be varied, the content of the operating memory must be correspondingly varied. In principle that is possible with all the means which can be used for programming the memory. In accordance with an advantageous feature of the invention this is achieved by the fact that a logic circuit, on interrogation of the operating memory, checks a transfer from one memory cell to the next of logic "1" to logic "0" signals, and from this sends out an inscribing signal which operates so that, instead of the first "0" following the logic "1" signals; a logic "1" signal is located and this increases the operating width by one needle. This enlargement can of course take place not only through 1 needle, but also through 2, 3 or more needles.In a similar fashion, by means of the logic circuit instead of the last logic "1" a logic "0" signal can be inscribed and the operating width thereby narrowed. This narrowing can also take place over 2, 3 or more needles per stroke. This variation of the content of the operating memory made by the logic circuit occurs for each stroke where a command in suction prevails.

Where larger areas are cast off it is advantageous to have the data which has to be fed into the operating memory "ready" in an auxiliary memory. When a command instruction occurs the content thereof is then read into the operating memory so that the cast-off width stored in the auxiliary memory can be applied quickly from one stroke to the next for varying the content of the operating memory.

The present invention is further described hereinafter by way of example, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic illustration of a knitted portion of a garment; Figure la is a diagrammatic illustration of a further knitted portion of the garment; Figure 2 is a circuit diagram of one embodiment of the present invention; and Figure 3 is a diagrammatic illustration of the method of operation of an operating memory 12 and auxiliary memories 24, 25 of the circuit of Figure 2.

Figure 1 shows a knitted garment portion 1 having a first zone A of constant width a (the starting width of the portion) an adjoining zone B progressively of increasing width up to a maximum width b, a third zone C of constant operating width b, a further zone D of constant operating width d, and a final zone E of constant operating width equal to the starting width a. The change from zone C to zone D is a step change through a respective cast-off knitted width y, at each side of the portion 1; y, = (bd)/2. The change from zone D to zone E is also a step change through a respective cast-off knitted width yz at each side of the portion 1. Thus Y2 = (d-a)/2.

Figure la shows a knitted garment portion 2 having a zone A' of constant width a' (the starting width), succeeded by a second zone B' of progressively increasing width to a maximum width b'. A third zone C' of progressively reducing width from an initial width b' to a minimum width c' adjoins zone B'.

The knitted portions 1 and 2 have patterns which are shown diagrammatically in Figures 1 and la and in both cases are designated 3. In knitting the portion 1 as shown in Figure 1 therefore there must be a progressive increase in the knitting stroke of the machine over the zone B; this is effected by adding a respective needle at the end of each stroke of the carriage of a flat knitting machine.

For example, when the carriage is moved from right to left a needle is added at the left-hand end; when the carriage is moved from left to right a needle is added at the right-hand end. As soon as the maximum width b is arrived at no further needles are added and knitting continues with a constant knitting width. In stepping from zone C to zone D and from zone D to zone E the needles previously effective over the portions y, and Y2 of the knitting strokes are cast off. During subsequent knitting strokes of the flat knitting machine in the zone E the needles covering the widths Y1 and y, are no longer operated.

Figure 2 shows a circuit for controlling a two-cambox flat knitting machine for producing a knitted portion according to Figure 1. Before describing the operation of the circuit it should be understood that command instructions are produced at the terminals 21, 30, 31 by a control appliance (not shown) which gives, or does not give, specific control signals per stroke or per row of knitting stitches. Such a control appliance can be a programmed data carrier, for example a punched strip, or a control programme or the like. The signals for operating the needles are applied to a needle selector system (not shown) through conductors 4 and 5. Conductor 4 goes to the leading needle selector system and conductor 5 to the next succeeding such system. The signal through the conductors 4, 5 determine whether knitting shall be performed, and thus the pattern.

The conductors 4 and 5 are outputs from a control circuit 6 to which patterning information is supplied through a conductor 7.

'Control signals determining the operating knitting width are passed to the control circuit 6 through conductors 8 and 9. These dictate whether the patterning information from the conductor 7 is passed or not through the mulitplex-arrangement to the conductors 4, 5. If control signals are applied to the control circuit 6 via the conductors 8, 9 there is knitting, and this in accordance with the patterning data fed through conductor 7.

If control signals are absent then there is no knitting. The presence of control signals on conductors 8, 9 consequently determines the operating width in accordance with the carriage movement. The control circuit 6 is in substance an AND-gate, the control signals determining the patterning data being fed to one input and those determining the operating width are fed to another, respectively from the conductors 8, 9. The control circuit 6 further incorporates means (not shown) for switching the conductors 8, 9 to the preceding or to the succeeding cambox in each case depending on the direction of travel of the carriage. To control this procedure a signal from terminal 11 is passed through conductor 10 to the control circuit 6 to indicate the direction of movement of the needle selector system controlled through the conductors 4 and 5.A detailed description of the control circuit 6 is however not necessary because the functions explained above can be produced without difficulty by a skilled worker. All that is significant in the present invention is the fact that the control circuit 6 so operates that when appropriate control signals are applied thereto along the conduc tors 8, 9 the patterning data is transmitted to the camboxes of the flat knitting machine, whilst this transmission is interrupted or blocked in the absence of such control signals.

The production of the control signals ap plied to the conductors 8, 9 will now be described. It will be assumed that when the control signals are logic "1" there is to be knitting in accordance with the patterning data, whilst when they are logic "0" there is no knitting.

The circuit of Figure 2 includes an operating memory 12 the output of which is connected through conductor 13 and a logic circuit 14 first to the conductor 8 and secondly through an OR-gate 15 to the conductor 9. The operating memory 12 has a bit storage location for each needle in the bed of the flat knitting machine. These storage locations are interrogated in succession in accordance with the travel of the carriage along the bed. Depending on whether the content of each location is a logic "1" or a logic "0" signal an appropriate control signal is wans- mitted through the logic circuit 14 to the conductor 8 and to conductor 9 Thus the logic circuit 14 aots as a conductor from conductor 13 to conductor 8 or to the OR- gate 15.

The storage locations of the operating memory 12 are interrogated by signals reaching the operating memory 12 through conductors 16 which are associated with the different count outputs of a counter 17. Timing signals are produced synchronously with the travel of the carriage over the flat knitting machine bed, a timing signal thus appearing for each needle and are counted by the counter 17. As the counter 17 counts each timing signal it interrogates successive corresponding storage locations in the memory 12 via conductors 16 so that, as a consequence and synchronously with the travel of the carriage the content of the operating memory 12, i.e. of the storage locations associated with the individual needles, is checked to determine whether there shall be knitting or not.

One method of varying the content of the operating memory 12 will be explained below. The logic circuit 14 checks whether or not a change from logic "1" to logic "0" signal occurs in the course of the interrogation of succeeding storage locations. A change of this nature defines, as described above, the operating width of a knitted portion. If such a change occurs the logic circuit 14 transmits a signal via a conductor 19, to a further a logic circuit 20. The decision is reached with the help of known circuit devices, for example appropriately devised flipflops, and do not therefore need to be further explained. If at the same time a command signal is applied lo the terminal 21, the logic circuit 20 sends a register signal to the operating memory 12 through a conductor 22.Then in the operating memory 12 one or more logic "1" signals are written into the next storage locations which follow on the last "1" storage location to change the logic "0" state to a logic "1" signal before the checked change from logic "1" to logic "0" occurs. Thus for the next carriage stroke the operating width which is written into the operating memory 12 is increased by one or more needles. This procedure continues as long as there is a control command at the terminal 21. At the same time the logic circuit 20 applies a signal to conductor 23 and thus through the OR-gate 15 to conductor 9.Whilst therefore the content of the operating memory 12 is read into the circuit 6 through conductor 8, the content of the memory 12 is also read into the circuit 6 with an increase of one or more places through conductor 9 whereby the additive combination of the content of the operating memory 12 with an additional signal, which appears on conductor 23, is created in the OR-gate 15. This enlargement of the content of the operating memory 12 at conductor 8 or 9 is necessary because in the case of a two cambox machine where there is an addition of needles dependent on the direction of carriage travel, different control signals have to be made available in the two camboxes.

If command instruction is absent at the terminal 21 knitting continues at a constant width, that is to say the content of the operating memory 12 remains the same.

The advantages described are obtained by checking the transition from logic "0" to logic "1" in the operating memory, and variations in the content of the memory can of course be made accordingly. In the transition from logic "1" to logic "0" in the memory cell, instead of the last logic "1" signal of the latter logic "0" signal may be written, thus making a withdrawal of one needle per carriage stroke etc. In general this variation in the operating memory 12 can be described by the fact that when a command instruction is applied specific logic operations result which lead to a predetermined variation of the content of the memory and thus the operating width.

A further method of varying the content of the operating memory 12 is described below. This is used in the embodiment in the transitions from zone C to zone D (castoff width y,) and during the transition from zone D to zone E (cast-off width y..). Auxiliary memories 24 and 25 are used for this purpose. Reference is also made in this respect to Figure 3. Figure 3 shows different widths of the memory content for three knitted portions 1', 1", 1"'. Il. is the content of the operating memory 12, I24 that of the auxiliary memory 24, and 125 that of the auxiliary memory 25. In each case a logic "1" signal is stored in the hatched areas and a logic "0" signal in the remainder of the storage locations. Interrogations of the auxiliary memories takes place through conductors 16.In the event of simultaneous application of operating instructions at the terminals 30 and 31 respectively the contents of the auxiliary memories 24 and 25 respectively are read out through the conductors 26 and 27 respectively, AND-gate members 28, 29 respectively and read inverted into the operating memory through an OR-gate 32 if the operating memory is in a reading condition. This is brought about by a signal in conductor 22 transmitted from the logic circuit 20 if a command instruction has passed to the terminal 30 or 31 through the OR-gate to the circuit 20. Now regarding as an example the knitted portion 1', the knitting operation is started with the operating width a' as 112.

A widening of the knitting width b' then follows in the manner described above, and then a knitting with the constant width b'.

The cast-off through y to d' takes place by reason of the fact that when a command signal is applied to the terminal 30 the content 12,4 of the auxiliary memory 24 is read inverted into the operating memory 12 so that-because of the invertion-there is an extinction of the operating memory 12 over a width which includes the throw-off width yl' in such a way that logic "1" signals, only are now fed over the operating width d' into the operating memory 12.This is followed by a further knitting at a constant widtb Thereafter the cast-off over Y2' to the starting width a' is effected as follows; with a command instruction at the terminal 31, the content I25 of the auxiliary memory 25 is read inverted into the operating memory 12 so that-because of the invertion-an extinction of the operating memory 12 occurs over the further cast-off width Y2', whereby the operating width remains at the starting width a.

The conductors 32, 33, 34 are used to read a specific content into the auxiliary memories 24, 25 or to extinguish them WHAT WE CLAIM IS:- 1. A device for controlling the operating width of a flat knitting machine comprising a control circuit operable responsively to reception of control signals from a memory to transmit pattern data signals to a needle selector system of the machine in synchronism with the movement of the machine carriage, and wherein the memory is an operating memory which has respective storage locations associated with the needles of the flat knitting machine over the complete width of the machine bed, and the operating width of the machine is determined by stored information in the memory.

2. A device as claimed in claim 1, further comprising a logic circuit coupling the control circuit to the memory and operable, responsively to a change of information read from successive storage locations and in the presence of a command instruction to increase or reduce the operating width stored in the operating memory by a preselected amount.

3. A device as claimed in claim 1 or 2 further comprising at least one auxiliary memory the content of which is read into the operating memory in response to a control command instruction.

4. A device as claimed in claim 3 wherein the content of the auxiliary memory is read inverted into the operating memory whereby the memory content of the auxiliary memory corresponds to a cast-off width effected when the flat knitting machine changes over from one stroke into the next stroke.

5. A device as claimed in any of claims 1 to 4 further comprising a counter operable to count timing pulses derived from the movement of the flat knitting machine carriage and successively with each count to interrogate the storage locations of the memory or memories.

6. A device as claimed in claim 2 or any of claims 3 to 5 when appendant to claim 2 wherein an output signal of the logic circuit to increase said width is added to the content read out from the operating memory into an OR-gate and the added signal is passed as a control signal to the control circuit.

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

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. checking the transition from logic "0" to logic "1" in the operating memory, and variations in the content of the memory can of course be made accordingly. In the transition from logic "1" to logic "0" in the memory cell, instead of the last logic "1" signal of the latter logic "0" signal may be written, thus making a withdrawal of one needle per carriage stroke etc. In general this variation in the operating memory 12 can be described by the fact that when a command instruction is applied specific logic operations result which lead to a predetermined variation of the content of the memory and thus the operating width. A further method of varying the content of the operating memory 12 is described below. This is used in the embodiment in the transitions from zone C to zone D (castoff width y,) and during the transition from zone D to zone E (cast-off width y..). Auxiliary memories 24 and 25 are used for this purpose. Reference is also made in this respect to Figure 3. Figure 3 shows different widths of the memory content for three knitted portions 1', 1", 1"'. Il. is the content of the operating memory 12, I24 that of the auxiliary memory 24, and 125 that of the auxiliary memory 25. In each case a logic "1" signal is stored in the hatched areas and a logic "0" signal in the remainder of the storage locations. Interrogations of the auxiliary memories takes place through conductors 16.In the event of simultaneous application of operating instructions at the terminals 30 and 31 respectively the contents of the auxiliary memories 24 and 25 respectively are read out through the conductors 26 and 27 respectively, AND-gate members 28, 29 respectively and read inverted into the operating memory through an OR-gate 32 if the operating memory is in a reading condition. This is brought about by a signal in conductor 22 transmitted from the logic circuit 20 if a command instruction has passed to the terminal 30 or 31 through the OR-gate to the circuit 20. Now regarding as an example the knitted portion 1', the knitting operation is started with the operating width a' as 112. A widening of the knitting width b' then follows in the manner described above, and then a knitting with the constant width b'. The cast-off through y to d' takes place by reason of the fact that when a command signal is applied to the terminal 30 the content 12,4 of the auxiliary memory 24 is read inverted into the operating memory 12 so that-because of the invertion-there is an extinction of the operating memory 12 over a width which includes the throw-off width yl' in such a way that logic "1" signals, only are now fed over the operating width d' into the operating memory 12.This is followed by a further knitting at a constant widtb Thereafter the cast-off over Y2' to the starting width a' is effected as follows; with a command instruction at the terminal 31, the content I25 of the auxiliary memory 25 is read inverted into the operating memory 12 so that-because of the invertion-an extinction of the operating memory 12 occurs over the further cast-off width Y2', whereby the operating width remains at the starting width a. The conductors 32, 33, 34 are used to read a specific content into the auxiliary memories 24, 25 or to extinguish them WHAT WE CLAIM IS:-

1. A device for controlling the operating width of a flat knitting machine comprising a control circuit operable responsively to reception of control signals from a memory to transmit pattern data signals to a needle selector system of the machine in synchronism with the movement of the machine carriage, and wherein the memory is an operating memory which has respective storage locations associated with the needles of the flat knitting machine over the complete width of the machine bed, and the operating width of the machine is determined by stored information in the memory.

2. A device as claimed in claim 1, further comprising a logic circuit coupling the control circuit to the memory and operable, responsively to a change of information read from successive storage locations and in the presence of a command instruction to increase or reduce the operating width stored in the operating memory by a preselected amount.

3. A device as claimed in claim 1 or 2 further comprising at least one auxiliary memory the content of which is read into the operating memory in response to a control command instruction.

4. A device as claimed in claim 3 wherein the content of the auxiliary memory is read inverted into the operating memory whereby the memory content of the auxiliary memory corresponds to a cast-off width effected when the flat knitting machine changes over from one stroke into the next stroke.

5. A device as claimed in any of claims 1 to 4 further comprising a counter operable to count timing pulses derived from the movement of the flat knitting machine carriage and successively with each count to interrogate the storage locations of the memory or memories.

6. A device as claimed in claim 2 or any of claims 3 to 5 when appendant to claim 2 wherein an output signal of the logic circuit to increase said width is added to the content read out from the operating memory into an OR-gate and the added signal is passed as a control signal to the control circuit.

7. A device for controlling the operating

width of a flat knitting machine, substantially as hereinbefore described with reference to the accompanying drawings.