GB1596010A - Device for controlling the time sequence of racking programme carriers in circular knitting machines - Google Patents

Description

(54) DEVICE FOR CONTROLLING THE TIME SEQUENCE OF RACKING PROGRAM CARRIERS IN CIRCULAR KNITTING MACHINES (71) We, ELITEX, koncern textilniho strojirenstvi of 22 Bonzeny Nemcove, Liberec, Czechoslovakia, a body corporate organised and existing under the laws of Czechoslovakia 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: The present invention relates to a device for controlling the time sequence of racking programme carriers in circular knitting machines.

Circular knitting machines are known for manufacturing hosiery goods which are equipped with a device for controlling the time sequence of racking a control chain, said device comprising an electronic computer with a mechanically assembled programme, said computer controlling the operation of an electromagnet which locks the racking lever of the control chain. A mechanical programme for the electronic computer is then assembled on a cylindrical drum which is attached to the control drum of the machine. The device operates reliably, however it is necessary to turn both the cylindrical drum and thus also the control drum upon programme conversion. this causing all operations to be performed which depend on the rotation of the control drum.

This disadvantage is solved by a further device, which comprises again an electronic computer and a mechanical programme however in which the drum with the assembled programme is not connected to the control drum but is provided with a cam for the purpose of controlling the racking pawl of the control drum via a lever. Upon programme change for the electronic computer it is not necessary to turn the control drum.

Both known devices have however a common disadvantage consisting in that the electronic computer is sensitive to machine vibrations and pollution of the atmosphere, this being not always restricted in knitting mills to a tolerable extent. Moreover frequent inspections and skilled attendance are further indispensible conditions for its correct operation. Besides, these devices are rather expensive.

The purpose of the present invention consists in mitigating the above disadvantages.

According to the present invention there is provided a circular knitting machine comprising a driving pawl, a driving ratchet and freely rotatable control ratchets, mounted coaxially side-by-side for cooperation with the driving pawl, a programme carrier driven by the driving ratchet, and programme elements carried by the programme carrier for cooperation with the control ratchets, each control ratchet having a diameter greater than the diameter of the driving ratchet, and the control ratchets having in their outer circumferences recesses interrupting the teeth thereof with different numbers of teeth between the recesses, the inner edges of the recesses being on the same diameter which is at most equal to the diameter of the rest circle of the driving ratchet, whereby the driving pawl can only rack the driving ratchet and thus the programme carrier when there is mutual alignment of the recesses in the control ratchets opposite the operating range of to-and-fro movements of the driving pawl, and the number of to-and-fro movements of the driving pawl during which the programme carrier is not racked is determined by which control ratchet is moved to bring its recess out of said alignment by cooperation with a programme element carried on the previously racked programme carrier and thus to bring its teeth into racking cooperation with the driving pawl.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an axial section of a part of a programme carrier and control ratchets together with a programme element for selecting the control ratchet and the racking pawl; Figure 2 shows a part of a programme carrier in a section normal to its axis together with the arrangement of programme elements for selecting the control ratchet, the latter being represented in a position in which a programme element engages its selecting lever and in which the locking lever which is attached thereto is in inoperative position; Figure 3 is the same as Figure 2, with the locking lever holding the selection lever out of engagement with the programme element of the control ratchet; and Figure 4 is the same as Figure 1, but in axial section, in which the locking lever of the control ratchets is shown.

A small diameter knitting machine for manufacturing hosiery goods is provided with a programme carrier 1, which is mounted rotatably on shaft 2 mounted firmly in the machine frame (not represented). The programme carrier 1 is provided on its cylindrical surface with programme pins 3, co-operating with scanning levers. For better understanding only one scanning lever 4 is represented. The said scanning levers control particularly nonpower functions of the knitting machine, relative to their time sequence upon knitting the knitwork. The programme carrier 1 is provided with a driving ratchet 5, a driving pawl 6 co-operating therewith, the latter being driven by a not shown transmission from the needle cylinder of the machine.

On shaft 2 is mounted firmly disc 7, on a step 7' on which are arranged freely rotatable control ratchets 8, 9, 10, 11, 12. In the step 7' there is a recess 13 (Figure 2) which is engaged by a rectangularly cranked operative end 14' (Figure 4) of a locking lever 14 mounted swingably on shaft 2.

The control ratchets 8 to 12 increase in diameter in the direction axially away from the driving ratchet 5, as shown in Figures 1 and 4, the smallest control ratchet being bigger than the driving ratchet 5 and inner recesses 15 being provided on each thereof.

Sprung selecting levers 16 are arranged swingably in said recesses 15, and bear against the step 7' or pass through recess 13 in said step 7'. Interrupting the teeth of the control ratchets 8, 12 are outer recesses 17 with their radially inner edges 17' (Figure 3) of arcuate shape and for all control ratchets 8 to 12 of the same diameter, which is smaller than or equal to the rest circle of the driving ratchet 5. The length of each edge 17' is longer than the length of a tooth of the driving ratchet 5. The number of inner recesses 15 and outer recesses 17 is the same, said recesses being angularly displaced relative to each other because of the angular displacement between locating recess 13 and the point of action of driving pawl 6, as shown in Figures 2 and 3.

Between the outer recesses 17 of control ratchet 8 are two teeth, in control ratchet 9 four teeth, in control ratchet 10 eight teeth, in control ratchet 11 sixteen teeth and in control ratchet 12 thirty two teeth, the angular spacing of the teeth being the same on all control ratchets 8 to 12. These teeth numbers obviously might be different in view of the goods to be knitted in the machine, or relative to whether the machine is a single or two cylinder machine. Then even the number of control ratchets might be different, the driving pawl 6 embracing always with its operative end both the control ratchets and the driving ratchet 5.

In the programme carrier 1 are mounted in grooves 1' firmly programme elements 18 of sheet-like shape, at the operative ends of which are butts 18' which are arranged in accordance with the programme, and which are situated below the diameter of the step 7' of disc 7. The programme elements 18 are removable, one butt 18' being assigned to each control ratchet 8 to 12, the programme elements 18 thus having the same number of rows of butts 18' as there are control ratchets, i.e. in the given case five rows.

The device as specified above operates as follows:- At the beginning of the knitting process, all control ratchets 8 to 12 are arranged in such a manner that certain outer recesses 17 or the appurtenant inner recesses 15 are mutually aligned. The driving pawl 6 thus engages only the driving ratchet 5, i.e.

engages its teeth along the length of edge 17'. E.g. after performing one racking of programme carrier 1 the situation as shown in Figure 2 is reached. The driving pawl 6 is in its rear position and selecting levers 16 of all control ratchets 8 to 12 bear against the surface of programme carrier 1. the operative end 14' of locking lever 14 permitting the selection levers 16 to bear against programme carrier 1. On the programme element 8, which comes. upon further racking of programme carrier 1, into contact with the selecting levers 16, is butt 18' only below control ratchet 10, the latter being displaced by pressure of butt 18' on the selecting lever 16 and its teeth 10' passing over to the position as shown in Figure 2, which is denoted by dash lines. The driving pawl 6 thus cannot engage the driving ratchet 5, of which the teetch are covered, and engages control ratchet 10. Upon hav ing performed eight racking motions of control ratchet 10 a further recess 17 on control ratchet 10 comes into alignment with the recesses 17 of the remaining control ratchets 8, 9, 11, 12 and a further racking of driving ratchet 5 and thus programme carrier 1 is performed. If e.g. on a further programme element 18 butts 18' are situated below control ratchets 10 and 12, both said control ratchets 10 and 12 are displaced into the operative range of driving pawl 6.

At first, the driving pawl 6 engages control ratchet 12, as said ratchet has a larger diameter, and thereafter, upon having performed thirty two racking motions, said driving pawl 6 begins to engage control ratchet 10. Upon having performed eight racking motions, by control ratchet 10, driving pawl 6 performs again a racking motion of ratchet 5. Thus, programme carrier 1 is stopped for the time of forty racking motions.

The length of stoppage of the programme carrier is thus influenced in the above manner, whereby the time sections between separate machine changes and the number of courses in the separate sections of the knitted fabric are determined, i.e. in the welt part, the leg part, the heel part, the instep or sole part, and the toe part. Certain angular sections on the programme carrier 1 thus correspond to said sections on the knitted fabric, of which the length. or the number of knitwork courses is determined by the possibility of changing the projection of butts 18' on programme elements 18. The latter can be also displaced angularly, thus influencing also the performing of changes in view of the racking of programme carrier 1.The change of programme elements 18 can be performed for an arbitrary section of the product, either upon machine stoppage, or even during operation, when dismounting.

It is further possible to displace the locking lever 14, or its operative end 14' into the position as shown in Figure 3. upon machine failure and spoiled knitted fabric.

Thus all selecting levers 16 are lifted and cannot be controlled by butts 18' of select ing elements 18. The control ratchets 8 to 12 are thus out of action and the programme carrier 1 is automatically turned to its start position. However, this operation can be also secured when using the locking lever 14 but instead by displacing the driving pawl 6 in the direction towards the dashed position as shown in Figure 4, thus engaging only the driving ratchet 5.

WHAT WE CLAIM IS: 1. A circular knitting machine compris ing a driving pawl, a driving ratchet and freely rotatable control ratchets mounted coaxially side-by-side for cooperation with the driving pawl, a programme carrier driven by the driving ratchet, and programme elements carried by the programme carrier for cooperation with the control ratchets, each control ratchet having a diameter greater than the diameter of the driving ratchet, and the control ratchets having in their outer circumferences recesses interrupting the teeth thereof with different numbers of teeth between the recesses, the inner edges of the recesses being on the same diameter which is at most equal to the diameter of the rest circle of the driving ratchet, whereby the driving pawl can only rack the driving ratchet and thus the programme carrier when there is mutual alignment of the recesses in the control ratchets opposite the operating range of to-and-fro movements of the driving pawl, and the number of to-and-fro movements of the driving pawl during which the programme carrier is not racked is determined by which control ratchet is moved to bring its recess out of said alignment by cooperation with a programme element carried on the previously racked programme carrier and thus to bring its teeth into racking cooperation with the driving pawl.

2. A circular knitting machine as claimed in claim 1, wherein the control ratchets increase in diameter in the direction axially away from the driving ratchet and have on their inner circumferences inner recesses in which are swingably arranged sprung selecting levers for cooperation with the programme elements of the programme carrier.

3. A circular knitting machine as claimed in claim 2, wherein the control ratchets are mounted on a step of a disc, which is mounted on a shaft of the programme carrier, a recess being provided in said step, the sprung selecting levers of the control ratchets engaging through said recess upon their rotation, the part of the cylindrical surface of the programme carrier in which the programme elements are mounted and situated below the diameter of the step of the disc.

4. A circular knitting machine as claimed in claim 3, wherein on the programme carrier is swingably mounted a locking lever, of which a rectangularly cranked operative end engages the recess in the step of the disc.

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

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. ing performed eight racking motions of control ratchet 10 a further recess 17 on control ratchet 10 comes into alignment with the recesses 17 of the remaining control ratchets 8, 9, 11, 12 and a further racking of driving ratchet 5 and thus programme carrier 1 is performed. If e.g. on a further programme element 18 butts 18' are situated below control ratchets 10 and 12, both said control ratchets 10 and 12 are displaced into the operative range of driving pawl 6. At first, the driving pawl 6 engages control ratchet 12, as said ratchet has a larger diameter, and thereafter, upon having performed thirty two racking motions, said driving pawl 6 begins to engage control ratchet 10. Upon having performed eight racking motions, by control ratchet 10, driving pawl 6 performs again a racking motion of ratchet 5. Thus, programme carrier 1 is stopped for the time of forty racking motions. The length of stoppage of the programme carrier is thus influenced in the above manner, whereby the time sections between separate machine changes and the number of courses in the separate sections of the knitted fabric are determined, i.e. in the welt part, the leg part, the heel part, the instep or sole part, and the toe part. Certain angular sections on the programme carrier 1 thus correspond to said sections on the knitted fabric, of which the length. or the number of knitwork courses is determined by the possibility of changing the projection of butts 18' on programme elements 18. The latter can be also displaced angularly, thus influencing also the performing of changes in view of the racking of programme carrier 1.The change of programme elements 18 can be performed for an arbitrary section of the product, either upon machine stoppage, or even during operation, when dismounting. It is further possible to displace the locking lever 14, or its operative end 14' into the position as shown in Figure 3. upon machine failure and spoiled knitted fabric. Thus all selecting levers 16 are lifted and cannot be controlled by butts 18' of select ing elements 18. The control ratchets 8 to 12 are thus out of action and the programme carrier 1 is automatically turned to its start position. However, this operation can be also secured when using the locking lever 14 but instead by displacing the driving pawl 6 in the direction towards the dashed position as shown in Figure 4, thus engaging only the driving ratchet 5. WHAT WE CLAIM IS:

1. A circular knitting machine compris ing a driving pawl, a driving ratchet and freely rotatable control ratchets mounted coaxially side-by-side for cooperation with the driving pawl, a programme carrier driven by the driving ratchet, and programme elements carried by the programme carrier for cooperation with the control ratchets, each control ratchet having a diameter greater than the diameter of the driving ratchet, and the control ratchets having in their outer circumferences recesses interrupting the teeth thereof with different numbers of teeth between the recesses, the inner edges of the recesses being on the same diameter which is at most equal to the diameter of the rest circle of the driving ratchet, whereby the driving pawl can only rack the driving ratchet and thus the programme carrier when there is mutual alignment of the recesses in the control ratchets opposite the operating range of to-and-fro movements of the driving pawl, and the number of to-and-fro movements of the driving pawl during which the programme carrier is not racked is determined by which control ratchet is moved to bring its recess out of said alignment by cooperation with a programme element carried on the previously racked programme carrier and thus to bring its teeth into racking cooperation with the driving pawl.

2. A circular knitting machine as claimed in claim 1, wherein the control ratchets increase in diameter in the direction axially away from the driving ratchet and have on their inner circumferences inner recesses in which are swingably arranged sprung selecting levers for cooperation with the programme elements of the programme carrier.

3. A circular knitting machine as claimed in claim 2, wherein the control ratchets are mounted on a step of a disc, which is mounted on a shaft of the programme carrier, a recess being provided in said step, the sprung selecting levers of the control ratchets engaging through said recess upon their rotation, the part of the cylindrical surface of the programme carrier in which the programme elements are mounted and situated below the diameter of the step of the disc.

4. A circular knitting machine as claimed in claim 3, wherein on the programme carrier is swingably mounted a locking lever, of which a rectangularly cranked operative end engages the recess in the step of the disc.

5. A circular knitting machine, substan

tially as hereinbefore described with reference to the accompanying drawings.