GB1580254A

GB1580254A - Device for the cutting of weft in a weaving loom

Info

Publication number: GB1580254A
Application number: GB922877A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-03-11
Filing date: 1977-03-04
Publication date: 1980-11-26
Also published as: FR2343843A1; DE2708764C2; DE2708764A1; JPS52148265A; FR2343843B1; NL7702376A; ES456707A1; CS191484B1; CH599375A5

Description

(54) A DEVICE FOR THE CUTTING OF WEFT IN A WEAVING LOOM (71) We, ,VYZKUMNY A A VYVOJOVY USTAY ZAVOD17 VSEOBECNEHO STROJIRENSTVI, of 76, Gottwaldova, Brno, Czechoslovakia, a Corporate body 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 cutting weft in a weaving loom having a mechanism for multi weft weaving.

Non-conventional weaving systems, particularly those with pneumatic or hydraulic weft insertion, in which a weft length is prepared for each weft insertion, are provided with a device for weft cutting mounted at the weft insertion side of the loom.

Devices are known for cutting weft, which are classified according to their design and the time when cutting actually takes place, i.e. before interlacing or after interlacing of the inserted weft in the warp.

A particular requirement is imposed on weft cutting when weaving with two or more different wefts. In this case, in addition to a device for the preparation and insertion of the weft, a device for selecting the weft is required, such devices cooperating closely with the cutting device. Before the actual cutting, it is necessary to position the inserted wefts from the separate nozzles in the determined sector corresponding to the position of the weft and the opening of the knife blades.

One of the devices hitherto known is a cutting device in which the weft is inserted into the shed from a weft supply bobbin, the device being controlled synchronously with the movement of the weft inserting elements and consisting of two mutually oppositely movable guided cutting jaws each of which is provided with a blade. One of the blades is provided on one edge with an entrapping notch. The entrapping notch is averted from the shed and is opened towards the direction of weft insertion, the blades being positioned in a plane parallel to the direction of weft insertion.

The disadvantage of this device lies in the forming of the shaped blade in one of the cutting jaws and in the impossibility of using the whole blade length for cutting.

the positioning of the blade in a plane parallel to the direction of weft insertion does not appear to be advantageous.

We have sought to overcome the disadvantages of prior art devices.

Accordingly the present invention provides a device for cutting weft in a weaving loom, the device comprising a stationary cutting jaw, a movable cutting jaw, guiding shields associated therewith a holder carrying the shields which are fixedly but adjustably mounted relative to each other and are provided with entrapping notches, the shields are arranged to entrap without gripping and introduce and position the weft between the cutting edges of the cutting jaws.

By the device of the present invention, it is possible to use the whole cutting length of the knife blades because of the displaceable shields and cutting jaws. Upon cutting, the overlapping of the blade is kept to a minimum, whereby the life of the cutting edges of cutting jaws and the total life of the cutting jaws is increased.

The invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is an elevation of the cutting device in a direction opposite to that of weft insertion; Figure 2 is a plan view of the device partly in section; and Figure 3 is a part sectional view of Figure 1 with parts omitted for clarification.

A bracket 1 is attached at one end to a loom frame (not shown) and carries at its other end a fastening holder 2 of a cutting device, the holder 2 being attached to the bracket 1 preferably by screws 3. This type of fastening makes the cutting device adjustable in the direction of the weaving plane R. The holder 2 carries a stationary cutting jaw 4 which is attached to it e.g. by screws 5. A movable cutting jaw 6 is pivotably mounted by means of a pin 7 which serves as a pivot therefor. This pin 7 is supported at one end on the stationary cutting jaw 4 and passes through the movable cutting jaw 6 and a sleeve 8.

Further, a spring 9 is positioned on the pin 7, the end of which may carry a nut 10. The pressure force by which the movable cutting jaw 6 is pressed against the stationary cutting jaw 4 is adjusted by altering the position of nut 10 relative to the pin 7. The movement of jaw 6 can be derived from a main shaft (not shown) via a cam mechanism by means of lever 11 and adjustable tie rod 12. The connection between the movable jaw 6 and the lever 11 is by means of screw 13, this enabling the opening angle of the edges of jaws 4 and 6 and thus the cutting point on cutting jaws 4 and 6 to be changed. Because it is possible to alter the opening angle of the edges of the jaws and because it is possible to displace the whole cutting device in the direction of the weaving plane R, the lifetime of the cutting jaws can be significantly prolonged.

On the holder 2 of the cutting device, a device is mounted which makes possible the introduction of the weft between the edges of the cutting jaws 4 and 6 and its positioning and stabilizing at the cutting point. This device is advantageously constructed in such manner, that it comprises a shield 14, screws 15, a shield 16, a block 17 and a nut 18.

The shields 14 and 16 serve on one hand for directing and guiding the weft thread to the cutting point by means of their guiding edges and on the other hand for positioning and stabilizing the weft thread, by means of entrapping notches 19 in the shields 14 and 16, at the cutting point.

The shield 14 is fixed to the block 17 by means of a pin secured by the nut 18. The shield 16 which is adjustably mounted by means of the screws 15 and can be adjusted up and down within the extent of the open slots which the screws 15 pass through.

Both shields can move forwards and back together with the block 17 within the extent of the open slot machined in the block 17 for screw 20.

Thus, the position of the cutting point 21 relative to the binding point is adjusted.

The weft is fed by nozzles 23 and 24. The reed is denoted by reference 22.

The device according to the present invention operates in such manner, that the weft is introduced by the reed 22 between the shields 14 and 16 via the leading edge of the shield to the cutting point 21. Upon removal of the reed 22, the weft is held at the cutting point 21 in the entrapping notch 19 of one of the shields 14 or 16 according to the position of the nozzle 23 and 24. In that position the weft remains uncut during the insertion of the next weft so that the weft is not affected by the cutting of the previous weft. The cutting operation takes place at the moment before the changing of the positions of the nozzles 23 and 24. The cutting is performed by a movement of the movable cutting jaw 6 against the stationary cutting jaw 4, the movable jaw 6 being controlled by the elements 11 and 12 and further members thereof (not shown).

The device according to the present invention can be used in textile machines which weave with several different wefts.

WHAT WE CLAIM IS: 1. A device for cutting weft in a weaving loom the device comprising a stationary cutting jaw, a movable cutting jaw, guiding shields associated therewith, a holder carrying the shields which are fixedly but adjustably mounted relative to each other and are provided with entrapping notches, the shields are arranged to entrap without gripping and introduce and position the weft between the cutting edges of the cutting jaws.

2. A device as claimed in Claim 1, wherein the jaws are adjustably connected to a control lever.

3. A device as claimed in Claim 1 or 2, wherein one of the shields is mounted on the holder and the other of the shields is displaceably mounted so as to be movable in a direction transverse to the weaving plane.

4. A device as claimed in any of Claims 1 to 3, wherein one shield is mounted on the holder by means of a block which is displaceably mounted on the holder in a plane parallel to the weaving plane, the first shield being displaceably arranged on the

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

Claims

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

A bracket 1 is attached at one end to a loom frame (not shown) and carries at its other end a fastening holder 2 of a cutting device, the holder 2 being attached to the bracket 1 preferably by screws 3. This type of fastening makes the cutting device adjustable in the direction of the weaving plane R. The holder 2 carries a stationary cutting jaw 4 which is attached to it e.g. by screws 5. A movable cutting jaw 6 is pivotably mounted by means of a pin 7 which serves as a pivot therefor. This pin 7 is supported at one end on the stationary cutting jaw 4 and passes through the movable cutting jaw 6 and a sleeve 8.

Further, a spring 9 is positioned on the pin 7, the end of which may carry a nut 10. The pressure force by which the movable cutting jaw 6 is pressed against the stationary cutting jaw 4 is adjusted by altering the position of nut 10 relative to the pin 7. The movement of jaw 6 can be derived from a main shaft (not shown) via a cam mechanism by means of lever 11 and adjustable tie rod 12. The connection between the movable jaw 6 and the lever 11 is by means of screw 13, this enabling the opening angle of the edges of jaws 4 and 6 and thus the cutting point on cutting jaws 4 and 6 to be changed. Because it is possible to alter the opening angle of the edges of the jaws and because it is possible to displace the whole cutting device in the direction of the weaving plane R, the lifetime of the cutting jaws can be significantly prolonged.

On the holder 2 of the cutting device, a device is mounted which makes possible the introduction of the weft between the edges of the cutting jaws 4 and 6 and its positioning and stabilizing at the cutting point. This device is advantageously constructed in such manner, that it comprises a shield 14, screws 15, a shield 16, a block 17 and a nut 18.

The shields 14 and 16 serve on one hand for directing and guiding the weft thread to the cutting point by means of their guiding edges and on the other hand for positioning and stabilizing the weft thread, by means of entrapping notches 19 in the shields 14 and 16, at the cutting point.

The shield 14 is fixed to the block 17 by means of a pin secured by the nut 18. The shield 16 which is adjustably mounted by means of the screws 15 and can be adjusted up and down within the extent of the open slots which the screws 15 pass through.

Both shields can move forwards and back together with the block 17 within the extent of the open slot machined in the block 17 for screw 20.

Thus, the position of the cutting point 21 relative to the binding point is adjusted.

The weft is fed by nozzles 23 and 24. The reed is denoted by reference 22.

The device according to the present invention operates in such manner, that the weft is introduced by the reed 22 between the shields 14 and 16 via the leading edge of the shield to the cutting point 21. Upon removal of the reed 22, the weft is held at the cutting point 21 in the entrapping notch

19 of one of the shields 14 or 16 according to the position of the nozzle 23 and 24. In that position the weft remains uncut during the insertion of the next weft so that the weft is not affected by the cutting of the previous weft. The cutting operation takes place at the moment before the changing of the positions of the nozzles 23 and 24. The cutting is performed by a movement of the movable cutting jaw 6 against the stationary cutting jaw 4, the movable jaw 6 being controlled by the elements 11 and 12 and further members thereof (not shown).

The device according to the present invention can be used in textile machines which weave with several different wefts.

WHAT WE CLAIM IS: 1. A device for cutting weft in a weaving loom the device comprising a stationary cutting jaw, a movable cutting jaw, guiding shields associated therewith, a holder carrying the shields which are fixedly but adjustably mounted relative to each other and are provided with entrapping notches, the shields are arranged to entrap without gripping and introduce and position the weft between the cutting edges of the cutting jaws.
2. A device as claimed in Claim 1, wherein the jaws are adjustably connected to a control lever.
3. A device as claimed in Claim 1 or 2, wherein one of the shields is mounted on the holder and the other of the shields is displaceably mounted so as to be movable in a direction transverse to the weaving plane.
4. A device as claimed in any of Claims 1 to 3, wherein one shield is mounted on the holder by means of a block which is displaceably mounted on the holder in a plane parallel to the weaving plane, the first shield being displaceably arranged on the

block so as to be movable in a direction transverse to the weaving plane.
5. A device for the cutting of weft in a weaving loom, substantially as herein described with reference to and as shown in the accompanying drawings.