GB1603966A - Looms - Google Patents

Abstract

In the weaving machine having two weaving tracks (12, 12a) arranged next to one another (twin weaving machine), the heald frames (6, 10) assigned to the two weaving tracks (12, 12a) and furthermore the two reeds (8, 9) and the two fabric draw-off rollers (14, 14a) work in a manner offset to one another in time (phase-shifted mode of operation). The respective masses, to be set in motion, of these units or the masses of their drive parts can thereby be kept lower, with the result that the drive power also becomes correspondingly lower. <IMAGE>

Description

(54) LOOMS (71) We, SULZER BROTHERS LIMITED, a Company organised under the laws of Switzerland, of Winterthur, Switzerland, 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 loom constructed to operate with at least one pair of laterally adjacent sheets of warp threads.

The term "laterally adjacent" as used herein in respect of sheets of warp threads will be understood to refer to sheets spaced from one another in a direction parallel to the plane of the sheets.

According to the present invention, there is provided a loom constructed to operate with at least one pair of laterally adjacent sheets of warp threads having first means for performing a function in the weaving operation on one of the sheets of warp threads, and second means, separate from the first means, for performing the same function in the weaving operation on the other of the sheets of warp threads, the first and second means being arranged to operate out of phase with one another, and being separately driven from the loom.

The means for performing a function in the weaving operation may be any of the following: The weft insertion means may include picking means, catching means and combinations thereof, the means for shed forming may include shafts, the means for beating up the inserted weft threads may include a reed and indexing means may include means for letting off and taking up the warp and cloth respectively. Due to the time-shaft, i.e. the phase-shifted mode of operation of the individual parts of the loom within each work phase, i.e. during complete work cycles of 360" rotation of the main shaft of the loom, it is possible to reduce the masses which are to be placed into motion during weaving.Consequently, it is beneficially possible to have a lower drive pjower capacity, and in the case of weft insertion with air or water jets to have weaker or smaller compressors and possibly with reduced storage capacity. If desired, with out-of-phase operation of the parts, for instance by arranging for two reeds to operate in opposition to one another, it is possible completely or partially to realise mass compensation.

If, for instance, during weft insertion by an air jet, the main shaft of the loom moves, during the insertion operation, through only a relatively small angular displacement, then there is only required a phase shift of, for instance, 10 to 30 between the insertion of the weft into one shed and that into the other shed. Consequently, it is possible to employ a continuous reed, i.e. a reed extending over both sheets of warp threads, for accomplishing a common beating up on both such sheets and, also, to employ continuous shafts which conjointly control the warp threads of both sheds.

The invention may be carried into practice in various ways but one loom embodying the invention will now be described by way of example with reference to the single figure of the accompanying drawing which shows the loom schematically in perspective.

The drawing shows a twin loom comprising two side frames 2, an intermediate floor mounted bearing pedestal 2a for a preferably two-part warp beam 3 from which there are wound-offthe warp threads 4 which are guided over a back rest 5. The warp beam 3 is rotated by means of a conventional and thus merely schematically illustrated warp letoff motion 18. The warp threads 4 forming the two sheets 12 and 12a, which collectively constitute the pair 27, respectively pass through the associated shafts 6 and 10.

In the illustrated position of the loom, the shafts 6 are in their open shed position, so that there is formed a shed 81. At the same time that this is occurring the shafts 10 are in their closed shed position. Thus, all of the shafts 10 of the sheet 12a are located at the same height.

Each of the shafts 6 and 10 is equipped with healds 7 having eyelets 7a through which the warp threads are threaded. Thereafter, the warp threads of the two sheets pass respectively through two reeds 8 and 9.

Like the shafts 6 and 10, the reeds 8 and 9 also operate in a timeshifted mode, in other words, out of phase. Consequently, at the moment shown in the drawing, the reed 8 is located in its rearward position, while the other reed 9 is in its forward beating-up position.

Mounted in front of the reeds 8 and 9 are guide teeth 32b and 32a, respectively, which in conjunction with the related sley shafts 20 and 20a, respectively, are placed into the customary oscillating movement.

When the shafts 6 and the reed 8 are in their appropriate positions, a weft thread 23 is inserted into the shed 81 by means of the weft insertion mechanism 25 to which the weft thread is delivered from a supply bobbin 21. Weft thread insertion is accomplished essentially along an insertion path 31, and the inserted weft thread is sucked up by a suction nozzle 34 of a central combined catching motion 33 located in the centre region 32 between the two sheets 12 and 12a.

Thereafter, the inserted weft thread 31 is beaten up by the reed 8 into the cloth 12.

At this time, the other reed 9 moves into its rearward position where it remains during such time as the reed 8 is accomplishing its beating-up action. By the action of the shafts 10 the sheet 12a is shedded, so that the nozzle 29 of the weft insertion mechanism 26 at the other side of the sheet pair 27 can insert a weft thread 24 into the shed thus formed, this weft thread being delivered from the other supply bobbin 22.

Thus cloth fabrics 30, 30a are formed at the fell 11 of each of the sheets 12 and 12a.

The cloth fabrics 30 and 30a are drawn-off by a two-part take-up roll 13, 13a. The two parts 13, 13a are controlled and are rotated out-of-phase relative to one another by means of a largely conventional and therefore merely schematically indicated cloth take-up motion 41. The cloth fabrics 30 and 30a then pass from the two-part cloth take-up roll 13 and 13a to a two-part guide roll 14 and 14a and then to a two-part cloth beam 15 and 15a, respectively. The rolls 13, 13a and 14, 14a and the beam 15, 15a, instead of being formed as two-part roll structures of double rolls could be constructed, if desired, to be one-part (coninuous).

Due to the time-shifted out-of-phase mode of operation of the means 25, 26, 33 for the insertion of the weft, the shafts 6, 10 for forming the sheds and the reeds 8, 9 for beating-up the inserted weft threads, it is possible to design the loom such that the parts of such means have correspondingly lower masses than they would if they operated in-phase. Consequently, there is also achieved the beneficial result that the drive power requirements of the main motor (not shown) of the loom are lower and equally there can be used a weaker or smaller compressor for producing the air jets for insertion of the weft threads. Also it may be possible to employ a reservoir for storing compressed air for insertion of the weft thread which is of low volume or even to have no reservoir at all.

As a general rule, also the devices 13, 13a and 15, 15a for cloth take-up operate in a phase-shifted manner and can be provided with slip couplings, especially in the case of the cloth beam 15, 1 spa. The time-shifted mode of operation of the components can be realised, for instance, by means of angularly offset driven cams and associated cam follower roll levers.

In a modified construction employing air jet insertion of the weft, only the devices 25, 26 and 33 for the insertion of the weft threads operate in an out-of-phase relationship to one another, the phase shift being approximately 10 of main shaft rotation.

The picks into the two sheets 12 and 12a are therefore separated by only an extremely brief time interval. This is possible because the duration of each individual air jet insertion is brief, extending over only a very small angular rotation of the main shaft.

Because of this small separation, shed forma tioncan beaccomplished by means of common shafts extending over both sheets 12 and 12a and, equally, beat-up of the two sheets can be performed in-phase by means of jointly acting reeds 8, 9 mounted on a continuous sley shaft 20. With this modification there is only attained the advantage of lower drive power of the air compressor and, possibly, a compressed air reservoir of lower capacity.

In another modified construction (not shown), the two weft thread insertions into the sheds of the sheets 12 and 12a are accomplished in a time-shifted manner by means of a central weft insertion mechanism arranged in the central region 32 directing the wefts towards the outer sides of the sheds, i.e. towards the outer selvages. In yet another arrangement (not shown), weft is inserted into one of the sheds from the outside edge towards the central region 32 and into the other shed from the central region towards the associated outside edge so that the direction of travel of the weft through the sheds of the two sheets 12, 12a is in the same direction although the insertions into the two sheds are out of phase with one another as with the other arrangements described above.

Instead of using a combined catching motion 33 as shown in Figure 1, there can be used two separate catching motions arranged next to one another in the central region 32. Each of these two catching motions can be mounted to be movable along the path of weft insertion 31, means being provided to secure the catching motions in their selected positions.

Further, a number of pairs 27 of sheets 12, 12a can be arranged juxtapositioned, wherein each such pair contains two sheets 12 and 12a with corresponding devices for weft insertion, shed forming, beating up and so forth. Instead of inserting the weft threads by means of air jets, it is possible to use water jets or other weft insertion means, such as gripper projectiles and rapiers.

Although the invention has been described in connection with a loom having one pair of sheets of warp threads and, as mentioned above, it can be applied to a loom having a number of such pairs, the invention can also be applied to a loom constructed to operate with an odd number of sheets greater than one.

Attention is drawn to our copending British Patent Applications No. 19289/78 (Serial No. 1603964) and 19290/78 (Serial No. 1603965).

WHAT WE CLAIM IS: 1. A loom constructed to operate with at least one pair of laterally adiacent sheets of warp threads having first means for performing a function in the weaving operation on one of the sheets of warp threads, and second means, separate from the first means, for performing the same function in the weaving operation on the other of the sheets of warp threads, the first and second means being arranged to operate out of phase with one another, and being separately driven from the loom.

2. A loom as claimed in Claim 1, in which each said means is a weft insertion means.

3. A loom as claimed in Claim 1, in which each said means is a shed forming means.

4. A loom as claimed in Claim 1, in which each said means is beating-up means.

5. A loom as claimed in Claim 1, in which each said means is a warp let-off means.

6. A loom as claimed in Claim 1, in which each said means is a cloth take-up means.

7. A loom constructed and arranged to operate substantially as described herein with reference to the accompanying drawing.

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

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. can be mounted to be movable along the path of weft insertion 31, means being provided to secure the catching motions in their selected positions. Further, a number of pairs 27 of sheets 12, 12a can be arranged juxtapositioned, wherein each such pair contains two sheets 12 and 12a with corresponding devices for weft insertion, shed forming, beating up and so forth. Instead of inserting the weft threads by means of air jets, it is possible to use water jets or other weft insertion means, such as gripper projectiles and rapiers. Although the invention has been described in connection with a loom having one pair of sheets of warp threads and, as mentioned above, it can be applied to a loom having a number of such pairs, the invention can also be applied to a loom constructed to operate with an odd number of sheets greater than one. Attention is drawn to our copending British Patent Applications No. 19289/78 (Serial No. 1603964) and 19290/78 (Serial No. 1603965). WHAT WE CLAIM IS:

1. A loom constructed to operate with at least one pair of laterally adiacent sheets of warp threads having first means for performing a function in the weaving operation on one of the sheets of warp threads, and second means, separate from the first means, for performing the same function in the weaving operation on the other of the sheets of warp threads, the first and second means being arranged to operate out of phase with one another, and being separately driven from the loom.

2. A loom as claimed in Claim 1, in which each said means is a weft insertion means.

3. A loom as claimed in Claim 1, in which each said means is a shed forming means.

4. A loom as claimed in Claim 1, in which each said means is beating-up means.

5. A loom as claimed in Claim 1, in which each said means is a warp let-off means.

6. A loom as claimed in Claim 1, in which each said means is a cloth take-up means.

7. A loom constructed and arranged to operate substantially as described herein with reference to the accompanying drawing.