EP3445903B1

EP3445903B1 - Weaving reed for a rapier weaving machine

Info

Publication number: EP3445903B1
Application number: EP17725355.6A
Authority: EP
Inventors: Koen Bruynoghe; Peter Garnett
Original assignee: Vandewiele NV
Current assignee: Vandewiele NV
Priority date: 2016-04-22
Filing date: 2017-04-21
Publication date: 2021-03-03
Anticipated expiration: 2037-04-21
Also published as: CN109072506B; BE1024132B1; CN109072506A; EP3445903A1; WO2017182991A1; BE1024132A1

Description

The present invention relates to a weaving reed for a rapier weaving machine, comprising several reed dents, each of which comprises a recess and/or a projection, wherein the recesses of these reed dents form a guide passage and/or the projections of these reed dents form a guide rib, wherein the guide passage and/or the guide rib are provided for guiding a rapier of the rapier weaving machine with a clearance.
In addition, the present invention relates to an assembly of such a weaving reed and a rapier for a rapier weaving machine.
Furthermore, the present invention relates to a rapier weaving machine which comprises such an assembly.
Finally, the present invention relates to an assembly of a rapier weaving machine and warp threads which are incorporated in a fabric by means of the rapier weaving machine.
The present invention is particularly suitable for Axminster rapier weaving machines.
Rapier weaving machines comprise one or several rapiers for introducing weft threads in a shed between warp threads in order to form a fabric. A weft thread introduced by means of one or several rapiers is beaten against the fabric, which has already been produced, by means of a weaving reed. This is repeated in successive weft introduction cycles in order to form the fabric.
A critical point during the introduction of a weft thread by means of a rapier is the moment when transfer means have to transfer this weft thread from this rapier. These transfer means may consist, for example, of a second rapier if the weaving machine works according to the principle of divided rapiers. The transfer point, where the second rapier receives the weft thread from the first rapier, is then situated centrally in the weaving machine, at the centre of the weaving reed. If only one rapier carries the weft thread along through the shed, then this transfer point, where transfer means receive the weft thread from the rapier, is situated at an end of the weaving reed. With both types of weaving machines, the rapier carrying along the weft thread into the shed has to be accurately positioned in this transfer point in order to ensure correct transfer of the weft thread. Any second rapier which receives the weft thread also has to be accurately positioned in this transfer point for this purpose. Traditionally, rapiers were only guided by the warp threads in the shed in this case. However, as weaving speeds increased, the positioning of such rapiers in the transfer point became less and less accurate.
In order to ensure that a rapier is accurately positioned in the transfer point, even at increasing weaving speeds, it is known, for example from GB 2 314 095 A and US 5,664,609 , to configure the weaving reed in such a manner that it guides the rapier during its movement between the warp threads. To this end, the weaving reed comprises the features from the preamble of the first claim.
However, with these known solutions a limit has also been reached with regard to further increasing the weaving speeds.
GB 2 265 160 A and EP 0 199 882 A1 describe and illustrate related weaving reeds, in which spools are guided, rather than rapiers. In EP 0 199 882 A1 , a guide device is provided in addition to the weaving reed to provide further guidance for the spool towards a brake passage of a brake device, so that, when the brake channel wears out, the spool can still easily be braked.
It is the object of the present invention to provide a solution to positioning the rapier in the transfer point, thus enabling an increase in weaving speeds.
This object of the invention is achieved by providing a weaving reed for a rapier weaving machine, comprising several reed dents, each of which comprises a recess and/or a projection, wherein the recesses of these reed dents form a guide passage and/or the projections of these reed dents form a guide rib, wherein the guide passage and/or the guide rib are provided for guiding a rapier of the rapier weaving machine with a clearance, wherein at least a part of said reed dents are arranged in a centring zone which is situated between an end of the weaving reed and a transfer point of the weaving reed, which is situated at a different point of the weaving reed than where said end of the weaving reed is situated, and wherein the clearance in this centring zone decreases towards the transfer point of the weaving reed.
With rapier weaving machines having a single rapier, said transfer point will be situated at the other end of the weaving reed. With rapier weaving machines operating according to the principle of divided rapiers, this transfer point will be situated central to the weaving reed. More specifically, said transfer point may be arranged in the centre of the weaving reed.
With the solutions known from GB 2 314 095 A and US 5,664,609 , the weaving reed has to be completely stationary in order to be able to introduce the rapiers into the shed. The reason for this is that the rapiers, accurately guided with respect to the weaving reed, were moved along the entire length of the weaving reed. In this case, the weaving reed had each time to be moved from a starting position towards the fabric so as to be able to beat-up a weft thread and then had to be fully returned to this starting position and be stationary in this starting position in order to be able to bring the rapiers into the shed via this weaving reed. Only after the rapiers had been completely removed from the shed, it was possible to move the weaving reed back towards the fabric in order to beat-up the next weft thread. Thus, the weaving reed had to be stationary in said starting position for a relatively long period of time. This stationary period was a significant impediment to further increasing the weaving speeds.
With a weaving reed according to the present invention, the weaving reed no longer has to be completely stationary during the entire movement of the rapier, thanks to the varying clearance. After a weft thread has been beaten-up, the rapier can already be brought into the shed, while the weaving reed is still moving towards said starting position. The only requirement is that the weaving reed has completely returned to the starting position at the end of the movement of the rapier for the insertion of the weft thread, when this rapier in the weaving reed arrives at the location where the clearance of the reed dents is minimal. Due to the fact that the rapier can already be introduced into the shed while the weaving reed is still moving, higher speeds are possible.
In addition, with a weaving reed according to the present invention, the risk of warp threads jumping in the warp direction is limited, so that stripes no longer form in a fabric woven using this device, such as a carpet.
Preferably, all said reed dents which comprise a recess and/or a projection are successive reed dents of the weaving reed. However, it is also possible to alternate these reed dents having a recess and/or a projection with one or several reed dents without such a recess and/or projection, such as for example conventional reed dents. Successive reed dents with recesses may, for example, also alternate with one or several reed dents with projections, etc. The succession of such different reed dents may be implemented in a systematic or in an arbitrary way. The only thing which matters is that these reed dents together still form a guide passage and/or a guide rib for guiding the rapier with a clearance. Where reference is made below to successive reed dents with recesses and/or projections, optionally one or several reed dents which deviate from the former may be provided between these reed dents.
According to the invention, in order to reduce the clearance in the centring zone, in reed dents with said recesses, a corresponding dimension of these recesses is simply gradually further reduced viewed in a direction at right angles to the direction of movement of the rapier at successive reed dents (between which one or several reed dents without recesses may optionally be arranged) towards the transfer point. A corresponding part of the rapier which then engages in the recesses to guide the rapier in a guide passage formed by the recesses of successive reed dents will then initially be able to move over a relatively large distance, viewed in said direction, with respect to the reed dents and will be able to move less and less with respect to the reed dents as it gets closer to the transfer point, until it is finally blocked in this movement.
According to the invention, with reed dents having said projections, a corresponding dimension of these projections is simply increased in a direction at right angles to the direction of movement of the rapier at successive reed dents in this centring zone towards the transfer point. A corresponding part of the rapier with which this projection engages in order to guide the rapier by means of a guide rib formed by the projections of successive reed dents will then initially still be able to move over a relatively large distance, viewed in said direction, with respect to the reed dents and will be able to move less and less with respect to the reed dents as it gets closer to the transfer point, until it is finally blocked in this movement.
In a preferred embodiment of a weaving reed according to the present invention, some of said reed dents are arranged in a transfer zone at the location of the transfer point of the weaving reed, wherein said dimension of the recess and/or the projection for guiding the rapier in this transfer zone remains virtually constant. By means of such a transfer zone in which said clearance remains virtually constant, a particularly accurate positioning of a rapier, which is guided by such a weaving reed, in the transfer point can be ensured, as it is possible to ensure that the rapier, during its movement towards the transfer point, is no longer able to move in a direction along said dimension at right angles to said movement for the last part before the transfer point with respect to the weaving reed as a result of this clearance.
Such a transfer zone is preferably provided adjacent to the centring zone of a weaving reed according to the present invention.
Without such a transfer zone, it is also possible for the centring zone to continue straight to the transfer point.
When the transfer point is arranged between both ends of the weaving reed, preferably some of said reed dents are arranged in a second centring zone between the other end of the weaving reed than the first-mentioned end and the transfer point of the weaving reed, wherein, in this second centring zone, said dimension of the recess decreases towards the transfer point of the weaving reed and/or said dimension of the projection increases towards the transfer point of the weaving reed. The transfer point is typically arranged between both ends of the weaving reed, where a second rapier receives the weft thread supplied by the first rapier and takes it to the other end of the weaving reed. By means of this second centring zone, it is thus possible to ensure that this second rapier is positioned accurately in the transfer point.
If such a weaving reed with a second centring zone also comprises a said transfer zone, then this second centring zone preferably adjoins this transfer zone.
If such a weaving reed with a second centring zone does not comprise such a transfer zone, this second centring zone preferably adjoins the first-mentioned centring zone.
Reed dents with said recesses and/or projections will typically be more expensive than conventional reed dents. Also, such recesses and/or projections often cause weakened sections in the reed dents, making them more susceptible to wear. It is therefore preferred, with a weaving reed according to the present invention, to provide reed dents which are free of said recesses and/or projections in a zone next to the first-mentioned reed dents.
Alternatively, but less preferred, it is also possible to design all reed dents of the weaving reed like said reed dents with a recess and/or projection.
The object of the present invention is furthermore achieved by providing an assembly of an above-described weaving reed according to the present invention and a rapier for a rapier weaving machine.
If the reed dents of the weaving reed of such an assembly comprise said recesses in the first-mentioned centring zone, then preferably at least a part of the rapier is moveable through the recesses, wherein a lateral movement of the rapier is limited by side walls of the recesses.
More specifically, an assembly according to the present invention may comprise a second rapier for a rapier weaving machine.
The weaving reed of such an assembly is then preferably an abovementioned weaving reed with a second centring zone. If the reed dents of this weaving reed then comprise said recesses in the second centring zone, preferably at least a part of the second rapier is moveable through the recesses in the second centring zone, wherein a lateral movement of the second rapier is limited by side walls of these recesses.
If such an assembly according to the present invention with a weaving reed with reed dents with recesses in one or several centring zones also comprises a said transfer zone, then the reed dents of the weaving reed in the transfer zone preferably also comprise said recesses and then these recesses in the transfer zone preferably have a diameter corresponding to the diameter of the part of the first-mentioned rapier which is moveable through the recesses. If the assembly comprises two rapiers, then this diameter preferably also corresponds to the diameter of the part of the second rapier which is moveable through the recesses.
Preferably, the guide passage of the weaving reed of such an assembly is provided with an opening which leaves a movement of each rapier at right angles to the moving direction of this rapier through the said recesses and away from the weaving reed unimpeded.
With an assembly according to the present invention in which the reed dents of the weaving reed which comprise a recess and/or a projection comprise said projections, each rapier is preferably provided with a recess, in which said projections are at least partly extendable in order to guide this rapier.
If such an assembly according to the present invention with a weaving reed with reed dents with projections in one or several centring zones also comprises a said transfer zone, then the reed dents of the weaving reed in the transfer zone preferably also comprise said projections and then the projections in the transfer zone preferably have a diameter corresponding to the diameter of the recess in the first-mentioned rapier. If the assembly comprises two rapiers, then this diameter preferably also corresponds to the diameter of the recess in the second rapier.
The object of the present invention is furthermore also achieved by providing a rapier weaving machine which comprises an above-described assembly according to the present invention.
In addition, the object of the present invention is also achieved by providing an assembly of such a rapier weaving machine according to the present invention and warp threads which are incorporated in a fabric by means of the rapier weaving machine, wherein a said warp thread is a limiting element for limiting the movement of the rapier away from the weaving reed.
Alternatively, it is possible, for example using a hook-shaped element, to prevent the movement of the rapier at right angles to its moving direction and away from the weaving reed. However, preventing this movement by means of a hook-shaped element is less desirable, as the risk of the warp threads becoming stuck is greater with such a solution.
Adapting the weaving reed itself in order to provide further guidance, is also less desirable, since this weakens the weaving reed itself and makes it more susceptible to wear.
The present invention will now be described in more detail by means of the following detailed description of some embodiments of a weaving reed according to the present invention. The sole aim of this description is to provide illustrative examples and to indicate further advantages and particulars of the invention, and may therefore not be interpreted as a limitation of the area of application of the invention or of the patent rights defined in the claims.
In this detailed description, reference numerals are used to refer to the attached drawings, in which

Fig. 1 shows a first embodiment of an assembly of a weaving reed with a rapier according to the present invention, in cross section;
Fig. 2 shows a second embodiment of an assembly of a weaving reed with a rapier according to the present invention, in cross section;
Fig. 3 shows the weaving reed of the assembly from Fig. 1 in perspective view;
Fig. 4 shows the weaving reed of the assembly from Fig. 1 in top view;
Fig. 5 shows a centring zone of the weaving reed of the assembly from Fig. 1 in perspective view;
Fig. 6 shows the centring zone from Fig. 5 in top view.

The weaving reed (1) illustrated in Figs. 1 and 3-6 is configured for a rapier weaving machine which operates according to the principle of divided rapiers (6). In this case, a giver rapier (6) inserts a weft thread from a yarn store from one side of the rapier weaving machine in a shed (18) between spaced-apart warp threads (17) for a fabric. A taker rapier receives this weft thread from the giver rapier (6) midway along the weaving reed (1) and takes it to the other side of the rapier weaving machine. After a weft thread has been inserted in the shed (18) in this way, this inserted weft thread is beaten-up against the fabric which has already been woven at the front of the weaving machine by means of the weaving reed (1). In Fig. 1, the weaving reed (1) is moved to the left for this purpose. If desired, the warp threads (17) may change position (above/below the shed) in order to form again a shed (18) for inserting a subsequent weft thread.
In Fig. 1, one rapier (6) of these rapiers (6) is shown in cross section.
The illustrated weaving reed (1) is divided into different zones (7, 8, 9, 14), as is illustrated in Fig. 4.
In the centre of the weaving reed (1), where both rapiers (6) in the rapier weaving machine meet each other in a transfer point (12) for the transfer of a weft thread from the giver rapier (6) to the taker rapier, a transfer zone (8) is provided, in which the reed dents (2) all have the same diameter. These reed dents (2) each comprise a recess (3), with the recesses (3) of the various reed dents (2) forming a guide passage (5) for guiding both rapiers (6) towards the transfer point (12). This guiding operation is executed with great precision. The rapiers (6) are moveable through these recesses (3), wherein a lateral movement of the rapiers (6) is prevented as much as possible by the side walls of these recesses (3). To this end, the dimensions of the recesses (3) are chosen laterally, at right angles to the moving direction of the rapiers (6) (along a direction towards the already formed fabric, or moving away from the latter), corresponding to the dimensions of the rapiers (6). Here, the clearance between the rapiers (6) and the side walls of the recesses (3) is minimal.
A centring zone (7, 9) is arranged on either side of the transfer zone (8), adjacent to this transfer zone (8). In these centring zones (7, 9), the reed dents (2) again comprise recesses (3), with the recesses (3) of the various reed dents (2) forming a guide passage (5) in each centring zone (7, 9) for guiding a respective rapier (6). These recesses (3) do not entirely prevent a lateral movement of the rapiers (6) in these centring zones (7, 9). The clearance with which these rapiers (6) are guided in the respective centring zones (7, 9) decreases towards the transfer point (12), so that the rapiers (6) are gradually centred more and more in the recesses (3) and can thus be guided in the transfer zone (8) with minimal clearance. In Figs. 5 and 6, the reduction of this clearance can be seen more clearly. In order to achieve this decrease, the depth (di, d2) of the recesses (3) gradually decreases towards the transfer zone (8). In the illustrated embodiment, this decrease is linear. However, it is equally well possible to work out variants in which the decrease is not linear. Preferably, however, this decrease does proceed in a smooth manner. Due to the fact that this clearance decreases, a respective rapier (6) may already be introduced in this centring zone (7, 9) of the weaving reed (1) while the weaving reed (1) is still returning from the already formed fabric to its starting position after the beat-up of a previous weft thread.
At its ends (10, 11), the weaving reed (1) is provided with conventionally arranged reed dents (13), without said recesses (3), in each end zone (14). Due to the fact that these reed dents (13) do not comprise recesses (3), a respective rapier (6) can already be introduced in this end zone (7, 9) of the weaving reed (1) while the weaving reed (1) is still returning from the already formed fabric to its starting position after the beat-up of a previous weft thread.
The illustrated recesses (3) in the reed dents (2) are virtually U-shaped, with an opening at the top, which does not hinder the movement of the rapiers (6) in a direction away from the weaving reed (1). This movement is hindered by the warp threads (17), as can be seen in Fig. 1.
Alternatively or additionally to the recesses (3), the reed dents (2) in the centring zones (7, 9) and the transfer zone (8) may also be provided with projections (4), as illustrated in Fig. 2, with these projections (4) together then forming a guide rib for guiding the rapiers (6). In that case, the rapiers (6) are provided with a corresponding recess (15), in which these projections (4) can engage in order to guide the rapiers (6). The width of these projections (4) then increases in the centring zones (7, 9) towards the transfer point (12) and remains unchanged in the transfer zone (8). In the end zones (14), the reed dents are preferably free from such projections (4).
In alternative, but less preferred embodiments, said end zones (14) may also be omitted. Likewise, said transfer zone (8) may be omitted in alternative, but less preferred embodiments.
For weaving machines having one rapier (6), the weaving reed (1) may be constructed in analogous fashion, as the illustrated part of the weaving reed (1) between an end (10) and the transfer point (12), which in that case forms the other end of the weaving reed (1).

Claims

Weaving reed (1) for a rapier weaving machine, comprising several reed dents (2), each of which comprises a recess (3) and/or a projection (4), wherein the recesses (3) of these reed dents (2) form a guide passage (5) and/or the projections (4) of these reed dents (2) form a guide rib, wherein the guide passage (5) and/or the guide rib are provided for guiding a rapier (6) of the rapier weaving machine, and wherein at least some of said reed dents (2) are arranged in a centring zone (7) which is situated between an end (10) of the weaving reed (1) and a transfer point (12) of the weaving reed (1), which is situated at a different point of the weaving reed (1) than where said end (10) of the weaving reed (1) is situated, characterized in that in this centring zone (7), a dimension of the recess (3) for guiding the rapier (6) viewed in a direction at right angles to the direction of movement of the rapier (6) decreases with successive reed dents (2) towards the transfer point (12) of the weaving reed (1) and/or a dimension of the projection (4) for guiding the rapier (6) viewed in a direction at right angles to the direction of movement of the rapier (6) increases with successive reed dents (2) towards the transfer point (12).
Weaving reed (1) according to Claim 1, characterized in that some of said reed dents (2) are arranged in a transfer zone (8) at the location of the transfer point (12) of the weaving reed (1), wherein said dimension of the recess (3) and/or the projection (4) in this transfer zone (8) remains virtually constant.
Weaving reed (1) according to any of the preceding claims, characterized in that the transfer point (12) is arranged between both ends (10, 11) of the weaving reed (1), and in that a part of said reed dents (2) are arranged in a second centring zone (9) between the other end (11) of the weaving reed (1) than the first-mentioned end (10) and the transfer point (12) of the weaving reed (1), wherein, in this second centring zone (9), said dimension of the recess (3) decreases towards the transfer point (12) of the weaving reed (1) and/or said dimension of the projection (4) increases towards the transfer point (12) of the weaving reed (1).
Weaving reed (1) according to any of the preceding claims, characterized in that the weaving reed (1) comprises reed dents (13) which are arranged in a zone (14) next to the first-mentioned reed dents (2) and which are free of said recesses (3) and/or projections (4).
Assembly (16) of a weaving reed (1) and a rapier (6) for a rapier weaving machine, characterized in that the weaving reed (1) is a weaving reed (1) according to any of the preceding claims.
Assembly (16) according to Claim 5, characterized in that the reed dents (2) of the weaving reed (1) in the first-mentioned centring zone (7) comprise said recesses (3), and in that at least a part of the rapier (6) is moveable through the recesses (3), wherein a lateral movement of the rapier (6) is limited by side walls of the recesses (3).
Assembly (16) according to Claim 5 or 6, characterized in that the assembly (16) comprises a second rapier for a rapier weaving machine.
Assembly (16) according to Claims 6 and 7, characterized in that the weaving reed (1) is a weaving reed (1) according to Claim 3, in that the reed dents (2) of the weaving reed (1) in the second centring zone (9) comprise said recesses (3), and in that at least a part of the second rapier is moveable through the recesses (3) in the second centring zone (9), wherein a lateral movement of the second rapier is limited by side walls of these recesses (3).
Assembly (16) according to any of Claims 6 to 8, characterized in that the weaving reed (1) is a weaving reed (1) according to Claim 2, in that the reed dents (2) of the weaving reed (1) in the transfer zone (8) comprise said recesses (3), and in that the recesses (3) in the transfer zone (8) have a diameter corresponding to the diameter of the part of the first-mentioned rapier (6) which is moveable through the recesses (3).
Assembly (16) according to any of Claims 6 to 9, characterized in that the guide passage (5) is provided with an opening which leaves a movement of each rapier (6) at right angles to the moving direction of this rapier (6) through said recesses (3) and away from the weaving reed (1) unimpeded.
Assembly (16) according to any of Claims 5 to 10, characterized in that the reed dents (2) of the weaving reed (1) which comprise a recess (3) and/or a projection (4) comprise said projections (4), and in that each rapier is provided with a recess (15), in which said projections (4) are at least partly extendable in order to guide this rapier (6).
Assembly (16) according to Claim 11, characterized in that the weaving reed (1) is a weaving reed (1) according to Claim 2, in that the reed dents (2) of the weaving reed (1) in the transfer zone (8) comprise said projections (4), and in that the projections (4) in the transfer zone (8) have a diameter corresponding to the diameter of the recess (15) in the first-mentioned rapier (6).
Rapier weaving machine, characterized in that this rapier weaving machine comprises an assembly (16) according to any of Claims 5 to 12.
Assembly of a rapier weaving machine and warp threads (17) which are incorporated into a fabric by means of the rapier weaving machine, characterized in that the rapier weaving machine is a rapier weaving machine according to Claim 13, and in that a said warp thread (17) is a limiting element for limiting the movement of the rapier (6) away from the weaving reed (1).
Method for weaving using a rapier weaving machine having one or several rapiers (6) and a weaving reed (1), wherein a shed (18) is formed, the one or several rapiers (6) are brought into the shed (18) via the weaving reed (1) in order to insert a weft thread in the shed (18) and the weaving reed (1) is moved from a starting position towards an already woven fabric in order to beat-up this weft thread, characterized in that the rapier weaving machine is a weaving machine according to Claim 13, and in that, after the beat-up of the weft thread the one or several rapiers (6) are brought into the newly formed shed (18), while the weaving reed (1) is still being moved towards the starting position.