EP0310847A1

EP0310847A1 - Reed for looms

Info

Publication number: EP0310847A1
Application number: EP88115300A
Authority: EP
Inventors: Giovanni Prina
Original assignee: FILLATTICE SpA
Current assignee: FILLATTICE SpA
Priority date: 1987-10-09
Filing date: 1988-09-19
Publication date: 1989-04-12
Also published as: IT8722188A0; IT1222854B

Abstract

A reed for ribbon looms comprising a plurality of blades (21) arranged parallel to the direction of reciprocation of the reed (20) in which the blades (21) comprise a lower portion (22) having a front edge (23) defining a beating plane, and an upper curved portion (21) on one side of said plane. The reed (20) is attached to a support arm (28) controlled to reciprocate on an axis on the side of the reed (20) opposite that on which the warp threads heddles (11) are located.

Description

The present invention refers to improvements in weft beating devices for textile looms, particularly ribbon looms, in which a beating reed member comprising a plurality of parallely arranged blades is carried by a reciprocable arm whose movement is synchronized with the warp thread heddles and the picker needle.
In the weaving fabric ribbons or bands, the warp threads pass through a number of heddles in vertically reciprocable harness frames controlled by a dobby or similar device to form the shed, across which one or more weft threads are inserted by means of a suitable reciprocable needle. Each time one or more weft threads are inserted into the shed, a beating reed is advanced after the needle has been retracted, to beat up the weft thread or group of weft threads which have been inserted to bring the same near to the line of formation of the cloth.
Traditional reeds are substantially flat shaped and are carried by a reciprocating arm whose rotational axis is disposed on the side of the reed turned towards the warp thread heddles. This flat reed, resulting from the linear shape of its blades, and its positioning on the support arm, require a considerable space between the cloth formation line and the heddle harnesses, for the movement of the picker needle. Thus the reed must move through a fairly wide area and at its upper point its maximum oscillation may be about 80 - 90 mm; this requires the heddle harness to be suitable distanced, with a negative effect on the working of the loom, as well as increasing its overall dimensions. In fact, the farther the heddles are from the cloth formation line, the greater the vertical movement of the heddles must be, to open, or rather to reverse the shed after each picking or insertion of weft threads; thus the dobby takes up more space, the machine wears more and the maximum working speed of the loom is reduced.
An object of present invention is to supply a device of the type mentioned above comprising a reed of particular shape, and a particular disposition of the reed itself and of its control arm, which not only reduces the length of movement required by the reed, and therefore takes up less space, but also allows the heddles to be placed closer to the warp threads, and therefore increases the loom working speed.
The reed according to the present invention is characterized by the fact that each blade of the reed has a lower straight portion whose front edges defines the reed beating plane, and an arch shaped or curved upper portion, which is located of a side of the reed opposite to said beating plane. According to another feature of the invention, the reed is fixed to one side of a support arm which oscillates on a rotational axis on the front side of the reed, opposite that of the heddles; in this way a space sufficient for the passage of the picker needle can be created by a small angular movement of the support arm and an extremely limited maximum reed movement, of the order of 5 - 10 mm, thanks to a composite reed movement comprising a vertical descent or lowering movement of the beating plane below the cloth formation line to position the concave part of the reed in correspondence with the path of the needle.
These and other features of the beating reed device according to the present invention will be evident from the description which follows, referring to the attached drawings in which:

Fig. 1 is a side view showing the reed and the support arm, in a ribbon loom;
Fig. 2 is a top view of figure 1;
Fig. 3 is an enlarged detail of fig. 1;
Fig. 4 is an enlarged front view of the reed;
Fig. 5 is an enlarged side view of the reed;

The essential parts of a loom, used to weave ribbons, are exemplified in figures 1 and 2, in which a plurality of warp threads 10 passes through their corresponding heddles held on harnesses 11 caused to move alternately and reciprocate vertically to form the shed, controlled by a dobby or other suitable mechanism represented diagrammatically by cams 12 acting on levers 13 connected by means of tie rods 14 to heddle harnesses 11. In a way which is already known warp threads 10 are alternately woven with weft threads inserted into the shed by means of a needle 15 on a needle arm 16; needle 15 moves alternately or reciprocate between a fully outer position 15′ and a fully inserted position 15˝ as shown in figure 2. Therefore each weft thread inserted must be beaten in to line 17 of formation of the cloth ribbon 18; this operation is usually carried out by a reed provided on the upper end of an oscillating arm whose movement is synchronized with that of other parts of the loon.
According to the present invention reed 20 consists of plurality of blades 21, parallely arranged side by side and spaced apart so as to allow warp threads 10 to pass between them; each blade 21 has a particular shape comprising a lower rectilinear portion 22 whose front edge 23, together with those of the other blades, defines the beating plane of the reed, and an arch-shaped upper portion which in the specific case in figure 5 comprises an intermediate section 24 inclined backwards with respect to the reed beating plane, and an upper portion 25 which is slightly inclined forward and terminates at a distance behind the reed beating plane defined by the front edges 23 of the individual blades. The blades of the reed are held in uniformly spaced disposition by transverse frame elements 26 and 27. In the case illustrated, each blade 21 is defined by three linear portions of differing inclinations, however, in general terms, each blade must present an initial linear section, portion 22 in the specific case, which defines the weft beating plane, and an upper arch-shaped or bent section, positioned behind and at a distance from the front beating plane, so as to give the upper portion of the reed a concave shape, allowing the picker needle to pass by means of small angular movements of the reed which, at the same time, cause the same reed to move downwardly.
In this sense, according to a further characteristic of the invention, reed 20 is laterally supported by an oscillating arm 28 in such a way as to be moved angularly through about 10-12° and, at the same time, to descend vertically, bringing the concave part of the reed in line with cloth 18 in such a way as to allow needle 15 to pass. Reed 20 is thus located at the fore end of arm 28 to allow the beating plane to form an angle, e.g. of 80-90° with the longitudinal or main axis of the arm itself; support arm 28 is fixed to a reciprocating shaft 29 positioned under the plane on which the cloth 28 moves and to the side opposite that on which the warp thread heddles are located, with respect to both reed beating plane and line 27 of cloth formation 18. In other words, the lateral arrangement of reed 20 on the support arm and the inclined disposition of said arm must be such as to allow reed 20 to protrude upwards so that a small angular downwards displacement of arm 28 lowers the reed, causing it to pass from the position indicated by the continuous line in figure 3, in which the beating plane defined by the front edges 23 of the blades is in correspondence with line 17 of cloth formation, to an intermediate position 20′, in which the reed is fully lowered and almost completely retracted so as to allow insertion of needle 15, and subsequently to allow a further small angular displacement bringing the reed into position 20˝, with a time-delay sufficient for needle 15 to complete its cycle of insertion into the warp, returning to its starting or initial position.
From the above and from the attached drawings, it is therefore evident that the new shape and arrangement of the reed and its support arm allow a wide translational movement, sufficient to allow the passage of picker needle 15 into the warp, from a small angular downward displacement of the support arm, describing a substantially vertical circular path. This shape and arrangement of the reed not only allow the heddle harnesses 11 to be positioned closer to the cloth formation line 17, thanks to the reduce size of the reed movement, and thus to proportionally reduce the distance over which the heddles themselves are raised and lowered, with consequent working advantages, but also allow the machine to be operated at higher speeds, thus increasing the productivity.

Claims

1. A device to beat weft threads in a loom, comprising a reciprocating reed (20) supported by an arm (28) attached to reciprocating shaft (29), in which the reed (20) comprises a plurality of blades (21) arranged parallel to the direction of reciprocation, characterized by the fact that each blade (21) of the reed comprises a lower linear portion (22) having a front edge (23) defining a reed beating plane, and an upper bent or curved portion (24, 25) backwards positioned at a distance from said beating plane (23).

2. A device as in claim 1, characterized by the fact that the curved portion (24, 25) of the blades (21) defines a concave portion in the upper part of the reed.

3. A device as in claim 1, characterized by the fact that the upper bent or curved portion (24, 25) of each blade (21) of the reed includes an intermediate section (24) inclined backwards and an upper section (25) inclined forwards, terminating at a distance from the front beating plane.

4. A device as in claim 1, in which the reed (20) is positioned between the weaved cloth (18) and the warp thread heddles (11), characterized by the fact that the front edges (23) of the blades (21) defining the reed beating plane form an angle with the longitudinal axis of the support arm (28) and by the fact that the support arm (28) is attached to a reciprocating shaft (29) positioned at the side of the reed opposite to the heddles and at a distance from the cloth formation line (17).

5. A weaving machine comprising wrap threads (10) and heddles means (11) to held said wrap threads (10) in diverging planes, first control means (12, 13) to reciprocate said heddles means (11), a weft insertion needle (15) reciprocating into said diverging wrap threads and a reed (20) comprising a plurality of blades (21) arranged parallel to the direction of reciprocation, said reed (20) being supported by a reciprocating arm (28), characterized in that said reed (20) is upwardly supported and angularly arranged on a side of said reciprocating arm (28), said arm (28) being oriented in said direction of reciprocation, and said reed (20) comprising a lower reed portion (22) defining a front beating plane (23), and an upper concave portion (24, 25) rearwardly arranged in respect to said beating plane.