EP0038025B1

EP0038025B1 - An apparatus for regulating tension in warps of a weaving machine

Info

Publication number: EP0038025B1
Application number: EP19810102675
Authority: EP
Inventors: Hajime Suzuki; Yoshifumi Umemura; Masahiko Kimbara; Noboru Kobayashi
Original assignee: Toyoda Jidoshokki Seisakusho KK
Current assignee: Toyota Industries Corp
Priority date: 1980-04-12
Filing date: 1981-04-09
Publication date: 1985-07-31
Also published as: CS244410B2; DE3171545D1; EP0038025A3; CS272081A2; EP0038025A2

Description

The present invention relates to an apparatus for regulating the tension in the warp threads of a weaving machine comprising a tension lever swingably supported on said weaving machine and having a roller supported thereon for regulating the tension in said warp threads delivered from a warp beam, and passing over said roller; a weight lever swingably supported on said weaving machine and having a load at one end thereof; a link means operatively connected to said tension lever and said weight lever; and a means for varying a lever ratio in the system between said weight lever and said tension lever, said means comprising an elongated hole formed in said tension lever, to which one end of said link is connected by connecting means in such a manner that the connecting position is adjustable along said elongated hole.
In a weaving machine the warp threads - sometimes simply designated as warps in this application - delivered from a warp beam are fed to heddles through a plurality of rollers, such as a back roller and a tension roller. Conventionally an apparatus for regulating tension in warps is widely utilized for regulating the tension in the warps in accordance with, for example, the type of the woven fabric so that woven fabrics having a ground weave and hand which are in demand as manufactured fabrics can be manufactured. A so called weight lever type tension regulating apparatus has been commonly utilized. The apparatus comprises a tension lever for supporting a tension roller, and a loading means, such as a weight or a spring, connected to said tension lever in order to create a desired tension in warps by displacing said tension roller.
However, such a conventional apparatus has a disadvantage in that the adjusting of the loading means based on the kind of warps or the type of the woven fabrics is troublesome. Accordingly, the weaving operation is often deteriorated because of unsatisfactory adjustment of the loading means, such as a weight or a spring. More specifically, if the tension in warps created by the loading means is small, the response of the regulating apparatus becomes slow. Contrary to this, if the tension in warps created by the loading means is large, the response of the regulating apparatus becomes excessively high and adversely affects the weaving operation.
Further, FR-A-A21 43 169 discloses an apparatus of the general type indicated above. This known apparatus allows for a satisfactory adjustment of the loading means. However, according to this prior art concept, the link means is not in the same vertical plane as the elongated hole but is somewhat distant from said plane. Therefore, when the securing means of the connection is loosened, the forces generated by the weight tend to twist a pin of the linkage means inserted through the elongated hole. Such torsional twisting, however, causes a deformation of both the elongated hole and the connecting pin. Morever, the adjustment due to the forces generated by the weight is troublesome and time- consuming, even though the loom had been stopped.
Proceeding on the basis of this prior art the object underlying the invention is to provide for an easy adjustment of the lever ratio by which the tension in warps can easily be adjusted in a wide range without changing the load of the loading means, while simultaneously avoiding detrimental deformation of the elongated hole and/or the connecting pin of the linkage means.
This object is accomplished according to the invention in that said elongated hole of said tension lever extends in a vertical plane passing through said tension lever, and that the connecting means extend through said elongated hole such that said connecting means lie in said plane, said lever being supported by said link means from below.
Since according to the invention the link means to be adjusted relative to the tension lever can be secured in the same vertical plane, being occupied by the elongated vertical hole, a force applied at the connection between the lever and the link means by the weight causes no twist thereon, even if the securing member is loosened for the preparation of the adjustment. Thus, smooth and easy adjustment can be obtained even when the loom is in operation.
The present invention will now be explained in detail with reference to the attached drawings, wherein:

Fig. 1 is a side view of a weight lever type apparatus according to the invention for regulating tension in warps;
Fig. 2 is a partially enlarged cross sectional side view of Fig. 1;
Fig. 3 is a cross sectional view taken along the line XIII-XIII in Fig. 2;
Fig. 4 is a partial plan view of Fig. 2; and
Figs. 5 through 7 are partially enlarged cross sectional views which are utilized to explain the movement of a support member installed in the apparatus of Fig. 2.

A weight lever type apparatus according to the invention for regulating tension in warps will now be explained first with reference to Fig. 1. In Fig. 1, 1 denotes a shaft of a warp beam which is rotatably supported on a machine frame 2 of a weaving machine and which detachably supports a warp beam 3 between the shaft 1 and the side of the machine frame 2 facing the shaft 1. Reference numeral 4 denotes a speed change disposed on one side of the machine frame 2. The speed change device 4 has: an input shaft 4a driven by a conventional drive shaft (not shown) of the weaving machine, via a toothed belt 5; and an output shaft 4b transmitting the output power which is obtained by changing the speed by means of the speed change 4. The output shaft 4b has a pinion 6 attached thereto which engages with a spur gear 7. A bevel gear 8 coaxial with the spur gear 7 engages with another bevel gear which is coaxial- with a worm 10 meshing with a worm wheel 11 attached to one end of the shaft 1 of the warp beam. Accordingly, the output power of the speed change device 4 is transmitted to the shaft of the warp beam through the pinion 6, the spur gear 7, the bevel gears 8 and 9, the worm 10 and the worm wheel 11. As a result, the warp beam 3 is positively rotated in synchronization with the shedding operation of the weaving machine as the drive shaft rotates.
Reference numeral 12 denotes a back roller which is rotatably supported between the left ends of the machine frame 2 at a location above the warp beam 3 and which guides warps W delivered from the warp beam 3.
A pair of tension levers 26 (one of which is illustrated in fig. 1) are swingably supported on a shaft 15 located at the upper portion of a machine frame 2 and support a tension roller 16 therebetween by means of a shaft 27. Each tension lever 26 has an elongated hole 26a formed therein and extending in a vertical plane passing through said tension lever.
An intermediate lever 13 is located beneath the tension lever 26 and is swingably supported by means of a shaft 29. The lower end of an adjusting link 28 is swingably connected to the left end of the intermediate lever 13 by means of a connecting pin 30. The upper end of the adjusting link 28 is connected to the tension lever 26 through connecting means 32, 37, 38 which will be described in more detail below.
As a result of the above-explained construction, warps W delivered inclinedly and upward from the warp beam 3 through the back roller 12 are fed to heddles (not shown) through the tension roller 16. The change in tensions in warps is detected by the tilting movement of the intermediate lever caused by the vertical movement of the tension roller 16.
Reference numeral 17 denotes a weight lever swingably supported on the machine frame 2 by means of a shaft 18. The weight lever 17 has a pin 17b secured to the left end thereof which serves to hang down a hanging hook 19 with balance weights 20 or to connect a tension spring 20' which is illustrated by a dot and dash line in fig. 1. A connecting rod 21 has the upper end thereof connected to the right end of the intermediate lever 13; and a connecting pin 23 at the lower end thereof for connecting it to the portion adjacent to the right end of the weight lever 17. As a result of this constructions, a tilting movement of the intermediate lever 13 caused by the change in tension in warps causes that the weight lever 17 is also tilted by means of the connecting rod 21.
A speed change lever 24 connected to a speed change shaft 4c of the speed change device 24 is connected to the weight lever 17 by way of a synchronizing link 25, so that the reduction ratio of the speed change device 4 is varied in accordance with the tilting movement of the weight lever 17 caused by the change in tension in warps, and so that the rotational speed during unwinding operation of the warm beam 3 is controlled in order to maintain an adequate tension in warps regardless of the change in tension.
The above referenced connecting means will now be described in more detail with reference to figs. 2 and 3 of the drawings.
Reference numeral 32 denotes a support member supported on the top of an adjusting link 28 via a universal joint 38 (Fig. 3). As illustrated in Fig. 2, the support member 32 has: an engaging surface 32a formed on the upper surface thereof and facing the lower side of the tension lever 26; and two pairs of rollers 33 and 34 rotatable along the lower surface of the tension lever in a direction of the elongated hole 26a, one pair is at the right and the other pair is at the left of the adjusting link in Fig. 2. Reference numeral 35 denotes an index formed in a triangular prism shape and inserted into the elongated hole 26a as illustrated in Fig. 4 so that it corresponds to the graduations 36 formed on the tension lever 26.
Reference numeral 37 illustrated in Figs. 2 through 4 denotes a securing member formed in a hexagonal prism and having a bulged portion 37a and a male thread portion 37b. The securing member 37 also serves as a handle during the adjusting operation. The male thread portion 37b of the securing member 37 passes through the elongated hole 26a formed in the tension lever 26 and meshes with a female thread formed on the engaging surface 32a, so that the bulged portion 37a is in abutment with the upper surface of the tension lever 26, and so that the tension lever 26 is securely sandwiched between the bulged portion 37a and the support member 32.
The operation for securing the support member 32 at a desired position relative to the tension lever 26 will now be explained. As illustrated in Figs. 2 and 3, while the engaging surface 32a of the support member 32 is in contact with the lower surface of the tension lever 26, the securing member 37 is tightened. After the bulged portion 37a of the securing member 37 abuts the upper surface of the tension lever 26, the support member 32 is lifted. Then, the engaging surface 32a of the support member 32 is urged to the lower surface of the tension lever 26, so that the location of the support member 32 is secured. Under this condition, the rollers 23 and 24 are slightly separated from the lower surface of the tension member. As a result, after the securing operation is completed, the adjusting link 28 is integrally connected to the tension lever 26 and is swingable about the universal joint 38, and the lever ratio 1₃/1₄ of the tension lever 26 is set as illustrated in Fig. 1.
Operation for moving the support member 32 in order to vary the lever ratio will now be explained. The securing member 37 is loosened, and then, the securing member 37 is swung in a direction designated by the arrow A in Fig. 5. Accordingly, the support member 32 is swung around a fulcrum P which is the right end of the engaging surface 32a facing the lower surface of the tension lever 26. When the securing member 37 which now serves as a handle is further swung, the end of the engaging surface also separates from the lower surface of the tension lever 26, and the fulcrum P displaces onto one pair of rollers 33. The rollers 33 turn along the lower surface of the tension lever 26 so that the support member 32 is smoothly moved in a direction the same as that designated by the arrow A. Based on the indication between the index 35 and the graduations 36, the movement of the support member 32 is stopped at an appropriate position, and then, the securing member is tightened in a manner as explained above.
Contrary to this, if the support member is required to be moved in a reverse direction, the securing member 37 swung in a direction designated by the arrow B (Fig. 7). Then the other rollers 24 serve as a fulcrum P, and the support member 21 moves in a direction the same as that designated by the arrow B.
Since the lever ratio varying operation explained above can be performed by only swinging the securing member 37 after it is loosened, the operation can be carried out while the weaving machine is operating.
The following embodiments which are not illustrated are also available.

(1) In spite of a universal joint 38, a support member 21 and an adjusting link 28 may be swingably connected to each other by way of another pivot member.
(2) If the support member 32 can be rigidly secured to a tension lever 26, it is unnecessary for rollers 33 and 34 to be separated from the tension lever 26 when the support member 32 is secured to a desired position.

The apparatus for regulating tension in warps constructed in such a manner as explained above operates as follows. When the securing member 37 of the adjusting link 28 is located at one end of the elongated hole 26a near the shaft 15 the lever ratio 1₃:1₄ of the tension lever 26 is minimum. Further, when the connecting pin 23 of the connecting rod 21 is located at position A far from the shaft 18 the lever ratio 1₁:1₂ of the weight lever is also minimum. When the location of the securing member 37 is moved along the elongated hole 26a to the far end thereof while the weight 20 or the spring 20' is maintained constant, the moment exerted on the tension lever 26 caused by the weight 20 through the weight lever 17 and the adjusting link 28 is increased due to the change of the lever ratio of the tension lever. As a result, the tension in warps W is increased.
When the connecting rod 21 is moved from position A to position B, the lever ratio of the weight lever is increased, and accordingly, the tension T in the warps W is increased. Therefore, the tension can be adjusted in a wide range without changing weight 20.
As explained above, since in this apparatus the adjusting link 28, which is capable of adjustment of the lever ratio of the tension lever 26, is disposed between the tension lever 26 and the intermediate lever 13, the tension T in warps can stably be adjusted in a wide range compared with the conventional apparatus for regulating tension in a warps while the weight 20 is unchanged. In addition, the tension in warps can easily be adjusted by a simple operation wherein the position of the adjusting link 28 is varied.
When the weight 20 is changed at two stages only in the above-explained embodiment, the tension T in warps W is varied in a remarkably wide range.

Claims

1. An apparatus for regulating the tension in the warp threads of a weaving machine comprising:

a tension lever swingably supported on said weaving machine and having a roller supported thereon for regulating the tension in said warp threads delivered from a warp beam, and passing over said roller;

a weight lever swingably supported on said weaving machine and having a load at one end thereof;

a link means operatively connected to said tension lever and said weight lever;

and a means for varying a lever ratio in a system between said weight lever and said tension lever, said means comprising an elongated hole formed in said tension lever, to which one end of said link means is connected by connecting means in such a manner that the connecting position is adjustable along said elongated hole,

characterized in that said elongated hole (26a) of said tension lever (26) extends in a vertical plane passing through said tension lever (26), and that the connecting means (37) extends through said elongated hole (26a) such that said connecting means (37) lie in said plane, said lever (26) being supported by said link means (28) from below.

2. An apparatus according to claim 1, which further comprises a guide roller means (33, 34) disposed at a position where said link means (28) is connected to said tension lever (26) and serving to guide the relative movement between said link means (28) and said tension lever (26) while the lever ratio varying operation takes place.

3. An apparatus according to claim 1, which further comprises a support member (32) supported at the top end of said link means (28) and supporting said guide roller means (33, 34) for slidably engaging with said tension lever (26), and said connecting means comprising a securing member (37) threaded with said support member (32) through said elongated hole (26a) formed in said tension lever (26) for securing said support member (32) at a predetermined location relative to said tension lever (26).

4. An apparatus according to claim 3, wherein said support member (32) is pivoted at said top end of said link means (28), and said guide roller means comprises at least two rollers (33, 34) which are on opposite sides of a pivotal joint (38) between said support member (32) and said link means (28).

5. An apparatus according to claims 3 and 4, wherein, when said tension lever (26) and said support member (32) are secured to each other by means of said securing member (37), said support member (32) has an engaging surface with is forcedly engaged with said tension lever (20), so that said rollers (33, 34) located at both sides of said engaging surface are separated from said tension lever.

6. An apparatus according to claim 4, wherein said securing member (37) further serves as an operation handle for displacing said guide roller means (33, 34) together with said support member (32) with respect to said tension lever (26).