Linkage mechanism, linkage device, and stretcher

Abstract

To prevent rail wear that contributes to drawing machine vibration.SOLUTION: A link mechanism constitutes a link device used in a drawing machine. The link mechanism has a base member, outer rail holders 24a provided on one end side of the base member and provided with a plurality of guide rollers that moves along a rail 14, inner rail holders provided at the other end of the base member and provided with a plurality of guide rollers that moves along the other rail provided inside the rail 14, a link plate, one end of which is rotatably connected to the outer rail holders 24a and the other end of which is rotatably connected to the other link mechanism, and a clip provided on one end side of the base member on which the outer rail holders 24a are provided, and which grips the membrane. The outer rail holder 24a is provided with a roller cover 50 that covers at least one of the plurality of guide rollers moving along the rail 14.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a link mechanism, a link device, and a stretching machine.

Background Art

[0002] There is known a stretching machine that stretches a film such as a sheet or a film in the longitudinal or transverse direction while conveying it. For example, Patent Document 1 discloses a simultaneous biaxial stretching machine that performs longitudinal stretching and transverse stretching of a sheet-like material at the same time. The simultaneous biaxial stretching machine disclosed in Patent Document 1 includes an endless link device, and the endless link device includes an equal-length link device formed in a folding ruler shape.

[0003] The equal-length link device disclosed in Patent Document 1 includes a rail and a plurality of rollers that move while rolling on the rail.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a stretching machine, it is desirable to prevent wear of the rail, which is one of the causes of vibration.

[0006] Other problems and novel features will become apparent from the description of this specification and the accompanying drawings.

Means for Solving the Problems

[0007] According to one embodiment, the link mechanism constitutes a link device used in a stretcher for stretching a film. The link mechanism includes an outer rail holder having a plurality of guide rollers that move along a first rail, and an inner rail holder having a plurality of guide rollers that move along a second rail provided inside the first rail, wherein the outer rail holder includes a roller cover that covers at least one of the plurality of guide rollers that move along the first rail. [Effects of the Invention]

[0008] According to one embodiment, rail wear, which is one of the causes of vibration in the extension machine, is reduced. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the configuration of a thin film manufacturing system in one embodiment. [Figure 2] This is a schematic plan view showing the structure of a stretching machine that constitutes a thin film manufacturing system. [Figure 3] This is another plan view schematically showing the structure of a stretcher that constitutes a thin film manufacturing system. [Figure 4A] This is a schematic plan view showing the link mechanism and rails. [Figure 4B] This is another plan view schematically showing the link mechanism and rails. [Figure 5] This is a magnified perspective view showing some of the linkage mechanisms. [Figure 6] This is a plan view showing some of the linkage mechanisms in detail. [Figure 7] This is an enlarged perspective view of the outer rail holder. [Figure 8A] This is an explanatory diagram showing the roller cover provided on the outer rail holder. [Figure 8B] This is a bottom view showing the roller cover installed on the outer rail holder. [Figure 9] This is an explanatory diagram showing the function of the roller cover provided on the outer rail holder. [Figure 10]It is a perspective view showing a modified example of a roller cover provided on an outer rail holder. [Figure 11] It is a perspective view showing a modified example of a link device. [Figure 12A] It is a side view showing the inner surface of a partial rail disposed in the heat fixation region of a stretching machine. [Figure 12B] It is a side view showing the outer surface of the partial rail shown in Fig. 12A. [Figure 13A] It is a side view showing a modified example of a groove formed on the side surface of a rail. [Figure 13B] It is another side view showing a modified example of a groove formed on the side surface of a rail.

Mode for Carrying Out the Invention

[0010] Hereinafter, an embodiment will be described in detail based on the drawings. In all the drawings for explaining the embodiment, members having the same or substantially the same function are denoted by the same reference numerals, and repeated explanations thereof are omitted.

[0011] <Configuration of Manufacturing System> Fig. 1 is a schematic diagram showing the configuration of a thin film manufacturing system including a stretching machine. The thin film manufacturing system 1 shown in Fig. 1 has an extrusion device (extruder, kneading extruder) 2, a T-die 3, a raw sheet cooling device 4, a stretching machine 5, a take-up device 6, and a winding device 7.

[0012] In the thin film manufacturing system 1, a thin film is manufactured by the following process. First, raw materials are supplied to the raw material supply section (raw material inlet, hopper) 2a of the extrusion device 2. The raw materials supplied to the extrusion device 2 are composed of a resin material (for example, a pellet-shaped thermoplastic resin material), additives, and the like.

[0013] The raw material supplied to the extrusion device 2 is transported (conveyed) while being kneaded (mixed). Specifically, the raw material supplied to the extrusion device 2 is melted and kneaded while being sent forward by the rotation of the screw within the extrusion device 2. The raw material (kneaded material) kneaded by the extrusion device 2 is supplied to the T-die 3. The kneaded material supplied to the T-die 3 is extruded from the slit of the T-die 3 toward the raw roll cooling device 4. The kneaded material supplied from the extrusion device 2 to the T-die 3 is formed into a predetermined shape (here, a film shape) by passing through the T-die 3.

[0014] The kneaded material extruded from the T-die 3 is cooled in the raw roll cooling device 4 to become the film 8. The film 8 is a resin film in a solidified state (solid state). More specifically, the film 8 is a thermoplastic resin film. From the T-die 3, the film 8 is continuously extruded. As a result, the film 8 is continuously supplied to the stretching machine 5.

[0015] The film 8 supplied to the stretching machine 5 is stretched in the MD direction and the TD direction by the stretching machine 5. The film 8 subjected to the stretching process (stretching treatment) by the stretching machine 5 is conveyed to the winding device 7 via the take-up device 6 and wound around the winding device 7. The film 8 wound around the winding device 7 is cut as necessary.

[0016] The thin film manufacturing system 1 shown in FIG. 1 manufactures a thin film by the above-described process. However, the thin film manufacturing system 1 can be variously modified according to the characteristics of the thin film to be manufactured and the like. For example, an extraction tank may be installed near the take-up device 6 shown in FIG. 1, and a plasticizer (e.g., paraffin, etc.) contained in the film 8 may be removed.

[0017] The stretcher 5, which constitutes the thin film manufacturing system 1, stretches the film 8 in both the MD and TD directions while transporting it in the MD direction. In other words, the MD (Machine Direction) direction is the transport direction of the film 8. The TD (Transverse Direction) direction is the direction that intersects with the transport direction of the film 8. Therefore, in the following explanation, the MD direction may be referred to as the "transport direction" or "longitudinal direction," and the TD direction may be referred to as the "transverse direction." The MD direction (transport direction, longitudinal direction) and the TD direction (transverse direction) are directions that intersect each other, or more specifically, directions that are orthogonal to each other. In other words, the stretcher 5 is a stretcher that can transport the film 8 while simultaneously stretching it in two directions that intersect each other, and is generally called a "simultaneous biaxial stretcher."

[0018] <Stretching machine> Next, the stretcher 5 will be explained in more detail. Figures 2 and 3 are schematic plan views showing the structure of the stretcher 5. The stretcher 5 has a pair of link devices 10. The pair of link devices 10 are spaced apart from each other in a plan view. In the following explanation, one of the pair of link devices 10 may be referred to as "link device 10R" and the other as "link device 10L" to distinguish them. However, this distinction is merely for the convenience of explanation.

[0019] In Figures 2 and 3, the link device 10R is positioned on the right side (R side) with respect to the transport direction (MD direction), and the link device 10L is positioned on the left side (L side) with respect to the transport direction (MD direction). The link devices 10R and 10L are spaced apart in the TD direction and face each other in the TD direction with the membrane 8 in between.

[0020] The membrane 8 is transported in the MD direction through the space between the link device 10R and the link device 10L. In other words, the space between the opposing link devices 10R and 10L is used as a transport path for transporting the membrane 8.

[0021] Refer to Figure 3. The stretcher 5 is divided into three regions 20A, 20B, and 20C along the conveying direction (MD direction). Region 20A is the preheating region, region 20B is the stretching region, and region 20C is the heat-setting region. The preheating region 20A, the stretching region 20B, and the heat-setting region 20C are arranged in this order along the conveying direction (MD direction).

[0022] The inlet for the film 8 in the stretcher 5 (indicated as "IN" in Figures 2 and 3) is located in the preheating region 20A. The outlet for the film 8 in the stretcher 5 (indicated as "OUT" in Figures 2 and 3) is located in the heat-setting region 20C. Between the preheating region 20A, where the inlet for the film 8 is located, and the heat-setting region 20C, where the outlet for the film 8 is located, is the stretching region 20B, where the stretching process takes place.

[0023] The heat treatment section 9 covers a portion of the preheating area 20A, all of the stretching area 20B, and a portion of the heat-fixing area 20C. The heat treatment section 9 also covers the central portion of the link devices 10R and 10L, heating the film 8 transported by the link devices 10R and 10L. In this embodiment, the heat treatment section 9 is formed by an oven capable of heating the film 8 to a desired temperature. The film 8, while held by the link devices 10R and 10L, passes through the interior of the oven, which serves as the heat treatment section 9.

[0024] <Link device> Each of the link devices 10R and 10L has a plurality of link mechanisms 11 connected to form an endless chain, and each link mechanism 11 is equipped with a clip 21 for gripping the membrane 8. The membrane 8 is held by the clips 21 provided by the link mechanisms 11 that make up the link device 10R and by the clips 21 provided by the link mechanisms 11 that make up the link device 10L. That is, one side of the membrane 8 (right side / R side) is gripped by the plurality of clips 21 provided by the link device 10R, and the other side of the membrane 8 (left side / L side) is gripped by the plurality of clips 21 provided by the link device 10L.

[0025] Each of the link devices 10R and 10L further has a pair of rails 13 and 14 positioned on a support base (bed), in addition to the multiple link mechanisms 11. In each of the link devices 10R and 10L, rail 13 is positioned inside rail 14. In other words, rail 14 is positioned outside rail 13. Therefore, rail 13 is sometimes called the "inner rail" and rail 14 is sometimes called the "outer rail". Also, rail 13 is sometimes called the "reference rail" or "SP rail", and rail 14 is sometimes called the "MD rail".

[0026] The rails 13 and 14 of each link device 10R and 10L are composed of multiple interconnected partial rails and are arranged in a ring shape across the preheating region 20A, the stretching region 20B, and the heat-fixing region 20C. More specifically, the rails 13 and 14 are folded back in the preheating region 20A where the entrance to the membrane 8 is located, and also folded back in the heat-fixing region 20C where the exit to the membrane 8 is located, thus arranging in a ring shape.

[0027] Three sprockets 19a, 19b, and 19c are provided inside the rail 13 of link device 10R. Similarly, three sprockets 19a, 19b, and 19c are provided inside the rail 13 of link device 10L. The sprockets 19a and 19b of each link device 10R and 10L are located in the preheating area 20A, and the sprocket 19c of each link device 10R and 10L is located in the heat-fixing area 20C. However, the sprockets 19a and 19b are located outside the heat-processing unit 9 which covers part of the preheating area 20A. Also, the sprocket 19c is located outside the heat-processing unit 9 which covers part of the heat-fixing area 20C. In other words, the sprockets 19a, 19b, and 19c of each link device 10R and 10L are located outside the oven cavity which serves as the heat-processing unit 9.

[0028] The multiple link mechanisms 11 of link devices 10R and 10L are arranged on rails 13 and 14 and move along rails 13 and 14. The sprockets 19a, 19b, and 19c of link device 10R shown in Figure 3 are engaged with the multiple link mechanisms 11 of link device 10R. Therefore, when the sprockets 19a, 19b, and 19c rotate, a driving force acts on the multiple link mechanisms 11 of link device 10R, causing these link mechanisms 11 to move (travel) along rails 13 and 14 of link device 10R. The sprockets 19a, 19b, and 19c of link device 10L shown in Figure 3 are engaged with the multiple link mechanisms 11 of link device 10L. Therefore, when the sprockets 19a, 19b, and 19c rotate, a driving force acts on the multiple link mechanisms 11 of link device 10L, causing these link mechanisms 11 to move (travel) along rails 13 and 14 of link device 10L. In other words, the rails 13 and 14 provided by the link devices 10R and 10L are guide rails for moving (traveling) multiple link mechanisms 11 in a predetermined direction.

[0029] In the following explanation, for each of the link devices 10R and 10L shown in Figure 3, the side facing the membrane 8 will be referred to as the "membrane side," and the side opposite the membrane side will be referred to as the "return side." In other words, the side on which the multiple link mechanisms 11 move from the inlet (IN) to the outlet (OUT) when the clip 21 is gripping the membrane 8 is the membrane side. On the other hand, the side on which the multiple link mechanisms 11 move from the outlet (OUT) to the inlet (IN) when the clip 21 is not gripping the membrane 8 is the return side.

[0030] Among the multiple link mechanisms 11, the pitch between adjacent link mechanisms 11 (sometimes called the "link pitch") changes according to the distance between rails 13 and 14. In other words, the pitch between adjacent link mechanisms 11 can be adjusted by adjusting the distance between rails 13 and 14.

[0031] Figures 4A and 4B are schematic plan views showing the link mechanism 11 and rails 13 and 14. As shown in Figures 4A and 4B, the smaller the distance L1 between rails 13 and 14, the larger the angle formed by adjacent link mechanisms 11, and the larger the pitch P1 between adjacent link mechanisms 11. On the other hand, the larger the distance L1 between rails 13 and 14, the smaller the angle formed by adjacent link mechanisms 11, and the smaller the pitch P1 between adjacent link mechanisms 11.

[0032] As previously described, each link mechanism 11 has a clip 21 that grips the membrane 8. Therefore, the pitch P2 between adjacent clips 21 increases or decreases in accordance with the increase or decrease in the pitch P1 between adjacent link mechanisms 11. Specifically, when the distance L1 between rails 13 and 14 decreases, the pitch P1 between link mechanisms 11 increases, and when the pitch P1 between link mechanisms 11 increases, the pitch P2 between clips 21 also increases (Figure 4A → Figure 4B). On the other hand, when the distance L1 between rails 13 and 14 increases, the pitch P1 between link mechanisms 11 decreases, and when the pitch P1 between link mechanisms 11 decreases, the pitch P2 between clips 21 also decreases (Figure 4B → Figure 4A).

[0033] Each of the multiple link mechanisms 11 is equipped with a clip 21. Therefore, the pitch P1 between two adjacent link mechanisms 11 and the pitch P2 between the two clips 21 provided by those link mechanisms 11 are the same. That is, in both Figure 4A and Figure 4B, P1 = P2 holds true.

[0034] <Operation of the stretching machine> The film 8 supplied from the raw material cooling device 4 shown in Figure 1 to the stretcher 5 is held by the link devices 10R and 10L at the inlet of the stretcher 5. Specifically, the film 8 is gripped by clips 21 provided on the link mechanisms 11 of the link devices 10R and 10L shown in Figures 2 and 3. More specifically, one side of the film 8 in the width direction is gripped by the clip 21 provided on the link mechanism 11 that constitutes link device 10R, and the other side of the film 8 in the width direction is gripped by the clip 21 provided on the link mechanism 11 that constitutes link device 10L.

[0035] The film 8, gripped on both sides in the width direction by clips 21, is transported from the inlet to the outlet of the stretcher 5 as the link mechanism 11, including the clips 21, moves, passing through the preheating region 20A, the stretching region 20B, and the heat-setting region 20C in that order. As the film 8 passes through the stretching region 20B, it is stretched in the MD and TD directions. After that, the film 8 reaches the outlet via the heat-setting region 20C and is released from the clips 21. The film 8 released from the clips 21 is transported to the take-up device 6, and from the take-up device 6 to the winding device 7.

[0036] As shown in Figure 3, in the preheating region 20A, the distance L2 between the rails 13 and 14 of the link device 10R and the rails 13 and 14 of the link device 10L (the distance between them in the TD direction) is approximately constant. Therefore, no stretching process in the TD direction is performed on the film 8 in the preheating region 20A. Consequently, in the preheating region 20A, the width of the conveyed film 8 (the dimension in the TD direction) does not change and remains constant.

[0037] Furthermore, in the preheating region 20A, the distance L1 between rails 13 and 14 on the membrane side of the link device 10R is approximately constant. Therefore, in the preheating region 20A, the pitch P1 of the link mechanism 11 on the membrane side of the link device 10R is approximately constant, and consequently, the pitch P2 of the clips 21 on the membrane side of the link device 10R is also approximately constant. Similarly, in the preheating region 20A, the distance L1 between rails 13 and 14 on the membrane side of the link device 10L is approximately constant. Therefore, in the preheating region 20A, the pitch P1 of the link mechanism 11 on the membrane side of the link device 10L is approximately constant, and consequently, the pitch P2 of the clips 21 on the membrane side of the link device 10L is also approximately constant. As a result, no stretching process in the MD direction is performed on the membrane 8 in the preheating region 20A. In other words, no stretching process is performed on the membrane 8 in either the TD direction or the MD direction in the preheating region 20A.

[0038] Next, the operation of the stretcher 5 in the stretching region 20B will be described. In the stretching region 20B, as the material moves in the transport direction (MD direction), the distance L2 between the rails 13 and 14 of the link device 10R and the rails 13 and 14 of the link device 10L (the distance between them in the TD direction) gradually increases. Therefore, in the stretching region 20B, the membrane 8 is pulled and stretched in the TD direction as it moves in the transport direction (MD direction). In other words, in the stretching region 20B, as the material moves in the transport direction (MD direction), the width of the membrane 8 (the dimension in the TD direction) gradually increases.

[0039] Furthermore, in the stretching region 20B, as the transport direction (MD direction) progresses, the distance L1 between rails 13 and 14 on the membrane side of the link device 10R gradually decreases, and the distance L1 between rails 13 and 14 on the membrane side of the link device 10L also gradually decreases. As a result, in the stretching region 20B, as the transport direction (MD direction) progresses, the pitch P1 of the link mechanism 11 on the membrane side of the link device 10R gradually increases, and accordingly, the pitch P2 of the clip 21 on the membrane side of the link device 10R also gradually increases. Similarly, in the stretching region 20B, as the transport direction (MD direction) progresses, the pitch P1 of the link mechanism 11 on the membrane side of the link device 10L gradually increases, and accordingly, the pitch P2 of the clip 21 on the membrane side of the link device 10L also gradually increases. As a result, in the stretching region 20B, as the transport direction (MD direction) progresses, the membrane 8 is pulled and stretched in the MD direction.

[0040] In other words, in the stretching region 20B, as it moves in the transport direction (MD direction), the film 8 is stretched in the TD direction and the MD direction. That is, in the stretching region 20B, the film 8 is subjected to stretching in the TD direction and the MD direction.

[0041] Next, the operation of the stretcher 5 in the heat-fixing region 20C will be described. In the heat-fixing region 20C, the distance L2 between the rails 13 and 14 of the link device 10R and the rails 13 and 14 of the link device 10L (separation distance in the TD direction) is approximately constant. Therefore, no stretching process in the TD direction is performed on the film 8 in the heat-fixing region 20C. Consequently, the width of the conveyed film 8 (dimension in the TD direction) does not change and remains constant in the heat-fixing region 20C.

[0042] Furthermore, in the heat-fixed region 20C, the distance L1 between rails 13 and 14 on the membrane side of the link device 10R is approximately constant. Therefore, in the heat-fixed region 20C, the pitch P1 of the link mechanism 11 on the membrane side of the link device 10R is approximately constant, and consequently, the pitch P2 of the clips 21 on the membrane side of the link device 10R is also approximately constant. Similarly, in the heat-fixed region 20C, the distance L1 between rails 13 and 14 on the membrane side of the link device 10L is approximately constant. Therefore, in the heat-fixed region 20C, the pitch P1 of the link mechanism 11 on the membrane side of the link device 10L is approximately constant, and consequently, the pitch P2 of the clips 21 on the membrane side of the link device 10L is also approximately constant. As a result, no stretching treatment in the MD direction is performed on the membrane 8 in the heat-fixed region 20C. In other words, no stretching treatment is performed on the membrane 8 in either the TD direction or the MD direction in the heat-fixed region 20C.

[0043] As described above, in the preheating region 20A, the pitch P1 of the link mechanism 11 on the membrane side of the link device 10R is kept constant, and the pitch P1 of the link mechanism 11 on the membrane side of the link device 10L is also kept constant. Subsequently, in the stretching region 20B, the pitch P1 of the link mechanism 11 on the membrane side of the link device 10R and the pitch P1 of the link mechanism 11 on the membrane side of the link device 10L are gradually increased. Then, in the heat-fixing region 20C, the pitch P1 of the link mechanism 11 on the membrane side of the link device 10R is again kept constant, and the pitch P1 of the link mechanism 11 on the membrane side of the link device 10L is also again kept constant. For this reason, on the membrane side of each of the link devices 10R and 10L, the pitch P1 of the link mechanism 11 in the heat-fixing region 20C is larger than the pitch P1 of the link mechanism 11 in the preheating region 20A. From another perspective, on the membrane side of each link device 10R and 10L, the pitch P2 of the clips 21 in the heat-fixing region 20C is greater than the pitch P2 of the clips 21 in the preheating region 20A. From yet another perspective, on the membrane side of each link device 10R and 10L, the separation distance L1 of the rails 13 and 14 in the heat-fixing region 20C is smaller than the separation distance L1 of the rails 13 and 14 in the preheating region 20A.

[0044] <Link mechanism configuration> Figure 5 is a perspective view showing some of the link mechanisms 11 that make up the link device 10 in an enlarged view. Figure 6 is a plan view showing some of the link mechanisms 11 that make up the link device 10 in an enlarged view.

[0045] As shown in Figures 5 and 6, each link mechanism 11 of the link devices 10R and 10L has, in addition to the clip 21, an upper link plate 22 and a lower link plate 23. Each link mechanism 11 further has an outer rail holder 24a, an inner rail holder 24b, and a base member 25 that spans the outer rail holder 24a and the inner rail holder 24b.

[0046] The outer rail holder 24a is positioned on the rail 14 and moves (runs) along the rail 14. The inner rail holder 24b is positioned on the rail 13 which is located inside the rail 14 and moves (runs) along the rail 13.

[0047] The upper link plate 22 and the lower link plate 23 are plate-shaped members that extend linearly in a plan view. The base member 25 is similar to the upper link plate 22 and the lower link plate 23 in that it extends linearly in a plan view. However, the base member 25 is thicker than the upper link plate 22 and the lower link plate 23.

[0048] In the following explanation, when the outer rail holder 24a and the inner rail holder 24b are not specifically distinguished, they may be collectively referred to as "rail holder 24".

[0049] <Rail holder> The rail holder 24 has a roller holding portion 31 and a shaft 32 provided at the longitudinal center of the roller holding portion 31. The roller holding portion 31 of the outer rail holder 24a is positioned on the rail 14 so as to cross the rail 14. Therefore, one longitudinal end of the roller holding portion 31 positioned on the rail 14 protrudes outward from the rail 14, and the other longitudinal end of the roller holding portion 31 protrudes inward from the rail 14 (the side facing the rail 13). Also, when the roller holding portion 31 of the outer rail holder 24a is positioned on the rail 14, the shaft 32 is positioned directly above the rail 14.

[0050] On the other hand, the roller holding portion 31 of the inner rail holder 24b is positioned on the rail 13, traversing the rail 13. Therefore, one longitudinal end of the roller holding portion 31 positioned on the rail 13 protrudes outward from the rail 13 (towards the rail 14), and the other longitudinal end of the roller holding portion 31 protrudes inward from the rail 13. Also, when the roller holding portion 31 of the inner rail holder 24b is positioned on the rail 13, the shaft 32 is positioned directly above the rail 13.

[0051] The shaft 32 of the outer rail holder 24a passes through one longitudinal end (base end) of the upper link plate 22, the lower link plate 23, and the base member 25. As a result, the base ends of the upper link plate 22, the lower link plate 23, and the base member 25 are rotatably connected by the shaft 32 of the outer rail holder 24a.

[0052] On the other hand, the shaft 32 of the inner rail holder 24b penetrates the other end (tip side) of the base member 25 in the longitudinal direction and protrudes from the base member 25. The shaft 32 of the inner rail holder 24b protruding from the base member 25 penetrates one end (tip side) in the longitudinal direction of the upper link plate 22 and lower link plate 23 of the adjacent link mechanism 11. As a result, the tip side of the base member 25 of the link mechanism 11 and the tip sides of the upper link plate 22 and lower link plate 23 of the adjacent link mechanism 11 are rotatably connected by the shaft 32 of the inner rail holder 24b.

[0053] From another perspective, the shaft 32 of the outer rail holder 24a is the axis of rotation at the base end of the upper link plate 22, the lower link plate 23, and the base member 25, while the shaft 32 of the inner rail holder 24b is the axis of rotation at the tip end of the upper link plate 22, the lower link plate 23, and the base member 25. From yet another perspective, the base ends of the upper link plate 22, the lower link plate 23, and the base member 25 are rotatably supported by the outer rail holder 24a, while the tip ends of the upper link plate 22, the lower link plate 23, and the base member 25 are rotatably supported by the inner rail holder 24b.

[0054] <clip> The clips 21 are provided on the base end side of the base member 25 of each link mechanism 11. The clips 21 have a main body 21a, a gripping part 21b, a spring part 21c, etc. The main body 21a is fixed to the base end side of the base member 25. The gripping part 21b is attached to the main body 21a so as to be movable up and down. The spring part 21c biases the gripping part 21b so that it moves downward. When the gripping part 21b moves downward due to the biasing of the spring part 21c, the membrane 8 is sandwiched between the main body 21a and the gripping part 21b. In other words, the membrane 8 is gripped by the clips 21. On the other hand, when the gripping part 21b moves upward against the biasing of the spring part 21c, the gripping of the membrane 8 is released.

[0055] <Guide roller> The rail holder 24 has a plurality of guide rollers that move along the rails 13 and 14. More specifically, the lower part of the outer rail holder 24a is provided with a pair of guide rollers 41 and 42 that face each other across the rail 14. Similarly, the lower part of the inner rail holder 24b is provided with a pair of guide rollers 41 and 42 that face each other across the rail 13. Each of the guide rollers 41 and 42 has a cylindrical shape with both axial ends open, and a flange is integrally molded to its upper end.

[0056] The guide roller 41 of the outer rail holder 24a is positioned on the outside of the rail 14, and its flange overlaps the outer edge of the upper surface of the rail 14. The guide roller 42 of the outer rail holder 24a is positioned on the inside of the rail 14, and its flange overlaps the inner edge of the upper surface of the rail 14.

[0057] The guide roller 41 of the inner rail holder 24b is positioned on the outside of the rail 13, and its flange overlaps the outer edge of the upper surface of the rail 13. The guide roller 42 of the inner rail holder 24b is positioned on the inside of the rail 13, and its flange overlaps the inner edge of the upper surface of the rail 13.

[0058] Therefore, the guide roller 41 of the outer rail holder 24a moves along the outside of the rail 14 while in contact with the rail 14, and the guide roller 42 of the outer rail holder 24a moves along the inside of the rail 14 while in contact with the rail 14. Also, the guide roller 41 of the inner rail holder 24b moves along the outside of the rail 13 while in contact with the rail 13, and the guide roller 42 of the inner rail holder 24b moves along the inside of the rail 13 while in contact with the rail 13.

[0059] Furthermore, the entire link mechanism 11 is supported by the rails 13 and 14 via the guide rollers 41 and 42 provided on the outer rail holder 24a and the inner rail holder 24b.

[0060] In other words, the guide rollers 41 and 42 provided on the outer rail holder 24a and the guide rollers 41 and 42 provided on the inner rail holder 24b are support rollers that support the link mechanism 11.

[0061] Each roller holding portion 31 of the rail holder 24 is attached to the lower end of a shaft 32 that protrudes below the base member 25, so as to be rotatable around the shaft 32 as the axis of rotation. More specifically, the roller holding portion 31 is attached to the lower end of the shaft 32 via a bearing.

[0062] As previously described, the roller holding portion 31 of the outer rail holder 24a extends across the rail 14 and protrudes to both sides of the rail 14. On the other hand, the roller holding portion 31 of the inner rail holder 24b extends across the rail 13 and protrudes to both sides of the rail 13.

[0063] A shaft (roller shaft) is provided at one end of the roller holding portion 31 of the outer rail holder 24a, which protrudes to the outside of the rail 14. Another shaft (another roller shaft) is provided at the other end of the roller holding portion 31 of the outer rail holder 24a, which protrudes to the inside of the rail 14. The upper part of each roller shaft is press-fitted into a mounting hole provided in the roller holding portion 31.

[0064] Similarly, a shaft (roller shaft) is provided at one end of the roller holding portion 31 of the inner rail holder 24b that protrudes to the outside of the rail 13. Another shaft (another roller shaft) is provided at the other end of the roller holding portion 31 of the inner rail holder 24b that protrudes to the inside of the rail 13. The upper part of each roller shaft is press-fitted into a mounting hole provided in the roller holding portion 31.

[0065] The guide roller 41 of the outer rail holder 24a is rotatably mounted on the lower part of a roller shaft that protrudes downward from one side of the roller holding portion 31. Similarly, the guide roller 42 of the outer rail holder 24a is rotatably mounted on the lower part of another roller shaft that protrudes downward from the other side of the roller holding portion 31. In other words, the guide rollers 41 and 42 of the outer rail holder 24a are rotatably held by the roller holding portion 31. More specifically, the guide rollers 41 and 42 are rotatably mounted on a roller shaft fixed to the roller holding portion 31 via bearings.

[0066] Similarly, the guide roller 41 of the inner rail holder 24b is rotatably mounted on the lower part of a roller shaft that protrudes downward from one side of the roller holding portion 31. The guide roller 42 of the inner rail holder 24b is rotatably mounted on the lower part of another roller shaft that protrudes downward from the other side of the roller holding portion 31. In other words, the guide rollers 41 and 42 of the inner rail holder 24b are rotatably held by the roller holding portion 31. More specifically, the guide rollers 41 and 42 are rotatably mounted on roller shafts fixed to the roller holding portion 31 via bearings.

[0067] <Roller cover> As previously described, the space between the opposing link devices 10R and 10L is used as a transport path for the membrane 8 (see Figure 3). The membrane 8 is gripped by clips 21 provided on the multiple link mechanisms 11 that make up the link devices 10R and 10L and moves along the transport path in the MD direction. Each clip 21 is provided on one longitudinal end (base end) of the base member 25, which is equipped with an outer rail holder 24a that moves along the rail 14.

[0068] As a result, the membrane 8 conveyed by the link devices 10R and 10L passes near the rail 14 along the rail 14 (see Figures 5 and 6). At this time, the guide rollers 41 and 42 of the outer rail holder 24a come into contact with the rail 14 and move along the rail 14 while rotating. Also, the guide rollers 41 and 42 of the inner rail holder 24b come into contact with the rail 13 and move along the rail 13 while rotating. Therefore, the rails 13 and 14 wear down due to contact with the guide rollers 41 and 42. When the flatness of the rails 13 and 14 decreases due to wear, vibration occurs.

[0069] Therefore, to reduce wear on the rails 13 and 14, lubricating oil is supplied to the rails 13 and 14. More specifically, multiple oil supply ports to which oil supply pipes are connected are provided on the underside of the rails 13 and 14. Furthermore, vertical through holes are formed inside the rails 13 and 14, penetrating them vertically. One end of the vertical through hole communicates with an oil supply port, and the other end opens onto the upper surface of the rails 13 and 14.

[0070] The lubricating oil supplied to the oil supply port flows out from the opening of the vertical through hole (top oil supply hole) onto the upper surface of rails 13 and 14, and spreads onto the upper and side surfaces of rails 13 and 14. In other words, an oil film is formed on the surface of rails 13 and 14.

[0071] The formation of an oil film on the surface of rails 13 and 14 reduces wear on rails 13 and 14. However, as guide rollers 41 and 42 rotate and move along rails 13 and 14, there is a risk that the lubricating oil adhering to the guide rollers 41 and 42 may scatter into the surrounding area. Furthermore, there is a risk that the scattered lubricating oil may adhere to the film 8. The likelihood of lubricating oil scattering and adhering to the film 8 increases as the moving speed (travel speed) of the link mechanism 11 increases.

[0072] Furthermore, the film 8 passes in the vicinity of the rail 14. Therefore, the lubricating oil scattered by the guide rollers 41 and 42 of the outer rail holder 24a, which moves along the rail 14, is more likely to adhere to the film 8 than the lubricating oil scattered by the guide rollers 41 and 42 of the inner rail holder 24b, which moves along the rail 13.

[0073] Furthermore, the guide roller 41 of the outer rail holder 24a, which moves on the outside of the rail 14, is closer to the film 8 than the guide roller 42 of the outer rail holder 24a, which moves on the inside of the rail 14. In other words, the lubricating oil scattered by the guide roller 41 of the outer rail holder 24a is most likely to adhere to the film 8.

[0074] Therefore, the outer rail holder 24a of this embodiment is provided with a cover capable of preventing lubricating oil from splashing into the surrounding area. Figure 7 is an enlarged perspective view of the outer rail holder 24a. Figure 8A is an explanatory diagram showing the cover provided on the outer rail holder 24a. Figure 8B is a bottom view showing the cover provided on the outer rail holder 24a. Note that the cover provided on the outer rail holder 24a is not shown in Figures 5 and 6.

[0075] The outer rail holder 24a is equipped with a roller cover 50 that covers at least one of the multiple guide rollers 41, 42 that move along the rail 14. The roller cover 50 consists of a cover member 51 that covers the guide roller 41 that moves on the outside of the rail 14, and a cover member 52 that covers the guide roller 42 that moves on the inside of the rail 14. In other words, the roller cover 50 of this embodiment individually covers both the guide rollers 41, 42 that the outer rail holder 24a has.

[0076] Each cover member 51, 52 includes an upper portion 53 that covers the roller holding portion 31 and a side portion 54 that covers the outer circumferential surface of the guide rollers 41, 42. However, the upper portion 53 and the side portion 54 are integrally molded from resin.

[0077] The side portions 54 of the cover members 51 and 52 are curved to conform to the outer circumferential surfaces of the guide rollers 41 and 42, and cover most of the outer circumferential surfaces of the guide rollers 41 and 42. More specifically, the side portion 54 of the cover member 51 covers at least half of the outer circumferential surface of the guide roller 41. Similarly, the side portion 54 of the cover member 52 covers at least half of the outer circumferential surface of the guide roller 42.

[0078] Cover members 51 and 52 are attached to both sides of the roller holding portion 31, respectively. More specifically, the upper surfaces 53 of cover members 51 and 52 are fixed to the upper surface of the roller holding portion 31 by screws 55. In addition, the side surfaces 54 of cover members 51 and 52 are fixed to the sides of the roller holding portion 31 by screws 56.

[0079] In other words, the roller cover 50 is detachable from the roller holding portion 31. More specifically, the cover members 51 and 52 are detachable from the roller holding portion 31 independently of each other. Alternatively, only one of the cover members 51 or 52 can be attached to the roller holding portion 31. If only one of the cover members 51 or 52 is attached, it is preferable to attach the cover member 51 from the viewpoint of preventing the lubricating oil from adhering to the film 8.

[0080] The cover members 51 and 52 attached to both sides of the roller holding portion 31 face each other with the shaft 32 in between. Alternatively, when the outer rail holder 24a is positioned on the rail 14, the cover members 51 and 52 face each other with the rail 14 in between.

[0081] In order for the outer rail holder 24a to move smoothly, a clearance must be provided between the roller cover 50 and the rail 14. However, if the clearance between the roller cover 50 and the rail 14 is too wide, there is a risk that lubricating oil may scatter into the surrounding area through the gap. Therefore, it is preferable to make the clearance between the roller cover 50 and the rail 14 as narrow as possible, within the range in which the roller cover 50 does not interfere with the rail 14. The clearance between the roller cover 50 and the rail 14 can be adjusted by increasing or decreasing the distance between the opposing cover members 51 and 52. Furthermore, the distance between the opposing cover members 51 and 52 can be increased or decreased by changing their shape, size, mounting position, etc.

[0082] Figure 9 is an explanatory diagram illustrating the function of the roller cover 50. The lubricating oil that has transferred from the rail 14 to the guide rollers 41 and 42 separates from the guide rollers 41 and 42 as they rotate. The lubricating oil that separates from the guide rollers 41 and 42 adheres to the roller cover 50 that covers the guide rollers 41 and 42. More specifically, the lubricating oil comes into contact with the inner surface of the roller cover 50 that is opposite to the outer surface of the guide rollers 41 and 42, and adheres to that inner surface. As a result, scattering of the lubricating oil into the surroundings is prevented, and adhesion of the lubricating oil to the film 8 is also prevented.

[0083] From another perspective, it is possible to supply a sufficient amount of lubricating oil to the rails 13 and 14 without worrying about lubricating oil adhering to the film 8. In other words, it is possible to reduce wear on the rails 13 and 14 of the link devices 10R and 10L and prevent the generation of vibrations.

[0084] In this embodiment, the roller cover 50 is provided on the outer rail holder 24a, which is closer to the film 8 than the inner rail holder 24b. However, the roller cover 50 can be provided not only on the outer rail holder 24a but also on the inner rail holder 24b. More specifically, the roller cover 50 may be provided on the inner rail holder 24b, covering at least one of the multiple guide rollers 41, 42 that the inner rail holder 24b has. By providing roller covers 50 on both the outer rail holder 24a and the inner rail holder 24b, the scattering of lubricating oil into the surroundings and the adhesion of lubricating oil to the film 8 can be prevented even more reliably.

[0085] The roller cover 50 of this embodiment is composed of two independent members (cover members 51 and 52). Therefore, it is possible to selectively attach either the cover member 51 or the cover member 52 to the outer rail holder 24a or the inner rail holder 24b. For example, only the cover member 51 can be attached to the outer rail holder 24a. Alternatively, both the cover member 51 and the cover member 52 can be attached to the outer rail holder 24a, and only the cover member 51 can be attached to the inner rail holder 24b. In this case, the three guide rollers (guide rollers 41 and 42 on the outer rail holder 24a and the guide roller 41 on the inner rail holder 24b) are covered by the roller cover 50.

[0086] Furthermore, the following can be understood from Figures 5 and 6: Guide roller 41 of the outer rail holder 24a is the guide roller closest to the membrane 8 among the four guide rollers included in the link mechanism 11. Also, guide roller 42 of the outer rail holder 24a is the guide roller second closest to the membrane 8 among the four guide rollers included in the link mechanism 11.

[0087] Furthermore, the guide roller 41 of the inner rail holder 24b is the third closest guide roller to the membrane 8 among the four guide rollers 40 included in the link mechanism 11. And the guide roller 42 of the inner rail holder 24b is the furthest guide roller from the membrane 8 among the four guide rollers 40 included in the link mechanism 11.

[0088] <Variations of roller cover> Figure 10 is a perspective view showing one modified example of the roller cover 50. The roller cover 50 provided on the illustrated outer rail holder 24a covers both the guide rollers 41 and 42 of the outer rail holder 24a together.

[0089] As previously described, the guide roller 41 of the outer rail holder 24a moves along the outside of the rail 14, and the guide roller 42 of the outer rail holder 24a moves along the inside of the rail 14. In other words, the roller cover 50 shown in Figure 10 covers both the guide roller 41 that moves along the outside of the rail 14 and the guide roller 42 that moves along the inside of the rail 14.

[0090] From another perspective, in the roller cover 50 shown in Figure 10, the cover member 51 and the cover member 52 shown in Figure 7 are connected and integrated.

[0091] The roller cover 50 shown in Figure 10 is fixed to the roller holding portion 31 by screws 55 and 56, just like the roller cover 50 shown in Figure 7. In other words, the roller cover 50 shown in Figure 10 is detachable from the roller holding portion 31. The roller cover 50 shown in Figure 10 can also be attached to the roller holding portion 31 of the inner rail holder 24b shown in Figures 5 and 6.

[0092] <Modified Link Device> Figure 11 is a perspective view showing one modified example of the link device 10. However, the link device 10 shown in Figure 11 has the same basic structure as the link device 10 described so far. Therefore, the link device 10 shown in Figure 11 can replace the link device 10 described so far and constitute the extension machine 5 described so far.

[0093] Therefore, we will omit explanations of configurations that are identical or substantially identical to the link device 10 already described, and will only explain the differences.

[0094] The rails 13 and 14 of the link device 10 shown in Figure 11 have multiple grooves 60 formed in them that can hold lubricating oil. More specifically, multiple grooves 60 are formed on the inner surface 15 and outer surface 16 of each rail 13 and 14.

[0095] However, the grooves 60 are formed only in certain sections of the rails 13 and 14, not over the entire length of the rails. More specifically, the grooves 60 are formed only in the sections of the rails 13 and 14 within the heat-fixed region 20C.

[0096] Rail 13 is formed by multiple annularly connected partial rails 13a. Grooves 60 are formed on the inner surface 15 and outer surface 16 of the partial rails 13a located in the heat-fixing region 20C (Figure 3) of the stretcher 5. Similarly, rail 14 is formed by multiple annularly connected partial rails 14a. Grooves 60 are formed on the inner surface 15 and outer surface 16 of the multiple partial rails 14a located in the heat-fixing region 20C (Figure 3) of the stretcher 5.

[0097] Figure 12A is a side view showing the inner surfaces 15 of the partial rails 13a and 14a located in the heat-fixing region 20C. Figure 12B is a side view showing the outer surfaces 16 of the partial rails 13a and 14a shown in Figure 12A.

[0098] The grooves 60 formed on the inner surface 15 and outer surface 16 of the partial rails 13a and 14a are inclined with respect to the longitudinal direction of the rails 13 and 14 (partial rails 13a and 14a) and are parallel to each other.

[0099] More specifically, each groove 60 is inclined at an angle θ (θ=2°) with respect to a virtual straight line (reference line) parallel to the upper surface 17 and lower surface 18 of the rails 13, 14 (partial rails 13a, 14a).

[0100] Furthermore, the leading edge (upper end) and trailing edge (lower end) of adjacent grooves 60 in the longitudinal direction of rails 13 and 14 (partial rails 13a and 14a) overlap vertically. As a result, the leading edge (upper end) of an adjacent groove 60 is located above the trailing edge (lower end) of groove 60, and the trailing edge (lower end) of another adjacent groove 60 is located below the leading edge (upper end) of groove 60.

[0101] The total length La of each groove 60 is 55.0 mm, and the overlap length Lb between adjacent grooves 60 is 10.0 mm. Furthermore, the distance D from the tip (upper end) of each groove 60 to the upper surface 17 of rails 13 and 14 (partial rails 13a and 14a) is 2.0 mm.

[0102] The inner surface 15 and outer surface 16 of the partial rails 13a and 14a are provided with horizontal through-holes 62 that connect vertical through-holes 61 formed inside the partial rails 13a and 14a with grooves 60. One end of the horizontal through-hole 62 communicates with the vertical through-hole 61, and the other end opens to the bottom surface of the groove 60.

[0103] Therefore, a portion of the lubricating oil supplied to the aforementioned lubrication port flows out from the opening of the vertical through hole 61 (top lubrication hole) onto the upper surface 17 of the rails 13 and 14 (partial rails 13a and 14a), and spreads onto the upper surface 17, inner surface 15, and outer surface 16 of the rails 13 and 14. Another portion of the lubricating oil supplied to the lubrication port flows out through the vertical through hole 61 and the horizontal through hole 62, and then flows out from the opening of the horizontal through hole 62 (side lubrication hole) into the groove 60. The lubricating oil that flows into the groove 60 then spreads onto the inner surface 15 and outer surface 16 of the rails 13 and 14.

[0104] As described above, the lubricating oil that has spread to the inner surface 15 and outer surface 16 of the rails 13 and 14 is spread (stretched) in the longitudinal direction of the rails 13 and 14 by the guide rollers 41 and 42 that move in contact with the rails 13 and 14. In other words, an oil film is formed on the surface of the rails 13 and 14.

[0105] Furthermore, some of the lubricating oil that spreads across the inner surface 15 and outer surface 16 of the rails 13 and 14 is retained in the grooves 60. In other words, the lubricating oil remains on the surface of the rails 13 and 14 for an extended period. As a result, an oil film continues to form on the surface of the rails 13 and 14 for an extended period. Moreover, because the grooves 60 overlap vertically, the lubricating oil that drips down the sides of the rails 13 and 14 is effectively captured and retained.

[0106] As previously described, the distance L2 between the rails 13 and 14 of link device 10R and the rails 13 and 14 of link device 10L (separation distance in the TD direction) is maximum in the heat-fixed region 20C of the stretcher 5. Therefore, the force that the rails 13 and 14 receive from the guide rollers 41 and 42 is maximum in the section of the heat-fixed region 20C. Alternatively, the partial rails 13a and 14a located in the heat-fixed region 20C are more susceptible to wear than the partial rails 13a and 14a located in other regions.

[0107] Therefore, in this embodiment, grooves 60 are formed on the sides of the partial rails 13a and 14a that form a portion of the rails 13 and 14 (heat-fixed region), thereby improving the oil film maintenance performance in that section. As a result, wear of the rails 13 and 14 is effectively reduced, and the occurrence of vibration is prevented.

[0108] Making the groove 60 deeper allows more lubricating oil to be retained in the groove 60. However, if the groove 60 becomes too deep, the lubricating oil will not spread easily. Also, oil residue and other debris will tend to accumulate in the groove 60. Therefore, the depth of the groove 60 is preferably 0.5 mm or less.

[0109] The inclination angle θ of the grooves 60 formed on the sides of rails 13 and 14 is not limited to 2°. Figures 13A and 13B are side views showing one modified example of the grooves 60 formed on the sides of rails 13 and 14. The inclination angle θ of the grooves 60 formed on the inner surfaces 15 of the partial rails 13a and 14a shown in Figure 13A is 0°. Alternatively, the grooves 60 shown in Figure 13A are parallel to the longitudinal direction of rails 13 and 14 and are also parallel to each other. Furthermore, the entire lengths of adjacent grooves 60 overlap vertically.

[0110] Similarly, the inclination angle θ of the grooves 60 formed on the outer surfaces 16 of the partial rails 13a and 14a shown in Figure 13B is 0°. Alternatively, the grooves 60 shown in Figure 13B are parallel to the longitudinal direction of the rails 13 and 14, and are also parallel to each other. Furthermore, the entire length of adjacent grooves 60 overlaps vertically.

[0111] Although the rail holder 24 shown in Figure 11 is not equipped with a roller cover 50, a roller cover 50 may be provided.

[0112] Although the present invention has been specifically described above based on embodiments and examples, it goes without saying that the present invention is not limited to the above embodiments or examples, and can be modified in various ways without departing from its essence.

[0113] For example, the guide rollers 41 and 42 of each link mechanism 11 are not limited to rollers with flanges (flanged rollers).

[0114] The groove 60 may be formed along the entire length of the rails 13 and 14, or it may be formed in only a portion of the rails other than the heat-fixing area. The number and position of the vertical through holes 61 and horizontal through holes 62 can be changed as appropriate. In addition, the horizontal through holes 62 may be opened on the side of the rails 13 and 14 instead of the bottom surface of the groove 60. In other words, the side lubrication holes may be provided on the inner surface 15 or outer surface 16 of the rails 13 and 14 instead of the bottom surface of the groove 60. [Explanation of Symbols]

[0115] 1. Thin film manufacturing system 2. Extruder 3 T-die 4 Fabric cooling device 5 Stretching machine 6. Collection device 7. Winding device 8 membrane 9. Heat treatment 10, 10R, 10L Linkage Device 11 Link mechanism 13, 14 rails 13a, 14a Partial rail 15 Inner surface 16 External surface 17 Top side 18 Bottom side 19a, 19b, 19c sprocket 20A preheating area 20B stretching area 20C heat fixing area 21 clips 21a Main body 21b Grip part 21c Spring part 22 Upper link plate 23 Lower link plate 24 Rail holder 24a Outer rail holder 24b Inner rail holder 25 Base member 31 Roller holding part 32 shafts 41,42 Guide rollers 50 Roller Cover 51, 52 Cover members 53 Top part 54 Side part 55, 56 Screws 60 grooves 61 Vertical through hole 62 Horizontal through hole L1,L2 separation distance La Total Length Lb Overlap Length P1, P2 pitch

Claims

1. A link mechanism that constitutes a link device used in a stretching machine for stretching a film, Base member and An outer rail holder provided on one longitudinal end of the base member and equipped with a plurality of guide rollers that move along the first rail, An inner rail holder provided on the other end of the base member in the longitudinal direction, and comprising a plurality of guide rollers that move along a second rail provided inside the first rail, A link plate having one longitudinal end rotatably connected to the outer rail holder and the other longitudinal end rotatably connected to another link mechanism, The base member on which the outer rail holder is provided is provided at one end in the longitudinal direction and has a clip for gripping the membrane, The plurality of guide rollers in the outer rail holder include guide rollers that move outside the first rail and guide rollers that move inside the first rail, The outer rail holder includes a roller holding portion that rotatably holds the guide roller, The outer rail holder comprises a roller cover composed of a first cover member and a second cover member. The first cover member is detachably attached to the roller holding portion and covers the guide roller that moves outside the first rail. The second cover member is a link mechanism that is detachably attached to the roller holding portion and covers the guide roller that moves inside the first rail.

2. In the link mechanism described in claim 1, The link mechanism comprising the first cover member and the second cover member, each including an upper portion that covers the roller holding portion and a side portion that covers the outer circumferential surface of the guide roller.

3. In the link mechanism described in claim 1, The inner rail holder is a link mechanism comprising a roller cover that covers at least one of the plurality of guide rollers that move along the second rail.

4. A link device used in a stretching machine for stretching a film, Rails and It has a plurality of link mechanisms that are connected to form an endless chain and move along the rail, Each of the aforementioned link mechanisms is, Base member and An outer rail holder provided on one longitudinal end of the base member and equipped with a plurality of guide rollers that move along the first rail, An inner rail holder provided on the other end of the base member in the longitudinal direction, and comprising a plurality of guide rollers that move along a second rail provided inside the first rail, A link plate having one longitudinal end rotatably connected to the outer rail holder and the other longitudinal end rotatably connected to another link mechanism, The base member on which the outer rail holder is provided is provided at one end in the longitudinal direction and has a clip for gripping the membrane, The plurality of guide rollers in the outer rail holder include guide rollers that move outside the first rail and guide rollers that move inside the first rail, The outer rail holder includes a roller holding portion that rotatably holds the guide roller, The outer rail holder comprises a roller cover composed of a first cover member and a second cover member. The first cover member is detachably attached to the roller holding portion and covers the guide roller that moves outside the first rail. The second cover member is a link device that is detachably attached to the roller holding portion and covers the guide roller that moves inside the first rail.

5. In the link device according to claim 4, A linkage device in which each of the link mechanisms has an inner rail holder that includes a roller cover that covers at least one of the plurality of guide rollers that move along the second rail.

6. In the link device according to claim 4, A linkage device in which the first cover member and the second cover member include an upper surface portion that covers the roller holding portion and a side surface portion that covers the outer circumferential surface of the guide roller.

7. A link device used in a stretching machine for stretching a film, Rails and It has a plurality of link mechanisms that are connected to form an endless chain and move along the rail, Each of the aforementioned link mechanisms is, Base member and An outer rail holder provided on one longitudinal end of the base member and equipped with a plurality of guide rollers that move along the first rail while in contact with the first rail, An inner rail holder provided on the other end of the base member in the longitudinal direction, comprising a plurality of guide rollers that move along the second rail while in contact with the second rail provided inside the first rail, A link plate having one longitudinal end rotatably connected to the outer rail holder and the other longitudinal end rotatably connected to another link mechanism, The base member on which the outer rail holder is provided is provided at one end in the longitudinal direction and has a clip for gripping the membrane, Multiple grooves capable of holding lubricating oil are formed on the sides of the first rail and the second rail. A linkage device in which the groove is formed only in a portion of the first rail and the second rail.

8. In the link device according to claim 7, Each of the grooves formed in the first rail is inclined with respect to the longitudinal direction of the first rail and is parallel to each other. A linkage device in which each of the grooves formed in the second rail is inclined with respect to the longitudinal direction of the second rail and is parallel to each other.

9. In the link device according to claim 7, Each of the grooves formed in the first rail is parallel to the longitudinal direction of the first rail and parallel to each other. A linkage device in which each of the grooves formed in the second rail is parallel to the longitudinal direction of the second rail and is parallel to each other.

10. A stretching machine for stretching a membrane, It has a pair of link devices for transporting and stretching the aforementioned membrane, Each of the aforementioned link devices comprises a rail and a plurality of link mechanisms connected to form an endless chain and moving along the rail. Each of the aforementioned link mechanisms is, Base member and An outer rail holder provided on one longitudinal end of the base member and equipped with a plurality of guide rollers that move along the first rail, An inner rail holder provided on the other end of the base member in the longitudinal direction, and comprising a plurality of guide rollers that move along a second rail provided inside the first rail, A link plate having one longitudinal end rotatably connected to the outer rail holder and the other longitudinal end rotatably connected to another link mechanism, The base member on which the outer rail holder is provided is provided at one end in the longitudinal direction and has a clip for gripping the membrane, The plurality of guide rollers in the outer rail holder include guide rollers that move outside the first rail and guide rollers that move inside the first rail, The outer rail holder includes a roller holding portion that rotatably holds the guide roller, The outer rail holder comprises a roller cover composed of a first cover member and a second cover member. The first cover member is detachably attached to the roller holding portion and covers the guide roller that moves outside the first rail. The second cover member is detachably attached to the roller holding portion and covers the guide roller that moves inside the first rail, in a stretching machine.

11. In the stretching machine according to claim 10, A stretcher in which each of the link mechanisms has an inner rail holder that includes a roller cover that covers at least one of the plurality of guide rollers that move along the second rail.

12. In the stretching machine according to claim 10, A stretching machine, wherein the first cover member and the second cover member include an upper portion that covers the roller holding portion and a side portion that covers the outer circumferential surface of the guide roller.

13. A stretching machine for stretching a membrane, It has a pair of link devices for transporting and stretching the aforementioned membrane, Each of the aforementioned link devices comprises a rail and a plurality of link mechanisms connected to form an endless chain and moving along the rail. Each of the aforementioned link mechanisms is, Base member and An outer rail holder provided on one longitudinal end of the base member and equipped with a plurality of guide rollers that move along the first rail, An inner rail holder provided on the other end of the base member in the longitudinal direction, and comprising a plurality of guide rollers that move along a second rail provided inside the first rail, A link plate having one longitudinal end rotatably connected to the outer rail holder and the other longitudinal end rotatably connected to another link mechanism, The base member on which the outer rail holder is provided is provided at one end in the longitudinal direction and has a clip for gripping the membrane, Multiple grooves capable of holding lubricating oil are formed on the sides of the first rail and the second rail. A rail extender in which the groove is formed only in a portion of the first rail and the second rail.

14. In the stretcher according to claim 13, A stretcher in which the grooves are formed only in the sections of the first rail and the second rail within the heat-fixing regions.

Images