SPLITTER FOR SYNTHETIC RESIN FILM
United States Patent 3662934
A novel splitter to be used to split synthetic resin film into a network of continuous fibrous strands. The splitter comprises a shaft, a plurality of blade disks, and a pair of supports each having on one side of it a protuberance. The blade disks fitted on the shaft are pressed by the supports and are assembled as a whole in a helical form along inclined planes of the protuberances.
US Patent References:
SPLITTER
Matsui et al. - September 1970 - 3527393
Radially split disc formed into a spiral for siping tires
James - September 1955 - 2717639
Milling machine for graining panels
Feiner - June 1960 - 2940489
APPARATUS FOR CUTTING A CONTINUOUSLY MOVING STRIP OF MATERIAL
Pittman et al. - April 1970 - 3504718
SPLITTER
Matsui et al. - September 1970 - 3527393
Radially split disc formed into a spiral for siping tires
James - September 1955 - 2717639
Milling machine for graining panels
Feiner - June 1960 - 2940489
APPARATUS FOR CUTTING A CONTINUOUSLY MOVING STRIP OF MATERIAL
Pittman et al. - April 1970 - 3504718
Inventors:
Nara, Takasi (Nara-shi, JA)
Nakao, Isao (Nara-shi, JA)
Nakao, Isao (Nara-shi, JA)
Application Number:
05/006734
Publication Date:
05/16/1972
Filing Date:
01/29/1970
View Patent Images:
Export Citation:
Assignee:
Sekisui Kagaku Kogyo Kabushiki Kaisha (Osaka, JA)
Primary Class:
Other Classes:
83/672, 83/676, 83/664, 28/219
International Classes:
B26F1/20; B26F1/24; D01D5/42; B26F1/00; D01D5/00; B26D1/28
Field of Search:
225/97 83/664,665,672,676,470
Primary Examiner:
Yost, Frank T.
Claims:
1. A splitter for synthetic resin film comprising a shaft; a plurality of blade disks each disk having a shaft hole at the center thereof, a plurality of keen projections around the circumference thereof and a notch extending from the periphery thereof to the shaft hole, said blades being mounted on the shaft with said notches in alignment with each other; said keen projections being saw-toothed and formed by two sides, one of which is located forward relative to the direction of rotation of the blade disks and at an angle of 60° to 80° with respect to a radius passing through the foot of the said side and the center or rotation of the blade disk; and a pair of supports each having a shaft hole at the center and having a protuberance on one side which consists of a wall projecting substantially perpendicular to said side and a gentle helical inclined plane extending from the top of the wall to the base thereof, said supports being mounted on the shaft with the helical inclined planes of the protuberances opposed to the outermost blade disks and the edges of the perpendicular walls against the edges of the notches in the blade disks, whereby the plurality of the blade disks are pressed by said supports and twisted in a helical form along the inclined planes of the protuberances.
2. A splitter as set forth in claim 1 further comprising washer members each having a smaller diameter than that of a standard circle drawn through the keen points on the blade disk and having a shaft hole at its center and a notch extending from the periphery of the washer to the shaft hole thereof, said washer members being stacked alternately with the blade disks on the shaft.
3. A splitter as set forth in claim 2 wherein the diameter of said washer member is 0.2 to 1.6 mm smaller than a standard circle drawn through the keen edges of the blade disks.
4. A splitter as set forth in claim 1 wherein said shaft has male threads on both the ends thereof, and said splitter further comprises nuts threaded onto said threads pressing said supports against said blade disks.
2. A splitter as set forth in claim 1 further comprising washer members each having a smaller diameter than that of a standard circle drawn through the keen points on the blade disk and having a shaft hole at its center and a notch extending from the periphery of the washer to the shaft hole thereof, said washer members being stacked alternately with the blade disks on the shaft.
3. A splitter as set forth in claim 2 wherein the diameter of said washer member is 0.2 to 1.6 mm smaller than a standard circle drawn through the keen edges of the blade disks.
4. A splitter as set forth in claim 1 wherein said shaft has male threads on both the ends thereof, and said splitter further comprises nuts threaded onto said threads pressing said supports against said blade disks.
Description:
The present invention relates to a splitter for synthetic resin film and more particularly to a splitter to be used to split synthetic resin film into a network of continuous fibrous strands.
There has heretofore been proposed, as a splitter for synthetic resin film, a splitter comprising a plurality of blade disks and a plurality of circular washer members alternately stacked on a common shaft. In such a splitter, the axial distances between blade edges is fixed by the thickness of the blade disks and the washer members and cannot be made less. This means that the number and spacing of the slits or the slit pattern on the film is restricted. Thus, with such a splitter fibrous strands having a pleasant sensation to the touch cannot be produced.
In the course of developing the present invention, the inventors manufactured a splitter which comprises a plurality of blade disks each disk having at its center a shaft hole, a number of keen projections around its circumference, and a notch extending from its circumference to the shaft hole. These blade disks are fitted on the shaft in such a manner that the notches are in alignment. Flanges are secured to the shaft at both ends of the plurality of blade disks and bolts for pressing said blade disks are slid into these flanges. In this splitter, each blade disk is twisted in the axial direction of the shaft into a spiral form, the disk parting at the notch. The keen projections on the blade disk are arranged in positions slightly offset from the positions of the corresponding projections on adjacent blades. For instance, if a blade disk having 100 projections is twisted 1 mm in the axial direction of the shaft, the projections will be at intervals of 1/100 mm in the axial direction of the shaft. According to this splitter it is theoretically possible to adjust the extent of movement of a number of bolts and to thereby set the degree of twist of the blade disks appropriately and split the film very minutely and finely without being limited by the thickness of the blade disk. However, in the practical use it is very difficult to develop this feature of this splitter thoroughly for the following reason. That is, the operation of determining the degree of twist of the blade disk by adjusting the extent of movement of the many bolts is not only complicated, but also is difficult to distort the blade disk so that the projections are arranged in a helical smooth line at equal intervals, so that a slit pattern of desired design can be obtained.
It is the object of the present invention to provide an apparatus whereby a fine slit pattern of desired design is formed on synthetic resin film and thereby fibers having a pleasant feel can be easily and accurately produced.
According to the present invention there is provided an apparatus for splitting synthetic resin film, which comprises shaft; a plurality of blade disks, each having at its center a shaft hole, a plurality of keen projections around its circumference and notch extending from its circumference to the shaft hole, and which blade disks are fitted on the said shaft so that the notches are in alignment. Two supports are provided each support having at its center a shaft hole and on its one side a protuberance which consists of a wall projecting almost perpendicular to the side and a plane gently inclined in helical form from the edge of the wall to a base along the side of the support. The supports are secured on the shaft so that the protuberances face both sides of the outer most ones of the plurality of blade disks secured and assembled on shaft. The edge of the wall projects perpendicular to the side of the support and is positioned against the edge of the notches in the blade disks, so that a plurality of blade disks are pressed by supports and twisted into a helical form along the inclined plane of the protuberances.
In one embodiment of the present invention, the blade disks have keen projections which are saw-toothed and have two sides one of which is located forward relative to the direction of rotation of the blade disk and at an angle of 60° to 80°with respect to a normal passing the foot of the said side, the normal being of a circle having its center at the center of rotation of the blade disk.
In another embodiment of the present invention, the splitter is provided with circular washer members each of which has a smaller diameter than a standard circle drawn through the tips of the keen projections on the blade disks, and has at its center a shaft hole, and has a notch extending from the circumference to the shaft hole, and which are stacked on the shaft alternately with the blade disks so that the notches are aligned with the notches of the blade disks.
Further the diameter of washer member is 0.2 to 1.6 mm smaller than that of the standard circle drawn through the tips of the keen projections of the blade disks.
In another embodiment of the present invention, the shaft is threaded on both ends, a nut is threaded on said threaded parts of the shaft and thereby blade disks are pressed by protuberances on the supports.
Other and further features of the present invention will be more clear by the following description of the invention with reference to the accompanying drawings.
FIG. 1 is a plan view showing an embodiment of the blade disks of the present invention.
FIG. 2 is an enlarged partial plan view showing another embodiment of the blade disk.
FIGS. 3a and 3b are perspective views illustrating one embodiment of a pair of supports.
FIG. 4 is a side view partly in section showing a splitter of the present invention.
FIG. 5 is a plan view showing one embodiment of a washer member according to the invention.
FIG. 6 is a diagrammatic view of an apparatus showing the use of a splitter according to the invention.
In order that the invention may be more clearly understood and more readily carried into effect, one embodiment thereof will be described in more detail below with reference to the accompanying drawings.
In FIGS. 1 and 2, numeral 11 designating the disk portion of blade disk 1. The material of the disk is preferably rigid, and should have a thickness of 0.2 mm or above or should be steel plate. Numeral 12 designates a shaft hole provided at the center of disk 11. The shape is illustrated as circular, but it can be any shape which is the same as the cross-sectional form of the shaft fitted with blade disk 1. Numeral 13 designates a plurality of keen projections located on the circumference of disk 11. It is preferable that the projections be provided so that their tips are located in alignment on the circumference of a circle concentric with disk 11. The shape of the projection influences greatly the efficiency of splitting the synthetic resin film.
The inventors have found that the shape of projection 13 is best when it has a saw-toothed form. In FIG. 2, with an increase in angle θ of side 131, resistance introduced when projection 13 cuts into the film decreases and moreover projection 13 leaves the film smoothly after the completion of cutting without damaging the film. However, if angle θ becomes too great, the number of projections which can be provided on a disk having a specified size gets smaller and the disk becomes unsuitable for splitting film. The angle θ aforementioned is between the side 131 which is one of two sides 131 and 132 forming the saw-toothed projection and is the side located forward relative to the rotating direction of the blade disk 1, and a radius through the foot of the said side 131 of a circle having its center at the center of rotation of blade disk 11. According to this experience, it is preferable that angle θ ranges from 60° to 80°. In providing the circumference of disk 11 with projections 13, it is preferable that projections 13 be cut or punched together with disk 11 as a whole from a plate and then finished so they are keen. However blades having sharp forms such as needle points, etc. previously prepared may be secured to the circumference of the disk. An when blade disk 1 has been prepared by processing metal plates such as steel plate, it is preferable that after the processing, chemical treatments combining hardening and surface treatments, for instance a treatment according to Parker's method be used. When blade disks are processed, small barbs around the circumference of projection 13 occur. If they are allowed to remain without being removed, they damage film and cause fuzzing when synthetic resin film is being split. Said chemical treatments can eliminate these barbs completely. Numeral 14 designates a notch which extends from the circumference of disk 11 to shaft hole 12 provided at one place in the disk. Numeral 15 designates a recess, into which a wedge is driven, mounted on the circumference of shaft hole 12 and located in a predetermined position relative to the notch.
There is no limit to the size of blade disk 1 but in practical use the diameter of a standard circle drawn with through tips of projections 13 ranges preferably from 15 to 100 mm.
In FIGS. 3a and 3b , a pair of supports 2 are shown. Numeral 21 designates a shaft hole, and numeral 22 designates a recess for inserting a wedge. They are arranged so as to correspond to shaft hole 12 of blade disk 1 and recess 15 on shaft hole 12. The cross sectional shape of support 2 is that of a ring having an optional size. Numeral 23 is a protuberance mounted on one of the sides of support 2, which comprises wall 231 protruding from the side of support 2 almost perpendicular thereto and inclined plane 232 gently extending in a helical form from edge 24 of wall 231 to base 25, said edge 24, that is a ridge formed by the junction of wall 231 and inclined plane 232 being positioned at the end of notch 14 of blade disk 1.
In FIG. 4 a plurality of blade disks 1 thus constructed and a pair of supports 2 are secured on on shaft 3 in an assembly which constitutes a splitter to split a synthetic resin film. Numeral 3 designates a shaft and at both ends of the shaft are male threads. The shaft is provided with a surface groove (not shown) extending parallel to the axis thereof for receiving a wedge. Blade disks 1 are arranged so that notches 14 are in alignment with each other, resulting in recesses 15 also being in alignment with each other, and recesses 15 are opposed to said groove of shaft 3. A pair of supports 2 are secured on shaft 3 so that edges 24 of walls 231 face notches 14 of blade disks 1. A wedge is driven into the space formed by recesses 15 of blade disks 1, recesses 22 of supports 2, and the groove of shaft 3 to prevent the blade disks and the supports from moving in the peripheral direction of shaft 3. Nuts 4 are threaded from both sides of supports 2 onto the male threads on both ends of shaft 3 and a plurality of blade disks 1 and supports 2 are thereby secured on the shaft. Under these conditions, blade disks 1 are pressed in the axial direction of the shaft with by protuberances 23 of supports 2 and deformed along projected, inclined walls 232 in a helical form. The positions of projections 13 on the circumference of blade disks 1 are shifted in the axial direction also. For instance, when blade disk 1 having 100 projections 13 at equal distances therearound is deformed in a helical form so that notch 14 opens 1 mm in the axial direction, projections 13 arranged in alignment on the blade disk are located in positions shifted from each other at equal intervals of 1/100 mm in the axial direction.
Numeral 5 in FIG. 4 shows washer members stacked alternately with blade disks 1 on the shaft. Washer members 5 are circular and provided with shaft holes 51, recesses 52 and notches 53 as in blade disks 1. The thickness of each washer member may be optional except the diameter thereof is smaller than that of a standard circle drawn through the projections 13 of blade disk 1. These washer members 5 also act as means for adjusting the gauge of projections 13 in the axial direction but act more to adjust height h or projection 13. According to the experience of the inventors, with an increase in height h of projection 13, "fuzzing" which is undesirable for the product increases when the film is split, and in handling the conventional thickness of synthetic resin film, when the height h of projection 13 is in to a range from 0.1 to 0.8 mm, "fuzzing" can be prevented. However, in manufacturing blade disk 1 with a plurality of projections 13 having such a small height h it requires much labor and is very expensive to finish the base as well as the tip of projection 13. In the present invention, this problem has been solved by stacking blade disks 1 and washer members 5 alternately with each other, the diameter of the latter being 0.2 to 1.6 mm smaller than that of a standard circle drawn through the tips of projections 13, thereby covering the unnecessary base of projections 13 and adjusting height h of projections 13 to an appropriate value.
One embodiment of an apparatus for using splitter will be described below with reference to FIG. 6.
In FIG. 6, numeral 1 designates a blade disk having a plurality of projections constituting a splitter according to the present invention. This blade disk is arranged to rotate at an optional speed in the direction of the arrow so that said side 131 of projection 13 is positioned forward relative to the rotation of the disk. The rotation of blade disk 1 is carried out with a drive system (not shown). Numeral 6 designates a film, which is moved at a specified speed in the direction of the arrow by feed rolls 71 and take-up rolls 72. Synthetic resin film, which is uniaxially drawn and easy to split longitudinally is best as such a material. The splitting of film 6 is carried out by bringing it into contact with rotating projections 13 of blade disk 1 by means of guide rolls 81 and 82 during the transportation of film 6 between rolls 71 and 72. The length of slit formed in the film can be varied by changing the length of the film contacting the blade disk 1 which change is performed by moving guide rolls 81 and 82 up and down. Or it can be controlled by changing the ratio of linear speed of projection 13 to the running speed of film 6.
As stated above, since a plurality of blade disks are mounted on the shaft and axially twisted in a helical form in the present splitter, many sharp projections disposed on the circumference of the blade disk are located in positions axially shifted from each other. Accordingly the splitter of the present invention can split film very finely by appropriately setting the degree of twisting of the blade disk and thereby arranging the projections at intervals less than the thickness of the blade disk. Further as the distortion of the disk can be such as to form it into the predetermined shape, being pressed by the protuberances of the supports, the operations of distorting the blade disk to obtain a desired slit pattern are so simple that they can be done accurately by any operator, requiring no skill at all.
In the present invention washer members and blade disks are arranged alternately with each other, and so it is possible to optionally adjust the height of the projections by appropriately choosing the thickness of the washer member and to manufacture the splitter at a low cost, which splitter has projections having a low height and suitable for splitting film finely. Further when projections are damaged, the mere replacement of the blade disks having damaged projections will do, and consequently, the maintenance is very simple. In the present invention, the arrangement of the projections can be varied by an optional selection of the following:
1. Gauge of projections 13,
2. Thickness of blade disk 1,
3. Whether washer member 5, is used or not; thickness of washer member 5.
It is to be understood that various changes and modifications can be made by one skilled in the art without departing from the scope and spirit of the invention.
There has heretofore been proposed, as a splitter for synthetic resin film, a splitter comprising a plurality of blade disks and a plurality of circular washer members alternately stacked on a common shaft. In such a splitter, the axial distances between blade edges is fixed by the thickness of the blade disks and the washer members and cannot be made less. This means that the number and spacing of the slits or the slit pattern on the film is restricted. Thus, with such a splitter fibrous strands having a pleasant sensation to the touch cannot be produced.
In the course of developing the present invention, the inventors manufactured a splitter which comprises a plurality of blade disks each disk having at its center a shaft hole, a number of keen projections around its circumference, and a notch extending from its circumference to the shaft hole. These blade disks are fitted on the shaft in such a manner that the notches are in alignment. Flanges are secured to the shaft at both ends of the plurality of blade disks and bolts for pressing said blade disks are slid into these flanges. In this splitter, each blade disk is twisted in the axial direction of the shaft into a spiral form, the disk parting at the notch. The keen projections on the blade disk are arranged in positions slightly offset from the positions of the corresponding projections on adjacent blades. For instance, if a blade disk having 100 projections is twisted 1 mm in the axial direction of the shaft, the projections will be at intervals of 1/100 mm in the axial direction of the shaft. According to this splitter it is theoretically possible to adjust the extent of movement of a number of bolts and to thereby set the degree of twist of the blade disks appropriately and split the film very minutely and finely without being limited by the thickness of the blade disk. However, in the practical use it is very difficult to develop this feature of this splitter thoroughly for the following reason. That is, the operation of determining the degree of twist of the blade disk by adjusting the extent of movement of the many bolts is not only complicated, but also is difficult to distort the blade disk so that the projections are arranged in a helical smooth line at equal intervals, so that a slit pattern of desired design can be obtained.
It is the object of the present invention to provide an apparatus whereby a fine slit pattern of desired design is formed on synthetic resin film and thereby fibers having a pleasant feel can be easily and accurately produced.
According to the present invention there is provided an apparatus for splitting synthetic resin film, which comprises shaft; a plurality of blade disks, each having at its center a shaft hole, a plurality of keen projections around its circumference and notch extending from its circumference to the shaft hole, and which blade disks are fitted on the said shaft so that the notches are in alignment. Two supports are provided each support having at its center a shaft hole and on its one side a protuberance which consists of a wall projecting almost perpendicular to the side and a plane gently inclined in helical form from the edge of the wall to a base along the side of the support. The supports are secured on the shaft so that the protuberances face both sides of the outer most ones of the plurality of blade disks secured and assembled on shaft. The edge of the wall projects perpendicular to the side of the support and is positioned against the edge of the notches in the blade disks, so that a plurality of blade disks are pressed by supports and twisted into a helical form along the inclined plane of the protuberances.
In one embodiment of the present invention, the blade disks have keen projections which are saw-toothed and have two sides one of which is located forward relative to the direction of rotation of the blade disk and at an angle of 60° to 80°with respect to a normal passing the foot of the said side, the normal being of a circle having its center at the center of rotation of the blade disk.
In another embodiment of the present invention, the splitter is provided with circular washer members each of which has a smaller diameter than a standard circle drawn through the tips of the keen projections on the blade disks, and has at its center a shaft hole, and has a notch extending from the circumference to the shaft hole, and which are stacked on the shaft alternately with the blade disks so that the notches are aligned with the notches of the blade disks.
Further the diameter of washer member is 0.2 to 1.6 mm smaller than that of the standard circle drawn through the tips of the keen projections of the blade disks.
In another embodiment of the present invention, the shaft is threaded on both ends, a nut is threaded on said threaded parts of the shaft and thereby blade disks are pressed by protuberances on the supports.
Other and further features of the present invention will be more clear by the following description of the invention with reference to the accompanying drawings.
FIG. 1 is a plan view showing an embodiment of the blade disks of the present invention.
FIG. 2 is an enlarged partial plan view showing another embodiment of the blade disk.
FIGS. 3a and 3b are perspective views illustrating one embodiment of a pair of supports.
FIG. 4 is a side view partly in section showing a splitter of the present invention.
FIG. 5 is a plan view showing one embodiment of a washer member according to the invention.
FIG. 6 is a diagrammatic view of an apparatus showing the use of a splitter according to the invention.
In order that the invention may be more clearly understood and more readily carried into effect, one embodiment thereof will be described in more detail below with reference to the accompanying drawings.
In FIGS. 1 and 2, numeral 11 designating the disk portion of blade disk 1. The material of the disk is preferably rigid, and should have a thickness of 0.2 mm or above or should be steel plate. Numeral 12 designates a shaft hole provided at the center of disk 11. The shape is illustrated as circular, but it can be any shape which is the same as the cross-sectional form of the shaft fitted with blade disk 1. Numeral 13 designates a plurality of keen projections located on the circumference of disk 11. It is preferable that the projections be provided so that their tips are located in alignment on the circumference of a circle concentric with disk 11. The shape of the projection influences greatly the efficiency of splitting the synthetic resin film.
The inventors have found that the shape of projection 13 is best when it has a saw-toothed form. In FIG. 2, with an increase in angle θ of side 131, resistance introduced when projection 13 cuts into the film decreases and moreover projection 13 leaves the film smoothly after the completion of cutting without damaging the film. However, if angle θ becomes too great, the number of projections which can be provided on a disk having a specified size gets smaller and the disk becomes unsuitable for splitting film. The angle θ aforementioned is between the side 131 which is one of two sides 131 and 132 forming the saw-toothed projection and is the side located forward relative to the rotating direction of the blade disk 1, and a radius through the foot of the said side 131 of a circle having its center at the center of rotation of blade disk 11. According to this experience, it is preferable that angle θ ranges from 60° to 80°. In providing the circumference of disk 11 with projections 13, it is preferable that projections 13 be cut or punched together with disk 11 as a whole from a plate and then finished so they are keen. However blades having sharp forms such as needle points, etc. previously prepared may be secured to the circumference of the disk. An when blade disk 1 has been prepared by processing metal plates such as steel plate, it is preferable that after the processing, chemical treatments combining hardening and surface treatments, for instance a treatment according to Parker's method be used. When blade disks are processed, small barbs around the circumference of projection 13 occur. If they are allowed to remain without being removed, they damage film and cause fuzzing when synthetic resin film is being split. Said chemical treatments can eliminate these barbs completely. Numeral 14 designates a notch which extends from the circumference of disk 11 to shaft hole 12 provided at one place in the disk. Numeral 15 designates a recess, into which a wedge is driven, mounted on the circumference of shaft hole 12 and located in a predetermined position relative to the notch.
There is no limit to the size of blade disk 1 but in practical use the diameter of a standard circle drawn with through tips of projections 13 ranges preferably from 15 to 100 mm.
In FIGS. 3a and 3b , a pair of supports 2 are shown. Numeral 21 designates a shaft hole, and numeral 22 designates a recess for inserting a wedge. They are arranged so as to correspond to shaft hole 12 of blade disk 1 and recess 15 on shaft hole 12. The cross sectional shape of support 2 is that of a ring having an optional size. Numeral 23 is a protuberance mounted on one of the sides of support 2, which comprises wall 231 protruding from the side of support 2 almost perpendicular thereto and inclined plane 232 gently extending in a helical form from edge 24 of wall 231 to base 25, said edge 24, that is a ridge formed by the junction of wall 231 and inclined plane 232 being positioned at the end of notch 14 of blade disk 1.
In FIG. 4 a plurality of blade disks 1 thus constructed and a pair of supports 2 are secured on on shaft 3 in an assembly which constitutes a splitter to split a synthetic resin film. Numeral 3 designates a shaft and at both ends of the shaft are male threads. The shaft is provided with a surface groove (not shown) extending parallel to the axis thereof for receiving a wedge. Blade disks 1 are arranged so that notches 14 are in alignment with each other, resulting in recesses 15 also being in alignment with each other, and recesses 15 are opposed to said groove of shaft 3. A pair of supports 2 are secured on shaft 3 so that edges 24 of walls 231 face notches 14 of blade disks 1. A wedge is driven into the space formed by recesses 15 of blade disks 1, recesses 22 of supports 2, and the groove of shaft 3 to prevent the blade disks and the supports from moving in the peripheral direction of shaft 3. Nuts 4 are threaded from both sides of supports 2 onto the male threads on both ends of shaft 3 and a plurality of blade disks 1 and supports 2 are thereby secured on the shaft. Under these conditions, blade disks 1 are pressed in the axial direction of the shaft with by protuberances 23 of supports 2 and deformed along projected, inclined walls 232 in a helical form. The positions of projections 13 on the circumference of blade disks 1 are shifted in the axial direction also. For instance, when blade disk 1 having 100 projections 13 at equal distances therearound is deformed in a helical form so that notch 14 opens 1 mm in the axial direction, projections 13 arranged in alignment on the blade disk are located in positions shifted from each other at equal intervals of 1/100 mm in the axial direction.
Numeral 5 in FIG. 4 shows washer members stacked alternately with blade disks 1 on the shaft. Washer members 5 are circular and provided with shaft holes 51, recesses 52 and notches 53 as in blade disks 1. The thickness of each washer member may be optional except the diameter thereof is smaller than that of a standard circle drawn through the projections 13 of blade disk 1. These washer members 5 also act as means for adjusting the gauge of projections 13 in the axial direction but act more to adjust height h or projection 13. According to the experience of the inventors, with an increase in height h of projection 13, "fuzzing" which is undesirable for the product increases when the film is split, and in handling the conventional thickness of synthetic resin film, when the height h of projection 13 is in to a range from 0.1 to 0.8 mm, "fuzzing" can be prevented. However, in manufacturing blade disk 1 with a plurality of projections 13 having such a small height h it requires much labor and is very expensive to finish the base as well as the tip of projection 13. In the present invention, this problem has been solved by stacking blade disks 1 and washer members 5 alternately with each other, the diameter of the latter being 0.2 to 1.6 mm smaller than that of a standard circle drawn through the tips of projections 13, thereby covering the unnecessary base of projections 13 and adjusting height h of projections 13 to an appropriate value.
One embodiment of an apparatus for using splitter will be described below with reference to FIG. 6.
In FIG. 6, numeral 1 designates a blade disk having a plurality of projections constituting a splitter according to the present invention. This blade disk is arranged to rotate at an optional speed in the direction of the arrow so that said side 131 of projection 13 is positioned forward relative to the rotation of the disk. The rotation of blade disk 1 is carried out with a drive system (not shown). Numeral 6 designates a film, which is moved at a specified speed in the direction of the arrow by feed rolls 71 and take-up rolls 72. Synthetic resin film, which is uniaxially drawn and easy to split longitudinally is best as such a material. The splitting of film 6 is carried out by bringing it into contact with rotating projections 13 of blade disk 1 by means of guide rolls 81 and 82 during the transportation of film 6 between rolls 71 and 72. The length of slit formed in the film can be varied by changing the length of the film contacting the blade disk 1 which change is performed by moving guide rolls 81 and 82 up and down. Or it can be controlled by changing the ratio of linear speed of projection 13 to the running speed of film 6.
As stated above, since a plurality of blade disks are mounted on the shaft and axially twisted in a helical form in the present splitter, many sharp projections disposed on the circumference of the blade disk are located in positions axially shifted from each other. Accordingly the splitter of the present invention can split film very finely by appropriately setting the degree of twisting of the blade disk and thereby arranging the projections at intervals less than the thickness of the blade disk. Further as the distortion of the disk can be such as to form it into the predetermined shape, being pressed by the protuberances of the supports, the operations of distorting the blade disk to obtain a desired slit pattern are so simple that they can be done accurately by any operator, requiring no skill at all.
In the present invention washer members and blade disks are arranged alternately with each other, and so it is possible to optionally adjust the height of the projections by appropriately choosing the thickness of the washer member and to manufacture the splitter at a low cost, which splitter has projections having a low height and suitable for splitting film finely. Further when projections are damaged, the mere replacement of the blade disks having damaged projections will do, and consequently, the maintenance is very simple. In the present invention, the arrangement of the projections can be varied by an optional selection of the following:
1. Gauge of projections 13,
2. Thickness of blade disk 1,
3. Whether washer member 5, is used or not; thickness of washer member 5.
It is to be understood that various changes and modifications can be made by one skilled in the art without departing from the scope and spirit of the invention.