Background Art As well known to those skilled in the art, a plastic film is very thin and very pliable, thus being easily stretchable. When it is necessary to cut such a plastic film into a desired rectangular piece, the plastic film is spread out on a flat table prior to being cut vertically and horizontally using a cutter, such as a sharpened scissors or knife. In such a case, the plastic film may be cut vertically prior to horizontally or cut horizontally prior to vertically.

On the other hand, a rolled plastic film, wound around and fed from a bobbin, may be cut longitudinally with a constant width using a simple rotary cutter prior to being cut transversely with a desired length using a sharpened cutter, such as a scissors or knife.

In the prior art, a board cutter, having a blade lever in the same manner as a paper-trimming cutter, has been used for cutting a plastic film. In such a board cutter, the blade lever with a cutting blade is moved relative to the fixed blade of a table, thus cutting the plastic film into a desired piece through a scissoring motion.

However, it is impossible for such a board cutter to longitudinally cut a rolled plastic film fed from a bobbin.

Therefore, when it is necessary to cut a rolled plastic film into a rectangular piece using such a board cutter, the film is cut longitudinally with a constant width using a scissors or a knife prior to being cut transversely with a desired length using the board cutter.

On the other hand, a rotary cutting machine has been propose and used to cut such a rolled plastic film into a desired piece. In such a rotary cutting

machine, two rotary cutters are mounted to opposite end portions of a rotating shaft with a desired interval being formed between the two cutters. The rolled plastic film is fed from the bobbin and passes over the two cutters, thus being cut along two longitudinal lines with a desired constant width. However, this rotary cutting machine cannot cut the plastic film transversely. Therefore, it is necessary for a user of such a rotary cutting machine to cut the film transversely with a desired length using a scissors or a knife after cutting the film longitudinally with a desired constant width using the cutting machine.

Since the conventional rotary cutting machines, used for cutting a rolled plastic film into a desired rectangular piece, are designed to cut the film along a single direction, they are free from a means for commonly cutting the film horizontally and vertically or in X-and Y-axial directions. Therefore, the conventional film cutting machines are very inconvenient to users since they force the users to move the films several times on tables while trimming the films using the machines. This also makes the thin and pliable films undesirably stretched or deformed, and so it is very difficult to trim a rolled plastic film into a desired rectangular piece.

The conventional film cutting machines are thus problematic in that they result in a large quantity of film loss, damage the film surface and are very inconvenient to the users. Another problem of the conventional film cutting machines resides in that the operational efficiency of the machines is very low.

Disclosure of the Invention Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a portable cutting machine, which is designed to cut a rolled plastic film, wound around and fed from a bobbin, horizontally and vertically or in X-and Y-axial directions into a rectangular piece with desired width and length.

Another object of the present invention is to provide a cutting machine, which effectively, quickly and clearly cuts a variety of sheets, such as a plastic

film, a plastic sheet and wallpaper, horizontally and vertically or in X-and Y-axial directions into a rectangular piece with desired width and length.

In order to accomplish the above objects, the present invention provides a cutting machine for plastic films. The machine of this invention has a film feeding unit and a film drawing unit. The film feeding unit consists of two rollers rotatably held on opposite sidewalls of a housing at their opposite ends and are used for primarily feeding a plastic film from a bobbin. The film drawing unit consists of two rollers rotatably held on the sidewalls of the housing at their opposite ends and are used for drawing the film from the film feeding unit while appropriately tensioning the film. The cutting machine also has two cutting units, or a longitudinal cutting unit and a transverse cutting unit. The longitudinal cutting unit is positioned between the feeding and drawing units and is used for cutting the film longitudinally. The longitudinal cutting unit has two rotary cutting units. Each of the two rotary cutting units has both a cutting roller and a support roller and is movable along a plurality of upper and lower guide rails extending in parallel to the rollers of the film feeding and drawing units. The two rotary cutting units of the longitudinal cutting unit are also selectively fixed to the guide rails, thus being adjustable in an interval between them. The transverse cutting unit is positioned behind the film drawing unit and is used for cutting the film transversely. The transverse cutting unit has a rotary cutting unit, which consists of a rotary cutting disc and a pinion gear commonly mounted to a rotating shaft. The pinion gear also engages with a rack gear of a guide rail, and so the rotary cutting unit of the transverse cutting unit is movable along the guide rail in opposite directions by a chain transmission mechanism, thus cutting the film transversely. A drive unit, provided on a sidewall of the housing, drives all the units of the cutting machine of this invention. The cutting machine thus effectively, quickly and clearly cuts a rolled plastic film, wound around and fed from a bobbin, longitudinally and transversely while continuously feeding the film.

In the cutting machine of this invention, the two cutting units are individually produced as a module, and so they are easily set or removed from the housing.

In the operation of the cutting machine, the plastic film, horizontally fed from the bobbin by the film feeding and drawing units, is primarily cut longitudinally along two lines by the rotary cutting units of the longitudinal cutting unit while maintaining a desired constant width.

The film is, thereafter, cut transversely by the rotary cutting unit of the transverse cutting unit, thus finally forming a desired rectangular film piece. In such a case, the rotary cutting unit of the transverse cutting unit is moved along the guide rail by the chain transmission mechanism.

During the operation of the cutting machine, the desired length of the film may be automatically measured by a counter (not shown), which counts the length of the film fed by the film drawing unit. Alternatively, the desired length of the film may be manually measured using a scale.

Due to the longitudinal and transverse cutting units, the cutting machine of this invention cuts the film in X-and Y-axial directions, thus effectively, quickly and clearly cutting the film into a desired rectangular piece without moving the film on a table different from conventional cutting machines.

The film after a cutting operation of the cutting machine maintains its flatness and is free from being partially stretched or deformed, and so it is possible to clearly cut the film into a desired piece having a precise dimension using the cutting machine.

Since the units of the cutting machine are produced as modules, it is possible to effectively produce the cutting machines through a mass production while reducing the production cost and improving the productivity of the machines.

The cutting machine of this invention is light in weight and is portable, thus being easily movable in any place. The cutting machine is easy to operate, and so a user easily operates the machine even though he may not be well-skilled.

In addition, all the rotary cutting units are set within the housing of the machine, thereby being free from causing injury to users. This finally improves the operational safety of the cutting machine.

All the units of the cutting machine are produced as modules, and so it is

possible to change damaged or malfunctioning units with new units without purchasing a new cutting machine. This finally reduces the maintenance cost of the cutting machine.

The cutting machine of this invention is less likely to be broken, but is necessarily abraded at the cutting blades of the rotary cutting units. Such an abraded cutting blade may be easily sharpened using a conventional grinding machine or may be changed with a new one. This also reduces the maintenance cost of the cutting machine.

The cutting machine is effectively used for cutting a variety of sheets, such as ultraviolet-coated films, plastic films and wall papers. This cutting machine is more preferably used for cutting a rolled film.

Brief Description of the Drawings The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Fig. 1 is a partially exploded perspective view of a cutting machine in accordance with the preferred embodiment of the present invention; Fig. 2 is a perspective view of a longitudinal cutting unit included in the cutting machine of this invention; Fig. 3 is a side sectional view of a rotary cutting unit included in the longitudinal cutting unit of Fig. 2; Fig. 4 is a front view of the rotary cutting unit of Fig. 3; Fig. 5 is a perspective view of a transverse cutting unit included in the cutting machine of this invention; Fig. 6 is a top plan view of the transverse cutting unit of Fig. 5; Fig. 7 is a side sectional view of the transverse cutting unit of Fig. 5; Fig. 8 is a front view of a rotary cutting unit included in the transverse cutting unit of Fig. 5; Fig. 9 is a side sectional view of the rotary cutting unit of Fig. 8;

Fig. 10 is a front view of the rotary cutting unit of Fig. 8; and Fig. 11 is a perspective view of a drive unit included in the cutting machine of this invention.

Best Mode for Carrying Out the Invention Fig. 1 shows the construction of a cutting machine in accordance with the preferred embodiment of this invention.

As shown in the drawing, the cutting machine of this invention comprises a housing"A"having a plurality of units, or a film feeding unit"B", a film drawing unit"C", a longitudinal cutting unit"D", and a transverse cutting unit "E". This cutting machine is designed to cut a rolled plastic film, wound around and fed from a bobbin, horizontally and vertically or in X-and Y-axial directions into a rectangular piece having desired width and length. In the above cutting machine, the film feeding unit"B"consists of two rollers and is used for feeding the plastic film from the bobbin horizontally. The film drawing unit"C"consists of two rollers and is used for drawing the film from the film feeding unit"B" horizontally while appropriately tensioning the film. The longitudinal cutting unit"D"has two rotary cutting units and is used for longitudinally cutting the film using the cutting rollers of the two rotary cutting units. In the longitudinal cutting unit"D", the two cutting units are designed to be movable along a plurality of guide rails, thus being adjustable in the interval between them. The transverse cutting unit"E"has one rotary cutting unit and is used for transversely cutting the film using a rotary cutting disc of the cutting unit. In the transverse cutting unit "E", the rotary cutting unit is movable along a guide rail by a chain transmission mechanism, thus cutting the film transversely.

The housing"A"has two sidewalls 102 on opposite sides of its bottom wall 101, with a boss 103 being provided on the inside surface of each sidewall 102 at a front portion and being used for holding an associated end of a bobbin"b" of a rolled plastic film"f'.

Two inside recesses 102a and 102b are formed abreast on the top edge of

each sidewall 102 of the housing"A"and respectively and removably seat the two cutting units"D"and"E"therein.

The film feeding unit"B"consists of two rollers, or drive and driven rollers 201 and 202, which are held on the two sidewalls 102 at their opposite ends and are parallely placed at lower and upper positions while being brought into external contact with each other. On the other hand, the film drawing unit"C" consists of two rollers, or drive and drawing rollers 301 and 302, which are held on the two sidewalls 102 at their opposite ends and are parallely placed at lower and upper positions while being brought into external contact with each other. The two rollers 301 and 302 of the film drawing unit"C"are parallel to the rollers 201 and 202 of the film feeding unit"B".

The two drive rollers 201 and 301 of the two units"B"and"C"are operated in conjunction with the gears of a drive unit"F", which will be described later herein. The two units"B"and"C"cooperate with each other while feeding the plastic film"f"from the bobbin"b"horizontally.

The driven roller 202 and the drawing roller 302 are adjustable in their positions relative to their associated drive rollers 201 and 301 using adjusting screws provided at the upper portions of the sidewalls 102. The object of such an adjustment in the positions of the two rollers 202 and 302 is to adjust the nip pressure between the two rollers 201 and 202 of the feeding unit"B"and the nip pressure between the two rollers 301 and 302 of the drawing unit"C".

In the cutting machine of this invention, the above-mentioned structure of the two units"B"and"C"is well known to those skilled in the art.

As shown in Fig. 2, the longitudinal cutting unit"D"consists of two upper guide rails 401 and one lower guide rail 402. The two upper guide rails 401 parallely extend at the upper portion of the unit"D"while being held by two sidewalls 403 at their opposite ends, thus forming the upper frame of the unit"D".

The lower guide rail 402 extends at the lower portion of the unit"D"in parallel to the two upper guide rails 401 while being held by the two sidewalls 403 at its opposite ends.

As shown in Figs. 3 and 4, each rotary cutting unit of the longitudinal

cutting unit"D"consists of two bodies, or upper and lower movable bodies 404 and 406. The upper body 104 has a top guide plate 405, which has a lower projection 405a and movably engages with the guide groove 401a of a rail 401 at the projection 405a. On the other hand, the lower body 406 has a guider 406a and movably engages with the guide groove 402a of the lower guide rail 402, thus being movable along the lower guide rail 402.

The top guide plate 405 is movably mounted to one of the upper guide rails 401 by an adjusting screw 405b, which is tightened by a but 405c within the guide groove 401 a of the guide rail 401. A handle 405d is provided at the top of the screw 405b and is used for selectively fixing the rotary cutting unit to the upper guide rails 401 at a desired position.

A cutting roller 408, having an annular cutting blade 407 along its circumferential surface, is rotatably set within the upper body 404 while being normally biased downwardly by a spring 412. That is, the cutting roller 408 is fitted over a rotating shaft 409 and is rotatably mounted to a bracket 410. The bracket 410 is set within the upper body 404, with a pressure plate 413 being positioned above the top plate of the bracket 410. The spring 412 is positioned between the top plate of the bracket 410 and the pressure plate 413. The pressure plate 413 is stopped by the lower end of an adjusting screw 414 screwed into the guide plate 405, and so the bracket 410 is adjustable in its downward pressure by the adjusting screw 414.

The opposite ends of the rotating shaft 409 of the cutting roller 408 are movably seated in the bearing holes 404a of the upper body 404 so as to be slightly movable in a vertical direction. Therefore, the cutting roller 408 having the cutting blade 407 is also adjustable in its downward pressure.

In the lower body 406, a support roller 408a is supported by a bracket 410a at its rotating shaft 409a. The above support roller 408a engages with the cutting roller 408 of the upper body 404 and is rotatable along with the cutting roller 408. The support roller 408a has an annular groove along its circumferential surface at a position corresponding to the annular cutting blade 407 of the cutting roller 408.

The two bodies 404 and 406 are normally integrated into a single body by a side connection plate 415, and so the two bodies 404 and 406 are movable along the guide rails 401 and 402 at the same time.

However, since the connection plate 415 is designed to separate the two bodies 404 and 406 from each other, it is possible to separately move the two bodies 404 and 406 to desired positions prior to integrating them into a single body.

The above longitudinal cutting unit"D"has a plurality of mounting holes 401 d at its opposite ends and is mounted to the recesses 102a of the housing"A" using set screws passing through the mounting holes 401d. In the drawings, the two rotary cutting units of the longitudinal cutting unit"D"are designated by the reference character"k". Due to the adjustable rotary cutting units"k", it is possible for the longitudinal cutting unit"D"to cut the film while adjusting the desired width of the film.

A scale"s"is longitudinally attached along the front surface of one of the two upper guide rails 401. It is thus possible to precisely set a desired width of the film by appropriately positioning the points 405s of the top guide plates 405 of the two rotary cutting units"k"relative to the scale"s". That is, it is possible to precisely set a desired interval between the two rotary cutting units"k".

As shown in Figs. 5 to 7, the transverse cutting unit"E", positioned behind the film drawing unit"C"and used for cutting the film transversely, comprises two guide rails 502 and 503 extending in parallel to the rollers of the film drawing unit"C". The two guide rails 502 and 503 are held by two sidewalls 501 at their opposite ends. A lower frame 504 extends in parallel to the two guide rails 502 and 503 at the lower portion of the unit"E".

As shown in Figs. 8 and 9, the transverse cutting unit"E"has one rotary cutting unit, which is designated by the reference character"k'"in the drawings.

The above rotary cutting unit movably engages with the guide grooves 502a and 503a of the guide rails 502 and 503 at its top guide plate 505a, thus being movable along the guide rails 502 and 503. The above unit"E"has a cutter body 505. In the cutter body 505, a rotary cutting disc 506 and a pinion gear 507 are mounted to

opposite ends of a rotating shaft 508.

The cutter body 505 movably engages with a rack gear 507a of one of the guide rails 502 at the pinion gear 507, thus being movable along the rack gear 507a. The rotary cutting disc 506, eccentrically mounted to the rotating shaft 508, is movable along a spring-biased support 509 of the lower frame 504 while being brought into contact with the support 509. The cutting disc 506 forms a scissoring action in cooperation with a fixed cutting edge 506a, thus cutting the film transversely. In such a case, the support 509 is normally biased upwardly by a spring 509s, while the fixed cutting edge 506a is mounted along the top edge of the lower frame 504.

A pressure plate 504a, biased by a cam 504b and a spring 504c, is provided at the top wall of the lower frame 504. The pressure plate 504a may be thus separated from the top wall of the lower frame 504 by rotating the cam 504b.

In such a case, the film is allowed to pass through the gap between the plate 504a and the frame 504. When the pressure plate 504a is brought into elastic contact with the top wall of the frame 504 by returning the cam 504 to its original position, the plate 504 holds the film at the gap between the plate 504a and the frame 504.

The transverse cutting unit"E"also has a chain transmission mechanism used for moving the cutter body 505. In the chain transmission mechanism, a chain 511 movably passes through a hole 505b of the body 505 and is wrapped around two chain sprockets 510 and 510a at opposite ends of the unit"E"prior to being fixed to opposite end walls of the body 505 at its opposite ends. Therefore, the cutter body 505 is movable in a desired direction along the guide rails 502 and 503 by a rotating action of the two chain sprockets 510 and 510a.

When the cutter body 505 is moved in a desired direction along the guide rails 502 and 503 by the chain transmission mechanism, the pinion gear 507 is rotated along the rack gear 507a, thus forming a rotating force. This rotating force allows the cutting disc 506 to form a desired scissoring action in cooperation with the fixed cutting edge 506a while cutting the film transversely.

Since the cutting disc 506 is eccentrically mounted to the rotating shaft : 508 as best seen in Fig. 10, the disc 506 forms a waving action while being rotated

along the fixed cutting edge 506a, thus more easily forming the desired scissoring action.

In the same manner as that described for the longitudinal cutting unit"D", the transverse cutting unit"E"has a plurality of mounting holes 501d at its opposite ends and is mounted. to the recesses 102b of the housing"A"using set screws passing through the mounting holes 501d.

A power transmission gear 510c is provided at the sprocket 510 and is rotated in conjunction with the drive unit"F", which is provided at the sidewall of the housing"A"as will be described later herein.

During the operation of the cutting machine, the desired length of the film may be automatically measured by a counter (not shown), which counts the length of the film fed by the film drawing unit. Alternatively, the desired length of the film may be manually measured using a scale.

The drive unit"F"is set within a sidewall 102 of the housing"A"as shown in Fig. 11. When a drive gear 601 for the film feeding and drawing units "B"and"C"is rotated by a handle"HI", the rotating force of the gear 601 is transmitted to the drive rollers 201 and 301 through a plurality of transmission gears 602, thus rotating the two rollers 201 and 301 in the same direction and at the same velocity.

Of course, it should be understood that the drive unit for the two drive rollers 201 and 301 may be selected from a conventional chain transmission mechanism or a belt transmission mechanism in place of the gear transmission mechanism without affecting the functioning of this invention. In addition, the drive unit for the two drive rollers 201 and 301 may be operated by a small capacity motor in place of the handle"H I".

On the other hand, when a drive gear 603 for the transverse cutting unit "E"is rotated by a handle"H2", the rotating force of the gear 603 is transmitted to a gear 605 through a transmission gear 602a, a helical worm gear 604 and a helical worm 604a. Thereafter, the rotating force is transmitted to the drive sprocket 510 through the gear 510c, thus rotating the sprocket 510. This finally allows the chain 511 to be moved along with the rotary cutter unit"k'"in a desired direction

while cutting the film transversely.

In Fig. 11, the reference numeral 701 denotes a cover plate used for covering the drive unit"F"set within the sidewall 102.

The cutting machine of this invention will be operated as follows.

A desired width of the film is set using the scale"s"prior to fixedly positioning the two rotary cutting units"k"of the longitudinal cutting unit"D".

In such a case, the rotary cutting unit"k'"of the transverse cutting unit"E"is positioned at one end of the unit"E".

The leading end of the film"f'from the bobbin"b"passes through the nip between the two rollers 201 and 202 of the film feeding unit"B"prior to passing through the nip between the two rollers 301 and 302 of the film drawing unit"C".

When the leading end of the film"f'completely passes through the nip between the two rollers 301 and 302 of the film drawing unit"C", the drive gear 601 is rotated by the handle"H1". The drive rollers 201 and 301 of the two units"B" and"C"are thus rotated, and so the film"f"is smoothly fed from the bobbin"b" to the two cutting units"D"and"E".

In such a case, the leading end of the film passes through the gap between the pressure plate 504a and the top wall of the lower frame 504 of the transverse cutting unit"E". The rollers 201,202,301 and 302 of the film feeding and drawing units"B"and"C"feed the film horizontally. The film passes through the nips between the two pairs of rollers 408 and 408a of the longitudinal cutting unit"D", thus being longitudinally cut along two lines by the cutting blades 407 of the two cutting rollers 408.

After the film is longitudinally cut by the unit"D", the film is cut transversely to form a desired rectangular piece. In such a case, it is necessary to set the position of the fixed cutting edge 506a of the transverse cutting unit"E"to a position spaced apart from the leading end of the film by a desired length. After setting the position of the film relative to the cutting edge 506a, the pressure plate 504a is brought into pressure contact with the top wall of the lower frame 504 by controlling the cam 504b, thus holding the film without allowing the fil ta be undesirably moved. Thereafter, the drive gear 603 is rotated by the handle"142",

and so the rotating force of the gear 603 is transmitted to the drive sprocket 510 through the transmission gear 602a, the helical worm gear 604, the helical worm 604a and the gear 510c, thus rotating the sprocket 510.

The chain 511 is thus moved, and so the cutter body 505 is moved in a desired direction under the guide of the guide rails 502 and 503.

When the cutter body 505 is moved in a desired direction under the guide of the guide rails 502 and 503, the pinion gear 507 is rotated along the rack gear 507a while forming a rotating force. The cutting disc 506 is thus rotated by the rotating force of the pinion gear 507 and forms a scissoring action in cooperation with the fixed cutting edge 506a. The film is thus transversely cut by the scissoring action. Since the cutting disc 506 is eccentrically mounted to the rotating shaft 508, the disc 506 forms a waving action while being rotated along the fixed cutting edge 506a. Due to such a waving action, the cutting disc 506 more easily forms the desired scissoring action and clearly and linearly cuts the film without allowing the film to be undesirably pushed or deformed. The cutting machine of this invention thus cuts the plastic film longitudinally and transversely or in X-and Y-axial directions.

Industrial Applicability As described above, the present invention provides a cutting machine used for cutting a rolled plastic film longitudinally and transversely or in X-and Y-axial directions. The cutting machine of this invention has a film feeding unit, a film drawing unit, a longitudinal cutting unit and a transverse cutting unit. This cutting machine thus quickly and clearly cuts a thin and pliable plastic film longitudinally and transversely into a desired rectangular piece having a precise dimension.

In the cutting machine, the film is cut longitudinally and transversely into a desired piece while being stably held by rollers under pressure, thus being less likely to be deformed or damaged. This finally reduces film loss while cutting the film into desired pieces.

This cutting machine is preferably used for cutting a rolled film into desired pieces, and so it is possible to repeatedly cut the film. After a desired film cutting operation, the remaining film is stably and neatly kept wound around a bobbin set in the cutting machine.

The cutting machine of this invention is also preferably used for cutting a variety of sheets, such as plastic sheets or wall papers in addition to plastic films, into desired rectangular pieces. All the units of the cutting machine are produced as modules, and so it is easy to produce and repair the machine. The cutting machine of this invention is light in weight and is portable, thus being easily movable in any place. The cutting machine is also easy to operate, and so a user easily operates the machine even though he may not be well-skilled.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.