Film connecting/feeding apparatus

Information

  • Patent Grant
  • 6834826
  • Patent Number
    6,834,826
  • Date Filed
    Thursday, April 11, 2002
    22 years ago
  • Date Issued
    Tuesday, December 28, 2004
    19 years ago
Abstract
Film rolls at the delivery position and the standby position are supported by supporting units. The roll is passed from the standby position to the delivery position by means of the conveying member provided in the roll conveying unit. As a result, it is not necessary to support the rolls at the individual positions by use of the roll conveying unit, thus permitting simplification of the configuration of the unit. The conveying member has a configuration in which the same is attached to a conveying chain put around the sprockets to make it possible to achieve circumferential travel of the conveying member by a single driving motor. When delivering by connecting to the film from the delivery position, the leading end easily comes off the holding unit by inserting the folded leading end of the film from the standby position and holding the same there.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to a film connecting/feeding apparatus to be incorporated into a wrapping system. More particularly, the invention relates to a film connecting/feeding apparatus which makes it possible to continuously feed a film by connecting a trailing end of a film delivered from a film roll and a leading end of a spare film roll.




2. Description of the Related Art




Conventionally known film connecting/feeding apparatuses of this type include those disclosed in Japanese Unexamined Patent Application Publications Nos. 4-338056, 6-278921, 5-97122, and


5-112326.






Among others, Japanese Unexamined Patent Application Publications Nos. 4-338056 and 6-278921 disclose conventional apparatus having features in a conveying unit of the film roll.




As shown in

FIG. 17

, the web feeding apparatus


200


(film connecting/feeding apparatus) in 4-338056 comprises a rewinding position


202


, a standby position


204


and a feeding position


205


, and has a configuration in which the trailing end of a web


201




a


delivered from a web roll


201


held at the rewinding position


202


and the leading end of a web


203




a


delivered from a spare web roll


203


held at the standby position


204


are connected at the connecting position


205


.




The web feeding apparatus


200


has an annular driving belt


206


travelling around between the rewinding position


202


and the standby position


204


, and three bearings


207


are attached to the annular driving belt


206


at equal intervals. These bearings


207


can rotatably support web rolls, respectively.




When one


207


of these bearings


207


is moved to the rewinding position


202


and arranged there, another bearing


207


is moved to the standby position


204


and arranged there. The remaining bearing


207


is in standby at the middle among the positions.




As shown in

FIG. 18

, the web connecting/feeding apparatus


300


disclosed in Japanese Unexamined Patent Application Publication No. 6-278921 has swinging levers


304


and


305


. One


304


of the levers rotatably holds a spare web roll


303




a


at the tip thereof, and the other lever


305


rotatably holds a delivery web roll


303




b


. The levers


304


and


305


are driven by driving mechanisms


306


and


307


, respectively.




When all the web is delivered from the delivery web roll


303




b


, the lever


305


swings counterclockwise in

FIG. 18

, and excludes the roll core remaining at the tip of the lever


305


. Subsequently, the levers


304


and


305


oscillate in synchronization, and the web roll


303




a


held at the tip of the lever


304


is passed to the tip of the lever


305


.




Japanese Unexamined Patent Application Publications Nos. 5-971122 and 5-112326 disclose conventional apparatuses characterized by spare film leading end holding means at a connecting position.




The automatic connecting apparatus of a wrapping film disclosed in 5-97122 has a configuration in which the leading end of a film is held by vacuum sucking to bring the same into standby at the connecting position.




The paper connecting apparatus disclosed in 5-112326 has a configuration in which the leading end of a web is held by means of an adhesive tape to bring the same into standby at the connecting position.




As described above, the web feeding apparatus disclosed in Japanese Unexamined Patent Application Publication No. 4-338056 has a configuration in which the bearing


207


is provided directly on the annular driving belt


206


travelling around between the rewinding position


202


and the standby position


204


, and the web rolls


201


and


203


are held at the individual positions


202


and


204


by means of this bearing


207


. The bearing


207


rotatably supporting the web rolls should have a strong structure capable of withstanding the load and rotating force of the web rolls.




A plurality of such bearings


207


having a strong structure as described above are necessary. In addition, in order to support these bearings


207


by an annular driving belt


206


such as a chain or a belt, it is necessary to impart a strength sufficient to resist to the action of a considerable load to the annular driving belt


206


. Comprehensive satisfaction of these requirements poses a problem of a very high manufacturing cost.




Also in the web connecting/feeding apparatus


300


disclosed in 6-278921, provision of driving sections


306


and


307


for the levers


304


and


305


holding the web roll leads to troublesome control and poses the problem of a high manufacturing cost of the apparatus.




In the apparatus disclosed in 5-97122 and 5-112326, the film (web) leading end is held at the connecting position by an adhesive tape or vacuum sucking. These holding means use a large holding force in general acting on the film. This may cause a positional shift of the film from the delivery track when stripping off the film from the connecting position after connection of the film, thus impairing stable continuous delivery of the film.




SUMMARY OF THE INVENTION




The present invention was developed in view of these circumstances, and has an object to ensure stable continuous delivery of the film with a low manufacturing cost.




To achieve the above-mentioned object, the film connecting/feeding apparatus has a configuration in which there are set a delivery position where a delivery film roll is held; a standby position where a spare film roll is held; and a connecting position where a leading end of a film delivered from the spare film roll is held, and the leading end and a film delivered from the delivery position are connected; the apparatus comprising delivery supporting means, provided at the delivery position, which rotatably supports the axial core of a delivery film roll, and standby supporting means, provided at the standby position, which supports the axial core of the spare film roll; and an endless belt member which is put around a rotary member and circumferentially travels, and roll conveying means which comprises a conveying member which is attached to this endless belt member, and holds the axial core of the film roll; wherein the roll conveying means receives a spare film roll by means of the conveying member from the standby supporting means, conveys the film roll to the delivery position, and passes the same to the delivery supporting means.




According to the present invention in which there are provided delivery supporting means and standby supporting means which support the film roll, respectively, at the delivery position and the standby position, the necessity is eliminated to impart a function for supporting the film roll to the roll conveying means accounting for a particularly large ratio among items of parts cost of the apparatus. It is therefore possible to achieve a simpler configuration of the roll conveying means and thus to reduce the manufacturing cost for the apparatus as a whole.




Since the roll conveying means has a configuration in which the endless belt means is wound around the rotary members and the conveying member is attached to this endless belt member, it is possible to cause a circumferential movement of the conveying member by the rotational driving force by rotating the rotary member with a single driving source. It is not therefore necessary to provide a plurality of driving sources, thus permitting reduction of the number of driving sources, leading to a lower cost of the apparatus.




The film connecting/feeding apparatus of the invention may further comprise a discharge path for discharging the axial core having delivered the film; wherein the conveying member of the roll conveying means further receives an axial core having delivered the film, remaining at the delivery position from the delivery supporting means, and conveys the same to the discharge path.




According to this configuration, an axial core of which the film has been delivered to the delivery position never remains, and it is thus possible to pass a film roll without any trouble to the delivery supporting means by the conveying member.




The apparatus of the invention may have a configuration in which an operating board is attached to the apparatus main body so as to be opened and closed; a holding member which holds an inserted folded portion formed by folding the leading end of the film delivered from the standby position, with a side of the operating board as an operating surface is attached to the operating surface; and in the closed state of the operating board, the holding member is positioned at the connecting position.




According to this configuration, the holding member holding the leading end of the film delivered from the standby position can be positioned at the connecting position in the closed state of the operating board. It is therefore possible to accurately position the leading end of the film and stably accomplish connection with the film delivered from the delivery position.




Because the folded portion formed by folding the leading end of the film is held by inserting the same into the holding member, it is possible to prevent occurrence of a positional shift of the film as a result of easy trip of the leading end of the film from the holding member upon delivery after film connection.




The apparatus of the invention may have a configuration in which an operating position for carrying out an operation of folding the leading end of the film delivered from the standby position and causing the holding member to hold the folded position is set on the front side of the apparatus main body; and the operating board is arranged so that, in the opened state, the operating surface is placed upward at the operating position.




According to this configuration, it is possible to cause the holding member to easily hold the leading end of the film at the operating position, and improve operability thereof.




The apparatus of the invention may have a configuration in which an edge positioning section which guides edges on both sides of the film delivered from the standby position is formed on the operating surface of the operating board.




According to this configuration, it is possible to easily accomplish positioning of both edges of the film.




The apparatus of the invention may have an operating board made of a transparent material. By adopting this configuration, even when the operating board is closed, it is possible to easily confirm the internal state of the apparatus, thus permitting easier maintenance control.




The apparatus of the invention may have a configuration in which a feeding position at which the film roll is fed to the standby position, a discharge position set at the terminal end of the discharge path, and the operating position are arranged in the height direction on the front side of the apparatus main body.




In this configuration, the operation of feeding the film roll, the operation of holding the leading end of the film by the holding member, and the operation of removing the axial core after delivery of the film can be conducted on the front side of the apparatus main body, thus permitting remarkable improvement of operating efficiency.




The apparatus of the invention may have a configuration in which the apparatus comprises end detecting means which detects the end of the film delivered from the delivery position at a prescribed detecting position; and connecting position aligning means which delivers the end portion of the film of which the end has been detected by the end detecting means to the connecting position in response to the distance between the detecting position and the connecting position.




By adopting such a configuration, it is possible to achieve a wrapping loss under a pitch of wrapping bag during connection with the spare film, thus permitting minimization of wrapping loss.




The apparatus of the invention may have a configuration in which the apparatus comprises registration mark detecting means which detects a registration mark attached to the film delivered from the delivery position at a prescribed position; wrapping length storing means which stores a wrapping length set on the film delivered from the delivery position; and registration mark aligning means which aligns a registration mark position of a film of which the end has been detected by the end detecting means and of which the registration mark has been detected by the registration mark detecting means with the registration mark position of a film of which the leading end portion has been held at the connecting position, on the basis of a wrapping length stored in the wrapping length storing means and the distance between the registration mark detecting position and the connecting position.




According to this configuration, for various films of different wrapping lengths, it is possible to carry out pattern alignment automatically simultaneously with connection of films with reference to registration mark, thus improving operability.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a side view illustrating an overall configuration of a wrapping system into which the film connecting/feeding apparatus of the present invention is incorporated;





FIG. 2A

is a side view illustrating an overall configuration of the film connecting/feeding apparatus of the invention;





FIG. 2B

is an enlarged view of the opening/closing center axis and the inserting/guiding portion of a film based on a film guiding pin and a coil spring of the film connecting/feeding apparatus of the invention;





FIG. 3

is an enlarged side view of the configuration of the delivery supporting unit in the film connecting/feeding apparatus of the invention;





FIG. 4

is a plan view illustrating the configuration of the holding unit in the film connecting/feeding apparatus of the invention;





FIG. 5

is a partially enlarged side sectional view illustrating the configuration of the holding unit and the connecting unit in the film connecting/feeding apparatus of the invention;





FIG. 6

is a perspective view illustrating the holding method of the film leading end by the holding unit in the film connecting/feeding apparatus of the invention;





FIG. 7

is a block diagram illustrating the control system in the film connecting/feeding apparatus of the invention;





FIGS. 8A and 8B

are a principle view illustrating the calculating method of the amount of film delivery in the film connecting position aligning control operation of the film connecting/feeding apparatus of the invention;





FIG. 9

is a flowchart illustrating the film connecting position aligning control operation in the film connecting/feeding apparatus of the invention;





FIG. 10

is a flowchart, following that shown in

FIG. 9

, illustrating the film connecting position aligning control operation in the film connecting/feeding apparatus of the invention;





FIG. 11

is a flowchart illustrating the sealing control operation in the film connecting/feeding apparatus of the invention;





FIG. 12

is a flowchart illustrating the film roll replacing control operation in the film connecting/feeding apparatus of the invention;





FIG. 13

is a flowchart illustrating the maintenance operation of the film connecting/feeding apparatus of the invention;





FIG. 14

is a side view of the film connecting/feeding apparatus for illustrating the film replacing operation in the film connecting/feeding apparatus of the invention;





FIG. 15

is a side view of the film connecting/feeding apparatus following that shown in

FIG. 14

for illustrating the film replacing operation in the film connecting/feeding apparatus of the invention;





FIG. 16

is a side view for illustrating the maintenance operation of the film connecting/feeding apparatus of the invention;





FIG. 17

is a side view illustrating the configuration of a conventional film connecting/feeding apparatus; and





FIG. 18

is a side view illustrating the configuration of another conventional film connecting/feeding apparatus.











DESCRIPTION OF THE PREFERRED EMBODIMENTS




Optimum embodiments of the present invention will now be described with reference to the drawings.




[Overall Configuration of Wrapping Unit and Film Connecting/Feeding Apparatus]




First, the overall configurations of a wrapping system to which the film connecting/feeding apparatus of the invention is applicable, and the film connecting/feeding apparatus of the invention will now be described.




As shown in

FIGS. 1 and 2A

, the film connecting/feeding apparatus


1


is incorporated into the upstream side (right side in

FIG. 1

) of a wrapping system


120


. A delivery position


10


, a standby position


20


, and a connecting position


30


are set in the interior of the apparatus main body


2


of this film connecting/feeding apparatus


1


.




A delivery supporting unit


40


is provided at the delivery position


10


, and this delivery supporting unit


40


supports a delivery film roll


11


.




A film


12


delivered from the film roll


11


supported at the delivery position


10


is delivered while being guided by guiding rollers


3




a


to


3




c


. Delivery is conducted by a delivery roller


4


. The delivered film


12


is supplied to an upright bag-making/filling wrapping machine


121


arranged in the downstream (left side in

FIG. 1

) of the wrapping system


120


. The delivery roller


4


is rotation-driven by a delivery motor


5


, and the film


12


is delivered by the rotation driving force of this delivery motor


5


.




A standby supporting unit


50


is provided at the standby position


20


. A spare film roll


21


is supported by the standby supporting unit


50


. This standby supporting unit


50


is provided continuously up to the feeding position


50




a


of the spare film roll


21


formed on the front side of the standby supporting unit


50


.




A roll conveying unit


60


is provided in the apparatus main body


2


. The roll conveying unit


60


receives the spare film roll


21


from the standby position


20


and can pass the film roll


21


to the delivery position


10


.




The roll conveying unit


60


receives an axial core


11




b


having delivered the film remaining at the delivery position


10


and pass the axial core


11




b


to a discharge unit


70


arranged at the bottom of the apparatus main body


2


to permit discharge thereof.




The terminal end portion of the discharge unit


70


extends to the bottom of the front of the apparatus main body


2


. The terminal end portion is set at a discharge position


70




a


of the axial core


11




b


after film delivery.




A holding unit


80


is provided at the top opening of the apparatus main body


2


so as to be opened and closed. In the closed state of the top opening of the apparatus main body


2


, the holding unit


80


is in contact with the connecting position


30


. The holding unit


80


can hold the leading end portion


22




a


of the film


22


delivered from the spare film roll


21


at this connecting position


30


.




In the opened state of the top opening of the apparatus main body


2


, the holding unit


80


is in contact with an operating position


80




a


set on the top of the front of the apparatus main body


2


. At this operating position


80




a


, the holding unit


80


holds the leading end portion of the film


22


delivered from the spare film roll


21


.




A connecting unit


90


is provided below the holding unit


80


. When all the film


12


is delivered from the delivery position


10


, the connecting unit


90


has a function of heat-sealing the terminal end portion of the film


12


and the leading end portion


22




a


of the film


22


delivered from the standby position


20


at the connecting position


30


.




A terminal end position sensor


6


is provided in the apparatus main body


2


, and the terminal end position of the film


12


delivered from the delivery position


10


can be detected by the sensor


6


.




[Film Roll Supporting Unit, Roll Conveying Unit, and Discharge Unit]




The film roll supporting unit, the roll conveying unit and the discharge unit will now be described with reference to

FIGS. 2A

,


2


B and


3


.




The delivery supporting unit


40


has each two bearings


41




a


to


41




d


at upper and lower portions with the delivery position


10


in between, and these bearings


41




a


to


41




d


rotatably support the axial core


11




a


of the delivery film roll


11


. Therefore, when the film


12


is delivered from the film roll


11


and the axial core


11




a


rotates, the bearings


41




a


to


41




d


are rotated accordingly. As a result, it is possible to prevent mutual wear of the axial core


11




a


and the bearings


41




a


to


41




d.






From among these bearings


41




a


to


41




d


, the lower bearings


41




a


and


41




b


are fixed at the installation positions to the apparatus main body


2


. The upper bearings


41




c


and


41




d


are attached, on the other hand, to an air cylinder


42


, and are vertically movable under action of this air cylinder


42


.




In this configuration, when the air cylinder


42


is driven, the upper bearings


41




c


and


41




d


move downward, and the axial core


11




a


of the delivery film roll


11


is held between the lower bearings


41




a


and


41




b


. The axial core


11




a


is therefore stably supported without a play.




On the other hand, when the upper bearings


41




c


and


41




d


are moved upward by driving the air cylinder


42


, it is possible to separate these bearings


41




c


and


41




d


from the lower bearings


41




a


and


41




b


. As a result, it is possible to easily cause the axial core


11




a


of the delivery film roll


11


to come off these bearings


41




a


to


41




d.






The standby supporting unit


50


has a pair of feeding rails


51


on both sides thereof. The feeding rail


51


extends to the front side of the apparatus main body


2


. The trailing end thereof is arranged at the standby position


20


, and the front end thereof is arranged at a feeding position


50




a.






The feeding position


50




a


should preferably be set at a height allowing supply of the film roll


21


without operator's bending down.




The feeding rail


51


is formed in downward inclination from the front end toward the trailing end. A cavity


52


is formed by bending upward the trailing end. Therefore, when the film roll


21


is fed from the feeding position


50




a


, the axial core


21




a


moves under gravity to the trailing end while rolling on the feeding rails


51


. The axial core


21




a


of the film roll


21


having moved to the trailing end of the feeding rail


51


enters the cavity


52


and is held there.




In this embodiment, the film rolls


11


and


21


supported by the above-mentioned supporting unit


40


and the standby supporting unit


50


have a diameter of about 400 mm.




The roll conveying unit


60


has an endless conveying chain


64


(endless belt member) put around a driving-side sprocket


61


(driving-side rotary member) and two follower-side sprockets


62


and


63


(follower-side rotary members).




Two conveying member


66


and


66


are attached at an interval of


180


E to the conveying chain


64


. The conveying member


66


is formed into approximately J shape so as to enable the cavity


66




a


to hold the axial cores


11




a


and


21




a


of the film rolls


11


and


21


.




A driving motor


65


is attached to the rotation shaft of the driving-side sprocket


61


. By the driving force of this driving motor, the driving-side sprocket


61


is rotation-driven counterclockwise in the drawing. The driving force of the driving motor


65


is transmitted to the follower-side sprockets


62


and


63


via the conveying chain


64


to rotate the follower-side sprockets


62


and


63


. This makes it possible for the conveying chain


64


to circumferentially rotate counterclockwise in the drawing.




The track of the conveying chain


64


, i.e., the circumferential movement path of the conveying members


66


and


66


includes a film replacing path


67




a


, a conveying path


67




b


of the axial core


11




b


after film delivery, and a return path


67




c


of the conveying members


66


and


66


. Among others, the film replacing path


67




a


connects the delivery position


10


and the standby position


20


. The path


67




b


for conveying the axial core


11




b


after film delivery connects the delivery position


10


and the starting end of the discharge unit


70


. The return path


67




c


of the conveying members


66


and


66


connects the starting end of the discharge unit


70


and the standby position


20


. These paths


67




a


,


67




b


and


67




c


are formed along the individual sides of a virtual triangle.




Therefore, after delivery of the film


12


from the delivery position


10


, the conveying members


66


receive the remaining core


11




b


after film delivery from the supporting unit


40


by causing circumferential travel of the conveying member


66


. The conveying member


66


conveys the received axial core downward while holding the same in the cavity


66




a


. This permits passage and discharge of the axial core


11




b


to the discharge unit


70


.




The conveying member


66


receives the spare film roll


21


from the standby supporting unit


50


, and conveys the axial core


21




a


thereof, while holding the same in the cavity


66




a


, to the delivery position


10


. As a result, the spare film roll


21


is passed to the delivery supporting unit


40


, and replacing operation of the film rolls


11


and


21


is automatically executed.




After passing the spare film roll


21


to the delivery supporting unit


40


, the conveying members


66


are held in standby at the delivery position


10


.




The cavity


66




a


of the conveying member


66


, upon circumferential travel of the conveying member


66


, is set so that the travel track thereof interferes with the lower bearings


41




a


and


41




b


provided on the delivery supporting unit


40


. Therefore, the film roll


21


is passed to the delivery supporting unit


40


so that the axial core


21




a


rides over bearings


41




a


and


41




b.






In the state in which the conveying member


66


is in standby on the delivery supporting unit


40


, a gap is formed between the cavity


66




a


and the axial core


11




a


of the delivery film roll


11


, thus avoiding mutual contact. Therefore, even when the axial core


11




a


rotates upon film delivery, the axial core


11




a


and the cavity


66




a


never mutually wear.




The individual travel paths


67




a


to


67




c


of the conveying member


66


are set so as to have a short distance between them by bringing the individual sprockets


61


to


63


closer to each other, or bringing the delivery position


10


closer to the standby position


20


. This reduces the size of the film connecting/feeding apparatus


1


. For example, for the film replacing path


67




a


, a distance of about 410 mm is set. When the film rolls


11


and


21


having a diameter of 400 mm are held at the delivery position


10


and the standby position


20


, as described above, the interval between the film rolls


11


and


21


would be about 10 mm.




A maintenance request button


68


is provided on the apparatus main body


2


. By continuously pressing this maintenance request button


68


, it is possible to cause rotation of the driving motor


65


clockwise to achieve circumferential travel of the conveying member


66


in the same direction. As a result, at an emergency or during maintenance, it is possible to easily collect the same from the front side by conveying the delivery film roll


11


from the delivery position


10


to the standby position


20


.




Two conveying members


66


are attached to the conveying chain


64


in this embodiment, but only a single conveying member


66


may be attached.




The discharge unit


70


has a pair of discharge rails (discharge paths)


71


on both sides. The discharge rails


71


extend to the front side of the apparatus main body


2


, and the terminal end thereof is arranged at the discharge position


70




a


. The discharge position


70




a


is set at a height allowing the operator to take out the axial core


116


by only slightly bending down.




The discharge rail


71


is formed with a slight downward inclination from the starting end toward the terminal end. When the axial core


11




b


after film delivery is passed from the roll conveying unit


60


to the discharge rail


71


, therefore, the axial core


11




b


moves under gravity while rolling on the discharge rail


71


, and is discharged to the discharge position


70




a


at the terminal end.




Projections


72


are provided on the terminal end portions of these discharge rails


71


and


71


so that the discharged axial core


11




b


is certainly held at the discharge position


70




a.






[Configuration of Holding Unit and Connecting Unit]




The configuration of the holding unit


80


and the connecting unit


90


will now be described with reference to

FIGS. 4

to


6


.




The holding unit


80


has an operating board


81


attached to the top of the apparatus main body


2


so as to be opened and closed. In the closed state, the inner surface of the operating board


81


(hereinafter referred to as “operating surface


82


”) is arranged at the aforementioned connecting position


30


.




The operating board


81


is made mainly of a transparent material such as an acryl plate. At the connecting position


30


, the delivery film


12


and the spare film


22


are heat-sealed. The portion of the operating board


81


corresponding to the connecting position


30


is made of a heat-resistant material such as a Teflon sheet or silicone rubber.




A holding member


83


is provided on the portion corresponding to the connecting position


30


of the operating surface


82


of the operating board


81


. The holding member


83


has a function of holding the leading end


22




a


of the film


22


delivered from the standby position


30


at the connecting position


30


.




The holding member


83


has a pressing plate


83




b


extending from the lower end of the base


83




a


along the operating surface


82


. The pressing plate


83




b


has a free leading end. The pressing plate


83




b


is therefore flexible around the base.




The pressing plate


83




b


is formed with an upward inclination from the base toward the leading end which is bent downward. An opening


83




c


formed between the leading end and the operating surface


82


of the operating board


81


serves as an insertion port into which the leading end


22




a


of the film


22


can be inserted.




A pair of side end positioning members


84


and


84


are arranged at two places in the delivery direction of the film


22


on the operating surface


82


of the operating board


81


. These side end positioning members


84


are formed into a sheet shape, and guide the side edge of the film


22


along the inner ends thereof.




The side end positioning member


84


is connected to a supporting member


84




a


. The supporting member


84




a


is movable along a long groove


84




b


extending to sides of the operating board


81


.




The side end positioning member


84


is therefore movable sideways and can flexibly cope with a change in position of both sides of the film


22


or a change in the width. The side end positioning member


84


and the supporting member


84




a


are coupled via a screw


84




c


. It is possible to hold the operating board


81


between the side end positioning member


84


and the head


84




d


of the supporting member


84




a


by tightening the screw


84




c


through rotation of the supporting member


84




a


. The side end positioning member


84


is thus secured.




The side end positioning member


84


provided to the left in front has a trailing end


84




e


positioned at a registration mark aligning position for aligning the position of a registration mark


22




b


affixed to the film


22


.




A slit


85


extending sidewise is formed on the front side with a distance from the trailing end


84




e


of the side end positioning member


84


. This slit


85


serves as a leading end aligning position for positioning the leading end


22




a


when holding the leading end


22




a


of the film


22


.




A plurality of suction holes


86


are provided on the operating surface


82


of the operating board


81


. These suction holes


86


communicate with a suction pump not shown through a vacuum chamber


86




a


provided in the operating board


81


. It is therefore possible to apply suction force of the suction pump to the suction holes


86


, and consequently, hold by suction the sheet surface of the film


22


.




As shown in an enlarged view in

FIG. 2B

, a film guiding pin


88


and a coil spring


89


in pair are provided under an opening/closing center shaft of the operating board


81


. In the closed state of the operating board


81


, guiding from the film roll


21


to the operating surface


82


is accomplished by holding the film


22


between the film guiding pin


88


and the coil spring


89


.




In the opened state, the operating board


81


is formed so that the operating surface


82


is directed upward, and the operating surface


82


is arranged at the operating position


80




a


set on the top of the front of the apparatus main body


2


(see FIG.


2


A). The operating surface


82


arranged at the operating position


80




a


is set at a height permitting operation by the operator in an upright posture while looking down the object.




In the open state of the operating board


81


, the operating surface


82


is set by aligning in the height direction with the feeding position


50




a


of the above-mentioned spare film roll and the discharge position


70




a


of the axial core


11




b


after film delivery. The operator can therefore carry out operations at the same place without moving.




The method for holding the leading end


22




a


of the film


22


delivered from the standby position


20


by means of the holding unit


80


will now be described.




First, in the closed state of the operating board


81


, the side end edge of the film


12


delivered from the delivery position


10


and the inner end of the side end positioning member


84


are positionally aligned (see FIG.


4


). In this case, since the operating board


81


is made of a transparent material, it is easy to confirm the position of the side edges of the film


12


via the operating board


81


even in the closed state.




Then, the operating board


81


is opened toward the front side of the apparatus main body


2


so that the operating surface


82


is directed upward (see FIG.


2


A). The film


22


is delivered from the standby position


20


, and the registration mark


22




b


affixed to the film


22


is aligned with the trailing end


84




e


of the side end positioning member


84


.




Then, the film


22


is cut with reference to the slit


85


provided on the operating board


81


by use of a cutting tool such as a cutter to position the leading end


22




a


of the film


22


at the slit


85


. This makes it possible to keep the leading end


22




a


of the film


22


always at a certain position relative to the registration mark


22




b.






The leading end


22




a


of the film is folded, and the folded portion is inserted through an opening


83




c


of the holding member


83


by means of an inserting jig


80




b


(see FIG.


6


). By inserting the leading end


22




a


of the film


22


as described above, the folding reaction of the leading end


22




a


of the film


22


makes it possible to elastically hold in the holding member


83


.




When inserting the leading end


22




a


into the holding member


83


, insertion should be accomplished so that the folded portion comes into contact with the base


83




a


of the holding member


83


. As a result of such insertion, it is possible to keep a constant film length from the registration mark


22




b


of the film


22


to the connecting position


30


.




Since the pressing plate


83




b


of the holding member


83


is formed so as to be deflected around the base, it is possible to easily cause deflection of the pressing plate


83




b


when inserting the leading end


22




a


. It is therefore possible to easily insert the leading end


22




a


of the film


22


into the holding member


83


because the distance between the pressing plate


83




b


and the operating surface


82


of the operating board


81


becomes larger.




Then, after holding the film


22


between the film guiding pin


88


and the coil spring


89


, the operating board


81


is closed (see FIG.


2


A). In this closed state, the film


22


is held between the film guiding pin


88


and the coil spring


89


. In addition, because the film is sucked by the suction holes


86


provided on the operating surface


82


of the operating board


81


, the film


22


never sags, and the film


22


can be certainly held on the operating surface


82


(see FIG.


5


).




The configuration of the connecting unit


90


will now be described in detail.




The connecting unit


90


has a guiding plate


91


and a heater block


92


and has a configuration in which a film


12


delivered from the delivery position


10


on the upper surface side of the guiding plate


91


is guided to the heater block


92


.




The heater block


92


is arranged below the connecting position


30


. A heating surface


92




a


is formed on the upper surface side opposite to the holding unit


80


of the heater block


92


. An electric heater is built in the heater block


92


, and temperature of the heating surface


92




a


can be set at a prescribed value by controlling output of the electric heater.




The heater block


92


is attached to an air cylinder not shown, and vertically movable by the driving force of the air cylinder. By moving the heater block


92


upward by driving the air cylinder, therefore, it is possible to hold the film


12


delivered from the delivery position


10


and the leading end


22




a


of the film delivered from the standby position


20


with the operating board


81


for heat sealing.




The air cylinder communicates with a compressed air source not shown via a solenoid valve. By opening and closing the solenoid valve, compressed air is supplied for driving.




[Control System of Film Connecting/Feeding Apparatus]




The control system of the film connecting/feeding apparatus will now be described with reference to

FIGS.7

,


8


A and


8


B.




As shown in

FIGS. 7

,


8


A and


8


B, the control system


100


of the film connecting/feeding apparatus comprises a film connecting operation control section


101


, a sealing operation control section


102


, and a film roll replacing operation control section


103


.




A terminal end detecting signal of the film


12


transmitted from a terminal end detecting sensor


6


, a registration mark detecting signal to the film


12


transmitted from a registration mark sensor


104


provided on the delivery path of the film


12


, and a revolutions detecting signal transmitted from an encoder


105


detecting the amount of rotation of the delivery motor


5


are entered into the film connecting operation control section


101


.




The wrapping length of the film as set by a touch panel


106


is entered into the film connecting operation control section


101


which serves as storage means storing the wrapping length.




The film connecting operation control section


101


has various functions for aligning the heat sealing position set at the terminal end of the film


12


on the basis of these input data with the connecting position


30


.




The film connecting operation control section


101


has a function of calculating the amount of delivery of the film


21


for aligning the heat sealing position of the film


12


with the connecting position


30


on the basis of the wrapping length d, the distance L between the terminal end detecting position and the connecting position


30


of the delivery film


12


previously set in the operation control section


101


, the distance X between the registration mark sensor


104


and the connecting position


30


, and the film length S from the registration mark aligning position to the connecting position


30


for the film


22


.




A typical method for calculating the delivery amount will be described on the basis of the following formulae (1) to (7). First, by use of Formula (1), the number n of wrapping bags to be formed by the film included between the registration mark sensor


104


and the connecting position


30


is calculated. The difference ΔP between the position of the registration mark


12




a


of the film


12


and the registration mark aligning position upon detecting the registration mark is calculated in accordance with Formula (2), on the basis of the proposed number n of formed wrapping bags, the wrapping length d, the distance X between the registration mark sensor


104


and the connecting position


30


, and the film length S between the registration mark aligning position in the film


22


and the connecting position


30


.




Then, by use of Formula (3), the proposed number m of wrapping bags from the registration mark aligning position to the terminal end of the film


12


is calculated. Then, the length β from the final registration mark


12




a


to the terminal end of the film


12


is calculated on the basis of the amount of delivery y of the film


12


during a period from detection of the terminal end of the film


12


to detection of the first registration mark


12




a


and the like in accordance with Formulae (4) and (5).




For the case where there is a step of pattern aligning (with reference to registration marks), the amount of delivery P


1


or P


1




a


of the film


12


is calculated using the thus calculated values, in accordance with Formula (6) or (6a).




When there is no step of pattern alignment (relative to the film terminal end), the delivery amount P


2


of the film


12


is calculated by use of Formula (7).







n


=(


X+S


)/


d


(counting fractions as one)  (1)






Δ


P=nd


−(


X+S


)  (2)










m


=(


L−S


)/


d


(counting fractions as zero)  (3)








(


X+L−y


)/


d=N


(counting fractions as zero)  (4)










X+L−y−Nd=β


  (5)










P




1


=


md+ΔP


(where,


d−S+a


>β)  (6)










P




1




a


=(


m


+1)


d+ΔP


(where,


d−S+a


<β or


d−S+a


=β)  (6a)










P




2


=


L−a


  (7)






where,




X: distance between the registration mark sensor


104


and the connecting position


30


;




S: film length from registration mark aligning position in film


22


to connecting position


30


;




n: proposed number of formed bags from registration mark sensor


104


to connecting position


30


;




d: wrapping length;




m: proposed number of formed bags from registration mark aligning position to terminal end detecting position;




L: distance between terminal end detecting position of delivery film


12


and connecting position


30


;




y: delivery amount of film


12


during period from detection of terminal end of film


12


to detection of first registration mark


12




a;






N: proposed number of formed bags from registration mark sensor


104


to terminal end detecting position;




β: length from final registration mark


12




a


to terminal end of film;




a: constant (length from heat-sealing position of film


12


to film terminal end);




P


1


: delivery amount of film


12


relative to registration mark when d−S+a>β;




P


1




a


: delivery amount of film


12


relative to registration mark when d−S+a<β or d−S+a=β;




P


2


: delivery amount of film


12


with reference to film terminal end.




A film connecting operation control section


101


a control signal of the delivery roller


4


to the delivery motor


5


on the basis of these calculated values, outputs this control signal to the delivery motor


5


, and conducts connecting position aligning operation. In this connecting position aligning operation, an operating program of the delivery motor


5


is incorporated in advance in the film connecting operation control section


101


so that the delivery motor


5


operates at a low speed when heat-sealed portion of the film


12


reaches a certain position relative to the connecting position


30


.




The sealing operation control section


102


has a function of performing sealing operation by issuing control signals to the solenoid valve


108


of the heater block


92


for a certain period of time, on the basis of input signals of the sealing time set by a touch panel


106


and signals transmitted from a timer


107


counting this sealing period.




The sealing operation control section


102


has a function of setting a certain temperature for the heating surface


92




a


of the heater block


92


by issuing control signals to the electric heater of the heater block


92


, on the basis of input signals of the sealing temperature set on the touch panel


106


.




A detecting signal of the axial core


11




a


of the film roll


11


transmitted from the delivery position sensor


109


provided near the delivery position


10


, a detecting signal of the axial core


21




a


of the film roll


21


transmitted from the standby position sensor


110


provided near the standby position


20


, and a signal issued by pressing the maintenance request button


68


are entered into the film roll replacing operation control section


103


.




The film roll replacing operation control section


103


has a function of generating control signals to the driving motor


65


of the driving-side sprocket


61


on the basis of these input signals, issuing these control signals to the driving motor


65


, and performing film replacing operation and the like.




The film roll replacing operation control section


103


has a function of issuing control signals to the solenoid valve


111


driving the air cylinder


42


of the delivery supporting unit


40


provided at the delivery position


10


.




Then, the individual control operations by the control system


100


of the film connecting/feeding apparatus will be described with reference to

FIGS. 9

to


16


.




Upon confirmation of detection of the terminal end position of the film


12


on the basis of the signal from the terminal end detecting sensor


6


(S


1


), the film connecting operation control section


101


starts counting of the amount of rotation of the delivery motor


5


, on the basis of a signal from the encoder


105


(S


2


).




Then, when conducting pattern alignment with reference to the position of the registration mark


12




a


affixed to the film


12


(S


3


), upon confirmation of detection of the registration mark


12




a


of the film


12


on the basis of a signal from the registration mark sensor


104


, the film connecting operation control section


101


calculates the delivery amount of the film


12


relative to the registration mark


2




a


(S


5


), upon confirmation of detection of the registration mark


12




a


of the film


12


(S


4


).




Upon confirming that the heat-sealed position reaches a certain position relative to the connecting position


30


with reference to the registration mark (S


6


), the film connecting operation control section


101


issues an operating instruction to the delivery motor


5


to switch over the rotational speed of the delivery motor


5


to a low speed (S


7


).




Then, upon confirming that the heat-sealed position reaches the connecting position


30


(S


8


) on the basis of a signal from the encoder


105


, the film connecting operation control section


101


issues a stop instruction to the delivery motor


5


to stop the delivery motor


5


(S


9


), thus completing the film connecting positioning operation relative to the registration mark.




When carrying out film connection positioning operation with reference to the terminal end of the film


12


, the film connecting operation control section


101


calculates the delivery amount of the film


12


with reference to the film terminal end (S


10


).




Upon confirming that the heat-sealed position based on the film terminal end reaches a certain position relative to the connecting position


30


(S


11


), the film connecting operation control section


101


issues an operating instruction to the delivery motor


5


to switch over the rotation speed of the delivery motor


5


to a low speed (S


7


), and continues to perform similarly the film connection positioning operations.




Then, upon confirming that the film connection positioning operation by the film connecting operation control section


101


(S


20


), the sealing operation control section


102


issues an operating instruction to the solenoid valve


108


of the heater block


92


to open the solenoid value


108


, moves the heater block


92


upward, and performs sealing operation (S


21


).




Then, upon confirming that a set sealing time has elapsed on the basis of a signal from the timer


107


(S


22


), the sealing operation control section


102


issues an operating instruction to the solenoid valve


108


to close the solenoid valve


108


, moves the heater block


92


downward, and completes the sealing operations (S


23


).




The sealing operation control section


102


issues an operating instruction to the delivery motor


5


to start up the delivery motor


5


(S


24


), and resumes delivery of the film


12


by means of the delivery roller


4


.




The folded portion formed by folding the leading end


22




a


of the film


22


is elastically held in the holding member


83


in this embodiment. When delivering after film connection, therefore, the leading end


22




a


of the film


22


easily comes off the holding member


83


, thus permitting prevention of occurrence of a positional shift of the connected films.




Then, upon confirming that the sealing operation by the sealing operation control section


102


is completed (S


30


), the film roll replacing operation control section


103


issues an operating instruction to the solenoid valve


111


of the air cylinder


42


provided in the delivery supporting unit


40


to close the solenoid valve


111


, moves upward the air cylinder


42


, i.e., the upper bearings


41




c


and


41




d


, and releases the holding state of the axial core after delivery of the film by the bearings


41




a


to


41




d


of the delivery supporting unit


40


(S


31


).




Then, upon confirming that there is an axial core


21




a


of the spare film roll


21


at the standby position


20


on the basis of a signal from the standby position sensor


110


(S


32


), the film roll replacing operation control section


103


issues an operating instruction to the driving motor


65


of the driving-side sprocket


61


to drive the driving motor


65


counterclockwise in the drawing (S


33


), moves the conveying member


66


from the delivery position


10


, and conveys the axial core


11




a


having delivered the film to the discharge unit


70


.




The conveying member


66


present on the 180E-opposite side receives the axial core


21




a


of the spare film roll


21


from the standby position


20


, and conveys this film roll


21


to the delivery position


10


(see FIG.


14


).




Then, upon confirming that the axial core


21




a


of the spare film roll


21


reaches the delivery position


10


from a signal from the delivery position sensor


109


(S


34


), the film roll replacing operation control section


103


issues a stop signal to the driving motor


65


to stop the driving motor


65


(S


35


; FIG.


15


).




The film roll replacing operation control section


103


issues an operating instruction to the solenoid valve


111


of the delivery supporting unit


40


to release the solenoid valve


111


, and moves the upper bearings


41




c


and


41




d


downward to hold the axial core


21




a


of the film roll


21


between the upper and lower bearings


41




a


to


41




d


(S


36


), thus completing the film roll replacing operation.




Upon confirming that the maintenance request button


68


provided on the apparatus main body


2


of the film connecting/feeding apparatus


1


is pressed down (S


40


), the film roll replacing operation control section


103


issues an operating instruction to the driving motor


65


of the driving-side sprocket


61


while the maintenance request button


68


is pressed down, to cause clockwise rotation of the driving motor


65


(S


41


), and conveys the film roll


111


at the delivery position


10


to the standby position


20


.




Upon confirming that the axial core


11




a


of the film roll


11


reaches the standby position on the basis of a signal from the standby position sensor


110


(S


42


), the film roll replacing operation control section


103


issues a stop instruction to the driving motor to stop the driving motor


65


(S


43


; see FIG.


16


).




According to the present invention, as described above, there are provided delivery supporting means and standby supporting means supporting the film roll at the delivery position and the standby position, respectively. It is not therefore necessary to impart a function for supporting the film roll to the roll conveying means accounting for an important weight in the apparatus parts cost. It is therefore possible to simplify configuration of the roll conveying means, thus permitting reduction of the manufacturing cost for the apparatus as a whole.




Furthermore, the roll conveying means comprises an endless belt member put around a rotary member and a conveying member is attached to this endless belt member. It is therefore possible to cause rotation of the rotary member with a single driving source and to achieve circumferential travel of the conveying member under the effect of the rotational driving force thereof. It is not therefore necessary to provide a plurality of driving sources, thus reducing the number of driving sources and permitting reduction of the apparatus cost also in this respect.




In addition, the folded portion formed by folding the leading end of the film delivered from the standby position is held by inserting into the holding member. Upon delivery after film connection, therefore, the leading end of the film easily comes off the holding member, thus preventing occurrence of a positional shift of the film.



Claims
  • 1. A film connecting/feeding apparatus defining a delivery position where a delivery film roll is held; a standby position where a spare film roll is held; and a connecting position where a leading end of a film delivered from said spare film roll is held and said leading end and a film delivered from said delivery position are connected; comprising:delivery supporting means arranged at said delivery position for rotatably supporting an axial core of a delivery film roll, standby supporting means arranged at said standby position for supporting an axial core of the spare film roll, said standby supporting means being separate from said delivery supporting means; a rotary member; an endless belt member arranged to run around said rotary member, and roll conveying means for holding the axial core of the film roll, said roll conveying means comprising a conveying member attached to said endless belt member, wherein said roll conveying member is arranged to receive a spare film roll from said standby supporting means, remove said spare film roll from said standby supporting means, convey said spare film roll to said delivery position, and pass said spare film roll to said delivery supporting means at said delivery position upon movement of said endless belt member.
  • 2. A film connecting/feeding apparatus according to claim 1, further comprising:a discharge path for discharging the axial core after having delivered the film; wherein the conveying member of said roll conveying means further receives an axial core after having delivered the film, from said delivery supporting means and conveys the axial core to said discharge path.
  • 3. A film connecting/feeding apparatus according to claim 1, further comprising:a main body; an operating board attached to said main body so as to be opened and closed; a holding member which holds an inserted folded portion formed by folding the leading end of the film delivered from said standby position, with a side of said operating board as an operating surface is attached to said operating surface; and in the closed state of said operating board, said holding member is positioned at said connecting position.
  • 4. A film connecting/feeding apparatus according to claim 3, wherein an operating position for carrying out an operation of folding the leading end of the film delivered from said standby position and causing the holding member to hold the folded position is defined on a front side of said main body; andsaid operating board is arranged so that, in the opened state, said operating surface is placed upward at said operating position.
  • 5. A film connecting/feeding apparatus according to claim 4, further comprising a discharge path for discharging the axial core after having delivered the film, wherein a feeding position at which the film roll is fed to said standby position, a discharge position defined at a terminal end of said discharge path, and said operating position are arranged in the height direction on the front side of said main body.
  • 6. A film connecting/feeding apparatus according to claim 3, wherein an edge positioning section which guides edges on both sides of the film delivered from said standby position is formed on said operating surface of said operating board.
  • 7. A film connecting/feeding apparatus according to claim 3, wherein said operating board is made of a transparent material.
  • 8. A film connecting/feeding apparatus according to claim 1, further comprising:end detecting means for detecting an end of the film delivered from said delivery position at a prescribed detecting position; and connecting position aligning means for delivering an end portion of the film of which the end has been detected by said end detecting means to said connecting position based on a distance between said detecting position and said connecting position.
  • 9. A film connecting/feeding apparatus according to claim 8, further comprising:registration mark detecting means for detecting a registration mark attached to the film delivered from said delivery position at a prescribed position; wrapping length storing means for storing a wrapping length set on the film delivered from said delivery position; and registration mark aligning means for aligning a registration mark position of a film of which the end has been detected by said end detecting means and of which the registration mark has been detected by said registration mark detecting means with the registration mark position of a film of which the leading end portion has been held at said connecting position, on the basis of a wrapping length stored in said wrapping length storing means and a distance between said registration mark detecting position and the connecting position.
  • 10. A film connecting/feeding apparatus according to claim 1, wherein said delivery supporting means comprise a plurality of bearings arranged to support the axial core of the delivery film roll, said conveying means being arranged to transfer the axial core of the spare film roll from said conveying member onto said bearings.
  • 11. A film connecting/feeding apparatus according to claim 10, wherein said conveying member is arranged relative to said bearings such that after said conveying member transfers the axial core of the spare film roll onto said bearings, said conveying member is held in a standby position at said delivery position in which said conveying member is not in contact with said axial core.
  • 12. A film connecting/feeding apparatus according to claim 1, further comprising a main body, said delivery supporting means comprising a plurality of bearings connected to said main body and said standby supporting means comprising a pair of feeding rails extending on a front side of said main body.
  • 13. A film connecting/feeding apparatus defining a delivery position where a delivery film roll is held, a standby position where a spare film roll is held and a connecting position where a leading end of a film delivered from the spare film roll is held and the leading end and a film delivered from the delivery position are connected; comprising:delivery supporting means arranged at the delivery position for rotatably supporting an axial core of the delivery film roll; standby supporting means arranged at the standby position for supporting an axial core of the spare film roll; a rotary member; an endless belt member arranged to run around said rotary member; roll conveying means for holding the axial core of the film roll said roll conveying means comprising a conveying member attached to said endless belt member and arranged to receive a spare film roll from said standby supporting means, convey said spare film roll to the delivery position, and pass said spare film roll to said delivery supporting means; a main body; an operating board attached to said main body so as to be opened and closed; and a holding member which holds an inserted folded portion formed by folding the leading end of the film delivered from said standby position, with a side of said operating board as an operating surface being attached to said operating surface, and in the closed state of said operating board, said holding member being positioned at said connecting position.
  • 14. A film connecting/feeding apparatus according to claim 13, wherein an operating position for carrying out an operation of folding the leading end of the film delivered from the standby position and causing the holding member to hold the folded position is defined on a front side of said main body; andsaid operating board is arranged so that, in the opened state, said operating surface is placed upward at said operating position.
  • 15. A film connecting/feeding apparatus according to claim 14, further comprising a discharge path for discharging the axial core after having delivered the film, wherein a feeding position at which the film roll is fed to the standby position, a discharge position defined at a terminal end of said discharge path, and said operating position are arranged in the height direction on the front side of said main body.
  • 16. A film connecting/feeding apparatus according to claim 13, wherein an edge positioning section which guides edges on both sides of the film delivered from the standby position is formed on said operating surface of said operating board.
  • 17. A film connecting/feeding apparatus according to claim 13, wherein said operating board is made of a transparent material.
  • 18. A film connecting/feeding apparatus including delivery position where a delivery film roll is held, a standby position where a spare film roll is held and a connecting position where a leading end of a film delivered from the spare film roll is held and the leading end and a film delivered from the delivery position are connected; comprising:delivery supporting means arranged at the delivery position for rotatably supporting an axial core of the delivery film roll; standby supporting means arranged at the standby position for supporting an axial core of the spare film roll; a rotary member; an endless belt member arranged to run around said rotary member; roll conveying means for holding the axial core of the film roll, said roll conveying means comprising a conveying member attached to said endless belt member and arranged to receive the spare film roll from said standby supporting means, convey the spare film roll to the delivery position, and pass the spare film roll to said delivery supporting means; end detecting means for detecting an end of the film delivered from the delivery position at a prescribed detecting position; and connecting position aligning means for delivering an end portion of the film of which the end has been detected by said end detecting means to the connecting position based on a distance between the detecting position and the connecting position.
  • 19. A film connecting/feeding apparatus according to claim 18, further comprising:registration mark detecting means for detecting a registration mark attached to the film delivered from the delivery position at a prescribed position; wrapping length storing means for storing a wrapping length set on the film delivered from the delivery position; and registration mark aligning means for aligning a registration mark position of a film of which the end has been detected by said end detecting means and of which the registration mark has been detected by said registration mark detecting means with the registration mark position of a film of which the leading end portion has been held at the connecting position, on the basis of a wrapping length stored in said wrapping length storing means and a distance between said registration mark detecting position and the connecting position.
Priority Claims (1)
Number Date Country Kind
2001-113901 Apr 2001 JP
US Referenced Citations (11)
Number Name Date Kind
794578 Wood Jul 1905 A
2005037 Johancen et al. Jun 1935 A
2389443 Lyle Nov 1945 A
2745464 Auerbacher et al. May 1956 A
3176928 Saunders Apr 1965 A
3197017 Ungerer Jul 1965 A
4173314 Curran et al. Nov 1979 A
4386741 Weiss et al. Jun 1983 A
4564150 Keene et al. Jan 1986 A
4729519 Tafel et al. Mar 1988 A
4934621 Jacobs Jun 1990 A
Foreign Referenced Citations (6)
Number Date Country
58-074445 May 1983 JP
01-261150 Oct 1989 JP
04-338056 Nov 1992 JP
05-97122 Apr 1993 JP
05-112326 May 1993 JP
6-278921 Oct 1994 JP