Film leader and arrangement for coupling film to leader

Abstract: A coupling structure capable of coupling films (3) to a leader (L1) with high reliability. The leader (L1) has a leader body (1) formed with first holes and second holes in its rear with respect to the feed direction of the leader. Sheet members (5) having fingers (7) are stuck on the leader body (1) so that the fingers (7) extend across the respective first holes. Film each having a hole in its leading end are coupled to the leader body (1) by inserting their leading ends through second holes into the first holes until the fingers (7) engage in the holes formed in the films.

Description: The present invention relates to a leader according to the preamble of independent claim 1. Especially, this invention relates to a leader used in automatically developing photographic films and a coupling means for coupling such a leader to films. When developing films in an automatic film developing machine of the type that utilizes a leader to guide films, films 61 from patrone 60 are connected at their leading ends to a leader 62 as shown in Fig. 18 and fed in the machine guided by the leader 62. The leader 62 is a flexible synthetic resin sheet formed with a plurality of holes 63 arranged in the feed direction at equal intervals and adapted to engage a leader feed sprocket provided in the film developing unit. If a film 61 should separate from the leader 62 and sink into a developing tank filled with a developing solution, it has to be taken out of the tank while interrupting the developing operation. This work is troublesome and time-consuming. Also, there is the possibility that the film might be inadvertently exposed to light while taking it out of the developing tank. In order to prevent such an accident, every film 61 has to be securely connected to a leader 62. Films 61 are usually connected to the leader 62 by means of splicing tapes 64. But splicing tapes 64 are difficult to handle, firstly because they have to be applied to the films and the leader while placing them on a special workbench to couple them together with high accuracy, and secondly because it is troublesome to detach the tapes from the films and the leader after developing films. The use of such tapes are also disadvantageous from an economical viewpoint because they are not reusable. US patent No. 4110774 discloses a coupling means that requires no splicing tape. Rather, in this arrangement, a film is hooked to a leader as shown in Figs. 19 and 20. The coupling means shown in these figures comprises a tongue 72 defined between two cuts 71 formed in the rear end of a leader 70 in the form of a flexible sheet, and an opening 74 formed in the leading end of a film 73. The film is coupled to the leader 70 by inserting the tongue 72 of the leader into the opening 74 of the film so that a neck portion 75 of the tongue engages the side edges of the opening 74. Since no splicing tape is needed in this arrangement, the film can be coupled to the leader economically. Since the tongue 72 extends rearwardly with respect to the feed direction of the leader 70, it will never get caught or stuck in the film feed path, so that it is possible to feed the leader 70 smoothly through the film feed path. Also, it is possible to couple the film to a desired point of the leader with high accuracy. In order to insert the tongue 72 into the opening 74 or to pull it out of the opening 74, the former has to be bent arcuately in the width direction because the width W1 of the tongue 72 is larger than the width W2 of the opening 74. Such a delicate operation is beyond the capacity of a machine. Thus, in this arrangement, automatic connection and disconnection of the leader and the film are impossible. While being fed through the film feed path in the automatic film developing machine, the film 73 tends to be subjected to a rather large tensile force at a tuning point in the film feed path. Such tensile force tends to concentrate on the tongue 72, so that the tongue 72 may be deformed and come out of the opening 74. Thus, this coupling means cannot couple the leader and the film with sufficiently high reliability. Moreover, since the film 73 is bendable about the neck portion 75 of the tongue 72, it tends to meander and get damaged by being brought into contact with the film feed path. From prior art document US 5 381 204, a leader card attachable to a photographic film strip can be taken. Said leader card has a series of apertures which are engageable by, for example, gear teeth in a film processor to pull the leader card through the film processor. Said leader card or leader body comprises protrusions or hooks with front and rear ends with respect to the feeding direction of the leader, wherein said hooks are extending in the feed direction of said leader. A pair of said hooks are extending across an opening formed in said leader body, wherein rear ends of said protrusions or hooks are integrally formed with said leader body and the front ends thereof are substantially freely moveable within said opening. Furthermore, a tab portion is provided which also extends across said opening and is positioned between said hooks wherein the rear end thereof is freely moveable within said opening and the front end is fixed at the leader body. The related film strip comprises a pair of apertures for receiving said hooks and the tab portion is used for clamping said film strip in cooperation with said hooks. According to a further embodiment of the leader card as can be taken from prior art document US 5 381 204, hooks are provided which initially extend towards the film strip and then bend back to extend away from the film strip in order to secure the leading end of the film strip to the leader card. Said hooks are inserted up through apertures and the lead portion of each hook is tucked under the tab portion of the leader card to inhibit hooks from being removed from apertures. From prior art document EP-A-0 624 822 a leader body comprising means for attaching a film strip can be taken. Said prior art leader comprises a leader body having a plurality of holes formed at equal intervals for feeding said leader. At a rear end of said leader body a elongated opening for inserting a film is provided. Furthermore, pawls or hook means for engaging with an engagement perforation of the film strip are formed on said leader body at a position located forwardly with regard to said film inserting holes. Said pawls are extending in an inclined forward direction with regard to said leader body. A pressing plate is provided to cover the pawls and the film inserting openings. Thus, the film strip inserted through said opening and being engaged with the pawl at the engagement perforation is pressed by said plate to prevent the film from coming off. It is an objective of the present invention to provide a leader as mentioned above and a coupling means for coupling a film to a leader which enable the film to be connected to and disconnected from the leader easily, reliably and, if so desired, automatically. According to the present invention, said objective is solved by a leader having the features defined in the characterising portion of claim 1. Preferred embodiments are laid down in the dependent claims. Preferably, the protrusions of the leader may be portions of sheet members fastened to the front of the leader body, or may be integrally formed on the front edges of the film inserting holes. In this case, sheet members should be bonded to the back of the leader body to support the rear ends of the protrusions. Engaging holes are formed in the leading end of each film so that by inserting such films into the film inserting holes of the leader, the protrusions will engage in the engaging holes formed in the films. In order to stably and reliably connect films to the leader, it is preferable to provide the leader with film inserting cutouts in the rear of the film inserting holes and with engaging protrusions provided at both sides of the cutouts and adapted to engage both sides of a film inserted in each cutout. Instead of such cutouts and protrusions, second film inserting holes may be formed in the rear of the film inserting holes. Hereinafter, the present invention is illustrated and explained in further detail by means of preferred embodiments in conjunction with the accompanying drawings, wherein: Fig. 1 is a perspective view of a first embodiment; Fig. 2 is a sectional view taken along line II-II of Fig. 1; Fig. 3 is a sectional view showing an intermediate state of the film connecting step; Fig. 4 is an exploded perspective view of part of the leader and a sheet member; Fig. 5A is a perspective view of a second embodiment; Fig. 5B is its sectional view; Fig. 6 is a perspective view of a third embodiment; Fig. 7 is a sectional view taken along line VII-VII of Fig. 6; Fig. 8 is a schematic view of a film splicing device; Figs. 9A-9D show step by step the operation of a film disconnecting device; Fig. 10 is a perspective view of a fourth embodiment; Fig. 11 is a sectional view taken along line XI-XI of Fig. 10; Fig. 12 is a sectional view showing an intermediate state of the film connecting step; Fig. 13 is an exploded perspective view of a portion of the leader and a sheet member; Fig. 14 is a perspective view of a fifth embodiment; Fig. 15 is a sectional view of Fig. 14; Fig. 16A is a perspective view of a sixth embodiment showing the state before the second film inserting holes are formed; Fig. 16B is a perspective view of the same showing the second film inserting holes; Fig. 17A is a perspective view of the leader of the seventh embodiment; Fig. 17B is a perspective view of the leader and a film connected thereto; Fig. 18 is a perspective view of a conventional film connecting means; Fig. 19 is a front view of another conventional film connecting means; and Fig. 20 is a sectional view taken along line XX-X of Fig. 19. The embodiments are described with reference to Figs. 1-17. Figs. 1-4 show the first embodiment invention. As shown, a leader L1 comprises a flexible leader body 1 of a synthetic resin sheet. It is formed with a plurality of holes 2 arranged in the feed direction at equal intervals. It is fed in one direction by engaging a sprocket in the holes 2 and rotating it. The leader body 1 has holes 4 in the rear portion thereof on both sides of the holes 2. A film 3 can be inserted in each hole 4. The holes 4 have a width substantially equal to the width of the films 3. By inserting the films 3 into the holes 4, both edges of the films 3 abut both sides of the holes 4, so that they will scarcely shake while being fed. Sheets 5 are superimposed on the leader body 1 to cover the respective holes 4. They are fastened to the leader L1 by bonding or fusing. Each sheet member 5 has a window 6 that registers with the hole 4. Protrusions 7 are formed on the front edge (with respect to the feed direction of the leader) of each window 6. The protrusions 7 extend across the holes 4 in the feed direction of the leader L1 so that their free ends are supported on the leader body 1 near the rear edges of the holes 4. Each film 3 has holes 9 near its leading end in which the protrusions 7 are adapted to engage. In order to connect the films 3 to the leader L1 accurately with little possibility of their inclining relative to the leader L1, each film 3 should have more than one hole 9 to receive a plurality of protrusions 7. By inserting the leading end of each film 3 into the hole 4 and the window 6 from behind the leader L1, the protrusions 7 are deflected upward by being pushed by the leading end of the film 3 as shown in Fig. 3. When each film 3 is inserted until its holes 9 face the protrusions 7, the protrusions 7 will be urged into the holes 9 under their own resilient restoring force. By pulling back the film 3 in this state, the protrusions 7 are allowed to straighten back to their original rest positions. The film 3 is thus coupled to the leader L1 as shown in Fig. 2. In the above manner, each film 3 can be automatically coupled to the leader L1 by pushing it into the holes 4 by a predetermined distance and then pulling it back. Once coupled to the leader L1, the films 3 are rigidly connected to the leader L1 with the free ends of the protrusions 7 supported on the rear edges of the holes 4 so that they will not be deflected downward. The films 3 are fed, guided by the leader L1, into the film developing unit for development. Since the protrusions 7 extend rearward with respect to the feed direction of the leader, they will never get caught or stuck in the film feed path, so that the leader L1 and the films 3 can be fed smoothly in the film feed path. While being fed, the films 3 keep their both side edges abutting both sides of the holes, so that they will never shake or meander. While being fed, a tensile force may acts on the films 3 in such a way as to deform the protrusions 7 downward in Fig. 2. But actually, they will never be deformed that way because their free ends rest on the leader body 1 near the rear edges of the holes 4. Thus, the possibility of the films 3 coming off the leader is practically nil. To detach films 3 from the leader, they are pushed forward to raise the protrusions 7 until they completely come out of the holes 9, and then the films are pulled back. In their rest positions, the protrusions 7, formed integral with the sheet members 5, are flush with the top surfaces of the sheet members 5 fastened to the leader body 1. Thus, they are less likely to be deformed by being caught by e.g. fingertips than protrusions directly fastened the leader body 1. Figs. 5A and 5B show the second embodiment. In this embodiment, protrusions 7 extend rearward from the front edge (with respect to the feed direction of the leader) of each hole 4 formed in the leader body 1. Along the rear edge of each hole 4 are formed cutouts 10 in which the tips of the protrusions 7 are received. Sheets 11 are bonded or otherwise fastened to the back of the leader body 1 to cover the cutouts 10 and support the tips of the protrusions 7. Similar to the first embodiment, the protrusions 7 extend rearward with respect to the feed direction of the leader L1, so that the protrusions 7 are least likely to get caught or stuck in the feed path. It is also possible to automatically connect and disconnect the films and the leader. In both the first and second embodiments, by engaging the tips of the protrusions 7 in the cutouts 8 or 10, they are kept from rocking while being fed, so that the films 3 can be reliably kept connected to the leader by the protrusions. Figs. 6 and 7 show the third embodiment. In the third embodiment, cutouts 12 are formed in the rear (with respect to the feed direction of the leader L1) of the holes 4. Films 3 are inserted into the cutouts 12. The cutouts 12 have protrusions 13 on both sides which are adapted to engage both sides of the films 3. Their width is substantially equal to the width of the films 3, so that it is possible to prevent rocking of the films inserted in the cutouts. Otherwise, this embodiment is structurally the same as the first embodiment. Thus, like elements are denoted by like numerals and their description is omitted. In the third embodiment, the tip of each film 3 is inserted into the hole 4 of the leader L1 from its back until the protrusions 7 engage in the holes 9. The rear portion of the film 3 is then raised to push it into the cutout 12 while resiliently deforming the protrusions 13 upward. The film 3 is thus coupled to the leader L1. In the third embodiment, since the tips of the films 3 are inserted in the holes 4 and the cutouts 12, the protrusions 7 are much less likely to come out of the holes 9 even if a tensile force acts on the films 3 while being fed. Namely, the films 3 can be kept connected to the leader more reliably. Fig. 8 shows a splicing device for coupling the films 3 to the leader L1 shown in Figs. 6 and 7. It comprises a lower film guide 20 comprising a plurality of plate members 21, and an upper film guide 22 also comprising a plurality of plate member 23. A film turning path 24 is defined between the upper and lower film guides 20 and 22. This splicing device is used as follows: the leader L1 is positioned on the lower film guide 20; films 3 are fed through the cutouts 12 into the film turning path 24; and a pair of feed rollers 25, 26 are rotated to feed and insert the films into the holes 4 while deforming the protrusions 7 upward until the holes 9 face the protrusions 7 and the protrusions 7 engage in the holes 9 under their own resilient restoring force. Once the protrusions 7 engage in the holes 9, the upper film guide 22 and one of the feed rollers 25, which is supported on the upper film guide 22, are moved a distance equal to or greater than the width of the films 3 in the width direction of the films 3. Then, by moving the leader L1 in the direction of arrow, the films 3 can be pulled out of the lower film guide 20. By using this splicing device, the films 3 can be automatically coupled to the leader L1. Fig. 9 shows a device for disconnecting the film from the leader. This device is used as follows: the leader L1 and the films 3 spliced to the leader are fed forward by a front and a rear feed roller pairs 30 and 31 until the holes 4 come right over the tip of a separating tool 32 (see Fig. 9A; only the films 3 are fed further forward by rotating the rear feed rollers 31 to slacken the films 3 between the holes 4 and the cutouts 12 as shown in Fig. 9B; the separating tool 32 is pivoted up to push its tip into the holes while deforming the protrusions 7 upward as shown in Fig. 9C. The protrusions 7 thus come out of the holes 9. In this state, the rear feed rollers 31 are turned in reverse to back the films 3 until their tips come out of the holes 4 and the cutouts 12. Then, as shown in Fig. 9D, the separating tool 32 is pivoted downward, and the front and rear feed rollers 30 and 31 are rotated to discharge the leader L1 and the films 3 from the feed path. By using this device, it is possible to automatically disconnect the films 3 from the leader L1 shown in Fig. 6. This device can also be used to disconnect films 3 from the leader L1 shown in Figs. 1 and 5. Figs. 10 to 14 show the fourth embodiment. In this embodiment, the leader body 1 has first holes 40 and second holes 41 formed in the rear (with respect to the feed direction of the leader L1) of the first holes 40. Sheets 42 are bonded or otherwise fixed to the top of the leader body 1 so that windows 43 and 44 formed therein register with the first holes 40 and the second holes 41, respectively. Each sheet member 42 has protrusions 45 that extend from the front edge (with respect to the feed direction of the leader) of the window 43 rearwardly across the window 43 so that their free ends are received in cutouts 46 formed along the rear edge of the window 43 and supported on the leader body 1 near the rear edge of the first hole 40. In the fourth embodiment, each film is connected to the leader L1 by inserting the film 3 through the window 44 into the second hole 41 so that its tip protrudes from the back of the leader L1; then inserting the tip of the film through the first hole 40 into the window 43 while deforming the protrusions 45 upward as shown in Fig. 12 until the holes 9 face the protrusions 45; and finally pulling the film 3 back to allow the protrusions 45 to be engaged in the holes 9. With each film 3 connected to the leader as shown in Fig. 11, it contacts the rear edge of the window 44, the front edge of the second hole 41, and the rear edge of the first hole 40. Thus, even if it is subjected to a tensile force while being fed in the film developing unit, such a force is carried mainly by these contact portions, so that the protrusions 45 will not be subjected to undue force. But even if they are, the protrusions 45 are less likely to be deformed because their tips are supported on the leader body near the rear edge of the first hole 40. Thus, the films will very rarely separate from the leader. Since the widths of the first and second holes 40 and 41 are both substantially equal to the width of the films 3, it is possible to prevent meandering of the films 3 while being fed. The films can be disconnected from the leader by pushing each film from the second hole 41 toward the first hole 40 to raise the protrusions 45 above the sheet member 42 until the protrusions 45 disengage from the holes 9, and pulling back the film. The films 3 may be connected to or disconnected from the leader using the splicing device shown in Fig. 8 or the disconnecting device shown in Fig. 9. Figs. 14 and 15 show the fifth embodiment. In this embodiment, first and second holes 40 and 41 are formed in the rear portion (with respect to the feed direction of the leader) of the leader body 1. Protrusions 45 extend rearward from the front edge of the first holes 40. Their tips are received in cutouts 46 formed along the rear edge of the first holes 40 and supported on sheet members 47 bonded to the back of the leader body 1. The fifth embodiment can achieve substantially the same results/effects as the fourth embodiment shown in Fig. 10. Figs. 16A and 16B show the sixth embodiment. In this embodiment, instead of the sheet members 47 used in the fifth embodiment, ⊐-shaped cuts 48 are formed in the leader body in the rear (with respect to the feed direction of the leader) of the first holes 40. The portions of the leader body delineated by the cuts 48 are bent toward the backside of the leader body 1 to form second holes 41. The bent portions 49 are bonded to the back of the leader body 1 to support the tips of the protrusions 45. Figs. 17A and 17B show the seventh embodiment. In this embodiment, the second holes 41 have arcuate front and rear edges 50 and 51. Cutouts 52 are formed at both ends of the front edge 50. The leader body is also formed with vent holes 53 at portions where the films 3 overlap. Otherwise, this embodiment is structurally the same as the fifth embodiment shown in Fig. 5. Thus, like elements are denoted by like numerals and their description is omitted. In the seventh embodiment, since the second holes 41 have arcuate front and rear edges, the films connected to the leader are come into contact with the respective front and rear edges 50 and 51 at two points. Thus, when drying the films 3 after developing by blowing hot air, it is possible to completely and quickly vaporize any treating solution trapped between the films and the leader L1. Namely, developed films can be dried quickly and efficiently. By providing vent holes 53 in the leader body 1, it is possible to reduce the contact area between the leader body and the films and. thus to improve air permeability at the contact portion between the leader body 1 and the films 3. Thus, the drying efficiency improves further. Due to the reduced contact area, the films 3 are less likely to be damaged. The following are the major advantages of these embodiments: 1) By inserting the tip of each film into the hole formed in the leader body, the protrusions engage in the holes formed in the film. Thus, the film can be easily and, if so desired, automatically connected to and disconnect from the leader. 2) The protrusions have their free ends supported on the leader body or the sheet members near the rear edge of the holes for inserting films. The protrusions are thus less likely to be bent and sink into the holes, so that they can keep the films connected to the leader with high reliability. 3) By providing cutouts in the rear (with respect to the feed direction of the leader) of the film inserting holes and further providing engaging portions on both sides of each cutout, it is possible to connect the films more reliably to the leader. 4) Since the widths of the film inserting holes and cutouts are substantially the same as the width of the films, it is possible to prevent meandering of the films while being fed. 5) By forming the second holes in the rear (with respect to the feed direction of the leader) of the film inserting holes, the films can be more rigidly and reliably connected to the leader. 6) In the arrangement in which the second film inserting holes have arcuate front and rear edges, it is possible to completely removing treating solution by drying the films. By forming the vent holes, air permeability at the contact portions between the films and the leader improves, so that it is possible to dry films more efficiently. 7) Since the second film inserting holes have a width substantially equal to the width of the films, it is possible to prevent meandering of the films more reliably.

Claims: A leader (L1) comprising a leader body (1) formed of a flexible sheet and having a plurality of holes (2) formed at equal intervals along a straight direction in the leader body coinciding with a feed direction in an automatic film developing machine, for feeding the leader (L1) in said automatic film developing machine, said leader body (1) having protrusions (7, 45) for engaging with engaging holes (9) respectively formed on an end of films (3), said protrusions (7, 45) having front and rear ends with respect to said straight direction and said feed direction of the leader (L1) so as to extend in the feed direction of the leader (L1), characterized in that said leader body (1) comprises film inserting holes (4, 40; 6, 43) for inserting therein a film, so that the film extends through an inserting hole (4, 40; 6; 43), said film inserting holes (4, 40; 6, 43) are formed near a side portion of the leader body (1) perpendicularly to said straight direction and said feed direction of the leader (L1), wherein said protrusions (7, 45) are extending across said film inserting holes (4, 40; 6, 43), so that the front end of a protrusion (7, 45) is integral with said leader body (1), and the rear free end thereof is supported on an edge portion of a film inserting hole (4, 40; 6, 43). A leader according to claim 1, characterized in that said leader body (1) comprises sheet members (5, 42) fastened to a surface of said leader body (1) about said film inserting holes (4, 40), wherein said protrusions (7, 45) are formed integrally on said sheet members (5, 42). A leader according to claim 1, characterized in that said protrusions (7, 45) are integrally formed on one edge of said film inserting holes (4, 40), wherein sheet members (11, 49, 47) are fastened to the opposed edge in said leader body (1), and said protrusions (7, 45) have said rear free ends thereof supported on said sheet members (11, 49, 47). A leader according to any of claims 1 to 3, characterized in that said film inserting holes (4, 40; 6, 43) have a width substantially equal to the width of films (3) to be inserted in said film inserting holes (4, 40). A leader according to any of claims 1 to 4, characterized in that said leader body (1) has cutouts (12) in the side of the leader body near of said film inserting holes (4), into which films (3) can be inserted, and engaging protrusions (13) provided at both sides of said cutouts (12) and adapted to engage both sides of a film (3) inserted in said each cutout (12). A leader according to claim 5, characterized in that said cutouts (12) have a width substantially equal to the width of films (3) to be inserted in said cutouts (12). A leader according to any of claims 1 to 4, characterized in that said leader body (1) has second film inserting holes (41) in the side of the leader body near of said film inserting holes (40), into which films (3) can be inserted. A leader according to claim 7, characterized in that said second film inserting holes (41) have arcuate front and rear edges (50,51). A leader according to claim 7 or 8, characterized in that said leader body (1) has vent holes (53) at portions in the leader body in which portions of films (3) inserted through said second film inserting holes (41) into said film inserting holes (40) and portion of the leader body overlap. A leader according to any of claims 7 to 9, characterized in that said second film inserting holes (41) have a width substantially equal to the width of films (3) to be inserted into said second film inserting holes (41).

Inventors: ARIMOTO KEIGO, MASUDA SHIGERU, ARIMOTO, KEIGO, MASUDA, SHIGERU
Applicants: NORITSU KOKI CO LTD, NORITSU KOKI CO., LTD.
Application year: 1996
Main classification: G03D3
IPC codes: G03D3