US3865324A

US3865324A - Film unwinding system

Info

Publication number: US3865324A
Application number: US396870A
Authority: US
Inventors: Erich Binder
Original assignee: Gretag AG
Current assignee: Gretag AG
Priority date: 1972-09-22
Filing date: 1973-09-12
Publication date: 1975-02-11
Anticipated expiration: 1992-02-11
Also published as: DE2255726A1; FR2200549A1; DE7241790U; CH559919A5; JPS4988509A

Abstract

A system for unwinding film having a paper backing strip from a spool, the system including a holder for the spool which is moved into a first position at which the paper strip is unwound by a first take-up roll, the holder then being advanced to a second position at which the film is unwound by a second take-up roll while the first take-up roll is unwinding the paper strip. Drive is provided to rotate both the spool and the take-up rolls in the same direction which is opposite to the direction the film and strip are wound in the spool. This is accomplished by two rocker arms articulated about a common shaft, one arm having at least one drive roll to rotate the spool and the other arm carrying the take-up rolls, each of which forms a nip with an associated drawoff roll. The arms can be swung to admit the spool into a position at which it is driven to unwind the film and strip and another position at which a gap is formed between one of the take-up rolls and its associated draw-off roll to allow the spool to drop therethrough after unwinding.

Description

[ Feb. 11, 1975 United States Patent Binder FILM UNWINDING SYSTEM Primary Examiner-Edward J. McCarthy [75] Inventor: Erich Binder, Regensdorf Attorney, Agent, or Firm-Pierce, Scheffler & Parker Switzerland [57] ABSTRACT ding film having a paper backing A system for unwin [73] Assignee: Gretag Aktiengesellschaft,

Regensdorf, Switzerland Sept. 12, 1973 Appl. No.: 396,870

strip from a spool, the system including a holder for ool which is moved into a first position at which the sp [22] Filed:

the paper strip is unwound by a first take-up roll, the holder then being advanced to a second position at which the film is unwound by a second take-up roll Foreign Application Priority Data while the first take-up roll is unwinding the paper strip. Drive is provided to rotate both the spool and Sept. 22, l972 Switzerlandtf....................

the take-up rolls in the same direction which is opposite to the direction the film and strip are wound in the spool. This is accomplished by two rocker arms articulated about a common shaft, one arm having at least 50 60 l/ 27 41 n 6 11B m 6 m C Sn Um m ni 55 [58] Field of Search...... 292/65, 56 R, 67.1 R, 67.2,

292/673 674 one drive roll to rotate the spool and the other arm carrying the take-up rolls, each of which forms a nip e ve wnmw w w ckfl mO S aw w f t Og a ae .m n d mmm mm T w Cf .om m w we d -ihu tn da O e .Zl dh wiimme ol u rofl mhm wes mh det t flm 6h wa td e m fm SW om p S n d mmuknm had t] mf mm m wm o .l r wwdfiuw 5 RX H Z m n 2 4mm 22H .4 S H T QM N m m Wm m d mun" A Hum P "mmm ma m? mTm mw Aflee .iT M a RSWMIJH D E oooofi. T1137 [9999 NHHHH UGO-9 7b 2085 58 03 1 9754 6 96 0 5 .1 7.1

9 Claims, 9 Drawing Figures PMENTED FEB] 1 I975 SHEET 2 OF 7 PATENTED 1 3,865,324

SHEET u 0F 7 PATENTH] FEB] 1 I975 SHEET 5 OF 7 l FILM UNWINDING SYSTEM FIELD or THE INVENTION The invention relates to a system for unwinding strip material, more particularly photographic roll film material and in a preferred form is adapted to unwind films in which the exposed film strip is wound on a spool together with a protective paper stn'p such as Instamatic films.

BRIEF DESCRIPTION OF DRAWINGS In the accompanying drawings:

FIG. 1 is a perspective view showing the construction of a system in accordance with the present invention.

FIG. 2 shows details of FIG. 1.

FIG. 3 shows the drive connection between the individual components of the system shown in FIG. 1 taking an active part in the unwinding of the strip.

FIGS. 4 to 7 illustrate the sequence of functions in a specific use of the system illustrated in FIG. 1, and

FIGS. 8 and 9 show a different sequence of functions when unwinding Leica films.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The system illustrated in FIG. 1 comprises a spool holder I having

arms

2 and 3 which extend from a cross piece 4 in the form of a fork and which at their free ends are adapted to rotatably mount a spool 5 on which a strip of film 6 is wound. The arrangement is such that the spool 5 can be released after unwinding has been completed so that a new spool of film can be fixed in place. The

arms

2 and 3 are fixed to the cross piece 4 so as to be pivotable to a limited degree at right angles to their common plane. As will be apparent hereinafter, this provision enables the spool 5 to be mounted resiliently transversely of the spool axis. Although not shown in detail, the holder 1 is guided to be slidable to and from in a machine frame (not shown) substantially in the longitudinal direction of the

arms

2 and 3 and in the direction of the double arrow 7 and is moved accordingly as shown by the double arrow 8.

The holder 1 can be moved into a first operating position (FIGS. 1 and 3 and 5), in which the spool 5 is situated in an opening 9 between rolls (FIG. 4) the opening being formed between a first drive roll 10 and a first take up roll 11 associated therewith. These rolls are mounted opposite one another at opposite sides of the path of movement of the holder 1, so that the woundon film 6 is mounted for movement into and through the roll gap 9.

The drive roll 10 is mounted for rotation in a rocker arm 12 and is connected to a gearwheel 13 so as to rotate therewith (FIG. 1), the gearwheel meshing with an intermediate gearwheel 14 also mounted in the rocker arm 12. Gearwheel 14 meshes with a gearwheel 15 which is connected to a second drive roll 16 so as to rotate therewith and which is mounted together with the latter: in the rocker arm 12. The second drive roll 16 is offset from the first drive roll 10 by a predetermined distance in the direction of movement of the spool holder 1. The gearwheel 15 meshes with an intermediate gearwheel 17 mounted in the rocker arm 12 and meshing with a gearwheel 18. Together with a second draw-off roll 19 the gearwheel 18 is mounted on a shaft 20 so as to rotate therewith, said shaft being mounted for rotation in the machine frame 21 and, as shown at 22, forming the pivot bearing for the rocker arm 12.

On the opposite side of the draw-off roll l9"with respect to the gearwheel 18, the shaft 20'mounts another gearwheel 18' which rotates therewith and which meshes with a gearwheel 23. The latter is connected to a second take-up roll 24 so as to rotate therewith and is mounted for rotation together with the roll 24 in a rocker arm 25 which in turn pivots about the shaft 20 as shown at 26. The gearwheel 23 meshes with a gearwheel 27 which is connected to a contact pressure roller 28 so as to rotate therewith and which is mounted in the rocker arm 25 together with the roll 28. The gearwheel 27 is coupled to a gearwheel 30 via an intermediate gearwheel 29 mounted in the rocker arm 25, gearwheel 30 being coupled to a first draw-off roll 31 and being mounted together with the latter in the rocker arm 25. The first draw-off roll 31 (see also FIG. 2) has teeth 32 in its middle portion, said teeth engaging with corresponding teeth 33 of the first take-up roll 11 when the rocker arm 25 is in the rocked position shown in FIGS. 1 to 3. Roll 11 is mounted rotatably in a rocker arm 34 which is in turn pivotally connected to the machine frame at 35. A spring 36 (see for example FIG. 3) engages the rocker arm 34 to press the first take-up roll 11 against the first draw-off roll 31. The movement of the rocker arm 34 under the action of spring 36 is limited by a stop 37. Referring to FIGS. 1 and 3, the rocker arm 34 is moved away from the stop 37 by the first draw-off roll 31 engaging the first take up roll 11 when the rocker arm 25 is in the position illustrated.

In order to assume this and any other operating position explained herinafter, the rocker arm 25 is actuated by a control cam 38 (FIG. 1) which is mounted on a shaft 40 and which co-operates with a cam follower 41, the shaft 40 being mounted for rotation in the machine frame at 39. The cam follower 41 is secured to the middle of a link 42 which is articulated at one end 43 of an extension 44 of the rocker arm 25, the other end of the link 42 having a slot 45 through which the shaft 40 extends. The kinematics of this arrangement will be immediately apparent from the drawing and the above explanation. It will also be apparent that the control cam 38 does not necessarily have the contour shown (for illustrative purposes) but a contour which produces the required operating positions of the rocker arm 25, as will be explained hereinafter. The control cam 38 embodies a cyclic mode of operation and is accordingly driven from a geared motor (not shown) by a belt drive 47. This drive includes other control cams 48 which are also mounted on the shaft 40 and which each cooperate with one or more switches 49 to control the process as will be described hereinafter. This includes particularly the control of the holder 1 and the drive of the various rolls, which are connected to a step-by-step motor by means of another belt drive 46. The belt drives 46 and 47 are slip-free and can of course be replaced by a different form of drive connection. The belt drive 46 is connected to the shaft 20 by an intermediate gearwheel 50 and a gearwheel 18".

A film guide 51 is situated after the roll gap formed by the second draw-off roll 19 and the second take-up roll 24 and its inlet is formed by bottom and top guide rods 52, 53 (see also FIG. 2) which extend as into the roll gap. Feed means indicated by the arrow 54' are provided in the region of the film guide in order as will be apparent hereinafter to convey further the film strip entering the guide 51. Forjhis purpose, all the rolls include a freewheeling mechanism (not shown) so that the film strip can be advanced at an accelerated rate in the guide 51. Prior to this, the film transport is effected primarily by means of the

rolls

19 and 24, each having a central portion of reduced-diameter in order to contact the film strip only in the edge region of the latter. The other rolls also have a similar construction, except for the

rolls

31 and 11, but, as will be apparent hereinafter, the latter do not have to unwind the film strip but a protective paper strip. The operational direction of rotation of the rolls, which are driven by means of the set of

gearwheels

18, 18 and 18" except for the first take-up roll 11, is indicated by arrows in FIG. 3, the first take-up roll 11 being driven by the first draw-off roll 31. The first take-up roll 11 also has a freewheel device to prevent rotation against the operational direction of rotation.

For a better understanding of the preferred embodiment of the invention, other constructional details will be mentioned during the following description of its function. It will be assumed that the machine is initially being used for unwinding Instamatic" films or film material in which a protective paper strip is provided together with the rolled up film strip, the latter being secured at its front end to the protective paper strip at a distance from the front end of the latter by gluing, for example by means of an adhesive strip. The word "front applies only to the condition of such films before exposure. During exposure, in fact, the paper strip and hence also the film strip are wound on a spool and in the resulting wind up the previous front end of the two strips is situated at the back or on the inside. In accordance with this position of the end of the strip in the wound up of exposed film material with which we are concerned here, we shall hereinafter speak of an outer and an inner end of the protective paper strip and film strip respectively. The expression direction of reeling also relates to the reeled up exposed film strip and protecive strip i.e. the direction in which they are reeled onto spool 5. On this assumption, the film spool is fixed in the holder 1 in such manner that the direction of reeling is in the anti-clockwise direction with respect to the illustration, for example, in FIGS. 3 or 4. When the film spool 5 is fixed in the holder 1, the latter is situated in front of the roll gap 9 (FIG. 4) as considered in the direction of movement of said holder, the

bearer arms

2 and 3 being urged upwards (with reference to the drawing) by means of a spring 55 against a movable stop 56. In the initial position shown in FIG. 4, the rocker arm 25 has rocked to its maximum extent by means of the control system 57 (FIG. 1) the rocker arm having been rocked in the clockwise direction until the first draw-off roll 31 moves into the roll gap 9 and deflects the first take-up roll 11 to the left away from its abutment 37 against the action of the spring 36. In this condition the width of the roll gap 9 is the minimum possible due to the position adopted by the takeup roll 11 and the position of the rocker arm 12 which is urged by a spring 58 against the stop 59, the first drive roll occupying its nearest possible position to the take-up roll 11. This position of the individual components was referred to as the initial position hereinbefore. The expression initial position" refers to the actual unwinding process. Prior to the latter operation, however, a preparatory step may advantageously be carried out with those components which take an active part in the winding process situated in a somewhat different mutual position. For the sake of better understanding, however, this preparatory step will not be described until later. Accordingly, we shall describe here the processes which start when, or as a result of, the film spool 5 being advanced into the roll gap 9 and against the first draw-off roll 31 as shown in FIG. 5.

In this position, the first drive roll 10 and the first take-up roll 11 engage between the flanges ofthe spool 5, the drive roll 10 bearing directly on the wound-on protective paper strip and the take-up roll 11 touching the protective paper strip under the action of the

springs

58 and 55 respectively.

The first draw-off roll 31 is also situated between the flanges of the spool 5 and bears on the protective paper strip under the action of spring 69 which tends to rock the rocker arm 25 in the direction of a stop 60 (FIG. 5). The arrangement is such that in the position shown in FIG. 5 the first draw-off roll 31 is displaced by the reel to such an extent that the rocker arm 25 moves away from the stop 60. Under these conditions, the reeled up film strip 6 and its protective paper strip 61 (together with the spool 5) is rotated in the clockwise direction and hence in the opposite direction to the direction of reeling, the outer end of the protective paper strip very soon running against the first take-up roll 11 and in fact against the teeth 33 thereof. It will be recalled that this roll is driven in the clockwise direction by the first draw-off roll 31 by way of the said teeth, and is hence driven in the opposite direction to the direction of reeling of the spool 5, so that the outer end of the protective paper strip is deflected and is guided into the roll gap formed between the rolls 1] and 31. Here the protective paper strip 61 (see particularly FIGS. 1 and 2) is engaged by the intermeshing

teeth

32 and 33 of the draw-off roll 31 and of the take-up roll 11 and is transported in the direction of arrow 62, the end of the protective paper strip 61 interrupting the control beam ofa photoelectric sensor PE (FIGS. 1 to 3) which produces a signal. In response to this signal, the control system 57 first stops further drive of the rolls and in addition produces a further displacement of the holder 1 in the direction of the arrow 7' (FIG. 3) until the spool 5 occupies the position shown in FIG. 6, in which it is connected to the second drive roll 16 in a driving relationship similar to the driving relationship between the first drive roll 10 and the spool 5. In these conditions, the second take-up roll 24 is displaced somewhat by the spool 5 against the action of the spring 69. To enable this to take place, an appropriate rotation of the control cam 38 has previously been produced so that the cut-away portion 64 of the cam is situated opposite the cam follower 41 to enable to rocker arm 25 to swing to the position illustrated. The spring 36 also contributes to moving back the second take-up roll 24 if the spring force is appropriately selected. As soon as the pivot bearing has reached the position, illustrated in FIG. 6, the control system 57 rotates the rolls again by way of the drive motor (not shown) the roll of wound on film being rotated in the opposite direction to its direction of reeling, by way of the second drive roll 16 and by way of the

rolls

11 and 31 which continue to draw off the protective paper strip. In these conditions, the outer end of the film strip 65 passes beneath the roll 16 on to the second take-up roll 24 and is deflected by the latter into the roll gap formed between the roll 24 and the associated draw-off roll 19. Following this roll gap, the end of the film strip slides along the

guide rods

52 and 53 into the film guide 51 where, as already stated, it is engaged by a transport mechanism (not shown) and is transported in the direction of the arrow 54. This can be effected at a higher speed than the previous draw-off speed since the rolls participating in the film draw-off include a freewheeling mechanism. In principle, the drawing-off ofthe protective paper strip and of the film strip respectively is continued until the glued inner end of the film strip is released from the protective paper strip and this event is detected by means of another photoelectric sensor (not shown). A cutter device may be provided at a suitable place to cut off the trailing end of the film strip together with the adhesive strip adhering thereto. A photoelectric sensor, for example, is suitable for actuating this cutter device. A sensor of this kind is also provided at the inlet to the film guide 51 to transmit another control signal to the control system. This signal can, if required operate another cutter device which cuts the trailing end of the film strip for the purposes of splicing to a following film strip. The same or another corresponding cutter device must of course be used to cut the forward end of a film strip. With these steps it is possible for successively unwound film strips entering the film guide 51 to be spliced together and for the resulting combined strip to be wound on a reel of appropriate size, which is then fed to the further processing operations (e.g. developing, etc.). Precautions for the identification of the individual film strips would, of course, have to be taken at the same time.

Following upon the last-mentioned control signal, which is produced on sensing the end ofa film strip, the control system 57 causes the rolls to stop and the rocker arm 25 to rock in the anticlockwise direction until it reaches the position shown in FIG. 7.

As will be apparent from FIG. 7, a considerable gap forms between the first take-up roll 11 which is in its initial position, and the associated draw-off roll 31 thus releasing from the holder 1 the empty spool 5 which then drops through this gap. The return movement of the holder and the restoration of the rocker arm 25 into the positions shown in FIG. 4 is then effected by the control system 57. This completes one working cycle. The holder can now receive another full spool of film (the supply may also be effected automatically), from which the protective paper strip and the film strip respectively are released as described.

Before the initiation of the above-explained unwinding process itself, a preparatory step may be carried out as already stated. This could be effected with the rocker arm 25 and the rocker arm 34 in the positions shown in FIG. 7. If the spool 5 is pushed into the roll gap 9 as the preparatory step mentioned, with the

arms

34 and 25 in the said positions, and if the first drive roll 10 is then briefly rotated, the said roll exerts on the protective paper strip the drive expected of it. The spool of film cannot be rotated, however, since it is pressed against the first take-up roll 11 which, however, is prevented-from rotating in the anticlockwise direction by its frecwheel mechanism. Consequently, the first drive roll 10 pulls the protective paper strip 61 and thus tautens the film on the spool. In this way any loosening occurring when the spool of film is fixed in the holder can be eliminated. After a slight rotation of the first drive roll 10 for the purposes of this preparatory step, the

rocker arm 25 is then pivoted in the clockwise direction, the first draw-off roll 31 performing its function already described.

The system described can also be used for unwinding roll films without a protective paper strip (Leica films). For this purpose the rocker arm 25 shown in FIG. 8 is in the same position as it occupies at the end of a working cycle when unwinding lnstamatic" films (see H6. 7). The wound up film in this case 6' held in the holder 1 is fed to the second drive roll 16 (see FIG. 9) whereupon the rocker arm 25 is rocked in the clockwise direction until the take-up roll 24 and also the contact pressure roll 28 come into contact with the wound off film strip 65. The wound up film 6', as shown in FIG. 9, is driven by the drive roller l6and the contact pressure roller 28, the outer end of the film strip being deflected by the take-up 24 in the manner already described and is then fed to the roll gap formed between the roll 24 and its draw-off roll 19. At the end of the unwinding operation, the rocker arm 25 is rocked back as already described in connection with FIG. 7 and the empty spool is released from the holder 1. The remarks made in connection with the unwinding of an lnstamatic film naturally apply to the unwinding of Leica films.

What is claimed is:

1. A system for unwinding a strip of photographic film material wound up into roll form on a film spool which comprises a holder for supporting the film spool with the film rolled up thereon for rotation, a drive roll engageable with the surface of the roll of film for rotating the latter in the sense of unwinding the film strip, and means for taking up the outer end of the film strip as it is unwound comprising a take-up roll drivable in the same sense of rotation as that of said film roll, and a rotatably mounted draw-off roll resiliently pressed against said take-up roll and establishing a nip therebetween into and through which the wound off outer end of the film strip is led and drawn off.

2. A system for unwinding a strip of photographic film wound up into roll form on a film spool and wherein a paper strip is secured to the outer end of the film strip and forms the outer layers of the roll which comprises a holder for supporting the film spool with the film and paper strips rolled up thereon for rotation, said holder being movable longitudinally of itself be tween a first and second position, a first set of rolls cooperable with the film spool and rolled up paper strip when said holder is in said first position comprising a drive roll engageable with the surface of the rolled up paper strip for rotating the latter in the sense of unwinding the paper strip, and means for taking up the outer end of the paper strip as it is unwound comprising a take-up roll drivable in the same sense of rotation as that of said rolled up film and paper strip and a rotatably mounted draw-off roll resiliently pressed against said take-up roll and establishing a nip therebetween into and through which the wound off end of the paper strip is led and drawn off; and a second set of rolls cooperable with the film spool and the remaining rolledup film strip when said holder is in said second position comprising a drive roll engageable with the surface of the rolled up film strip for rotating the latter in the sense of unwinding the film strip, and means for taking up the outer end of the film strip as it is unwound comprising a take-up roll drivable in the same sense of rotation as that of said rolled up film strip, and a rotatably mounted draw-off roll resiliently pressed against said take-up roll and establishing a nip therebetween into and through which the wound off end of the film strip is led and drawn off.

3. A system as defined in claim 2 and which comprises a detecting element located adjacent the nip formed between the take-up roll and draw-off roll of said first roll set and responsive to passage of the wound off paper strip, and control means actuated in accordance with a response of said detecting element for shifting said film spool holder from said first to said second positions.

4. A system as defined in claim 3 wherein said first and second sets of rolls are rotatably journalled on elastically supported swivel arms.

5. A system as defined in claim 4 wherein the drive rolls of both roll sets are journalled on a first common swivel arm, wherein the draw-off roll of said first roll set and the take-up roll of said second roll set are journalled on a second common swivel arm, and wherein both of said swivel arms are mounted pivotally about the axis of the draw-off roll of said second roll set.

6. A system according to claim 5 wherein the take-up roll of said first roll set is rotatably journalled on a third swivel arm and wherein said second swivel arm is arranged to swing the draw-off roll of said first roll set towards and away from the take-up roll of said first roll set thereby to establish a gap therebetween in the swung away position through which the film spool can drop when the film strip has been drawn off.

teeth in their respective middle portions.

Claims

2. A system for unwinding a strip of photographic film wound up into roll form on a film spool and wherein a paper strip is secured to the outer end of the film strip and forms the outer layers of the roll which comprises a holder for supporting the film spool with the film and paper strips rolled up thereon for rotation, said holder being movable longitudinally of itself between a first and second position, a first set of rolls cooperable with the film spool and rolled up paper strip when said holder is in said first position comprising a drive roll engageable with the surface of the rolled up paper strip for rotating the latter in the sense of unwinding the paper strip, and means for taking up the outer end of the paper strip as it is unwound comprising a take-up roll drivable in the same sense of rotation as that of said rolled up film and paper strip and a rotatably mounted draw-off roll resiliently pressed against said take-up roll and establishing a nip therebetween into and through which the wound off end of the paper strip is led and drawn off; and a second set of rolls cooperable with the film spool and the remaining rolled-up film strip when said holder is in said second position comprising a drive roll engageable with the surface of the rolled up film strip for rotating the latter in the sense of unwinding the film strip, and means for taking up the outer end of the film strip as it is unwound comprising a take-up roll drivable in the same sense of rotation as that of said rolled up film strip, and a rotatably mounted draw-off roll resiliently pressed against said take-up roll and establishing a nip therebetween into and through which the wound off end of the film strip is led and drawn off.

7. A system according to claim 6 comprising pivot means for said swivel arms, said pivot means being responsive to the position of the film spool and of the state of unwinding of the film.

8. A system according to claim 2 wherein said second roll set includes a contact pressure roller for pressing the rolled up film against the drive roll of said second set.

9. A system according to claim 1 wherein said take-up roll and said draw-off roll are provided with meshed teeth in their respective middle portions.