FR2621709A1 - Device for introducing the free end of a photographic film into a developing machine - Google Patents

Abstract

Device for introducing the end of a film 5 into a developing machine 10 and for cutting the end of this film 5 by means of scissors, characterised: - on the one hand, in that the fixed blade 30 is integral with the support 14 for the roll 6 and is arranged in the direction of the unwinding of the film 5; - on the other hand, in that this roll support 14 is integral with an arm 6 articulated around a first spindle 17, the said arm 16 having a second spindle 18 on which is mounted a first toothed sector 19, integral with a rod 21, at the end 22 of which is articulated a second rod 23, joined in turn to the mobile blade 26; - and finally in that the toothed sector 20 meshes with a second fixed sector 20, integral with the frame 1.

Description

DEVICE FOR INSERTING THE FREE END OF A FILM
PHOTOGRAPHIC IN A DEVELOPMENT MACHINE.

 The invention relates to a device for introducing the free end of a photographic film into a machine for developing photographic films and for then automatically cutting the other end of this film, when the latter has been unwound from the reel, it also relates to negative film developing machines so equipped.

 In current film processors, the cutting device essentially comprises electromagnets integral with the knives, associated with cells for detecting the presence of the film. If more generally, this provision is satisfactory on the technical level, however it remains expensive and too sensitive to external influences.

 The invention overcomes these drawbacks. It aims at an automatic film introduction and cutting device which is simple, economical to construct, easy to operate and uses exclusively mechanical elements and therefore remains insensitive to external influences.

This device for introducing the free end of a photographic film into a developing machine and for cutting the other end of this film when it has been unwound from the reel, of the type
- in which the reel being unwound rests on a cradle-shaped support
- and in which the free end of the film is introduced into a pair of pressure rollers
- And in which the cutting is carried out by means of a shears constituted by a fixed knife and a movable knife, characterized:
- on the one hand, in that the fixed knife is integral with the reel support and is arranged in the direction of unwinding of the film
- on the other hand, in that said coil support is integral with an arm whose end is articulated around a first axis, parallel to the axis of the pair of rollers, said arm having a second parallel axis to the first and on which is mounted a first toothed sector secured to a connecting rod at the end of which is articulated a second connecting rod, in turn connected to the end of a movable knife, the other end of which is at its tower articulated around an axis integral with the fixed knife
- And finally, in that the toothed sector secured to the arm meshes in a second toothed sector, fixed secured to the frame of the machine.

 In other words, the invention consists in placing the reel unwound on a pivoting support integral with a first toothed pinion which in turn meshes on a second fixed toothed pinion, the first pinion then being integral with a first connecting rod which in turn drives a second connecting rod secured to the movable knife of the shears itself articulated on the fixed knife, secured to the support. Thus, when the film runs out, the traction exerted on it by the gears of the development rack is transmitted by the film itself, then causes the reel support to tilt forward, it that is to say towards the rollers, which causes the pivoting of the arm and thereby drives the first toothed section. In this movement, the first connecting rod is driven downwards.

Then, by means of the second connecting rod, the latter also pulls down the movable knife which, by pivoting at its other end, approaches and then covers itself with the fixed knife so as to cut the end of the film and detach it of the coil. At this time, the tension is released.

 Thus, a small and long displacement of the arm generates a large and rapid displacement of the first connecting rod and thereby a large and rapid displacement of the movable knife, which is sought for the cutting action.

Advantageously, in practice
- the assembly is placed in. a box secured to the machine frame, this box being closed by a light-tight cover
- the coil support, the articulation arm, the toothed sector, the first connecting rod are made of molded plastic
- the front face of the reel support opposite to that comprising the fixed knife has a stop intended to cooperate with a safety member which prevents the unexpected opening of the cover of the case during the film running.
- the movable knife is articulated at one end of the fixed knife secured to the spool holder.

 The manner in which the invention can be implemented and the advantages which result therefrom will emerge more clearly from the example of embodiment which follows, given by way of nonlimiting illustration, in support of the appended figures.

 Figure 1 is an exploded schematic view of the main elements of the device of the invention.

 Figure 2 is a sectional view in the direction of travel of the film of this device.

 FIG. 3 is a view in orthogonal section of the direction of FIG. 2.

 Referring to the figures, the processor according to the invention essentially comprises a frame (1) of molded plastic. Conventionally, this frame has its open face a pair of respectively rubberized (2) and smooth (3) pressure rollers, actuated by a crank (4) external to the frame (1). The film (5) from the reel (6) passes over the line of tangency (7) between the two rollers, then enters a channel (8) and more precisely on rails (9) to be brought above the development section designated by the general reference (10).

 According to the invention, the frame (1) has a housing designated by the general reference (11) comprising a cover (12) hinged at (13) on the housing. According to a first characteristic of the invention, the coil (6) is placed on a coil support (14), the two ends of which include flanges (15) intended to allow lateral positioning of the coil and a clipping (33) of blocking. The coil support (14) is integral with an arm (16) articulated at (17) about an axis parallel to the axis of the rollers (2,3). This arm (16) has a second axis (18) parallel to (17) on which is mounted a first toothed sector (19) movable which meshes in a second toothed sector (20) integral with the frame (1).

 According to another characteristic of the invention, the movable toothed sector (19) is integral with a first connecting rod (21) at the end (22) of which a second connecting rod (23) is articulated, in turn connected in ( 24) at the end (25) of the movable knife (26). According to another characteristic of the invention, the other end (27) of the movable knife (26) is articulated at (28) on the end of the fixed knife (30) which is fixed to the front of the spool holder (14 ) relative to the direction of advance of the film (5). The assembly includes elements (31, 32) intended to ensure sealing.

 In an improved version, the coil support (14) has on the front face at (33), that is to say on the face opposite to that comprising the fixed knife (30) a safety member symbolized by the reference (34 ), intended to prevent the unexpected opening of the cover (12) when the film (5) runs.

 The device operates as follows.

Thanks to the flanges (15), the coil (6) is fixed to the cradle (14). The film is then introduced at (7) by actuating the crank (4), then the cover (12) is closed which is then locked by means of (33) and (34), then using the crank (4), the film is introduced into the channel (9) until it meets the drive rollers of the processor rack.

 The film (5) driven by the rack scrolls, the cradle (14) then being in the rear position as shown in FIG. 2. At the end of the scrolling, the other end of the film (5) being attached to the reel ( 6), under the effect of the tension, the coil (6) is offset to the left. This causes the cradle (14) to pivot about the axis (17) and thereby the first toothed sector (19) around the second toothed sector (20). The end (22) of the connecting rod (21) is then pulled down. Thus, a slight and slow movement of the axis (18) leads to a large and rapid displacement of the point (22) and consequently of the fastener (24) and thereby (see fig. 3) quickly brings the wire (35) of the movable knife (26) in contact with the wire (36) of the fixed knife (30). Thus, the end of the film is effectively cut. The coil is then released and the tension released. The cover (12) is thus unlocked.

 This device has many advantages. We can cite the fact that it is a purely mechanical solution, therefore easy and economical to build, especially since it has few parts and these parts are advantageously molded, for example of plastic. This device is therefore found to be very reliable.

 The sealing baffles (31, 32) also make it possible to open the cover (12) for positioning and extracting the coil (6).

 In this way, this arrangement can be successfully used for low cost processors.

Claims (5)

 1 / Device for introducing the free end of a photographic film (5) into a development machine for the development of photographic films (10) and for cutting the other end of this film (5) when it has been unwound coil (6), of the type  - in which the reel (6) during unwinding rests on a support (14) in the form of a cradle  - And in which the free end of the film (5) is introduced into a pair of pressure rollers (2, 3)  - And in which the cutting is carried out by means of a shears constituted by a fixed knife and a movable knife, characterized  - On the one hand, in that the fixed knife (30) is integral with the support (14) of the spool (6) and is arranged in the direction of unwinding of the film (5)  - on the other hand, in that said coil support (14) is integral with an arm (16) whose end is articulated around a first axis (17), parallel to the axis of the pair of rollers (2,3), said arm (16) having a second axis (18) parallel to the first (17) and on which is mounted a first toothed sector (19) integral with a connecting rod (21) at the end ( 22) from which a second connecting rod (23) is articulated, in turn connected to the end (25) of the movable knife (26), the other end of which 27) is in turn articulated around an axis (28 ) secured to the fixed knife (30)  - And finally, in that the toothed sector (20) integral with the arm (16) meshes in a second toothed sector (20), fixed integral with the frame (1) of the machine.  2 / Device according to claim 1, characterized in that the assembly is placed in a housing (11) integral with the frame (1) of the machine, closed by a cover (12) light-tight.  3 / Device according to claim 1, characterized in that the coil support (14), the articulation arm (16), the two toothed sectors (19,20), the first connecting rod (21) are made of molded plastic .  4 / Device according to claim 1, characterized in that the front face of the coil support (14) opposite to that comprising the knife (30) fixed has a stop (33) intended to cooperate with a safety member (34) preventing the unexpected opening of the cover (12) of the casing (11) while the film (5) is running.  5 / Device according to claim 1, characterized in that the movable knife (26) is articulated to (28) at the end of the fixed knife (30) secured to the spool holder (14).