FR2796473A1 - Movie film reel has film end locked in hub slit by flange projections - Google Patents

Abstract

The film reel, comprising a hub (11) with a slit (34) for the film end and two flanges (12, 13), has the hub made from two coaxial rings (30, 31) connected by radial partitions (32) forming cavities (35) with end lugs. The film end is locked inside the hub cavity by projecting legs (20) on one flange which pass through the hub cavities and engage by means of end feet (22) with holes in the opposite flange. The reel's components can be made by injection moulding or other means.

Description

 The present invention relates to film reels and, more particularly, to reels for cinematographic film (for example 16 or 35 mm). The invention more particularly applies to the production of a core intended to receive, by winding, the cinematographic film and the realization of circular cheeks axially holding the film around the core.

A film core generally has, in its outer periphery, a slot or lumen for receiving a first end of the film to be wound. This end is engaged, if necessary after being folded on itself, in the slot to be temporarily held with the core. Then, the film is wrapped around the core while the latter is generally engaged on an axis to rotate it.

A camera is conventionally associated with a magazine containing a film driving mechanism and defining film reel receiving compartments. The virgin film is unwound from a supply reel engaged on an axis of a debtor compartment to an optical image unit being guided by rollers of the store. The exposed film is wound on a receiver reel engaged on a generally motorized axis of a receiving compartment of the magazine. Most often, the supply and receiving coils are coaxial by being wound on cores which cooperate with coaxial axes respectively debtor and receiver, linked to the store.

In the case of cinematographic films, a virgin film is generally wound around the core during manufacture while the core is devoid of an association with axial (lateral) support cheeks. The blank film reel is then mounted in a magazine, if necessary equipped with axial retaining cheeks. This is especially true for 35mm films. In applications to 16 mm films, the film reel is often associated with axial retaining cheeks or disks, before it is mounted in a camera magazine.

For cinematographic films, the cores of the bobi nes must respect a first constraint related to the film manufacturer. This constraint is that the internal diameter and the shape of the inner wall of the core are standardized to be compatible with cameras from different manufacturers.

 FIG. 1 very schematically shows a conventional example of coils 1 of film F of the type comprising a core 2 around which the film F is wound and two circular cheeks 3, 4 for axially holding the film. In the example of Figure 1, the cheeks 3, 4 are intended to be mounted on the core being associated with each other by axial screwing. Thus, the circular cheek 3 has, in its center and projecting from an inner face 5, a well 6 threaded in its inner face. The well 6 is intended to cooperate, in opposite form, with a well 7, threaded on its outer surface and projecting from an inner face 8 of the cheek 4. The wells 6 and 7 are axially empty to allow the assembly of the reel 1 on a store axis. In practice, the core 2 on which the film F has been wound is engaged on the well 6. Then, the cheek 4 is brought back to the assembly while being screwed by its well 7 on the cheek 3.

An assembly of the film in the form of a spool as shown in FIG. 1 is not perfect and has several disadvantages. A first disadvantage is that assembly by threading and tapping cheeks 3 and 4 requires a step to the left to prevent loosening of the coil during operation in a camera. Such a step left, unusual for the user, involves a risk of breakage when it wants to disassemble the cheeks to recover the film.

A second disadvantage is that the center diameter is considerably reduced with respect to the diameter of the core. Indeed, as the internal diameter of the core is imposed, the addition of the cheeks leads to a reduction in the diameter available to the axis of the camera store, which poses problems of centering. This leads to diameters often too small to allow the use of articulated locking systems that refocus the coil and thus facilitates handling.

 A third disadvantage, which is found in the systems not using axial retaining side cheeks, is that the film is not properly maintained in connection with the core when the coil is empty. Indeed, as indicated above, the core has an insertion slot of one end of the film before it is wrapped around the core. If the film must be able to be removed from the core, its holding on it by means of the slot of introduction of the free end is weak. This results in poor film performance on a conventional reel that usually requires the loss of part of the film footage for several security laps. If, during the initial assembly of a virgin film on a core, industrial installations can overcome this disadvantage, it is not the same for the end user wishing to mount a piece of film on a core of a blank reel .

 In addition, in the case where the coils that one wishes to use are equipped with cheeks axially holding the film, the very presence of the cheeks causes difficulties to mount the free end of the film on the core of the receiving coil. These disadvantages can be found in other applications where a film has to be wound on a side-cheek roll.

For example, US Pat. No. 4,254,919 discloses a film cassette in which the coils are formed of two lateral flanges connected to each other by internal projections forming the core. The system of this patent is devoid of removable core compared to the cheeks. In addition, it has the same disadvantages as those described above in relation to Figure 1, namely, essentially, that the end of the film is not held properly around the core despite its engagement in a slot of this- this.

The present invention aims to propose a new solution for mounting a film around a core associated with two axial holding cheeks.

More generally, the invention aims to provide a core adapted to receive, by winding, a film and which overcomes the aforementioned drawbacks related to the blocking of the end of the film.

The present invention aims, in particular, to provide a solution that allows a correct locking of the end of the film during its assembly coil.

The invention also aims to propose a solution that is compatible with the use of standardized cores, while preserving a diameter sufficient for good centering when the coil is in a store.

To achieve these objects, the present invention provides a cylindrical film core comprising, in its outer periphery, an insertion slot of one end of the film, the slot opening into a housing receiving means external to the core specific to blocking, by wedging, the end of the film, said means being actuated by relative rotation of less than one turn relative to the core, about its axis.

According to one embodiment of the present invention, the core comprises two coaxial rings connected by radial partitions, regularly distributed, which define receiving housing of said external means.

According to one embodiment of the present invention, one radial partition out of two, carries two tabs in planes approximately perpendicular to the axis of the core and parallel to each other.

According to one embodiment of the present invention, said tabs associated with the same radial partition depart in opposite directions in the corresponding housing.

According to one embodiment of the present invention, said tabs serve as removable assembly means of the core with at least one element carrying said external means.

According to one embodiment of the present invention, said housings are, at least partially, devoid of transverse partition.

The invention also relates to a coil of the type comprising two circular retaining cheeks and a core pro to receive a film by winding, the cheeks and the core being removably connectable and at least one cheek comprising own means blocking an end of the film engaged in a peripheral slot of the core.

According to one embodiment of the present invention, each cheek comprises, projecting from an internal face, means adapted to engage in the core, and to cooperate with it for locking, by rotation of less than a turn of the nucleus with respect to the cheek.

According to one embodiment of the present invention, the respective holding forces of the core flanges are different from each other.

According to one embodiment of the present invention, each cheek comprises projecting feet of an inner face which constitute said external means.

According to one embodiment of the present invention, the coil further comprises a lid, formed of a crown and a disc, for receiving the assembly consisting of the core, the film and the cheeks.

The invention further relates to a magazine for receiving a film reel, comprising means for automatically ejecting the cover of a reel. Then, a reception store of a film reel, comprising, associated with a receiving axis of a core of the invention, said means external to the core.

These and other objects, features, and advantages of the present invention will be set forth in detail in the following description of particular embodiments made non-limitatively in connection with the accompanying drawings, of which FIG. to illustrate the state of the art and the problem posed; Fig. 2 is an exploded perspective view of a reel according to an embodiment of the present invention; Figure 3 is a top view of a core according to an embodiment of the present invention; Figure 3A is a sectional view along line A-A 'of Figure 3; Figure 3B is a sectional view along the line B-B 'of Figure 3; Figure 4 is a partial sectional view of a fastening element of a core of a coil to a first cheek, according to one embodiment of the present invention; Figure 5 is a partial sectional view of a fastening element of a core to a second cheek of a coil, according to one embodiment of the present invention; Fig. 6 is an exploded perspective view of a film reel equipped with a hood according to an embodiment of the present invention; Figure 6A is a detail of the hood of Figure 6; Figure 7 is a very schematic sectional view of a coil as shown in Figure 6, in a mounting position in a camera store; and Figure 8 is a very schematic sectional view of the coil of Figure 7 once mounted in the magazine.

 The same elements have been designated by the same references in the different figures. For the sake of clarity, only the elements which are necessary for the understanding of the invention have been shown in the figures and will be described later. In particular, the constitution of a camera store has not been detailed and does not, unless otherwise specified, the object of the present invention.

it is a feature of the present invention to provide a co-operation of the core around which the film is to be wound with an element for blocking an end of the film engaged in a slot of the core. According to the invention, the core is adapted to cooperate with a locking element which can be carried by an axial retaining cheek of the film, by the camera magazine (for example, by a ring of the core receiving axis ), or by any suitable mechanism for receiving the core of the invention.

For the sake of simplification, the invention will be explained later in relation to a coil formed of a core associated with two lateral support cheeks. it should be noted, however, that the use of such cheeks is not obligatory and that the invention also applies to coils having side or only side cheeks, the core then cooperating directly with elements of the camera store or with the single cheek, as will be seen later.

According to the present invention, the end of the film is always engaged in a slot of the core, but is then locked during the establishment of one of the axial retaining cheeks of the film, or during the establishment of the core. on a single cheek or similar mechanism.

FIG. 2 represents, by an exploded perspective view, a reel 10 before assembly, according to an embodiment of the invention. The coil 10 is constituted by a core 11 intended to receive, by winding, a film, for example cinematographic (not shown), and two circular cheeks, respectively 12, 13 for axially holding the film around the core . Preferably, the cheeks 12 and 13 are made of elastically deformable plastic discs, and each is provided with a central removable mounting portion 14 on the core 11.

The constitution of the discs forming the cheeks 12 and 13 may be conventional and is a function of the application more particularly of the type of camera to which the coils are intended to be associated, the characteristic of the invention relating essentially to the central portion 14 of the cheeks 12 and 13 or the core receiving mechanism in an application to a direct mounting in a camera store.

 In the example of FIG. 2, each flange 12, 13 comprises, at the periphery, an edge 15 bevelled in the direction of the other flange of the coil 10. The bevels 15 are, in a conventional manner, intended to cooperate with Spacer discs when the spool is set up in a camera. An example of a camera with a spacer mechanism of this type is described in the French patent application No. 2,750,510 of the Applicant whose contents are incorporated herein by reference.

According to the invention, each cheek 12, 13 has, in its center, an axial orifice, respectively 16, 17, whose diameter corresponds to the diameter of the axial orifice 18 of the core 11. Thus, another characteristic of the invention is to conform the cheeks and the core so that the assembly can be performed without reducing the internal diameter of the core 11, thus without impairing the centering capacity of the coil by the addition of the cheeks 12 and 13. This characteristic participates in allowing a postponement of the blocking mechanism of the invention directly in a maga sin of a camera.

According to a preferred embodiment of the present invention, the central portion 14 of each cheek 12, 13 comprises, projecting from an inner face 12 ', 13', at least two fastening feet to the core 11. Preferably the feet 20 are regularly distributed around the orifice 16 or 17 of the cheek and, for reasons of symmetrical holding, are three in number per cheek in a preferred embodiment illustrated by the figures.

According to the invention, the core 11 is adapted to cooperate with the feet 20 of the cheeks 12 and 13. Thus, as is more clearly apparent from FIGS. 3, 3A and 3B which represent, respectively from above, in section along the line AA ' 3A and in section along line BB 'of Figure 3, a core 11 according to one embodiment of the invention, it is formed of two concentric rings 30, 31 connected to one another by radial partitions 32. The ring 30 is the ring of smaller diameter defining the axial orifice 18. The shape and the diameter of the ring 18 are, as indicated above and at least in an application of the invention to a cinematographic film reel, set by the normalization requirements. The ring 30 has, in particular, a vertical rim 33 (parallel to the axis), intended, in some cameras, to cooperate with a coupling means in rotation of a drive shaft.

The outer ring 31 comprises a slot 34 for introducing one end of the film to be wound around the core 11. This slot 34 may have different shapes depending on the application. In the example of Figure 3, the slot 34 has a bevel shape while in the embodiment of Figure 2, this slot has a rounded shape.

The number of walls 32 of the core is equal to the total number of feet 20 of the cheeks 12 and 13, so that each foot 20 has a housing 35 in the core 11.

In the preferred embodiment illustrated by the figures, each housing 35 opens axially on both sides of the core 11, that is to say that the core has no transverse partition. The goal is that each foot 20 can engage the core through it and, preferably, protruding from its opposite face as will be seen later. According to the invention, each leg 20 is provided with hooking elements adapted to cooperate in opposite shape with corresponding elements of the core 11.

In the preferred embodiment illustrated by the figures, each leg 20 has a vertical wall 21 (parallel to the axial direction of the coil) in a radial plane. This wall 21 extends from the inner surface of the central portion 14 and ends with an approximately hori zontal tab 22 (approximately parallel to the plane of the cheek). The tab 22 is connected, at one end, to the end of the wall 21 and its free end is directed towards the next leg 20. Thus, the shape of the tabs 22 is preferably circular to follow the general shape of the central portion 14 in which are provided the fastening elements. In addition, in the preferred embodiment of FIG. 2, each leg 20 comprises a second vertical wall 23, forming a square with the wall 21 in the external part of the central portion 14. Thus, the walls 23 have a rounded shape for The role of the walls 23 is, on the one hand, to stiffen the feet 20 by squaring and, on the other hand, to improve the light-tightness of the beam. mounted coil to protect the film against unwanted exposure.

On the core side, each housing 35 comprises a first portion 35 'devoid of axial obstacle to allow the integral passage of a foot 20 of one of the cheeks 12 or 13, and a second portion 35 "in which is formed an element of hooking 36, 37 intended to cooperate with the tab 22 of the corresponding foot.The elements 36 and 37 are, in the preferred embodiment illustrated in the figures, constituted by horizontal tabs (in a plane perpendicular to the axis of the coil) protruding 32 and terminated by a spout 38, 39 or similar means of clipping, able to cooperate, substantially opposite shape, with a tab 22. Thus, a first series of lugs 36 intended to coo pérer with the 20 of the cheek 12 is formed near the surface of the cheek-side core 13. Conversely, tabs 37 intended to cooperate with the legs 20 of the cheek 13 are placed closer to the surface of the core 11 which is located The removable assembly of one of the cheeks 12 or 13 to the core 11 of the invention is effected by engaging the feet 20 of this cheek in the first portions 35 'of the housing 35 of the core II associated therewith, then by rotating these two elements relative to each other in the direction of a usual screwing (with a step to the right) so that the tabs 22 of the feet 20 are clipped into the legs ( 36 for the cheek 12 and 37 for the cheek 13) corresponding core 11. Note that the general shape of the legs 36 and 37 of the core is rounded to follow the general shape of the housing 35.

Note also that, according to the invention, the rotation of a cheek relative to the core in the direction of its assembly is always performed in the direction of clockwise, that is to say in the direction usual for screwing. To do this, as the cheeks 12 and 13 have similar structures, that is to say that the free ends of their respective legs are in the same direction when the cheeks are seen on the same side, the legs 36 and 37 of the core 11 have, opposite one face of the core and as shown in Figure 3, opposite directions. Always seen from one face of the core, the tabs 36 project from partitions 32 in the direction of clockwise while the tabs 37 project from the same partitions 32 in the opposite direction of clockwise. However, the core 11 is, at least as regards the positions of the tabs 36 and 37, preferably symmetrical with respect to a median transverse plane. In other words, only one partition 32 on two of the core carries, projecting, tabs 36 and 37.

As is apparent from Figure 3B, the tabs 36 and 37 are not perfectly horizontal, but are preferably slightly inclined outwardly to promote clipping with the tabs 22 with a slight spring effect. They are thus preferably prestressed to bring the cheeks 12 and 13 back to the core. Preferably, the height of the feet 20 is greater than the height (the thickness) of the core 11. Thus, when in the assembled position with the core, the feet 20 protrude from the face of the core opposite the cheek at which they belong. The protruding portion is received by the opposite cheek in corresponding recesses 24 formed in the inner face of this cheek. An advantage of such an embodiment is that the light tightness of the coil once mounted is improved, thereby creating baffles for the passage of light.

According to the invention, the foot 20 of the cheek (for example 12) which cooperates with the tab 36 of the housing into which the slot 34 for introducing the film opens also serves to block the end of the film in the core. Indeed, the free end of the film is then pinched between the inner face of the ring 31 and the outer wall 23 of the corresponding foot 20. Here we see another role of the walls 23 of the feet 20 which is to improve the holding of the film on the core 11.

Conventionally, during the mounting of the film on the core 11, one end of the film is introduced through the slot 34 so that a section is inside the core 11, that is to say in a housing 35. This film end, which is in the housing 35, can be folded towards the lug 36 to leave free the part 35 'in which the foot 20 must be engaged before rotation. The rounded embodiment of the slope 34 illustrated in Figure 2 facilitates such a position of the end of the film without causing a fold of it. An advantage is that when the film is unrolled entirely from the core, its free end, which has no fold, can pass without damage in the mechanism of the camera. It should be noted that, according to the invention, the slot 34 preferably opens out approximately in the middle of the housing 35.

Note also that the respect of the condition of introduction of the film in one of the housing of the core requires that it is devoid of horizontal partition between the horizontal planes defined by the tabs 36 and 37, at least in the housing 35 where opens the slot 34. However, alternatively, it can provide a horizontal partitioning of the other parts of the core. In particular, if it is equipped with a third concentric ring, a horizontal partitioning may exist between the first and second crowns of smaller diameter provided that the housing 35 between the two outer rings which are intended to receive the feet 20 of the cheeks 12 and 13 remain accessible.

Still as a variant, there may be provided a simplified embodiment of the fastening elements of the cheeks to the core. For example, the feet 20 of the cheeks may be full and the housings 35 of the core 11 do not have a regular width but narrowing in the part 3511, so as to allow jamming by wedging a foot 20 in the manner of 'a corner. However, an advantage of the embodiment illustrated by the figures is that it ensures the holding of the elements in the axial direction. Indeed, by locking in the manner of a wedge, it is not guaranteed the axial positioning of the elements relative to each other.

According to another characteristic of the preferred embodiment of the invention, the unscrewing force to be printed on the cheeks 12 and 13 to separate them from the core 11 is not identical for the two cheeks. The goal is then, that the core can remain attached to one of the two cheeks (for example, the cheek 13) even when the reel is opened by removing the other cheek (for example, the cheek 12) to release the film .

According to the invention, this object is achieved by conforming the tabs 22, 36 and 37 so that the force to be printed for disassembly is different for the cheek 13 and the cheek 12. Preferably, the cheeks 12 and 13 of a coil of the invention are identical in every way. Therefore, the conformational difference is provided between the tabs 36 and 37 of the core 11.

Figures 4 and 5 illustrate such a preferred embodiment. FIG. 4 represents, partially and in section, a foot 20 of the cheek 13 in the mounted position with a tab 36 of the core 11. FIG. 4 represents, still partially and in section, a foot 20 of the cheek 12 in the assembled position with a paw 37 of the core. As illustrated in Figures 4 and 5, the feet 20 are identical whether it is that of the cheek 12 or the cheek 13.

 Each lug 22 has, in its inner face (that is to say the face directed towards the inner face of the corresponding cheek), a radial groove 25 between the wall 21 and an end spout 26 of the leg 22. The spout 26 preferably has an inclined portion 26 'to facilitate the engagement of the tab 36 or 37 corresponding.

According to the embodiment of FIGS. 4 and 5, the beaks 38 and 39 of the tabs, respectively 36 and 37, have different shapes so that the force necessary to rotate the corresponding cheek relative to the core 11 is stronger for the beaks 38 of the grooves 25 are separated from the notches 38 by the grooves 25 only. In the example of FIG. 4, the spout 38 has edges that are substantially at right angles whereas, in FIG. rounded shape facilitating its clearance of the groove 25.

It will be noted that, as a variant, provision can be made to differentiate the respective spouts of the feet 20 of the cheeks 12 and 13, the legs 36 and 37 of the core 11 being then all identical. However, an advantage of the preferred embodiment of the invention illustrated in Figures 4 and 5 is that a single mold is then necessary to achieve the cheeks 12 and 13. Note that the two cheeks then comprise the means necessary for blocking of the film in the slot 34 of the core. Indeed, any foot 20 can play this role, which facilitates assembly.

An advantage of the present invention is that it makes it possible to block the initiation of a film in the reel in a safe manner by the simple assembly of one of the cheeks of the reel.

 Another advantage of the present invention is that, compared to conventional cheek rolls, it preserves the inner diameter of the core 11, which optimizes the centering of the film reel when mounted in the magazine of a camera.

Another advantage of the present invention is that the core of the coil is perfectly versatile. Indeed, it can be used without play in applications where the film reel is mounted directly in a store that ensures itself an axial retention. The core of the invention in fact preserves the two functions of conventional nuclei, namely, the normalized shape of its inner ring and the presence, in its outer ring, of a slot for the engagement of a film primer. A single mold is therefore necessary to make cores 11, which can either be used in a conventional manner, or be associated with the cheeks of the invention to form a hand held axial coil, or be associated with one or two cheeks or elements. equivalents. The diameter of these elements is not necessarily that of a full coil but they reproduce one or more characteristics of the central portion 14 to implement one or more functions of the core.

In particular, a core of the invention can be used in a camera magazine provided with a mechanism reproducing the feet of one of the cheeks exposed above. The mounting of the core on the axis of the magazine is then accompanied by a rotation of a portion of a tower (for example, less than 1 / 12th of a revolution by repre ning the example of a six-unit core 35 ) to block the core on the axis at the same time that the end of the film is blocked on the core. In this case, the magazine cover is, preferably, footless since it is generally not rotatably mounted and its direct connection to the core is rather to be avoided. it should be noted that, even in this case, the core may be strictly identical to that described above to be associated with cheeks. Indeed, the difference in hand forces expected for the cheeks is preferably fixed by the core and, in the case of direct mounting in a store, associate the locking of the film to an easily removable lock on the axis is a preferable solution. A core according to the invention can even be used without implementing the film blocking function, but by implementing only a removable assembly function of the core to a store axis of a camera, thanks to the legs (of preferably 37) of the core and corresponding lugs 22 formed in feet 20 or equivalent associated with the axis of the store.

Note that the number of feet 20 may be greater than three per cheek. The choice of the number of feet (and thus of the housings of the core 11) depends on the application and, in particular, on the diameter of the core 11. However, it will be ensured that this number is compatible with a correct hooking by means of the legs 22 and with their engagement in the core, which requires that each housing 35 has an angular length at least equal to twice the angular length of the tabs 22.

FIG. 6 represents, by an exploded perspective view, an alternative embodiment of a coil according to the invention in which this coil is associated with a protective cover 40.

 As before, the coil is essentially composed of a core 11 on which is wound a film F and two cheeks 12 and 13 of axial retention of the film.

According to the embodiment of FIG. 6, a cover or cover 40 covers the whole of the coil to protect the film from light, this cover 40 essentially consists of a ring 41 with a diameter slightly greater than the diameter of the cheeks 12 and 13, and a disc 42 closing one side of the ring except for a central orifice 43 of diameter much greater than the diameter of the axial orifice 18 of the core 11. The cover 40 is intended for it is engaged on the assembled coil 10 and presents, preferably in the inner periphery of the free end of the crown 41, a groove 44 adapted to cooperate with the beveled peripheral end 15 of the cheek 13 for a removable lock.

The ring 41 has a slot 45, intended for the step of the primer of the film F to allow the mounting thereof in the store of a camera without exposing it to light as will be seen later in relation with the figures 7 and 8. The slot 45 is parallel to the axis of the coil, is blind one side that 42 and is open groove side 44.

FIG. 6A is an enlargement of the ring 41 in the region of the slot 45 in the vicinity of the groove 44. This figure shows that, in this embodiment, the internal groove 44 corresponds, on the outside, to a bead 46.

A coil associated with a cover 40 as shown in FIG. 6 may, in a particular embodiment of the invention, be associated with a camera magazine for automatic release of the cover when the film reel is in place. .

This embodiment is illustrated by Figures 7 and 8 which show, very schematically and in section, such a coil, associated with a camera store 50.

For the sake of simplicity, not all details of the spool 10 have been shown in FIGS. 7 and 8. In particular, the mounting elements of the flanges 12 and 13 at the core 11 have not been shown. In FIGS. 7 and 8, however, it has been pointed out that the end bevel 15 of the cheeks 12 and 13 can extend into an outer peripheral rim of these cheeks, and that the thickness of the central portions 14 of the cheeks 12 and 13 is adapted to the magazine 50 and its axis 51. This is compatible with what has been explained above, namely that the core 11 has a normal internal diameter regardless of the store, while the cheeks 12 and 13 can be dedicated to a particular application related to a store or a camera of shots.

The magazine 50 has been shown very schematically as its outer peripheral wall 52, its bottom 53, and its axis 51. For the sake of simplicity, insofar as the details of the store are not the subject of the present invention , all these elements have been symbolized by one piece. it will be noted, however, that, of course, these elements are in practice distinct and include, in particular for the axis, rolling means. According to the invention, the lateral wall 52 of the magazine comprises an inwardly directed recess 54 for cooperating with the peripheral rim 46 of the cover 40. In the example of FIGS. 7 and 8, the peripheral rim 46 of the cover 40 has been shown inverted with respect to the embodiment of FIG. 6. The choice of one or the other of the embodiments depends on the application and the constitution of the redan of the magazine 50 for the functionality which will be described below.

In FIG. 7, the spool 10 associated with the cover 40 has been represented at the beginning of insertion in the magazine 50. The spool 10 is thus engaged by its orifice 18 on the axis 51 of the magazine whose internal diameter is dimensioned to be able to receiving, not only the spool, but also the cover 40. When the rim 46 of the cover reaches the step 54, the rim 46 moves slightly by elasticity and then releases the spool 10 formed of the core 11 and the cheeks 12 and 13, which falls at the bottom of the magazine around the axis 51 while the cover 40 remains overhanging.

The introduction of the coil into the magazine is therefore done without putting the film in the light, this setting to light being delayed as much as possible. It will also be noted that the presence of the slot 45 in the cover makes it possible, if necessary, to lock the film F in the rollers and drive rollers of the camera or the magazine, before removing the cover 40.

 The extraction of the lid 40 is facilitated by the diameter of the opening 43 which, as previously indicated, is substantially larger than the diameter of the orifice 18. Thus, the user can pass his fingers between the cover 40 and the cheek 12 to remove the cover. In such an embodiment, the baffles at the passage of light made by the cheeks 12 and 13 in their central portion 14 play an important role because of the opening 43. Alternatively, a cover 40 may be provided having a disk 42 full and provided, in this case, a gripping means to extract it from the magazine once the coil set up. Of course, the present invention is susceptible of various variations and modifications which will be apparent to those skilled in the art. In particular, the respective sizing of the elements is within the abilities of those skilled in the art as a function of the application and the functional indications given above, in particular, as a function of the width of the film and the diameter of the coils. .

 In addition, although the foregoing description has been made more particularly in connection with a cinematographic film, the present invention is equally applicable to video, audio and, more generally, any reel for which similar problems arise. .

In addition, the adaptation of a store of a camera to equip locking elements and locking (the feet 20) described in relation to the side cheeks is within the reach of the skilled person from the functional indications given above. It will be noted simply that the feet will have to be carried by a mechanism linked in rotation to the rotation of the receiving axis of the core.

Finally, it will be noted that the shape of the various elements exposed in relation to the preferred embodiment of the invention is particularly suitable for injection molding.

 However, other methods of manufacture may be used.

Claims (14)

Rh # ications 1. cylindrical core (11) for film (F) comprising, in its outer periphery, a slot (34) for introducing one end of the film, characterized in that the slot opens into a housing (35) for receiving means (20) external to the core adapted to block, by wedging, the end of the film, said means being actuated by relative rotation of less than one turn relative to the core, about its axis. 2. Core according to claim 1, characterized in that it comprises two coaxial rings (30, 31) connected by radial partitions (32), regularly distributed, which define housing (35) for receiving said external means (20). . 3. Core according to claim 2, characterized in that one radial partition (32) out of two, carries two lugs (36, 37) in planes approximately perpendicular to the axis of the core and parallel to each other. 4. Core according to claim 3, characterized in that said tabs (36, 37) associated with the same radial partition (32) depart in opposite directions in the housing (35) corresponding. 5. Core according to claim 3 or 4, characterized in that said tabs (36, 37) serve as removable assembly means of the core with at least one element (12, 13) carrying said external means (20). 6. Core according to any one of claims 2 to 5, characterized in that said housings (35) are at least partially devoid of transverse partition. 7. Coil (10) of the type comprising two circular cheeks (12, 13) of axial retention and a core (11) adapted to receive a film (F) by winding, characterized in that the cheeks and the core are assembled from removably and in that at least one cheek comprises means adapted to block an end of the film engaged in a slot (34) peripheral of the core. 8. Coil according to claim 7, characterized in that each cheek (12, 13) comprises, projecting from an inner face (12 ', <B> 131), </ B> means (20) adapted to s engaging the core (11), and cooperating therewith for locking, rotating less than one turn of the core relative to the cheek. 9. Coil according to claim 7 or 8, characterized in that the respective holding forces of the cheeks (12, 13) to the core (11) are different from each other. 10. Coil according to any one of claims 7 to 9, characterized in that the core (11) is according to any one of claims 1 to 6. 11. Coil according to claim 10, characterized in that each cheek (12, 13) comprises feet (20) projecting from an inner face (12 ', 13') which constitute said external means. 12. Coil according to any one of claims 7 to 11, characterized in that it further comprises a cover (40) formed of a ring (41) and a disk (42), to see the set consisting of core (11), film (F) and cheeks (12, 13). 13. Magazine receiving a film reel (10) (F), characterized in that it comprises means (54) for automatically ejecting the cover (40) of a reel according to claim 12. 14. Magazine receiving a film reel (10) (F), characterized in that it comprises, associated with a receiving axis of a core (11) according to any one of claims 1 to 6, said external means (20) to the core.