US3923266A

US3923266A - Endless film winding or unwinding device

Info

Publication number: US3923266A
Application number: US423976A
Authority: US
Inventors: Jean Paul Boyer
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-12-12
Filing date: 1973-12-12
Publication date: 1975-12-02
Anticipated expiration: 1992-12-02
Also published as: FR2210299A5

Abstract

An apparatus for the continuous winding and unwinding of an endless band adapted to be fed to a utilization device comprising simultaneously winding two lengths of the endless band in superposition on a first rotating reel while simultaneously unwinding two superposed lengths of the band from a second reel rotating in opposite direction. One length of the band is passed from the second reel to the first reel while the second length of the band from the second reel is passed to the utilization device and the length of film traversing the utilization device is passed to the first reel. In order to feed the band to the second reel when it becomes empty the length of the band traveling from the utilization device to the first reel is displaced onto the hub of the second reel to form a loop so that the band can now be wound in two superposed lengths on the second reel while being unwound from the first reel, the direction of rotation of the reels being reversed.

Description

United States Patent [1 1 Boyer 1 Dec. 2, 1975 ENDLESS FILM WINDING OR UNWINDING DEVICE [76} Inventor: Jean Paul Boyer, Impasse Melies, 30

Redessan, France [22] Filed: Dec. 12, 1973 [2]] Appl. No.: 423,976

Primary Examiner-Billy S. Taylor Attorney, Agent, or Firm-Haseltine, Lake & Waters [57] ABSTRACT An apparatus for the continuous winding and unwinding of an endless band adapted to be fed to a utilization device comprising simultaneously winding two lengths of the endless band in superposition on a first rotating reel while simultaneously unwinding two superposed lengths of the band from a second reel rotating in opposite direction. One length of the band is passed from the second reel to the first reel while the second length of the band from the second reel is passed to the utilization device and the length of film traversing the utilization device is passed to the first reel. In order to feed the band to the second reel when it becomes empty the length of the band traveling from the utilization device to the first reel is displaced onto the hub of the second reel to form a loop so that the band can now be wound in two superposed lengths on the second reel while being unwound from the first reel, the direction of rotation of the reels being reversed.

45 Claims, 31 Drawing Figures US. Patent Dec. 2, 1975 Sheet 2 of 13 U.S. Patent Dec.2, 1975 Sheet 3of13 3,923,266

US. Patent Dec, 2, 1975 Sheet 4 of 13 3,923,266

I M U.S. Patent Dec. 2, 1975 Sheet5 of13 3,923,266

US. Patent Dec. 2, 1975 Sheet 6 0f 13 3,923,266

US. Patent Dec. 2, 1975 Sheet 8 0f 13 3,923,266

O o L e :5 15?; "7

U.S. Patent Dcc.2, 1975 Shet9of 13 3,923,266

Sheet 10 0f 13 US. Patent Dec. 2, 1975 US. Patent Dec. 2, 1975 Sheet 11 of 13 3,923,266

US Patent Dec. 2, 1975 Sheet 12 01*13 3,923,266

U. S. Patent Dec. 2; 1975 Sheet '13 of 13 3,923,266

ENDLESS FILM WINDING OR UNWINDING DEVICE BACKGROUND The invention relates to apparatus for continuous winding and unwinding of an endless band.

In a particular non-limitative embodiment, the invention is applicable to cinematographic projective apparatus and to magnetic reading apparatus.

In this exemplary embodiment, the objective of the invention is to permit cinematic projection or magnetic reading in continuous and automatic manner without it being necessary to reload the projector or the magnetic reader or to proceed with a rewinding of the film or bands.

In a general manner, the apparatus of the invention permit continuous and automatic feeding of an endless film or band of substantial length to a utilization or treatment apparatus.

By way of example, suitable utilization apparatus to which the invention is applicable are sound reproducing equipment, apparatus for controlling the operations of work machines and all types of apparatus capable of being utilized with tape or film of great length.

PRIOR ART Various methods and apparatus have been proposed to effect passage of an endless band through a utilization apparatus such as a movie projector and avoiding the need for rewinding the film at the end of the program.

Certain of these methods and apparatus have not passed the theoretical stage as they cannot be put into practice.

This is the case with a procedure consisting of forming a small loop, then introducing this loop into a hollow central hub of a plate mounted for rotation on a support capable of turning around an axleand carrying a second plate identical to the first on the other side of said axle, the band being then wound over nearly its entire length on the hub of the first plate while forming windings of two superposed lengths. In order to pass the outer length of the superposed thicknesses of the band to the drive system of the utilization apparatus, i.e., to make it follow the path provided in the latter, another small loop was formed retained at a convenient location and introduced into the central hub of the second plate which thus becomes the take-up plate whereas the first plate constitutes a supply plate up to the time when the latter becomes empty and the retained loop escapes from its hub at which time the takeup plate takes the role of the supply plate by an 180 rotation of the support. A suitable means is provided to rest between the two thickness of the band and to form a small retainer loop which is introduced into the central hub of the empty first plate which thus becomes the take-up plate, each plate being automatically rendered free when it alternatively supplies or takes-up following the position which it occupies.

Such procedure has not been put into practice as it is practically impossible to pivot the support carrying the plates by 180 when one plate is empty and the other carries a complete film program whose weight can be several tens of kilograms. Moreover, such pivoting movement requires an excessive amount of space.

According to other methods and apparatus, the film whose extremities are joined to constitute a closed loop is wound in superposed turns on the middle of a hub. One length of film is unwound from the interior of the hub and is fed to the projector and after passage therethrough is wound onto the outer periphery of the film on the hub.

Such arrangement is well known notably in the region of amateur film apparatus, and it allows the utilization of film or tapes, optical or magnetic, of relatively small length.

When a film of great length is projected, such as a full length picture, the various segments of the picture are connected one after the other in their order of passage and the band, thus constituted, is wound in proportion, on an enormous plate. It is necessary to rewind the film and reload the projector at the finish of the picture.

To avoid this disadvantage, it has been proposed to dispose the film on a first plate of great diameter and to unwind from the interior. After passage in the projector, the film is wound on a second plate. It is therefore necessary to change the positions of the supply plates and take-up plates and their directions of rotation. No such satisfactory arrangement has been made which supports the industrial and commercial interest which it promises. Additionally, it is necessary to pass a protective band between the turns of the film in an attempt to limit the abrasive effects due to rubbing of the film lengths against one another.

SUMMARY OF THE INVENTION An object of the invention is to provide an apparatus by which the disadvantages associated with the prior art are overcome.

A further object of the invention is to permit the mounting and projecting of a complete program, such as newsreels, cartoons, documentary film, commercial announcements and full-length feature film in succession on a single endless band having a substantial length of the order of 5,0006,000 meters or more without any risk to the film and under ideal conditions of winding and unwinding without any interruption of the projector.

The invention is characterized in that there is wound simultaneously two lengths of an endless band of film on a reel disposed in the interior of the endless band and on a reel disposed externally of the endless band, the film traveling along a path in which one length extends between the external reel and the downstream end of the projector at the time of feeding the interior reel when the latter is empty, and between the interior reel and the downstream end of the projector at the time of feeding the external reel when the latter is empty.

More specifically the invention comprises simultaneously winding two lengths of the endless band in superposition on a first rotating reel, while simultaneously unwinding two superposed lengths of said band from a second rotating reel, passing one length of the band from the second reel to the first reel while passing the second length of said band from the second reel to the utilization apparatus and passing the length of film traversing the utilization apparatus to said first'reel. The band travels along a closed loop between the reels and the utilization apparatus, one reel being in the interior of the loop, the other reel being external thereof.

In order to feed the film back to the supply reel after it has become empty, the invention further comprises diverting onto said second reel the length of the band traveling from the utilization apparatus to the first reel after said second reel is exhausted of band to form a loop so that the band can now be wound in two superposed lengths on said second reel while being unwound from the first reel, the direction of rotation of the reels being reversed.

The apparatus according to the invention comprises a first rotatable supply reel and a second rotatable takeup reel, reversible drive means for said reels, said reels being arrayed with respect to the utilization device such that two lengths of the band are wound in superposition on both reels and extend between both reels and the utilization device, one length on said second reel extending to the first reel, the other length on said second reel extending to said utilization device and traversing the same, said first reel receiving the length of the band issuing from the utilization device, said band forming a closed travel loop between said reels and the utilization device, one of said reels being in the interior of said loop, the other reel being external thereof; and feed means for placing against the second reel the length of band extending between the utilization device and said first reel when said second reel is empty whereby by reversing the direction of rotation of the reels the first reel can now become the take-up reel and the second reel the supply reel.

In further accordance with the invention said feed means comprises a feed arm pivotably mounted between said reels, and a retractable finger adjustably mounted on said arm for longitudinal displacement therealong and spring means acting on said arm and finger for urging said finger to a rest position out of contact with said band.

In further accordance with the invention each reel includes a hub having a notch in the periphery thereof in which the band is introduced as a loop by said finger, and a cheek with a curved ramp positioned to guide the finger to the notch in said hub.

In further accordance with the invention there is provided guide means including at least one movable guide roller at said inlet and outlet of the utilization device for forming respective loops of compensating and reserve amounts of said band.

In further accordance with the invention there is provided a selector including control means for controlling the movement of said feed arm between a rest position between said reels and two active feed positions in contact with the respective reels, means for halting the drive means of the take-up reel and activating the drive means of the supply reel when the latter is empty, means for maintaining the arm in feed position on the hub of the take-up reel for a sufficient time to wind a number of turns of band in the take-up reel so that when the arm is removed the band will continue to be wound on the take-up reel, and means for rocking said feed arm and/or retracting said finger.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic side elevational view of the installation according to the invention;

FIGS. 2 and 3 are schematic views intended to facilitate a comprehension of the operation of the installation;

FIG. 4 is an elevation view ofa reel used in the installation of the invention;

FIG. 5 is a diagrammatic elevation view showing the mounting of a microswitch in the hub of a reel;

FIG. 6 shows a control lever of the microswitch;

FIG. 7 is a schematic illustration in section of the rotatable support of the axle of a reel;

FIG. 8 is a detail view partly broken away and in section showing the articulation support of a feed arm of the installation;

FIG. 9 is a view similar to FIG. 1 in which certain elements have been omitted to reveal certain details of construction;

FIG. 10 is a perspective view of a selector apparatus controlling the operation of the installation;

FIG. 11 is a diagrammatic illustration of the principal elements of the selector apparatus showing their connection in a circuit diagram;

FIG. 12 is a front elevation view of the feed arm of the installation;

FIG. 13 is a top plan of the arm;

FIG. 14 is a rear elevation view of an extremity of the arm in partial section;

FIG. 15 is a sectional view taken on line ll515 in FIG. 14;

FIG. 16 is an end view, partly in section, apparatus for interrupting the drive of the reels;

FIG. 17 is a sectional view taken on line l7-17 in FIG. 16;

FIG. 18 is a top plan view, partly in section and on enlarged scale, of the apparatus shown in FIGS. 16 and 17;

FIG. 19 is a front elevation view diagrammatically illustrating a brake apparatus for the take-up reel utilizable in place of the apparatus in FIGS. 16-18;

FIG. 20 is a plan view of a movable assembly for a reserve loop of film at the exit of the film banding apparatus;

FIG. 21 is an elevation view diagrammatically illustrating a means for braking rotation of the reels when they operate as supply reels;

FIGS. 22-27a are schematic views showing the apparatus in various stages of operation.

DETAILED DESCRIPTION Reference will next be made to the drawings to describe an advantageous embodiment of an installation which is drawn in non-limitative manner to apparatus for cinematographic projection.

In this respect, the expression projector or projection apparatus which will he often employed hereafter should be taken as the equivalent of any suitable utilization" apparatus or operating apparatus, while the term film" should be considered as synonomous with the terms tape or band.

The installation comprises two

reels

1 and 2 which in characteristic fashion according to the invention are disposed one above the other and are mounted on respective axle supports permitting them to be driven in rotation by means of any suitable electric drive motor.

For this reason there is utilized hereafter terms such as upper, lower", vertical, horizontal and so forth. For other utilizations however, different positions of the reels can be adopted without departing from the invention.

The cinematographic film F is constituted as a closed loop and is fed from one reel to the other while traversing a projector P as will be explained more fully later.

The frames of the 'film constituting a complete program are arranged one following the other in their order of passage and the extremities of a band of great length, thus obtained, is assembled by a conventional adhesive. The endless band formed by such a complete program can thus have a very substantial length, for example, of the order of 5,000 to 6,000 meters or more.

According to a first characteristic feature of the invention, the winding hub of one of the reels is disposed in the interior of a closed loop which the film defines as it travels from one reel to the projector and back to the other reel as will be explained more fully later, while the winding hub of the second reel is external of the loop.

In the illustrated embodiment of the cinematographic projection apparatus, the reel disposed in the interior of the loop is reel 1 which will be called the upper reel hereafter. This arrangement is best seen in FIG. 26.

The reel 2 which will be called the lower reel is disposed at the exterior ofthe loop as can be seen in FIG. 23.

The

reels

1 and 2 each comprise a winding hub 3 of generally cylindrical form and two cheeks, of which one is a front cheek 4 and the other a rear cheek 5, both cheeks being solidly fixed to the winding hub.

The front check 4 has at least one notch 6 at the inner periphery thereof. The notch 6 registers with a cylindrical notch 3a formed at the periphery of the hub 3; cylindrical notch 3a has an axis extending parallel to the axis of the hub. The front cheek 4 of each reel comprises one or more blades and preferably, as seen in FIG. 4, three equally spaced blades 4a of particular form, this number suitably meeting conditions for mounting and utilization of the reels in the described application. The front and rear edges of each blade constitute two ramps of opposite inclination which join to form an angle whose apex is at the free extremity 4f of the blade.

With respect to the direction of rotation of the reels in their receiving function as the take-up reel, the front edge of each blade forms two

ramps

4b and 4c of opposite inclination. The exterior ramp 4c is rectilinear and forms an acute angle with respect to a line joining the extremity 4f of the blade and the axis of the reel. The interior ramp 4b is of concave curved form and its internal extremity extends directly into notch 3a at the periphery of the winding hub 3 of the reel. Thus, at the periphery of the hub 3 of each reel there are three cavities or cells 3a which will be called loop cavities hereafter.

The rear edgeof each blade is constituted by two rectilinear ramps 4d and 4e of opposite inclination, the exterior ramp 4e also forming an acute angle with the line joining the extremity 4f of the blade and the axis of the reel. The interior ramp 4d has a length much greater than that of the exterior ramp 4e, and ramp 4d extends to the region of the hub 3 of the reel. Ramp 4d also has an oblique disposition with respect to the line joining the axis of the reel and the extremity 4f of the blade and preferably is not sharp or capable of effecting a shearing function.

This conformation of the front cheek of each reel is effected, on the one hand, so that nothing opposes a feed arm 7 which will have just occupied the positions following alternative advance and start of the drive motors of the reels and on the other hand, to drive the film loop presented by a finger 7a of the feed arm to one of the loop cavities 3a. The finger 7a is guided by the curved ramp 4b of one of the blades 4a, in a manner which will become apparent later.

According to a characteristic disposition, the

reels

1 and 2 are driven in rotation in opposite directions in their respective operating functions.

In this respect when the upper reel 1 is the take-up reel it turns in clockwise direction, while the lower reel 2 is driven in the opposite direction as it unwinds and serves as the supply reel.

In these conditions, the curved ramp of the blades of the front cheek of one of the reels has an opposite disposition relative to the curved ramp of the blades of the other reel.

Accordingly, the portion of the length b (FIG. 2) of the film between the interior roller 10a of a group of rollers disposed at the entrance of the film handling apparatus and the tangent of winding T of this length on either one of the reels, effects a minimal angular inclination with respect to the limit positions of the feed arm 7. The finger 7a of the feed arm can thus easily occupy a rest or waiting position next to length b opposed to the side of the unwinding reel as will be seen hereafter.

In their receiving operation as take-up reels, the reels roll on an imaginary plane passing through the pivot axis of the feed arm, in a direction away from said axis.

The apparatus comprises a means for alternately controlling the feed to wind the film on one or the other of

reels

1 and 2.

According to a characteristic feature of the invention, this feed means is constituted by the pivoting arm 7, at the free extremity of which is retractable finger 7a. The finger 7a is mounted for longitudinal adjustable movement with respect to shaft 8 which pivotably carries the arm 7. The pivot axis of the arm is disposed at a level between the

reels

1 and 2, at a judicious distance from a plane passing throughthe centers of said reels.

Two groups of guide rollers are disposed respectively at the exit and at the entrance of the projector and the roller group at the entrance includes at least one tension and compensator roller 9 while the roller group at the exit includes at least one tension and compensator roller 10.

The groups of rollers, the particular arrangement of which will be explained in more detail in the following description, provide for reserve loops or film b and b downstream and upstream of the projector P or other utilization apparatus. The group of rollers including the roller 9 serve for guiding the length of film b towards the projector P, while the group of rollers including the roller 10 guides the length of film b leaving said projector. Other return and guide rollers 11 can be advantageously disposed in proximity to the periphery of the upper reel, notable to avoid contact of the lengths of the endless band traveling in opposite directions.

According to another characteristic feature of the invention, the means for control of the drive disposition of the arm 7 and of the drive motors of the reels are lodged in the hubs 3 of the reels. These means comprise a microswitch 12 (FIG. 5) connected to a collector 13 (FIG. 7) disposed on the external face of the rear cheek 5 of the reel and on which rubs a brush carried by the frame of the installation, as will be explained hereafter.

The switch 12 of each reel is actuated when the last turn of the film leaves the reel as it is unwound. Other suitable control apparatus could be lodged in the hub 3 of the reels, such as a photo-electric cell or the like.

Each reel is mounted on an axle l4 turning in bearings (not shown) which can be provided in vertical partition 16a of frame 16 of the installation.

In order to effect the operation of the apparatus of the invention, considering that the cinematographic programs are delivered to the users in the form of rolls of film from 300 to 600 meters in length, the segments of the programs are secured edge to edge and the film must now be formed into an endless band as will be explained hereafter with reference to FIGS. 2 and 3. The

' film whose extremities are not yet joined is wound on one of

reels

1 or 2, for example on the upper reel 1.

When all the program is wound on reel 1, the film is partially unwound from reel 1 and rewound on a third reel 15, which is preferably disposed on one side of the frame 16. This auxiliary reel has a winding capacity which is at least one-half of the winding capacity of

reels

1 and 2.

When one-half of the program has been wound on reel 15, the intermediate length of film is led against the hub of the lower reel on which are then simultaneously wound two lengths of the film, one of which is supplied by the upper reel, and the other by the auxiliary reel. Graduation marks provided on the front cheek of the reels permit determining with exactitude the median part of the film.

When the free extremities of the film have left the

reels

1 and 15, and the totality of the film is then wound on the lower reel; the film extremities are easily joined together to form an endless loop of which one length will be led, respecting the dispositions already described, against the winding hub of the upper reel.

It is nevertheless, evident that the development of the invention will lead distributors to deliver the cinematographic programs directly as closed loop of great length on a reel according to the invention, in order to avoid the preceding operation.

Referring to FIG. 2, the upper reel 1 (disposed at the interior of the closed loop) winds simultaneously two lengths of the film of which one length (b proceeds from the projector while the other is fed from the lower reel 2 (situated outside the closed loop). Reel 2 also unwinds length b, going to the projector P.

When the lower reel 2 is empty, the upper reel is disconnected from its drive motor and put in free rotation and the length b situated between the upper reel 1 and the downstream end of the projector is displaced (as shown in dotted outline in FIG. 2) by means. of pivotal arm 7 and finger 7a against the hub of the lower reel to introduce a small loop b of film into a cavity 3a in said hub.

The lower reel is driven in rotation in a direction opposite to that when it served as the supply reel.

By holding the film several seconds in the cavity 3a of the hub of the lower reel, two lengths of the endless band are simultaneously wound on the hub. One of these lengths (b comes from the projector P, while the second length is fed from the upper reel which simultaneously unwinds the length b going to the projector as seen in FIG. 24.

When the upper reel is empty, the lower reel is freely rotated and the length b situated between the lower reel and the projector is fed (as shown in dotted lines in FIG. 3) by means of finger 7a on arm 7 against the hub of the upper reel which is now situated in the opposite direction. The finger 7a introduces a small loop of film in the cavity 3a of the hub of the upper reel and as described previously, two lengths of film are simultaneously wound on this hub. One length comes from projector P while the other is fed from the lower reel which also unwinds length b, to the projector P.

According to the apparatus described, it is understood that there are alternatively wound two lengths of the endless band on one of the reels while the second reel unwinds in continuous and automatic manner. Accordingly, the film travels via length b, in uninterrupted manner to the projector or other utilization apparatus.

The operation of the apparatus will be described hereafter with reference to details of the principal elements there of.

As previously described, a microswitch 12 is lodged in the winding hub 3 of each reel. This switch serves to send a signal to an electro-magnetic apparatus to effect displacement of the feed arm 7 and the control of the drive motors for the reels after the last winding of the film unwinds from the supply reel.

As seen in FIG. 6, the switch has a control element of T shape with a vertical arm 12a and an upper horizontal branch 12c disposed parallel to the axis of the cylindrical hub 3. The arm 12a is slidingly mounted in a radial bore 3b in the hub 3 and the control element is subjected to the action of a spring 12b urging the upper branch 12c outwardly from the bore as seen in FIG. 5.

The control element is lowered in the bore when the film is wound on the hub 3, and it is automatically raised as soon as the last winding is unwound from the hub.

As illustrated in FIG. 7, the rotational drive of the reels is effected by means of a plate 18 secured on each shaft 14.

The front face of each plate 18 is provided with at least one entrainment spur 18a adapted to engage in a cavity 3c provided in the front face of the winding hub of the associated reel.

The rear face of the plate 18 comprises an insulating section carrying a conductive contact ring or collector 13 on which rubs a brush apparatus 28 which can be supported, for example, by the vertical partition 16a of the frame of the apparatus.

The electrical contact between the collector 13 and the switch 12 is realized via the engagement of the spur 18a in the cavity 3c, to which conductors are respectively connnected and led to the collector 13 and the switch 12 as seen in FIG. 5.

According to another feature of the apparatus it has already been noted that the finger 7a of the pivotal feed arm 7 is mounted for longitudinal displacement on the arm. Accordingly, as illustrated in FIGS. 12 to 15, the distance between the finger 7a and the pivot axis through shaft 8 is variable.

The shaft 8 is carried by the vertical partition 16a of the frame and permits pivoting movements of the feed arm 7 between a rest position and a feed position, for each

reel

1 and 2.

The feed arm permits the introduction of a small loop of film into one of the loop cavities in the hub of one of the reels such that the rotation of this reel assures the simultaneous winding of two lengths of film on the hub. When a sufficient number of windings have been wound, the finger is retracted and the arm assumes again its rest position.

The retractibility of the finger 7a of the feed arm can be effected by a displacement of this finger parallel to its axis, for example by means of a suitable electromagnetic apparatus.

According to a preferred embodiment, the retractibility of the finger 7a is obtained by a lateral pivoting movement of arm 7 perpendicular to the direction of pivoting of arm 7 between the reels.

For effecting this lateral pivoting movement the arm 7 is pivotably connected at a suitable point remote from its free extremity, by means of pointed screws 19 (FIG. 8). These screws are secured to two opposed walls 20a of a tubular support 20; the support 20 is fixed to the shaft 8.

The pivoting of the arm 7 is controlled by an electromagnetic apparatus constituted by an electromagnet 21 carried by the support 20 and capable of applying an attraction force on the front extremity of the arm 7 when it is energized.

One can advantageously use in this respect an electromagnet whose coils are carried by the support 20 and whose movable core is coupled to the arm 7.

A spring 22 is interposed between the support 20 and particularly, between the edge of a solid member integral with said support and the arm 7 at a location rearwardly of the axis of articulation 19, to automatically return said arm to its normal rest position when the attraction force applied by the electromagnet 21 is terminated.

A screw 23 is mounted in the front wall of the support 20 and rests against the front face of the inner portion of the arm 7 to regulate the degree of pivoting of the arm. It is to be understood that arm 7 has sufficient lateral clearance in support 20 to enable arm 7 to undergo sufficient lateral displacement to withdraw the finger 7a from the loop cavities. To facilitate its extraction from loop cavities 3a, the finger 7a has a conical form. The finger is constituted by a roller mounted for free rotation on an axle 7j.

As was previously indicated groups of rollers each including at least one stretcher and compensator roller 9 or are disposed, respectively upstream and downstream of the projector P.

These rollers serve the function of providing a reserve loop of a length of film sufficient to avoid tension between the film handling apparatus and the projector or for absorbing supplementary lengths fed by the projector or by the film handling apparatus.

In the particular application of the apparatus for cinematographic projection, the roller 10, in forming a compensating loop 11 of film avoids tension in the length b coming from the projector when the last winding of film is unwound by the supply reel, during the time necessary to stop the take-up reel and allow it to undergo free rotation in the opposite direction.

The roller 9 principally serves to absorb additional length of film resulting from the liberation of the last winding of film unwound by the supply reel in constituting a compensating loop or reserve of film [1,. (FIGS. 2 and 3) In order to provide a more substantial length to the compensating loops b and b.,, there can be employed more than one stretching and compensator roller for each of the film reserves respectively at the exit and at the entrance of the projector. The roller group disposed at the exit of the film handling apparatus and upstream of the projector comprises for example, three upper rollers 9a-9b-9c (FIG. 1) each mounted for free rotation on fixed axles supported by a bracket 16b fixed to the upper part of the frame 16 of the installation and two lower stretcher and compensator rollers 9-9. The rollers 9-9 are carried by a support 28 slidingly mounted on a guiding means, for example, constituted by two vertical columns 29, fixed at their opposite extremities, on the one hand to the bracket 16b and on the other hand to a solid foot of the base of the frame of the installation.

As can be seen in FIG. 20, the rollers 9-9 are coupled by a flexible member 30 advantageously constituted by a cable spring wound in a circulargroove constituting a pulley 31 at the rear portion of the rollers.

This arrangement permits braking the descent of the assembly of the support 28 and the rollers 9-9 at the time of liberation of the last winding from the supply or discharge reel.

The support 28 carries a bar or contact member 28a whose function will be explained later.

The axes of the upper fixed rollers 9a-9c preferably have an adjustable orientation.

The group of rollers disposed at the entrance of the filin handling apparatus and downstream of the projector comprises for example, four upper rollers l0a-10- b-10c-10d (FIG. 1) freely mounted for rotation on fixed axles carried by a bracket 16d fixed at the median part of the frame of the installation and three movable lower stretcher and compensator rollers l0-1010".

According to a characteristic feature, the installation is provided with means for braking the speed of winding of the take-up reel if the tension of the length of the band coming from the projector becomes too great. Such means is controlled by the position of the stretcher and compensator rollers l0, 10', 10" disposed at the entrance of the film handling apparatus downstream of the projector.

According to one embodiment, one or

more rollers

10, 10 and 10 are freely mounted for rotation at the extremity of a lever 24 (FIG. 19) of a braking apparatus for the film. The lever 24 is pivotably connected at its opposite extremity on an axle 25 mounted in a vertical wall of the frame, as seen in FIG. 19.

A belt 27 is applied on a pulley fixed in rotation on the lower reel 2 and one extremity of the belt is secured to the wall of the frame and the other extremity to lever 24. The belt permits the application of friction to the pulley 26 when the lever 24 is pivoted upwardly.

With reference to FIG. 3 wherein the lower reel 2 is the take-up reel, it is understood that as soon as it produces a tension in the film length b coming from the projector exceeding a normal value, this tension urges the roller 10 to move upwardly to diminish the length of the compensating loop b between the fixed rollers l0a-l0b.

The ascending movement of the roller 10 corresponds to a pivoting movement of the lever 24 of the braking apparatus to apply a braking force on the pulley 26 to slow down the rotation of the lower reel 2. The more the length of the compensating loop b diminishes, the greater the value of the braking force.

This same apparatus provides for the application of a braking action on the upper reel when this becomes the take-up reel. As can be seen in FIG. 2, in this situation, the length b, going to the projector is unwound from the lower reel which is now the supply reel, whereas the length b coming from the projector is wound on the upper reel 1. Simultaneously, a second length b unwinds from the lowerreel and is wound on the upper reel. Under these conditions, if the tension of the length 12 coming from the projector becomes too great, the braking apparatus acts, as already indicated,

. to slow the rotation of the lower reel which through the intermediary of the length b of film, applies an equivalent braking action on the upper reel.

According to a preferred construction, however, the rollers -10-10 for the formation of the film loop b are carried by a pivoting lever which can act on a disconnecting apparatus for the drive means of each of the reels.

The rollers l0-10-l0 are, for example, mounted at the extremity of a lever 32 pivotably connected to the frame of the installation, in proximity to the axle of the lower reel.

When the length of the loop b of the film at the entrance of the handling apparatus is less than a preestablished normal value, as ascending pivoting movement of the lever 32 acts on an apparatus for disengaging the drive means of the take-up reel.

Such means is illustrated in FIGS. 16 to 18 and comprises for each of the reels, a pulley 33 mounted freely rotatable on the axle 14 of the reel and on which pulley a belt is wound coupled to the drive pulley of the motor for driving the reel.

A clutch plate 35 is fixed on the axle l4 and consequently the axle 14 is driven from the drive motor by the pressure of the pulley 33 on said clutch plate.

The cooperating faces of the pulley 33 and of the plate 35 are provided, in known manner, with a lining of any suitable type of frictional material.

The pressure of the pulley 33 against the plate 35 is obtained by means of a clutch member 36 comprising a socket 36a slidingly mounted on the shaft 14 and a plate 36b of U-shape in which is lodged an axially movable nut 37 fixed in rotation by the walls of plate 36b. A ring 360 having a low coefficient of friction is advantageously interposed between the extremity of the socket 36a and the pulley 33.

The nut 37 is mounted on a screw 38 having a large pitch and axially fixed such that its rotation causes longitudinal movement of the nut.

The screws 38 and the axle 14 of the reels are, for example, rotatably mounted in a brace element 39 coupled to the vertical partition 16a of the frame of the installation, the brace element comprising a bearing 39a carrying the screw 38 and a bearing 39b for the axle l4.

Weak recall springs 40 are mounted on stems 41 and bear against an edge of the plate 36b and maintain the clutch member 36 in a position of equilibrium.

The plate member 36b slides on the shoulder of the element 39 carrying the bearings 39b.

The screw 38 is rigidly coupled to a lever 42 (lower reel) or 42' (upper reel) by being fixed at one of its extremities by a nut 43 on a carrier whose outer surface is smooth and rides in bearing 39a.

As seen in FIG. 9, levers 42-42 are coupled to respective ends of an articulated connecting rod 44.

The lever 42 of the disengaging apparatus of the lower reel has a greater length than that of the lever 42' of the disengaging apparatus of the upper reel.

Additionally, the free extremity of the lever 42 carries a laterally transported joint constituted by a roller 42a resting on lever 32. This roller is adapted to follow the lever 32 during ascending movements of lever 32. The lever 32 can be advantageously freely articulated, on a shoulder constituted by the external surface of the bearing 39a.

When the reserve of film b decreases below a preestablished normal value, for example, due to an excessive winding speed of the take-up reel the ascending pivoting movement of the lever 32 produces pivoting of lever 42 which transmits a rotation movement to the screw 38 which causes axial translation of the nut 37 which is displaced from the pulley 33. The clutch member 36 is now released from the pulley which is now loose on the axle 14. The take-up reel is thus no longer driven.

As the projector continues to feed film, the reserve loop of film h is increased and the lever 32 is again lowered permitting the descent by gravity of lever 42.

As the lever 42 again assumes its initial position, the pulley 33 is again pressed against the clutch plate 35 and the drive of the take-up reel is again effected.

It is to be noted that this action also concerns the lower reel as well as the upper reel as the lever 42 is coupled to the lever 42 by the connecting rod 44.

It is noted that the group of rollers 9-9-9a9b-9c are disposed in a vertical plane situated at the rear of the vertical plane containing the rollers 10-10-ll0"1- 0a-10b-10c-10d.

According to an important characteristic feature of the invention, the control of the drive motor (not shown in the drawings) of each of the reels and the pivoting movements of the feed arm 7 from a rest position to a feed position and vice versa is effected by the intermediary of a selector apparatus illustrated schematically in FIGS. 10 and 11.

The selector apparatus comprises an electric motor 45 which drives, via a reducer 46, a shaft 48 on which are mounted cams 49-50 cooperating with respective microswitches 51-52. The carns 49 and 50 have an identical profile and an inverse disposition. They present on their peripheries, respective notches 49a-50a.

As soon as the roller on a control arm of one of the microswitches 51-52 falls into the notch of the associated cam, it causes closing of the circuit feeding the drive motor of the reels and the energization of this mo- In the following description it will be considered that the cam 49 and the microswitch 51 control the operation of the drive motor for the upper reel 1, whereas the cam 50 and the microswitch 52 control the operation of the drive motor of the lower reel 2.

The means effecting the pivotal movement of the feed arm 7 from a rest position to a feed position and vice versa, is constituted by a crank plate 53 secured on the shaft 48 and coupled, by the intermediary of a connecting rod 54 to the arm 7, preferably by means of a second crank plate 55 secured to the rear extremity of the shaft 8 of the feed arm.

The rod 54 is articulated at its opposite extremities on respective crank

pins

53a and 55a on the crank

plates

53 and 55.

According to another characteristic feature, a cam 56 is also secured on the shaft 48 and cooperates with a microswitch 57 to stop the motor 45 following the four positions A, B, C, D of the arm 7 as follows:

A rest position in preparation for feeding the lower reel;

B a-feed position for the lower reel;

Claims

1. Apparatus for the continuous winding and unwinding of an endless band through a utilization device, said apparatus comprising a first rotatable supply reel and a second rotatable take-up reel, each of said reels having a hub reversible drive means for said reels, means arraying said reels with respect to the utilization device such that two lengths of the band are wound in superposition on both reels and extend between both reels and the utilization device, one length on said second reel extending to the first reel, the other length on said second reel extending to said utilization device and traversing the same, said first reel receiving the length of the band issuing from the utilization device, said band forming a closed travel loop between said reels and the utilization device, one of said reels being external thereof; and feed means for placing against the second reel the length of band extending between the utilization device and said first reel when said second reel is empty whereby by reversing the direction of rotation of the reels the first reel can now become the take-up reel and the second reel the supply reel, said feed means including a feed arm pivotably mounted between said reels and engagement means on said feed arm for engaging the band to place the same against said second reel when the latter is empty.

2. Apparatus as claimed in claim 1 wherein said reels are disposed vertically above one another.

3. Apparatus as claimed in claim 2 wherein the reel disposed in the interior of the loop is the upper reel.

4. Apparatus as claimed in claim 1 wherein said engagement means comprises a retractable finger adjustably mounted on said arm for longitudinal displacement therealong.

5. Apparatus as claimed in claim 4 wherein said engagement means further comprises spring means acting on said arm and finger for urging said finger to a rest position out of contact with said band.

6. Apparatus as claimed in claim 5 wherein each reel includes a hub having a notch in the periphery thereof in which the band is introduced as a loop by said finger, and a cheek with a curved ramp positioned to guide the finger to the notch in said hub.

7. Apparatus as claimed in claim 6 wherein one cheek of each said reel further comprises at least one blade having front and rear edges with two surfaces of opposite inclination intersecting at the tip of the blade, Said front edge defining said curved ramp.

8. Apparatus as claimed in claim 7 wherein said curved ramp extends directly into said notch in the hub.

9. Apparatus as claimed in claim 5 wherein said feed arm includes means for pivotal movement thereof in a direction perpendicular to the plane of pivotal movement between said reels to effect retraction of said finger from the hubs of said reels.

10. Apparatus as claimed in claim 9 comprising control means including an electromagnet for moving said arm from said rest position to active feed positions in contact with the hubs of said reels.

11. Apparatus as claimed in claim 5 wherein said finger has a conical shape.

12. Apparatus as claimed in claim 5 wherein said utilization device has an inlet and an outlet, said apparatus further comprising guide means including at least one movable guide roller at said inlet and outlet of the utilization device for forming respective loops of compensating and reserve amounts of said band.

13. Apparatus as claimed in claim 12 wherein one of said guide means is disposed in the region of the periphery of the reel disposed in the interior of the band loop and upstream of the utilization device.

14. Apparatus as claimed in claim 5 wherein said drive means drives said reels in respectively opposite directions, said reels rolling on imaginary planes passing through the pivot axis of said feed arm in a direction away from said axis.

15. Apparatus as claimed in claim 5 comprising a selector including control means for controlling the movement of said feed arm between a rest position between said reels and two active feed positions in contact with the respective reels, means for halting the drive means of the take-up reel and activating the drive means of the supply reel when the latter is empty, means for maintaining the arm in feed position on the hub of the take-up reel for a sufficient time to wind a number of turns of band on the take-up reel so that when the arm is removed the band will continue to be wound on the take-up reel, and means for rocking said feed arm for retracting said finger.

16. Apparatus as claimed in claim 15 wherein said control means of said selector comprise a shaft, cams fixed on said shaft for rotation therewith, and switches controlled by said cams and in turn controlling the drive means and feed arm.

17. Apparatus as claimed in claim 16 wherein said means for controlling movement of said feed arm comprises a crank plate secured on said shaft, and a crank shaft connected to said plate and coupled to said feed arm to move the same.

18. Apparatus as claimed in claim 16 wherein one of said cams has four operative positions, two corresponding to feed positions for the respective reels, the other two to rest positions.

19. Apparatus as claimed in claim 16 wherein the selector includes a motor for driving said shaft and delay means for delaying the starting of said motor and pivoting of the arm from the rest position, when the last turn is unwound from the supply reel.

20. Apparatus as claimed in claim 19 wherein said delay means comprises a switch controlling energization of said motor, and means for closing said switch when a reserve of said band at the inlet to said utilization device has absorbed the length of band coming from the last turn thereof on the supply reel.

21. Apparatus as claimed in claim 5 comprising means for permitting rocking of said arm in the feed position thereof as the band is wound on the reel.

22. Apparatus as claimed in claim 21 wherein said means permitting rocking of said arm is constituted by a construction wherein said arm includes two pivotably connected parts, one carrying said finger.

23. Apparatus as claimed in claim 19 comprising a delay circuit interposed between said motor and one of said cams so as to be operative when the arm is in a feed position.

24. Apparatus as claimed in claim 23 comprising a switch controlled by said one cam and connected to said delay circuit.

25. ApparatuS as claimed in claim 23 comprising a second delay circuit controlling operation of said arm and having a time delay less than the first delay circuit and closed at the same time thereas.

26. Apparatus as claimed in claim 25 comprising a circuit breaker with a time delay connected to the second delay circuit, to be activated thereby at the cessation of its time delay restriction, reverse rocking of the arm for retraction of the finger in said rest position.

27. Apparatus as claimed in claim 12 comprising means for disconnecting said drive means from the take-up reel when the band length coming from the utilization device is subjected to excessive tension, and means for sensing said excessive tension including a movable assembly carrying said guide means and subject to displacement when said band is subject to said excessive tension.

28. Apparatus as claimed in claim 27 wherein the sensing means comprises a pivotal level, said guide means including rollers mounted on said pivotal level, said lever including means for acting on the drive means to disconnect the same.

29. Apparatus as claimed in claim 28 wherein said disconnecting means includes a control lever for each reel, and a connecting rod pivotably connected to the control levers of both reels.

30. Apparatus as claimed in claim 29 wherein said control lever includes a roller at the free end thereof, said roller resting on said movable assembly to follow movements thereof.

31. Apparatus as claimed in claim 12 comprising means for braking said drive means for the take-up reel when the band length coming from the utilization device is subjected to excessive tension, and means for sensing said excessive tension including a movable assembly carrying said guide means and subject to displacement when said band is subject to said excessive tension.

32. Apparatus as claimed in claim 31 wherein the sensing means comprises a pivotal lever, said guide means including rollers mounted on said pivotal lever, said lever including means for acting on the drive means to brake the same.

33. Apparatus as claimed in claim 13 wherein said guide means comprises a support for said guide roller and vertical columns guidably mounting said support for ascending and descending movements.

34. Apparatus as claimed in claim 33 comprising means for braking descent of said support for the guide roller.

35. Apparatus as claimed in claim 34 wherein said guide means includes a second roller and said means for braking descent of said support comprises an endless cable wound in grooves provided in said rollers of the guide means.

36. Apparatus as claimed in claim 5 wherein said arm is tubular, said feed means further comprising a slide member telescopically mounted on said arm and carrying said finger, said arm having a slot, a boss integral with said finger and slidable in said slot, and a traction spring connected to said arm and to said slide member permitting return of said finger to rest position, said slide member being provided with a longitudinal passage for said spring.

37. Apparatus as claimed in claim 12 comprising safety switches positioned in the path of the guide means for stopping the drive means if said guide means travels beyond established limits.

38. Apparatus as claimed in claim 12 comprising a safety switch below said guide means for being actuated by said guide means upon fall thereof due to band breakage between the utilization device and the take-up reel.

39. Apparatus as claimed in claim 1 comprising braking means for exerting a braking force on the supply reel.

40. Apparatus as claimed in claim 39 wherein said braking means comprises a plate including one-way clutch means, said plate being coupled to said supply reel via said one-way clutch means when the reel is driven in the direction of rotation in which it serves as the supply reel, and a friction brake acting on said plate to oppose rotation thereof.

41. Apparatus as claimed in claim 7 wherein said one cheek includes three of said blades equally spaced on said hub.

42. Apparatus for the continuous winding and unwinding of an endless band through a utilization device, said apparatus comprising a first rotatable supply reel and a second rotatable take-up reel, reversible drive means for said reels each of said reels having a hub, means arraying said reels with respect to the utilization device such that two lengths of the band are wound in superposition on both reels and extend between both reels and the utilization device, one length of said second reel extending to the first reel, the other length on said second reel extending to said utilization device and traversing the same, said first reel receiving the length of the band issuing from the utilization device, said band forming a closed travel loop between said reels and the utilization device, one of said reels being in the interior of said loop, the other reel being external thereof; feed means for placing against the second reel the length of band extending between the utilization device and said first reel when said second reel is empty whereby by reversing the direction of rotation of the reels the first reel can now become the take-up reel and the second reel the supply reel, electromagnetic means coupled to said feed means and said drive means for controlling operation thereof, and a switch means for operating the electromagnetic means, said switch means including a control contact mounted in said hub of each reel.

43. Apparatus as claimed in claim 43 wherein said control contact comprises a lever mounted in a slot provided in said hub and a spring urging said lever outwardly from said slot at the periphery of said hub.

44. Apparatus as claimed in claim 43 wherein said lever is of T-shape and has an upper branch extending parallel to the axis of rotation of the hub.

45. Apparatus as claimed in claim 42 wherein said drive means includes a plate driven with each said reel and including a boss extending into a groove provided in said hub, said switch means including a switch carried by said hub and controlled by said control contact, and a circular collector mounted on said plate and connected to said boss such that electrical connection is established to said switch by the engagement of said boss in said groove, said collector being connected to said electromagnetic means.