US1565693A - Cinematographic-film printer - Google Patents

Description

Dec. 15, 1925. 1,565,693

E. J. WAY

CINEMATOGRAPHIC FILM PRINTER Filed April 23. 1925 Patented Dec. 15, 1925.

UNITED STATES EDWARD JOHN WAY, OF JOHANNESBURG, TRANSVAAL, SOUTH AFRICA.

CINEMATOGRAPHIC-FILM PRINTER.

Application filed April 23, 1923.

To all whom it may concern:

Be it known that EDWARD JOHN WVAY, British subject, residing at 1067 Cullinan Buildings, Simmonds Street, Johannesburg, Transvaal Province, Union of South Africa, has invented certain new and useful Improvements in Cinematographic-Film Printers, of which the following is a specification.

The present invention has reference more especially to printing cinematograph films, but is also applicable for other purposes which require two or more films to be delivered together and operated on before being separately collected.

In printing positive copies from a negative film it is customary to withdraw each film from the exterior of its coil, superimpose the negative and an unexposed positive film, pass them thus together through the mask of a printing machine and wind them onto separate spools, the winding pioceeding from the inside outwards. When another copy is required, it is necessary first to rewind the negative in order to bring its leading end outwards on the coil. This rewinding is sometimes minimized by leading the negative through several printing machines in series before rewinding it.

In the operation described film is damaged in the case of both the positive and negative by being pulled off its coil by the printing machine feeding mechanism; whilst the negative film is additionally damaged by the repeated re-winding.

The present invention aims to diminish the damage done to the films in the course of operations of the kind referred to. To this end the invention consists in delivering without tension two or more films from their coils simultaneously and at speeds in each case equal to the speed at which the film is moved by the feed mechanism of the printing or other machine. The invention further consists in an operation conducted as described in which the negative film, at least, is wound in such a manner as to he at once ready for redelivery in a repetition of the same operation, without the necessity of re-winding it.

Film printing apparatus according to the invention is illustrated somewhat conventionally in the accompanying drawing.

The drawing shows film delivering apparatus as described in my Letters Patent 1,539,224 of May 26, 1925, and comprising a film coil carrier 2 which is free to Serial No. 634,188.

rotate on a bearing 3. The carrier rotated by a friction wheel 4 which touches its under surface and which by positive connections 5 is driven at a constant speed in relation to the feed mechanism 6 of the printing machine. As said friction wheel rotates it is also moved radially outwards of the carrier. For this purpose the shaft 7 to which it is rigidly fixed is free to slide endwise and is fitted with collars 8 which engage a slipper .9. Said slipper is provided with a pin 10 which engages in a groove 11 formed in a drum 12. Said drum is rotated at a constant speed in relation to the rotational speed of the friction wheel 4 by gearing 13 and a clutch 14. The groove 11 is a helix of decreasing pitch outwardly, and is such as to advance the friction wheel 4 by one film thickness for each revolution of the carrier 2; or in other words at a uniform rate in relation to the rate of rotation of the carrier, the latter rate being a decreasing one due to the increasing diameter at which the friction wheel 4 touches it. With this arrangement film is positively fed out without tension from the interior of a coil on the carrier and its rate of delivery is constant in relation to the rate at which the feed'mechanism 6 passes it through the printing machine. The winding of the film is effected in the usual way, viz, from the centre of the coil outwardly so that the used coil is ready for delivery again without rewindmg.

According to this invention several film coils 15, 16, 17 are mounted on the rotating carrier 2 and film is delivered from each of them simultaneously. In the drawings 15 represents a negative film coil and 16 and 17 two unexposed positive film coils. All of said coils are formed with the same initial internal diameter, so that upon being placed on the rotating member 2 and thereby rotated together, each delivers film from its internal periphery at the same rate as the others. The mounting of the coils on the carrier 2 is effected in any convenient manner. They are shown as simply placed on top of one another and held by a broad flexible band 18 which is compressed by the iris diaphragm device 30 described in the specification of my Letters Patent No. 1,415,131, May 9, 1922.

The printing machine is provided with several masks 19 and 20 one for each positive film. The negative film is threaded up through the masks and wound as a coil 22 on a winding spool 23 which is of any suitable construction having a detachable cheek for enabling the wound coil to be removed.

Said spool 23 is rotated by a flexible shaft 24 driven by a friction wheel 28which touches the undersurface of the carrier 2, so that the spool 23 is rotated at a rate which decreases according to the diameter of the film coils l5 and 22 and is substantially equal to that of the carrier 2. A slight constant resistance such as to make the coil 22 coherent is applied to the film by a friction device 26 similar to a projector gate and described in my Letters Patent 1,539,224 of May 26, 1925.

The positive films 16 or 17 are threaded separately through the masks 19 and 20 respectively. The exposed positive films are collected in any suitable manner; for instance each may be separately wound on a spool 27. Said spools 27 may be driven positively With the spool 23 by mechanism 29.

It will be seen that by means of the arrangement described a number of positive prints may be obtained from the negative at one pass through the machine. All the films pass through the apparatus without being subject to material tension, so that the possibility of tearing the perforations or otherwise injuring the films is obviated. Moreover, the negative is so wound as to be at once available for use again and is not deteriorated by re-winding as is at present the case.

I claim:

1. In combination with a machine, such as a film printing machine adapted for operating on several films together and including film feeding mechanism, a rotatable carrier, adapted to carry several film coils, means geared to said film feeding mechanism for rotating said carrier to cause de livery of film from film coils on the carrier cluding film feeding mechanism, a rotatable carrier adapted to carry several film coils, means geared to the film feeding mechanism for rotating said carrier to cause delivery of film from the film coils on the carrier at the same linear rate at which the film is fed to the feed mechanism, a carrier for winding film, and a driving connection between the two carriers whereby the one is always rotated at substantially the same speed as the other.

3. In combination, a film printing machine having several masks and arranged for supplying a separate positive film to each mask, feed mechanism for feeding a negative film through said masks in succession, a rotatable film coil carrier, means for mounting thereon a negative film coil and one or more unexposed positive film coils, means geared with the feed mechanism for rotating said carrier with progressively diminishing angular speed, and means for winding the negative film.

In testimony whereof I have signed my name to this specification.

EDIVARD JOHN WAY.

Images