Untitled record

FRENCH REPUBLIC

PATENT

MINISTRY OF INDUSTRY

INDUSTRIAL PROPERTY SERVICE

PV n ° 102.603 / VW? 1,519,086

International classification: [gο] θ b IU * \ / '' ï /

---------- v ^ »VJ v /

Method and device for automatically changing the dafiS “views of dual-objective projectors.

Company known as: MEOPTA Narodni Podnik residing in Czechoslovakia.

Requested April 13, 1967, 3:08 p.m.^m, in Paris. Issued by order of February 19, 1968.

(Official Bulletin of Industrial Property, No. 13 of March 29, 1968.) (Patent application filed in Czechoslovakia on April 13, 1966, under No. 2,437-66 in the names of Messrs. Alois Kovarik and Jindrich Suciianek.)

The invention relates to a method for changing the slides in the projection opening of a projector equipped with two objectives whose axes are substantially parallel, projector which comprises a projection opening in the focal plane of each of the objectives and a magazine for common slides, of the locker type, which are mounted so that they can move in a direction parallel to the axes of the objectives, this projector being designed so that no light ray passes through the projection opening in which a slide is not inserted.

On the other hand, the invention relates to a device by means of which this method can be implemented. To effect the change of views in two-lens slide projectors, the method is already known in which the slides are placed in a common channel from which they can pass in the focal plane of a lens under the effect of their own weight. From this plane, they are moved by a view changer alternately in the projection opening of the first or second lens, the slide pushing back, at the time of its insertion, that qjii was placed in the projection opening in question. Following this, this last slide traverses sliding surfaces to enter the discharge channel of the slides.

The application of such a device makes it possible to produce automatic and simple projectors. On the other hand, it has a drawback of the fact that individual slides or groups of slides can be reversed during their transport, which destroys their succession and causes disturbances in the case where the projector is coupled to an acoustic device whose program is linked to individual slides. In addition, it is impossible to automatically perform the cyclic slide series projection, which is particularly suitable, for example when using the projector for advertising or the like.

Some of these drawbacks could be eliminated by using a locker type slide magazine. However, such a store can only be used with a projector equipped with a single lens. The use of known models of automatic changers with locker type slide magazines and dual-objective projectors necessarily results in an inversion of the succession of slides when a projection cycle is completed.

The object of the invention is to propose for the use of the apparatus with two objectives a method of changing the slides by which the advantages of the slide magazine of the locker type are preserved, and such that each projected slide can be brought into the box that originally contained it.

The subject of the invention is a method of changing the slides in the projection opening of a projector with two objectives whose axes are substantially parallel, a projector which has two projection openings in the projection plane of each of these objectives and which comprises a common slide magazine, of the locker type, mounted so that it can be moved in a direction parallel to the axes of the objectives, the projector being designed so that no light ray crosses the projection opening in the absence of a slide in the projection opening.

The invention also relates to a device for implementing this method, in which, during a change of slide in any one of the projection openings, the magazine is first of all moved by two boxes forward, then backward: during each movement of the magazine by two boxes forwards, the slide - 2 - [1.519.086] which is to be projected is inserted into the corresponding projection opening and, during the movement of the magazine from one box to the rear, the slide which has already been projected and which is in the second projection opening is reintroduced into the same box of the magazine from which it had previously been taken.

• This method can be implemented by means of a device according to the invention which comprises in combination: a projector of the type described, comprising a mechanism for moving a slide magazine of the locker type and a slide changer, a carriage, movable along two rails and provided with a displacement rack, being provided for positioning the slide magazine of the rack type. This carriage attracted by a spring in one direction and retained against the action of this spring by a retaining pawl, is moved step by step against the opposing force of the spring by a displacement pawl mounted rocking on its movable support capable of being moved alternately by a cam from a magazine push and by a spring fixed to the support of the displacement pawl.

The invention also relates to a device comprising the movable support of a displacement pawl, which is alternately set in motion by a cam whose periphery has on the one hand a large projection intended to move the store towards the 'before two boxes and, on the other hand, a small projection intended to release the carriage from its retaining pawl, this cam being further provided with a stopper pin for tilting the retaining pawl in the release position relative to the displacement rack.

Furthermore, the subject of the invention is a view changer provided with a left fork and a right fork for moving slides from the magazine towards a beam of rays from the left lens or from the right lens and to bring them back to the store, these forks being mounted movable on a guide rod perpendicular to the axes of the objectives, these forks being kinematically coupled, by means of levers and slides, with cams mounted on a rod of the view changer, this rod being connected by toothed wheels to the rod of a store pusher.

Finally, the subject of the invention is a carriage which carries a magazine and which is provided with a stopper in the path of which, at locations corresponding to the emitted positions of the carriage, end of stroke surfaces are formed on a member connecting pendulums which are held in their limit positions by springs and locking pins, these pendulums comprising pivots, a release member being mounted by its eyelet and by a fork on these pivots, this release member pushing back, in one of the limit positions of the pendulums, both the retaining pawl and the pawl for displacement out of engagement with respect to a rack for displacement of the magazine.

The process which is the subject of the invention and the form of construction of a device described below are illustrated by the appended drawings:

Figure 1 is a schematic view of the structure of a slide projector;

Figures 2 to 7 are schematic views of two operating cycles, during the successive projection of the first three slides of the store;

Figure 8 is a partial axial section of the magazine and the mechanism ensuring its movement;

FIG. 9 is a partial section passing through the lines AA of FIG. 8.

As shown in Figure 1, the slide projector is made up of two similar optical systems. The left system consists of the projection lens 11, the projection opening 13, the condenser system 130, the mirror 131 and the projection lamp 15. Similarly, the right system is formed by the projection lens projection 12, the projection opening 14, the condensation system 140, the mirror 141 and the common projection lamp 15. The optical axis 110 belongs to the left system and the optical axis 120 to the right system. Entered these two optical axes is arranged a magazine 10, the axis of which is designated by 100. The optical axes 110, 120 and the axis 100 of the magazine 10 are mutually parallel. In Figure 1, there is not shown the mechanism ensuring the movement of the magazine 10, nor the mechanism for individually inserting the slides from the magazine into one of the projection openings 13, 14 and bringing them back into the magazine 10. Likewise, the mechanism which interrupts, in the absence of a slide, the path of the light rays through the projection openings 13 or 14 has not been shown. The latter mechanism is known and produced for example according to German patent No. 1,120,177.

In FIGS. 2 to 7, in order to simplify the description, we have schematically drawn only the magazine 10, the left projection opening 13 and the right projection opening 14. On the other hand, we have shown slides 1 to 7 inside the store boxes. These slides are mounted in frames made according to any of the models already commonly used. With regard to the directions of movement indicated by the arrows in FIGS. 2 to 7, the movement towards the front or introduction into one of the projection openings is always indicated in solid lines, -

[1,519,086] while the arrow indicating the rearward movement or extraction from one of the projection openings is drawn in broken lines. The slide which has been extracted from the magazine is drawn in broken lines in all the figures.

Referring to Figures 1 to 7, the change of views is carried out according to the invention in the following manner. _

In FIG. 1, the magazine 10 is in its basic position, that is to say that the slide 1 of the magazine 10 is two boxes behind the plane of the projection openings 13, 14. When the initial phase of the movement, the magazine 10 moves two boxes of the magazine forward, that is to say in the direction of the arrow V. At the end of this phase, we find the conditions of Figure 2 . Slide 1 is extracted, by a mechanism not shown, from the first box of the magazine 10 in the direction of the arrow L towards the left projection opening 13. After which, the magazine 10 moves from one box to the back in the direction of arrow Z. This situation is that of FIG. 3 in which the slide 1, inserted in the projection opening 13, is projected by the corresponding optical system. The projection opening 14 is empty and the passage of the light rays through this opening is interrupted by any of the mechanisms known per se. The first operating cycle is completed. If the next slide 2 is to be projected, the magazine 10 is first of all moved forward in the direction of the arrow V (see fig. 3) by two more boxes, to take the position indicated in FIG. 4. At this time, the slide 2 is driven in the direction of the arrow P by the mechanism not shown, to be introduced into the right opening 14. The next phase then occurs, namely the displacement of the magazine 10 backwards by a box in the direction of the arrow Z and the slide 1 which is still in the left projection opening 13 is moved in the direction of the arrow M to the box where it was before being extracted therefrom ( see fig. 2). At the end of these operations, we are in the situation in FIG. 5: the left projection opening 13 is empty and the passage of the light rays through this opening is again interrupted, by a known device. Inside the right projection opening 14 is inserted the slide 2 which is then projected, while the slide 1 can again be in its box in the magazine 10. The following cycle is completed.

If another slide is to be projected, the above process is repeated. The magazine 10 is moved forward by two boxes in the direction of the arrow V, to occupy the position shown in FIG. 6. Slide 3 is driven in the direction of arrow L to be introduced into the left projection opening 13; the magazine 10 is moved by a box 5 in the direction of the arrow Z and the slide 2 is taken up in the right projection opening 14, driven in the direction of the arrow R to be replaced in its original box, so that the situation shown in figure 7 is similar to that of figure 5.

The operating cycle described is repeated and it is clear that after being projected, each slide is brought back to the box of the magazine 10 from which it had been taken.

The embodiment of a device according to the invention is illustrated by FIGS. 8 and 9.

The slides 1 to 7 are housed in series in the boxes of the magazine 10 which is placed and fixed against any lateral movement on a carriage 30, which is mounted movably on rails 40 and 50 fixed to a base 80 by means of rail carrier 60 and 70. To prevent accidental lateral movement of the slides 1 to 7 from the magazine 10, barriers 90, 91 are provided fixed to the base 80. Between the barriers 90, 91, at the level of the projection openings 13, 14, there are formed gaps for the passage of the slides 1 to 7 between the magazine 10 and the projection openings 13 and 14, as well as their return to the magazine 10. Below the carriage 30 is disposed a dowel 150 on which the breteRe 160 of a rope 170 is articulated, the other end of which is wound around a drum 180 to which it is fixed, this drum pivoting on a shaft 190 which is fixed to the base 80 by means of a screw 20. The drum 180 contains a spiral spring 21, the inner end of which is fixed to the shaft 190 of the drum 180 and the outer end of which is fixed to the periphery of the drum 180, in the opposite direction from the clockwise, the carriage 30 being attracted by this spring towards its rear position, that is to say its basic position. The carriage 30 is held in the mounting position, against the force exerted by the spiral spring 21, by a retaining pawl 22 which is pivotally mounted on a pivot bolt 23 and which is pushed by a spring 24 into the gripping position with a displacement rack 25 integral with the carriage 30. On the other hand, a rod 26 of a magazine push is rotatably mounted in the base 80, this rod being driven by an electric motor not shown. On the rod 26 of the magazine push is mounted a cam 27 of the magazine push, on the periphery of which rolls a roller 28 of the displacement pawl, this roller 28 being rotatably mounted in a support 29 of the displacement pawl 31, which is pivotally mounted on the base 80 and is attracted towards the cam 27 of the store push by a spring 300. The cam 27 of [1,519,086] -

magazine push has a large projection 68, a small projection 69 and a stop pin 700 which strikes the arm of the retaining pawl 22 during the rotation of the cam 27, momentarily tilting this retaining pawl 22 into engagement with the displacement rack 25. The upper end of the support 29 is provided with the displacement pawl 31, mounted tilting and pushed into engagement with the displacement rack 25 by a spring 32, position where it is held by a pin 33 fixed to the support 29 of the displacement pawl 31 .

On the base 80 are further mounted the left lens 11 and the right lens 12 by means of which the images are projected from the slides placed in the projection openings 13, 14 on the common projection screen which has no not been shown, so that their axes 110 and 120 are practically parallel. In the plane of the projection openings 13, 14 which corresponds to the focal plane of the objectives 11, 12, a left fork 38 and a right fork 39 are mounted by their upper part capable of translation on the guide rod 400 of the forks, this rod 400 being perpendicular to the axes of the objectives 11 and 12 and being fixed to the base 80. The right fork 39 is connected by a fork arm 41 to a right fork lever 56, which pivots by its lower part on a pivot 42 of the fork lever and, moreover, is connected by an articulated piece 43, by a transfer lever 44 and by an articulated piece 45, to a slide 46. This slide slides on guides 47 of the base 80. The slide 46 is provided with pivots 48 on which are mounted rotary rollers 49, one of which follows the periphery of the small cam 50 and the second rolls along the profile of the large cam 51, these two cams being mounted on the rod 52 of a slide pusher, rod which rotates on the base 80 and is connected by toothed wheels 53, 54 to rod 26 of the magazine pusher.

The rollers 49 bear at the same time and in diametrical position on the small cam 50 and the large cam 51 respectively, so that the movement of the slide 46 is closely guided in both directions. The drive mechanism of the left fork 38 corresponds exactly, in the inverted position, to the drive mechanism of the right fork 39 which has just been described.

On the base 80, along the carriage 30, two pivoting pendulums 57 switch between two limit positions where they are held by springs 58 and stop pins 59. The pendulums 57 are connected to an articulated part 600 which has surfaces stop 61 cooperating with a stop 63 fixed to the carriage 30. A release member 67 is mounted by its eyelet 65 and by a fork 66 on the pivots of the rockers 57, this release member 67 pushing, when the rocker 57 is in the rear position, the retaining pawl 22 and the movement pawl 31 , against the antagonistic force of their springs, out of engagement with respect to the displacement rack 25.

The operation of a device according to the invention is as follows. The electric motor not shown drives both the rod 26 and the cam 27 of the magazine push. At each rotation of the cam 27, the support 29 of the displacement pawl 31 is tilted under the effect of the large projection 68 of the cam 27 and this displacement pawl 31 pushes the displacement rack 25 with the carriage 30 and the magazine 10 - against the opposing traction of the spiral spring 21 - by two boxes towards the front, position in which the rack is immobilized by the retaining pawl 22. Once it is released, the support 29 of the displacement pawl 31 returns to its initial position under the effect of the traction of its spring 300. In addition to this movement, at each rotation of the cam 27 of the magazine push, the support 29 of the displacement pawl 31 is still tilted by the small projection 69 of the cam 27, which determines a forward movement of the carriage 30, but only by about one space, so as to release the displacement rack 25 the retaining pawl 22. At the same time the stop pin 700 of the cam 27 bears against the arm of the retaining pawl 22, the latter is expelled from the displacement rack 25, the support 29 of the displacement pawl 31 is released from the cam 27 of the pusher -store, the carriage 30 is brought back a notch towards the rear by the traction of the spiral spring 21, the retaining pawl 22 is released from the stop pin 700 and is pushed by the tension of the spring 24 engaged with the displacement rack 25, the carriage being held in this position.

The rotary movement of the rod 26 of the store pusher is transmitted by the toothed wheels 53, 54 to the rod 52 of the slide pusher and to the two pairs of cams 50, 51 ′ mounted on this rod 52. Under the effect of these cams, the two slides 46 are moved from one of their limit positions in the second. The movement of the slides 46 is transmitted by the transfer levers 44, the fork levers 55, 56 and by the connecting arms 41, 43, 45, both to the left fork 38 and to the right fork 39, which are moved in the same direction as the slides 46 from one of their limit positions in the second, that is to say from the middle of the magazine 10 to the middle of the corresponding projection opening 13, 14 and vice versa; thus, these forks cause the displacement of the slides which they have found in their path towards the projection openings 13, 14 and, in return, towards the store— 5 [1,519,086] sin 10. The forks 38, 39 are maintained in their limit positions by peripheral grooves 34 formed on the guide rod 400. Balls 35, arranged in the holes of the forks 38, 39, penetrate into these grooves 34 under the pressure of springs 36 held by countersunk screws 37.

In the case of the example described, the cam 27 of the magazine pusher performs two rotations and the cams 50, 51 of the slide pusher only one rotation for each operating cycle.

It is, of course, understood that. the embodiment of the invention which has been described above, with reference to the appended drawings, has been given for information only and is in no way limitative and that numerous variants can be made without departing from the scope of this. of the present invention.