DE1275353C2 - GLASSLESS NEGATIVE HOLDER FOR PHOTOGRAPHIC COPY AND ENLARGEMENT DEVICES, IN PARTICULAR ROLL COPY DEVICES - Google Patents

Description

35

The invention relates to a glassless negative holder for photographic copiers and enlargers, with interchangeable guide and pressure plates by means of dowel pins and dowel holes Can be connected to each other in pairs and magnetisehe means these plate pairs in their working position lock releasably on a carrier plate.

In the case of glassless negative holders for copying or enlarging purposes, it is known to have a guide plate and to connect a pressure plate by dowel pins and dowel holes. Controlling the The pressure plate takes place via an elaborate lever mechanism.

It is also known to arrange permanent magnets in the guide plate of a negative holder, which the Hold the pivoted pressure plate in the working position. An interchangeability of the guide plate for the purpose of transitioning to another negative format is not given with this arrangement. Through the hinged pressure plate, it is also not possible to use such a negative carrier in conjunction with Use roller copiers if the negative film to be copied is in both the transport direction the roll paper as well as transversely to its transport direction through the negative stage, namely by z. B. once the negative format 24 χ 36 mm and another time a negative format 18 χ 24 mm is to be copied. In this case, all four sides of the negative stage must be freely accessible be.

Furthermore, a glassless negative holder is known at the pressure plate and guide plate are connected by a hinge and on the Carrier plate four pot magnets are arranged, which protrude through recesses in the guide plate and so act on the pressure plate and hold it.

The guide plate of the negative holder is held by pins. The pressure magnets are only during the exposure time switched on When the magnets are switched off, the pressure plate is through two continuously acting springs slightly raised.

The present invention is based on the object of a glassless negative holder for photographic Copiers and enlargers - especially roller copiers - to create a film guide in two directions and its guide plate and pressure plate can be locked by magnetic means meant to be.

According to the invention this object is achieved in that in a glassless negative holder the initially mentioned type in the carrier plate four permanent magnets are arranged in pairs crosswise that the one pair on the guide plate and the other pair in a known manner through recesses in the Guide plate acts on the pressure plate

With this arrangement, both the replaceable guide plate and the replaceable Pressure plate independent of each other due to the permanent magnets in the working position held.

In order to keep the operator's hands free for inserting or continuing the negative carrier, in Embodiment of the inventive concept in the support plate thrust bolts mounted, which the guide plate act penetratingly on the pressure plate and at the same time by means of a foot pedal via a Bowden cable are actuatable.

A particularly expedient embodiment finally provides that the Bowden cable has a lever linkage with two axles rotatably mounted in the carrier plate, the two machined Have surfaces on which the pressure bolts are supported.

The invention is shown in the drawing using an exemplary embodiment. It shows

F i g. 1 a negative holder in an expanded Representation, with the guide and pressure plate for a negative format 24 χ 36 mm are designed.

2 shows the actuation mechanism for the pressure bolts controlling the pressure plate,

F i g 3 the formation of the guide and pressure plate for copying a negative size 18 χ 24 mm.

A carrier plate 1 can be fixedly connected to a roll copier in a manner not shown. She knows an opening 2 for the illumination beam path, which is kept larger than the largest to be copied Negative format A converging lens 3 is located in the carrier plate 1 as part of the lighting system as well as two lenses 4 and 5.

To the side of the boundary edges of the opening 2, permanent magnets 6a and 6 £> and 7a and 7b are mounted crosswise. A recess 8 is used to receive a guide plate 9. The latter has a cutout 10 which corresponds to the size of the negative format to be copied. Four conically extending dowel pins 11 are attached to the guide plate 9, the spacing of which corresponds to the width of the negative film 12. The guide plate 9 has two recesses 13 at the level of the permanent magnets 7a and 7b

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Pressure plate 14 has a cutout 15 which is kept somewhat larger than the cutout 10 located on the guide plate 9.

Four alignment holes 16 are used to receive the alignment pins 11. Two angled tabs 17 allow in connection with openings 18 a comfortable Handling of the pressure plate 14 when replacing. Two slots 19 incorporated in the guide plate 9 are used in conjunction with in the pressure plate 14 incorporated slots 20 for reading the characteristics attached to the edge of the film. In the carrier plate 1 four pressure bolts 21 are supported - they are supported on two also rotatable in the carrier plate 1 stored axles 22,23 by means of these Surfaces 24 from. Lever arms 25 and 26 are fastened to the two axes 22, 23 by means of a coupling 27 are connected. A double-armed lever 28 is by means of a stub axle 29 is mounted on the carrier plate 1. A Bowden cable 30 engages on his lower arm, the is operated by a foot pedal 31. The upper arm of the lever 28 is via a coupling 32 with the Lever arm 25 articulated.

When the foot pedal 31 is pressed, the axes 22, 23 are rotated, with the aid of the Surfaces 24 the pressure pins 21 are raised through holes 33 arranged in the guide plate 9 butt penetrating against the pressure plate 14 and thus lift it off the guide plate, so that now the film 12 can be moved. When the foot pedal 31 is released, the effect is achieved the return spring 34, the printed sheets 21 back into their Starting position.

When changing to another format, the guide plate 9 and the pressure plate 14 are against those exchanged with the desired cutouts. While FIG. 1 shows a negative holder, the is designed for the format 24 36 mm is shown in FIG. 3 the corresponding training in the format 18 χ 24 mm. In this case, the negative film 12 'is rotated by 90 ° over the carrier plate 1 between the Guide plate 9 'and the pressure plate 14' out.

For this purpose 2 sheets of drawings

Claims (3)

Patent claims: 1. Glassless negative holder for photographic copiers and enlargers, especially s roll copiers, in which the interchangeable guide and pressure plates can be connected to each other in pairs by dowel pins and dowel holes and magnetic means releasably lock these pairs of tarpaulins in their working position on a carrier plate, characterized in that in the Carrier plate (1) four permanent magnets (6a; 66; 7a; Tb) are arranged in pairs crosswise that one pair (6a; 6b) on the guide plate (9) and the other pair (7a; Tb) in per se known Acts through recesses (13) in the guide plate (9) on the pressure plate (14) 2. Glassless negative holder according to claim 1, characterized by in the carrier plate (1) mounted pressure bolts that penetrate the guide plate (9) and act on the pressure plate (14), which can be operated simultaneously by means of a foot pedal (31) via a Bowden cable (30). 3. Glassless negative holder according to claims 1 and 2, characterized in that the Bowden cable (30) via a lever linkage (25; 26; 27 and 28) with two rotatably mounted in the carrier plate (1) Axes (22; 23) is geared connected, which have two machined surfaces (24) on which support the pressure bolts (21).