DE2163278C3 - Photocopier with vacuum copier frame - Google Patents

Description

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The invention relates to a photocopying machine according to the preamble of claim 1.

Such a photocopying machine is known from British patent specification 8 67 201. With this well-known Machine are two vacuum copying frames with their backs placed against each other and with the help of one Lever mechanism can be swiveled through 180 °, so that the front is always one of the two vacuum copying frames facing a light source. It is impossible that both vacuum copier frames at the same time to be exposed. The exposure time is determined with the help of a shutter placed between the light source and the copy frame is arranged and controlled by a timer. The two vacuum copier frames are connected to a vacuum pump via respective manually operated valves.

The older German patent 20 60 827 is a contact copier for simultaneous double-sided Proposed exposure of printed circuit boards in which two copier frames are also coupled to one another are, so that one of the two copy frames in the preparation station and the other in the Exposure station is. The two copy frames can be slid one above the other on separate tracks guided.

The object of the invention is to provide a photocopier

60 ne of the type specified above so that on the one hand a simple structure and on the other hand a more flexible use with convenient operation result.

According to the invention, this object is achieved by the features in the characterizing part of the patent claim 1 solved.

Because the individual vacuum copying frames are arranged next to one another and independently of one another can be moved, the use of the machine is more flexible, as it is possible to have several Bring copying frames into the exposure station simultaneously or independently. The exposure time is determined by the dwell time of the vacuum copying frame in the exposure station, so that on the one hand a separate closure becomes superfluous and on the other hand in connection with the bias After the exposure time has elapsed, the vacuum copier frames automatically return to the preparation station is achieved. As in the case of several vacuum copying frames that can be exposed independently of one another Many shutters would have to be provided, means exposure time control by control the dwell time a considerable simplification of the machine structure.

Can station the bias of the vacuum frame in the preparation ^r in different ways by spring bias can be achieved by inclined guide tracks etc.. In an advantageous embodiment of the invention it is provided that the individual vacuum copying frames are connected to a counterweight by a rope guided over a pulley in order to achieve this prestress.

Another development of the invention provides that to simplify operation in the automatic Return of the vacuum copier frame whose connection with a vacuum source is disconnected. this expediently takes place with the help of valves in the preparation station, for example by a mechanical Stop and interrupt the connection to the vacuum source. As soon as the Vacuum copying frames leave the preparation station when moving into the exposure station, the valves are opened automatically so that the copy is held in place by vacuum.

The invention is hereinafter attached to an exemplary embodiment with reference to the schematic Drawings explained in more detail. It shows

F i g. 1 is a plan view of the photocopying machine;

2 shows a plan view of a copying frame on an enlarged scale,

Fig. 3 is a sectional view along the line 1II-III in Fig. 2, and

F i g. 4 shows a vertical section through the longitudinal axis of the machine.

The copier shown has a housing 10 which contains a number of fluorescent lamps 11, which are housed under a hood 12, and into which four vacuum copier frames 13 can be pushed individually by moving them by hand on horizontal guides 14 from a preparation station A. outside of the housing into an exposure station B , in which the copy frames are located under the lamps. Each copy frame 13 is attached to a rope 15 which runs over a pulley 16 and carries a weight 17 which normally holds the copy frame in the preparation station.

Each copy frame has, as in Fig. 2 and 3

shown, a base plate 18 resting on the guides J * slides, furthermore a thin, transparent, flexible one Lid 19, which is hinged to the base plate with the help of two clips 20, and a rubber pad 21, which is arranged between the base plate and the cover 5 and fastened to the base plate 18. That Original to be copied can be the cover; then when joining the In the frame for copying, a light-sensitive copy sheet is placed between the cover and the base. If a ι ο own ceiling! is used, the original and the copy sheet are stacked between the Place the pad and the lid. The copy material 23 is on the base with the help of alignment pins 22, which normally protrude through holes in the pad 21 upwards, brought into the correct position.

A sealing strip 24 made of rubber on the base plate encloses the base 21 on all sides and is separated from the latter by a suction channel 25 Hose 28 is connected to a vacuum container 29. The valve contains a plunger which is biased into the open position of the valve by a spring and which is seated on a push rod 30 which protrudes from the valve. When the copier frame is in the preparation station A , the push rod 30 rests against a fixed stop 31 and the valve is kept closed. However, as soon as the frame is pushed from the preparation station to the housing, the push rod 30 is released from the stop 31 and the spring opens the valve, so that negative pressure is applied to the suction line 26, whereby the cover 19 is pressed against the copy material 23. The negative pressure is also applied from the suction line 26 through holes 32 to the lower ends of the adjusting pins 22 in order to pull them downward. The base plate 18 has an opening 33 in the middle, which is open to the environment under the middle of the rubber pad 21. The negative pressure in the zone between the cover 19 and the base 21 both presses the cover down onto the copy material and pushes the center of the base up to the copy material. The negative pressure is supplied by continuously operating pumps (not shown), which are shown in FIG the vacuum container 29 maintain a negative pressure.

While the copy frame 13 advances into the housing, it operates a switch, not shown, which starts a timer 34 which can be set manually to the desired exposure time can. Separate, individually adjustable time switches are provided for the copy frames. When the timer is started, a solenoid is energized. The coil 35 of the solenoid is with the housing 10 connected and cooperates with a core 35 which is attached to the copy frame 13. The core enters the spool, when the copy frame is under the lamps 11, around the copy frame in its Position under the lamps to be held as long as the timer is running After the set time has elapsed Exposure time, the solenoid is de-energized, the weight 17 brings the copy frame into the preparation station back and the valve 27 closes and thus separates the negative pressure from the copier frame. That exposed material can now be removed from the frame and the frame can be used for the next Exposure to be prepared.

As an alternative to the construction described above, the core of the solenoid can be in its coil be arranged and act as a latch when the solenoid is energized to the frame in the Hold the exposure station. The counterweight can be omitted if the guides 14 are inclined arranged so that they rise towards the exposure station. The lamps 11 are permanently switched on, when the machine is in use. In order to get even exposure, the lamps are located at the inlet end of the hood 12 closer to the copy material than at the other end.

In the example shown, the alignment pins are used 22 as stops for the edges of the copy material. Alternatively, however, you can also use Enter alignment holes that have previously been punched in the material. Conveniently, everyone has Copy frame its own vacuum pump and vacuum vessel. The pad 21 and the Sealing strips 24 can have cylindrical projections on their underside, which are inserted into drilled holes in the Base plate 18 fit. The timers 34 are mounted so that they are convenient for the operator are visible. Each timer can have a mark to indicate how much of the set exposure time has already passed

The operator can of course also expose more than one copy frame at the same time.

For this purpose 2 sheets of drawings

Claims (4)

Patent claims: 1. Photocopier with a housing containing a light source, with several flat vacuum copying frames which are movably guided between a preparation station and an exposure station under the light source, and with a timer for controlling the exposure time, characterized in that the vacuum copying frame (13) is arranged side by side are and can be moved independently of one another to the exposure station (B) , and that in each case a magnetic retaining device (35, 36) controlled by the timer is provided which, for the duration of the exposure time, moves the vacuum copying frames against one of the vacuum copying frames in the direction of the preparation station (A) exerted pretensioning force in the Beiich processing station 2. Photocopying machine according to claim 1, characterized in that each vacuum copying frame (13) is connected by a rope (15) guided over a pulley (16) to a counterweight (17) which removes the vacuum copying frame from the exposure station (B) 'm the Preparation station f / ψdraws. 3. Photocopying machine according to one of the preceding claims, characterized in that the Retaining device (35, 36) for each vacuum copying frame (13) has its own solenoid (35) which is controlled by a respective independently adjustable timer (34). 4. Photocopier according to one of the preceding claims, characterized in that each vacuum copying frame (13) in the exposure station (B) via a hose (28) and separate valve (27) with a vacuum source (29) is in communication and that the valve is at The vacuum copying frame in the preparation station (A) can be closed automatically.