US2298097A - Photographic printer mechanism - Google Patents

Description

Oct. 6, 1942. K, POLHEMUS 2,298,097

I PHOTOGRAPHIC PRINTER MECHANISM Filed Aug. 2, 194o 2- Sheets-Sheet 2 INVENT OR.

JOH/V P0 EMA/J ATTORNEY 5 Patented Oct. 6, 1942 UNITED STATES PATENT OFFICE PHOTOGRAPHIC PRINTER MECHANISM John K. Polhemus, Binghamton, N. Y., assignor to General Aniline & Film Corporation, Binghamton, N. Y., a corporation of Delaware I Application August 2, 1940, Serial No. 349,575 (01. 95-13) 3 Claims.

This application deals with a photographic printing apparatusand more particularly with a novel combination latch and electric switch mechanism for such a printer.

Printers are well known in the prior art, which comprise a lamp house, a suitable transparent supporting platen for the material to be printed, and a pressure back for holding said material against the platen. In some of these printers electric switches have been provided which cooperate with the pressure back to illuminate the printing lamps as the back moves into position against the platen. With this type of switch it often happened that the printing 'lights were turned on beforethe back was completely in position.

With the defects of these prior art constructions in view, it is accordingly one object of the present invention to provide a novel switch mechanism for a photographic printing apparatus.

It is a further object to provide a switch which will not be operated until the customary pressure back has been completely moved to its holding position against the supporting platen.

Another object is to provide a combination latching mechanism and switch for the pressure back on such a printer.

A still further object is to provide a latch and switch which will cooperate to illuminate the printing lamps only after the operating arm for the pressure back has been fully depressed and then moved partly away from the platen again.

Further objects and advantages will be apparent from the following specification.

In the drawings, which form a part of this application and in which like reference characters indicate like parts:

Figure 1 is an enlarged sectional view of a combination latch and switch according to the present invention, said latch being in locked position and said switch closed;

Figure 2 is a view similar to Figure 1, but with the latchin releasing position and the switch open;

Figure 3 is an enlarged sectional view on the line 3-3 of Figure 1; and

Figure 4 is a perspective View of a complete printer embodying the constructions shown in the previous figures.

In order that those persons skilled in the art may fully understand the nature and scope of the present invention, I shall now give a concise and detailed description thereof. As shown in Figure 4, I have provided a suitable supporting frame I for the customary lamp house 8. Print- 55 ing lamps 9 are mounted in said lamp house in any desired manner. Above the frame and lamp house is a suitable supporting platen Ill on which the printing material is to be placed. In order to hold said material in printing position against said platen, I have provided the pressure back I I. This pressure back is linked to operating arms I2 by means of the control linkage I3. Arms I2 also carry resilient members I4-for engaging the pressure back II and insuring an even contact against the platen.

Operating arms I2 are pivotally mounted with respect to the platen and are provided with a horizontal handle bar l5 at the front of the apparatus. Pivoted to the handle bar I5 is a latch I6 which is movable between .locking and releasing positions under the influence of release bar IT. The construction of the pressure back, operating arms, and latch is fully described and claimed in the joint application of the present inventor and Bror W. Henrikson, for Pho tographic printing device, executed July 31, 1940, Serial No. 349,577. The particular pressure back mechanism of said application is extremely advantageous in combination with the switching device of the present invention.

As described in the above mentioned application, the latching member I6 is rotatable between the locking position of Figure 1 and the releasing position of Figure 2, by the action of release bar II in cam slot I8 on the latching member. The latch member is further hollowed out at I9 to accommodate the spring 20 which normally urges the release bar, and consequently the latching member, to the locking position of Figure 1. This spring is fastened at one end to the release bar and at the other end to a lug 2I in the latch member. the swingable arms 25 pivoted to the operating arms I2.

It will be apparent from the above mentioned application and from the foregoing description, that movement of the operating arms I2 and handle I5 away from the platen ID will carry the pressure back out of engagement with the platen by reason of the control linkage I3. Similarly, as handle I5 is moved-toward the platen, the back I I will move into platen-engaging position. After the back is completely in contact with the platen at all points, it is still possible to depress the handle I5 and arms I2 for a limited additional distance toward the platen. This additional movement will be permitted by the control linkage I3 and will be opposed by the resilience of spring members I4. As soon as the handle is The release bar I'I itself is carried by suitable circuit.

released, it will tend to undergo a return movement under the action of said spring members. The advantages of this permissible additional movement in connection with my novel switching means will be described below.

The latching member I6 is provided with a latching hook 22, which cooperates with a corresponding locking element 23 on the downwardly.

turned flange 24 of platen Hi. It will be apparent from the drawings that, as the operating arms 12 move toward the platen, the latching hook 22 will come in contact with the top edge of the flange 24. When the operating arms are moved toward the platen for the additional limited distance mentioned above, the hook will ride 'over this portion .of the platen by reason of its particular shape and will, in so doing, rotate the latching member l6 toward its releasing position against the action of spring 20. When the downward movement of arms 12 is complete, spring will restore the latch member and latching hook to their normal position in which the hook 22 will be directly below the corresponding looking element 23 and will be ready to engage said element when the arms [2 and latch l6 move upwardly. The necessary limited upward or return movement is obtained by the action of springs 14 previously mentioned.

According to the present invention, I have mounted a switch-actuating member 26 in a position to be engaged by the locking book 22 as said hook moves upwardly into latching position. This member 26 is pivoted at 21 to a bracket 28 fastened to the platen or frame. One end 29 of member 26 projects forwardly, as shown in Fig ures l and 2, and is free to move vertically in the path of locking hook 22 and adjacent the locking element or surface 23. Thus, as the hook 22 moves upwardly against surface 23, it will engage the end 29 of member and rotate said member in a clockwise direction in the drawin s.

The opposite end 30 of member 26 is provided with a switch-engaging screw SI and locking nut 32 and also with a limiting screw 33 and additional locking'nut 34. The function of these parts will be described in a moment.

In the preferred form of my invention, I have mounted a mercury switch 35 '(having the usual lead wires 36) on a rotatable lever 31 by means of a suitable bracket 38 (Figure 3). Said lever 31 is pivoted at 39 to a flange All on the platensupporting frame. Said lever 31 is provided at its other end with a horizontally turned flange or lug M, which is positioned just below the screw 3| on actuating member 26.

It will be apparent from the description just described that the clockwise movement of lever 26 will cause the lower end of screw 3| to engage the pivoted lever 37 and move said lever from the dotted line position of Figure 3 to the heavy line position in said figure. The mercury switch 35 is so mounted that this rotation from the dotted line to the heavy line position will make the necessary electrical contact between the terminals of lead wires 35 and thus illuminate the printing lamps 9, connected to the switch by a The limiting screw 33 with its locking nut 3 will engage the underside of platen ID, as shown in Figure 2, to limit the counter-clockwise rotation of member 25. Thus the open position of switch 35 and lever 37 will alsobe determined.

Since the end 29 of actuating member 25 is only engaged by the locking hook 22 of latch member l5, after said latch member and the operating arms I2 have been depressed the additional distance previously mentioned, it is obvious that switch 35 cannot be actuated until after the pressure back I I has reached its final position against the platen H]. In other words, the pressure back may be engaged completely against the printing material and platen and all necessary adjustments made before the arms l2 are depressed further, in order to latch the pressure back in place and actuate the switch. This actuation of the lighting switch on the up-stroke or return movement of the operating arms and handle is an essential feature of the present invention and gives rise to the above mentioned advantages over the previously known forms of construction. Since this particular actuation of the switch after the pressure back is completely in position, may be achieved by equivalent forms of construction readily apparent to those persons skilled in the art, it is not my intention to limit this invention to the precise construction disclosed in the drawings. The invention should be interpreted to include similar and equivalent arrangements within the spirit of the attached claims.

Now therefore I claim:

1. In a printing apparatus having a lamp house with printing lamps therein and a supporting platen thereon, the combination of a pressure back, an operating arm movably mounted with respect to said platen, means connecting said arm and back for movement of the latter into and out of engagement with the platen by operation of said arm, said arm being movable toward the platen for a limited additional distance after said back is in its final platen-engaging position, resilient means opposing said additional movement, a latch member pivoted on said arm for movement between locking and releasing positions, a corresponding locking element on said platen engaged by said latch member only when the latter is in looking position and said arm has been depressed said additional distance and released for partial return movement under the influence of said resilient means, and a switch operated by said latch to illuminate said lamps only on said return movement of the arm and latch to locking position.

2. In a printing apparatus having a lamp house with printing lamps therein and a supporting platen thereon, the combination of a pressure back, an operating arm movably mounted with respect to said platen, means connecting said arm and back for movement of the latter into and out of engagement with the platen by operation of said arm, said arm being movable toward the platen for a limited additional distance after said back is in its final platen-engaging position, resilient means'opposing said additional movement, a latch member pivoted on said arm for movement between locking and releasing positions, a corresponding locking element on said platen engaged by said latch member only when the latter is in looking position and said arm has been depressed said additional distance and released for partial return movement under the influence of said resilient means, a switch for said lamps, and a movable switch actuating member mounted near said locking element and operated by said latch to illuminate said lamps only on said return movement of the arm and latch to locking position.

3. In a printing apparatus having a lamp house with printing lamps therein and a supporting platen thereon, the combination of a pressure back, an operating arm movably mounted with corresponding locking element on said platen en- 10 gaged by said latch member only when the latter is in looking position and said arm has been depressed said additional'distance and released for partial return movement under the influence of said resilient means, a pivotally mounted mercury switch operated by said latch 'to illuminate said lamps only on said return movement of the arm and latch to locking position.

JOHN K. POLHEll/IU S.

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