US2391987A - Contact printing frame - Google Patents

Description

A. L. LEE

" jar; 1, 1946.

Filed May 3, 1944 IN VEN TOR. v A/fredl. Lee. BY sxw ATTURNE Y5.

Patented Jan. 1, 1946 CONTACT PRINTING FRAME Alfred L. Lee, Binghamton, N. Y., assignor to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware Application May 3, 1944, Serial No. 533,852

2 Claims.

This application pertains to contact printing frames such as are used for printing photographic negatives. The invention is more particularly concerned with the construction of such a frame from materials not involving metals and not involving the use of rivets, bolts, nails, screws, or other connecting means made from metals.

The printing frame itself is especially devised so as to make possible its production from wood, plastics, or other non-metallic materials. Its construction also makes possible the interconnection of the various parts by means other than metallic connecting elements of the usual type. The wooden parts are jointed according to any of the well known practices, and glue or other adhesive is employed in assembling and building up the frame. In addition to the use of wood or plastic materials, the frame includes a glass window, a leather or other flexible hinge, and felt or sponge rubber pads for the platen. Any suitable kind of wood may be used, and in certain instances plywood may be found advantageous.

The platen is maintained in position by an exceedingly simple but effective locking means which includes notched wedges and cross pieces or bars made from hard wood of a resilient nature or from other material having similar characteristics. The invention will be more specifically described by reference to the accompanying figures of drawing in which a preferred embodiment of the same is illustrated, and wherein:

Fig. 1 is an isometric view of a printing frame constructed according to the invention.

Fig. 2 is a sectional view through the frame illustrated in.Fig. 1 and taken just to one side of the center line of that frame.

Now referring to the figures of drawing, the printing frame is shown having one-half of the platen locked in position and the other half raised or swung upwardly. The basic framework consists of side pieces 10 and H and the end pieces l2 and I 3, these being connected or interlocked by any one of the usual joints employed in woodwork of this type. These frame members are rooved at their inner sides for the insertion of the glass plate or window 14. The side pieces l and I I are grooved throughout their entire length as at [5, but these grooves are blocked off at the ends by the stops [6 and i7 and at the center of the frame by a longer block l8. The construction at either side is the same.

The glass window 14 is set at about the center of the thickness of the end pieces l2 and I3, thus leaving a rectangular space within which the platen may fit. This platen is comprised of two parts l9 and 20 which are preferably equal in size, although not necessarily so. The two parts are connected by a leather hinge 2| which is glued to both the parts l9 and 20 and which allows onehalf of the platen to be raised independently of the other. Similarly, the platen is clamped or locked in place by inserting one-half within the rectangular space provided for it, locking it in position, then pressing down the other half and securing it in a similar manner. That is common practice in the use of such printing frames and needs no further description here. Each part of the platen has a felt pad 22 glued or otherwise attached at its lower surface. Instead of using felt, other fabrics 0r sponge rubber may be employed, and it is the function of these pads to press the negative and paper firmly against the glass window as the platen is locked in position.

For locking the opposite parts of the platen, bars 23 and 24 of hard or other wood of resilient nature are held within the slots l5 left between the stops I6 and I! and the elongated wooden block l8. The depth and length of the slots is such that the bars cannot be removed from them, once they have been assembled. Each platen is provided with a combined wedge 25, notch 25, and handle or grip 21. The incline of the wedge 25 and the depth of notch 26 are so proportioned that when a bar 23 or '24 is forced upwardly along the inclined surface of the wedge and is allowed to snap into notch 26, it will be flexed or tensioned sufiiciently to press the platen down against the paper and negative or against the glass window, with a force sufficient to hold the paper and negative firmly in position and to flatten any wrinkles or bulges in them. The grip or handle 2T serves to place the platen in position, to raise the halves of the platen, or for manipulating it in any other manner. These wedges are afiixed to the platen by gluing, but in the event the elements are made of plastic, either plate [9 or 20 and its wedge may be cast as one piece. The same applies to the remaining parts of the printing frame, except that in the event the frame work itself is made of plastic, provision must be made for setting the glass window in place and locking it.

In Fig. 2 a negative 28 and contact printing paper 29 have been placed in position against the glass window, one half of the platen has been locked in position against them and the other half is in position to be lowered and looked, after which, of course, the frame is inverted and the I printing paper subjected to light for recording the negative image on the paper, that being common practice and well known to those skilled in this art. The frame illustrated is of simplest type, but if desired, added features of refinement may be employed, for example, masking blades may be used and their construction may follow any of the well known practices. While it is unnecessary to use metallic parts, it is not intended to limit the invention by precluding use of metal, nor are the claims to be so construed unless so stated;

While the invention has been described in more or less specific terms and by reference to only one embodiment of the same, modifications will read ily suggest themselves to those skilled in the art, and it is intended that such 'rnodifications b iii eluded within the broader language ofthede s'cription and within the terms of the appended claims.

I claim: p M

1. Means for contact printing including in comb time frame, a window set in'saidframe, a'pla 'n at the back of s dfrain adapted to rea; negative and-pr n'g'mate ial m position against the wma'qw, 's'aidplaten e ng hinged and thereby dividedinto 'tWoparts'jswts attire sides be deflect ed to develop a platehiietaining tension.

combination a frame, a window set in said frame,

a platen at the back of said frame adapted to retain a neg'ative and printing material in position againstthe window, said platen being hinged 'alndlthereby divided into two parts, slots at the sides of theiranre and outside the edges of the platen, wedges on the platen formed with an inclined surface, a notch and an extension by which the platen is gripped and handled, cross bars having their ends held by and slidable With in the s ets and l p-meincune surracs 6f "the edges an intb'th notches, thefcbiist'ruc'tibn be" I that when held Within th ii'citchs, then s L1 LEE.

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