US2375491A - Press, particularly for photographic purposes - Google Patents

Description

y 1945- i A. w. PERRY 2,375,491

PRESS, PARTICULARLY FOR PHOTOGRAPHIC PURPOSES FiledDec. 18, 1943 2 Sheets-Sheet Andrew W Penliven for A I Ma /M41911- M y 8, 1945- A. w. PERRY PRESS, PARTICULARLY FOR PHOTOGRAPHIC PURPOSES Filed Dec. 18, 1943 2 Sheets-Sheet 2 u %m w @w wi v m; W WW1 M 0. M4

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Patented May 8, 1945 PRESS, PARTICULARLY FOR PHOTO- 1 GRAPHIC PURPOSES Andrew William Perry, Harrow, England, as-

signor to Pictorial Machinery Limited, London, England, a British company Application December 18, 1943, Serial No. 514,753 In Great Britain November 24, 1942 3 Claims.

This invention relates to presses, particularly in the form of contact printing frames for photographic purposes, of the type (hereinafter referred to as the type described) comprising two press members having flat faces of extended form, whereof one is movable bodily towards and away from the second, and pressure means that is operatively connected with the second press member and is arranged to force the movable press member towards the second press member.

It is an object of the present invention to provide an improved press of the type described having pressure means so constructed and arranged as to exert on sheet material arranged between the two press members, a uniform pressure in a direction normal to the sheet material.

According to the invention there is provided a press of the type described, wherein the pressure means comprises a support that is adapted to be fixed in relation to the second press memher, a plurality of pressure members that are rotatably mounted in spaced relation on the sup port, and are arranged to impart pressure to the movable press member at a plurality of positions spaced apart one from another for moving it towards the second press member, and actuating means for actuating the pressure members in unison. Owing to the pressure being applied to the movable press member at a number of situa tions on its outer surface, a uniform pressure is applied to the sheet material over its entire area.

The pressure members are preferably mounted to rotate in relation to their support.

Such rotary pressure members may be rotat able about axes that lie transversely of the direction of movement of the movable press member.

Conveniently, a plurality of spindles are journalled in bearings on the support, each of which spindles carries two pressure members arranged in spaced relation along it, for example at its ends, and an actuating member operatively connected to the spindles is arranged to rotate them in unison.

In a preferred constructioma plurality of pairs of brackets are mounted in spaced relation on the'movable pressmember, which brackets make sliding engagement with the support, and the pressure members are arranged to coact with, and exert their thrust through the brackets.

Other features of the invention relating to the mounting of the movable press member on the hinged support will be described hereinafter.

One embodiment of the invention is diagrammatically illustrated by way of example in the accompanying drawings, wherein- Figure 1 is a perspective view showing one form of press constituting a printing frame according to the invention,

Figure 2 is a side elevation thereof,

Figure 3 is a front end elevation,

Like reference characters designate like parts in all the views.

Referring to the drawings, one method of carrying the invention into practice will now be described by way of example, and not by way of limitation, with reference to a pressure-contact printing frame used for photographic purposes. A box it for containing a source of light, e. g., one or more electric lamps, not shown, has at the top thereof a sheet of transparent material I2, preferably glass, constituting a fixed press memher. A movable press member l4 constituted by a slab of wood having a sheet of soft material [6, e. g., felt, at its under. side is mounted, as described hereinafter, so as to swing from a vertical inoperative position, in which it permits a photographic negative to be placed on the glass sheet 12, and a sheet of light sensitive paper to be placed on the negative, to an operative horizontal position in which it lies adjacent to the top of the paper sheet.

In order to press the movable press member towards the glass plate, pressure means is provided comprising four L-shaped brackets 2!, 22, 23, 24, fixed by their horizontal limbs to the top of the woodslab I4. These brackets are arranged in two pairs 2!, 22 and 23, 24 arranged spaced apart at opposite sides of the centre of the slab I4, and each vertical limb has in it a vertical slot 26. A support designated generally 28, in the form of an oblong metal frame having a front end member 33, two side members 3|, 32, and a counterweight 33 at its rear end, has pins 34 at its opposite sides that take each into a slot 26 in the brackets to permit vertical movement of the support. The rear end portion of this oblong frame 28 is hinged at 35 to the rear side of the box to which the slab of wood is hinged, and its opposite end is provided with readily detachable means for securing it to the front side 38 of the box when pressure is to be applied. As illustrated, the detachable means is constituted by a pivoted fastener 40 in the form of a loop that is carried b the front end member 3!) of the frame 2.8 and is arranged to engage a pin 42 fixed on the front of the box It. This oblong frame 28 carries four bearing brackets 44, 45, 46, 41, one adjacent tension springs 68, 69, 10, H is two-fold:

to each slotted limb of the L-shaped brackets 2|, 22, 23, 24, and two parallel spindles 48, '50 are journalled respectively in the bearing brackets 44, 45 and the bearing brackets 46, 41. These spindles 48, 50 carry each two press members 52, 54 and 56, 58, respectively in the form of eccentrics, cams or the like, one on each end, each of which press members lies at the top of one of the slotted limbs of the L-shaped brackets 2|, 22, 23, 24. Actuating means for operating these eccentrics, or cams, comprises two arms 60,132, fixed at one end respectively to the middle of the spindles 48 and 50, the other ends of which arms pivo-tally carry an actuating member 64 in the form of a T-shaped rod, whereof thecross-piece 66 constitutes a hand-grip. Four tension coil springs 68, 69, 10, TI are provided, one adjacent to each bearing bracket 44, 45, 46, '41; the lower end of each of these springs is anchored to the horizontal limb of the adjacent L-shaped brackets 2|, 22, 23, "24, and itsupper end is anchored to a pin 12 on the adjacent bearing bracket. The wood slab I4 is thus resiliently mounted on its supporting hinged frame 28 and is arranged to float in relation thereto. The function of the (1) to maintain contact between the top pressure faces of the slotted limbs of the L-shaped brackets and the eccentrics thereon, thereby steadying the floating movable press member constituted by the wood slab, and (2) to keep this press member from contact with the lower fixed glass before the pressure means is actuated by the actuating member 64, as it is important that the top press member shall not touch the lower fixed press 1 member when being swung down into its operative position.

When pressure is to be applied to the sheet material in the contact printing frame, and the oblong frame of the pressure-imparting means has been fastened in its operative position with the movable press member situated just above the sheet material, it is only necessary manually to pull the actuating member '64, rotate the two spindles 4B, 50 and their eccentrics or cams in unison, whereby pressure is imparted by them through the vertical slotted limbs of the L-shaped brackets to the slab of wood, which is thereby moved bodily parallel to itself and pressed uniformly against the sheet material on the glass below it. In order to releasethe printing frame for removal of thesheet material, it is only necessary to move the actuating member 64 in the .opposite direction. release the fastening means 40 of the oblong metal frame 28 and swing the latter with the movable press member into a vertical position.

Various modifications may be made in the details of construction described above without departing from the invention. For example, the pressure means may comprise more than four brackets 2 I, 22, 23, 24 fixed to the top of the wood slab to give pressure points at from 3 in. to 24 in. centres or more as required. Similarly, the oblong metal frame 28 may carry more than four bearing brackets 44, 45, 46, 41 and there maybe more than two parallel spindles 48, 50 journalled in them. Again, there may bemore than four of said tension coil springs 68, 69, 10, H. Further,

the metal oblong frame 28 may carry two feet I4 at or near its front end for bearing on the top of the box It). Also, in some cases, the transparent sheet of a printing frame may constitute the movable press member, in which case the fixed press member will be constituted by opaque mate rial, e. g., wood.

I claim:

1. A press comprising two press members having fiat faces of extended form whereof one is movable bodily towards and away from the second, and pressure means that is operatively connected with the second press member and is arranged to force the movable press member towards the second press member, which pressure means comprises a support that is adapted to be fixed in relation to the second press member, a plurality of pairs of brackets mounted in spaced relation on the movable press member adjacent to the support, a plurality of rotary eccentric pres-- sure members arranged in pairs, one pair allotted to each pair of brackets, for imparting pressure through the brackets to the movable press memher, and actuating means for actuating the 'pres sure members in unison.

2. A press comprising two press members having flat faces of extended form, whereof one is slot mounted in spaced relation on the movable press member, a plurality of pressure members, oneallotted to each bracket, for imparting pressure to the movable press member, actuating means for actuating the pressure members in unison, which support has a plurality of fins extending each into a slot in a bracket, and a plurality of springs mounted in spaced relation on the support for resiliently supporting the movable press member.

3. A press comprising two press members having fiat faces of extended form, whereof one is movable bodily towards and away from the second, and pressure means that is operatively connected with the second press member and is arranged to force the movable press member towards the second press member, which pressure means comprises a support that is adapted to be fixed in relation to the second press member, a plurality of brackets each having a Vertical guide slot mounted in spaced relation on the movable press member, a plurality of spindles journalled on the support, each of which spindles carries two pressure members in the form of eccentrics arranged in spaced relation along it, and allotted each to one of said brackets, a manual actuating member that is operatively connected to the spindles and is arranged to rotate them in unison. which support has a plurality of pins extending each into a slot in a bracket, and a plurality of springs mounted on the support, one adjacent to each bracket, for resiliently supporting the movable press member.

ANDREW WILLIAM PERRY.

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