US2170622A

US2170622A - Suction printing frame

Info

Publication number: US2170622A
Application number: US159255A
Authority: US
Inventors: Sussin Max
Original assignee: ROBERT R ROBERTSON
Current assignee: ROBERT R ROBERTSON
Priority date: 1937-08-16
Filing date: 1937-08-16
Publication date: 1939-08-22
Anticipated expiration: 1956-08-22

Description

Aug. 22, 1939. M SUSSIN sUcTIoN PRINTING FRAME 4 Sheets-Sheen*l 2 Filed Aug. J6, 1937 Aug. 22, M 5U5S|N 2,170,622

SUCTION PRINTING FRAME Filed Aug. 16, 19157 4 Sheets-Sheet 3 Aug- 22, 1939- M. susslN SUCTION PRINTING FRAME Filed Aug. 16, 1937 4 Sheets-Sheet 4 7'0 GLAN/FET r 0 M n 4 m fede/@n Lm z, sym;

Patented Aug. 22, 1939 UNITED STATES iDATENT OFFiCh Robertson, Application August 16,

16 Claims.

This invention relates to exposure frames for photographic apparatus which said frames have certain of their functions imparted by power actuated means; for instance, means actuated by displacement of a fluid medium, preferably air, in a manner to develop vacuum to which means developing the functions of such frames will respond.

One object of the present invention is to provide improved .means through which to employ air pressure in performing the known expedient of pneumatically pressing against a surface of the exposure frame, the nlm-like sheet that has to be accurately held in position during the exposure process, for instance, by the use of a socalled blanket which backs up the sheet and beneath which the air is exhausted in order to permit atmospheric pressure to act against the outside surface of the blanket; the improved means being such that the vacuum. is maintained, not through communication with a vacuum tank or other large capacity air exhausting means, but through low capacity, directly applied, air displacing means which will act immediately from time to time as the vacuum is needed, and under such power control as will make it wholly responsive to the need, or cause it to be automatically thrown on and off as the vacuum falls belenT or rises to a predetermined order. To this end, one feature of the invention has to do with the establishment of air-exhausting communication with the space intermediate the glass of the printing frame and the iiexible septum or wall commonly referred to as the blanket, and with a power driven air displacing pump whose energizing power is released to the displacer or shut off therefrom by a vacuum control swtch that is responsive to the vacuum being naintained. The eifect of this procedure is to develop a vacuum of a predetermined order through means of a gauge-controlled air dispiacer and cause the blanket to safely press the sheet material against the glazing and hold the air displacer in readiness for restoring any lost vacuum 'that may result through leakage or other impairment and thereby insure against any damaging interruption to the work that might otherwise occur.

Another object is to employ the pneumatic principle for moving the printing frame from loading position to exposure position as well as for pressing the sheet against a surface of the frame and so correlating these two pneumatic iunctions that the printing frame must always be closed and sheet material must be pressed Chicago, Ill.

1937, Serial No. 159,255 (C1. -76) firmly into proper position before the frame can be moved toward exposure position. To this end, another feature of the invention resides in a vacuum actuated motor appropriately connected with a movable printing frame and subjected to the same vacuum influence as that which controls the blanket; the vacuum for both functions being generated by the air displacer at each printing operation so that the procedure is to iirst necessitate hermetic closure of and gripping the sheet within the printing frame, and generating the necessary vacuum therein and thereby creating the backing against which the vacuum motor must draw in developing the further vacuum necessary to actuate said motor; means being provided for holding the vacuum pending the exposure position; then releasing the vacuum as the means of reversing movement of the motor and finally relieving suction on the blanket as the frame returns to loading position. As in the case of the pressure of the blanket against the glazing induced by evacuation of the space intermediate these two confines, the vacuum which enables the motor to hold the frame in printing position, while developed by a limited drive of the air displacer, is constantly guarded by the readiness of the displacer to respond to the vacuum control switch that constantly reiiects the order of the vacuum maintained. Moreover, the system lends itself to safe operation and assurance against failure through means of the readily controlled passages of displaced air.

Finally, an object of the invention is to provide a system of controlling valves for the fluid passages which will determine the duration of the diierent phases of the operation, and particularly duration of light exposure through means of a timing element which will preferably be an adjustably timed electric switch controlling the circuits of electrically actuated valves.

In the accompanying drawings, in which the preferred embodiment of the invention is shown by way of illustration- Figure 1 is a side elevation of the upper portion of a frame upon which a printing frame is trunnioned for movement back and forth between loading and light exposure positions, together with means whereby the several functions of a frame may be insured in accordance with the premises of the invention.

Figure 2 is a partial top plan view of parts shown in Figure 1.

Figure 3 is a view showing the parts of Figure l in positions incident to the presentation of the printing frame to the light source.

l tor; and

have, in cooperation with -the trunnion 2 Figure 4 is a top plan view on a greatly1 enlarged scale, of latching Ymechanism employed for holding the printing frame in loading position until such latching mechanism is automatically released as an incident to the functioning of the means employed for sluiting the frame to exposure position.

Figure 5 shows parts of Figure 4 on the same scale, in side elevation.

Figure 6 is a detail view of the unlatching lever through means of which latching mechanism is brought under control of the frame-shifting mo- Figure 7 is a schematic view sho-wing the elements of automatic control in an electrically energized system.

Referring to Figures 1 to 6, I represents frame upon which is mounted, through means of trunnions 2 and trunnion bearings 3, the printing frame consisting of a bed l and a cover 5 hinged at 6 tosaid bed. Cover 5 is normally held closed by hasp l engaging over a pin 8, but when released by swinging the hasp 'I oi pin 3 and given manual elevation through a slight angle, the cover will automatically swing through the remainder of its arcuate opening movement under the influence of a spring 9 anchored at I@ upon the bed i and having its free end II connected to a horn I2 which extends downwardly past hinge 6 from bolts I3, |30, that secure it to the cover 5. A substantial advantage is realized by the location of the counterbalancing spring 9 beneath the printing frame and selecting its points of attachment IB and II so as to effect automatic movement only after a voluntary initiation of such movement.

Between the members i and 5 of the printing frame, a substantially hermetic chamber id is the maintained'by compression packings I5, or equivalent means, and this adapts the chamber to it, a pressure blanket it which is forced against the glazed portion 5 of the printing frame by creating an over-balance of air pressure on its face remote from the glazing. This is accomplished in the present instance preferably by creating a vacuum in the chamber id through means of exhaust connection Il terminating at ila within the chamber and having its other end tapped into suitable automatically controlled air displacing means, later described in connection with Figure '7, and among the important characteristics of which are controlled operation to develop required vacuum immediately from time to time in proportion to need, and with readiness to voperate at all times in maintaining a predetermined degree of evacuation.

To operate the printing frame 4, 5 upon its trunnions 2 from loading position, shown in Figure l, to expoLu-:e position with reference to an arc-'light X or other light source as shown in Figure 3, an anchorage pin i8 on the base sufficiently offset downwardly and to the left of in Figure l, receives a flexible draw chain I9 deflected downwardly around toothed idler 2G to a known type of vacuum motor 2i which is anchored to a bracket 22 (Figs. 1 and '7) connected by an exhaust pipe 23 to the same air displacer as that which controls the chamber Iii through connector i?. Exhaustion of air at a vacuum source common to connections i'I and 23 has the eiiect of evacuating chamber Iii and causing blanket I5 to rise and press sheet material against the glazing of the frame; and upon substantial exhaustion from chamber I4,

' drawing down chain further evacuation collapses vacuum motor ZI, l and swinging the printing frame to exposure position shown in Figure 3. The printing frame does not respond immediately to traction through the chain i9; on contrary, link 25 affords lost motion connection with anchor pin I8, and it is only when slack thus aorded and normally taken up by spring 25, is overcome by chain I9 that the iramebegins to move. This lost motion serves to permit release oi latch 26 that normally retains the entire printing frame in the loading position, before the frame can begin to swing. This latch, as better shown in Figures 4 and 5, comprises, in addition to its bolt 26, a draw-bar 2l pivoted to the. bolt at 28 and influenced normally forward andY toward latching position by spring 29. Draw-bar 2i has saddle connection 3B, 3l with bell crank lever 32 that is fulcrumed at 33 upon a fixed part oi the frame and is normally innuenced toward unlatching position by a pair o springs 31S having their free ends 35 connected to the lower horn 32a of said lever 32 and their fixed ends anchored at 36 upon the frame. Lever 32 is, however, normally prevented from responding to tension oi springs 34 by pin 3i carried by chain I9 and standing beneath horn 32h of the lever S2 until said chain is moved downward by vacuum motor 2i as an incident to shifting the frame from loading position to exposure position. In this last-mentioned function, starting with the parts in the positions shown in Figure l, the rst movement of chain i9 through the distance necessary to take up the lost motion between link 213 and pin I8, permits lever 32 to swing about its center 33 in response to springs 3 and until the body of said lever brings up against the stop 38. This movement of lever 32 will be sumcientto withdraw the bolt 26 from its keeper 39 which is mounted on and rises with the printing frame and permit the dog Gil to follow the keeper 39 upward until the dog d, under the influence oi spring ilI, enters in iront oi bolt 2t and holds the latter retracted until the frame returns to loading position, at which time keeper 39, which passes downward in the path oi dog 43, will displace said dog and permit bolt 25 to snap into engagement with the said keeper. Draw-bar 2'I at the beginning of bolt-retracting movement moves in a right line, so that recess 3i! cannot escape from pin 3l on lever 32, but completion of bolt-retraction brings said drawbar to a position in which it can swing upwardly under the displacing as well as retracting iniiuence of lever 32, so that when the frame is in exposure position shown in Figure 3, the parts will be in the positions also shown in that figure. Interruption of vacuum in motor 2i and the gradual streaming in of air underV atmospheric pressure causes said motor to expand and permit the parts to automatically return to the position of Figure l under the iniluence of gravity, to insure which the location of trunnions 2 and distribution of masses are specially determined.

Figure 5 shows the parts after the frame has reached loading position, the bolt has snapped into locking position and lever 32 is approaching its position of rest. These positions. are determined by the movement of the chain to its upper limit minus the lost motion of the link 2Q relatively to the pin I8. Upon completion of this lost motion under the influence Voi spring 25, pin 3l will have again coincided with recess 30, draw-bar 21 will have dropped to normal position and the assembly is at a state oi rest,

which it retains until the next time the frame is to be presented in exposure position, when the sequence of functions above described may be repeated.

Referring now to the schematic display of the automatic control system shown in Figure 7, 42 represents an electric motor, 43 a vacuum produoing pump driven thereby, 44 an oil trap introduced in the discharge 45 of said pump, 46 a normally closed electrically opened shut-olf valve in the intake 4'! of said pump, 48 a voluntarily adjustable throttle through which to control the speed of flow in opposite directions with respect to pump 43 and thereby prevent sudden or injurious movements to any of the parts iniiuenced by the vacuum or by re-admission of air to said parts, and 45 is a normally open but electrically closed shut-off valve in a breaker 5D for the vacuum in the system which can be read .et ell time@ upon standard vacuum gauge 5|. The above described elements numbered 42 to 5G, inclusive, duly equipped with electric supply circuits which are in turn under the control of suitable voluntary vacuum controlled and time actuated switches, are adapted to function in a manner to create, in front of the blanket l5 and in the vacuum motor 2|, vacuum appropriate to the functions already described; energizinCr of motor 42 to run the pump 43 being accompanied by the opening of the valve 46 and the closing of the valve 49, so that at a rate controllable by voluntary adjustment of throttle 48, the blanket Will gradually close upon the sheet material to be pressed against the glazing, followed by tion of the motor 2| with its influence through chain 9 upon the printing frame and its accessories; and this phase will continue with the following changes until the cycle of functions is completed.

52 represents the voluntarily set pilot switch to which the entire system responds, including the opening of valve 46, the closing of valve 49, and the supply of current to the vacuum actuated motor switch 53.

Another important feaure of the present invention resides in the conditon that vacuum actuated motor switch 53, which is a standard vacuum controlled switch purchasable in the market, assuming that the automatic control switch 52 has been manually closed, will energize motor 42 as often as vacuum falls below a predetermined order and will deenergize said motor whenever the desired vacuum is attained and so long as it retains an order sufficient to insure proper working of the blanket and the actuator 2|, so that, in accordance with an underlying characteristic of the present invention, it is not necessary to build up a larg-e reserve of vacuum with the possibility of its operating out of time transmitting excessive forces upon the mechanism, but, instead, vacuum is created of order necessary to insure the desired functions as often as there is demand for vacuum.

The system operated by voluntari nianipulation of switch 52, the voluntary opening and closing movements of which will determine the interval of time between movement of the freine to exposure position and its withdrawal therefrom, to which end switch 52 has its circuit closing arm 52a adapted to cooperate with a terminal 52h which will leave the system under manual control, or switch arm 52a, by throwing the switch 52 in a different direction, may be brought into cooperation with a terminal 52o connected to binding post 54a of time switch 54 so that having thrown switch 52, for instance, to the left in Figure 7, current will flow to the several instrumentalities, subject to automatic variation, however, by the motor switch 53, until a certain time has elapsed when the circuits will be opened,

valves

46 and 49 are opened, and vacuum relieved suiiciently to permit the motor and blanket to return to normal position. Blanket I6 will always function in advance of motor 2| in throwing the parts into function and will always move out of function after the frame returns to loading position.

55 is a relay in circuit with both the time switch 54 and the manual switch 52 and controlling a heavy duty switch 55a, in relation to which the said switches 52 and 54 serve as pilots.

56 represents a circuit which will include an arc light X (Fig. 3) as the actinizing source for the photographic exposure operation, and this circuit has its switch 56a (Fig. 7) controlled by relay 57- which is automatically energized by the attainment by motor 2| of the position which brings the exposure frame into exposure position. To insure this last-named function, relay 51 is in circuit with mercury circuit closer 58 mounted on a lever 59 (Figures 1 and 3) which rests upon motor 2| and rises and falls with the latter sufficiently to cause this mercury switch to function as desired. Thus, light source X in Figure 3 will be energized and extinguished contemporaneously with the attainment and relinquishment by motor 2| of its position corresponding to exposure position of the printing frame.

What is claimed is:

l.. In, photographic printing apparatus, the combination of a glazed frame, a member for pressing sheet material against the glazing of said frame and mounted for movement toward said ,glazing in response to an over-balance of air pressure on the side of said member remote from said glazing, means for mounting said frame and the sheet-pressing member for movement back forth between a loading position and a light-exposure position, a power driven air displacer adapted to develop said over-balance of air pressure7 an automatic power control for said air displacer responsive to pressure controlled by said displacer, releasing power to said displacer when the over-balance of pressure falls below a predetermined order, and interrupting the supply of power to the displaoer when said over-balance attains a predetermined order, and a motor for moving said frame and sheet-pressing member between said positions energized by the over-balance of air generated by the air displacer.

2. In photographic printing apparatus, the combination of a glazed frame, a member for `pressing sheet material against the glazing of frame mounted for movement toward said glazing in response to an over-balance of air pressure on the side of said member remote from said glazing, means for mounting said frame and the sheet-pressing member for moven ent back and forth between a loading position and a light-exposure position, a power driven air displacer adapted to develop said over-balance of air pressure, an automatic power control for said air difplacer responsive to pressure controlled by said displacer, releasing power to said displacer when the over-balance of pressure falls below a predetermined order, and interrupting the supply of power to the displacer when said over-balance attains a predetermined order, and a iiuid motor for moving said frame and sheetenergized by the over-balance of air generated by the air displacer to move the frame only after the nlm is pressed against the glazing.

3. In photographic printing apparatus, the combination of a glazed trame, a member for pressing sheet material against the glazing of 'isaid frame and mounted for movement toward Esaid glazing in response to an over-balance of air pressure on the side of said member remote from said glazing, means for mounting said `frame and the sheet-pressing member for movement back and forth between a loading position eand a light-exposure position, a power driven displacer adapted to develop a vacuum in the space intermediate the glazing 'and the member that presses the sheet material thereto, meansI responsive to the degree of vacuum in said space for controlling operation of said displacer, and a vacuum motor for moving said frame and sheet-pressing member between said positions and having its working chamber in communication with said intermediate space.

l. In a printing apparatus, a glazed frame, means for movably mounting said frame, a vacuum actuated sheet holding member on said frame, a vacuum motor imparting movement to said frame with respect to its light-exposure position, a common source vof vacuum connected withsaid frame and said motor, means for conecting the working space of said motor and the vacuum space of the frame, and means auto- `niatically responsive to predetermined variations in the vacuum in said frame interrupting and restoring the generation of vacuum in said motor and said frame;

5. In photographic printing apparatus, a printing frame, means for mounting said frame for movement thereof back and forth between loading position and exposure position and whereby the same normally assumes loading position, latching means operable to lock said frame in loading position, a motor for moving the frame to exposure position, and a connection between said latching means and said motor whereby said latch means is operated in accordance with the operation of said motor to unlatch the frame and vpermit the same to respond to said motor when the latter seeks to impart movement thereto.

6. Photographic printing apparatus as described in claim 5, in which the motor has lost `'motion connection with the frame and the said .connection between said latching means and motor releases the latch-opening means during lost motion between the motor and the frame.

7. Fhotographic printing apparatus as described in claim 5, in which means is provided whereby the latch automatically moves to latch position when left unrestrained and means is provided for holding the latch in unlatched position, and the motor positively overcomes the said latch and restores the latch to latching position when the motor permits the frame to return to loading position and to operate said latch holding means.

8. 1n photographic printing apparatus, a printing frame, means for mounting said frame for movement thereof back and forth between loading position and exposure position, a latch engageable with said frame for holding the frame in-loading position, a motor for moving the frame to exposure position, a connection through which the motor withdraws said latch from latching engagement with said frame and restores the latch to latching position, during return movement of the frame to loading position, and a detent having a part in the path of movement oi said frame for holding the latch out of latching position until said detent is displaced by the frame upon arrival thereof in loading position and in position to receive the latch.

9. In vacuum actuated photographie printing apparatus, the combination of a printing frame having means operated by vacuum, means for mounting said frame for movement between loading and exposure positions, a vacuum actuated motor for moving said frame between said positions, a motor actuated vacuum pump for said frame and said vacuum motor, a valve for maintaining and releasing vacuum created thereby, a vacuum actuated motor switch energizing the motor of said pump whenever the vacuum falls below a predetermined order and deenergizing said motor whenever the vacuum attains a predetermined higher order, a pilot switch controlling both said motor switch and said vacuum releasswitch, a light circuit including a light source adapted to illuminate said printing frame, and a switch for energizing and deenergizing said light source, said switch lbeing operated to open and closed positions by movements of said vacuum motor.

le. In photographic apparatus the combination with an exposure frame of the type that has a p-neumatically actuated holder for the element that is to be. exposed, means for mounting said exposure frame for movement from loading position to exposure position, a pneumatically actuated motor, a. connection between said motor and said frame through which the motor controls the movement of the frame toward the exposure position, means including air ducts through which the holder and the motor are respectively energized, said air ducts being in communication so that energizing of the motor is dependent upon energizing of the holder, and means for automatically controlling operation of said holder and said motor. Y

il. Photographic apparatus as described in claim l in which the pneumatically actuated holder and motor are both of the type that are energized by vacuum and the vacuum space of the motor has connection with the duct through which the holder is energized.

l2. Photographic apparatus as described in claim lo which includes a latch adapted to cooperate with the exposure frame to resist movement thereof toward the exposure position, and a releasing means for said latch, connected with and responsive to the motor that moves the frame toward the exposure position,

i3. Photographic apparatus including an exposure frame, means for mounting said frame for movement thereof from loading position to exposure position, an actuator having a connector through which it controls the frame, including lost motion means that delay response of the frame to the actuator, a latch cooperating with said frame to resist movement thereof toward the exposure position, and releasing means for said latch, controlled by the said connector and responding to that part ofthe movement oi said connector which occurs while the frame movement is being delayed by the lost motion means.

le. Photographic apparatus as described in claim i3, in which the releasing means for the latch comprises a lever that withdraws the deuntil the connector moves.

15. Photographic apparatus as described in claim 10 in of pneumatic energy therefrom; a pneumatically energized frame-actuator, having a connector through which it moves the frame to exposure position When the MAX SUSSIN.