US2836110A - Liquid dispensing apparatus for print developing machines - Google Patents

Description

F. H. FRANTZ May 27, 1958 LIQUID DISPENSING APPARATUS vFOR PRINT DEVELOPING MACHINES Filed Deo. 8, 1955 j. 3 F/G. f

ATTORNEYS United States Claims. (Cl. 95-89) This invention relates to a liquid dispensing apparatus and more particularly to a pumping system useful in delivering varying quantities of developing liquid in measured amounts.

In the art of diazotype printing and developing apparatus, aqueous ammonia is generally used asr the developing liquid for the print material. This liquid is gasied in a suitable chamber to which it must be fed in measured amounts.

The speed of developing the sensitized material depends on various factors. Of these, i't-,is essential that the right quantity of developing liquid be supplied to the chamber forl the particular speed at which the machine processes the print material.

Machines of this type generally have a variable speed which is at the discretion of the operator and the liquid supply must be adjusted to the chosen speed. In prior art machines, arrangements have been made to auto matically increase the supply of developing liquid as the machine speed was increased and vice versa. Such arrangements, however, lacked the flexibility of determining the exact amount of liquid to be delivered for the various speeds, which is an important factor.

As mentioned before, the aqueous ammonia is evaporated for the purpose of developing. The optimum eiciency of generating the vapor for development depends on the heat, the configuration of the evaporating chamber, as well as on the absorption quality of the paper processed for development. Consequently, it has been found that the relationship between speed at which the paper is processed and the amount of liquid to be furnished is not necessarily a linear one. Working with a certain type of print material may require a far less amount of liquid,-let us say in cubic centimeters per minute, than will some other material. This also holds true when the evaporator has a higher heat supply due, for example, to an increase in the line voltage supplying the electrical heaters.

It is seen from the above that the governing factors of optimum eticiency may vary and a simple speed re lated liquid supply is inadequate for proper processing.

Accordingly, it is the primary object of this invention to provide a developing liquid dispensing apparatus which is exible and adjustable as to the amount ofliquid delivered in relation to speed as well as to the unit quantity for any particular speed.

Another object of the invention is to provide a de* veloping liquid dispensing apparatus which may be adjusted to meter out discrete amounts of liquid at uniformly recurrent intervals independently from the speed of the print processing apparatus.

A particular feature of the invention is that the liquid delivery may be adjusted simultaneously with the adjustment of the processing speed of the machine but the discrete amounts to be delivered at any particular speed may be independently determined by the operator.

Other objects and features will be apparent from the following description of the invention, pointed out in particularity in the appended claims and taken inconnec# tiontwith the accompanying drawing in which: f

atentO y Patented May 2?, 'i958 ICC Fig. l is a side elevational view of the apparatus, partially in section;

Fig. 2 is a sectional view of Fig. l, through lines A-A, showing the construction of a variable fulcrum for a lever; and

Fig. 3 is a chart indicating the relationship between the quantity of liquid delivered at various adjustments provided in the apparatus. d

Referring to Figs. l and 2, the apparatus consists of a housing which is represented by front wall 4 and rear wall 5. The former may be part of the developing machine, since the entire apparatus may be built as an integral part of such machines. However, for the sake of simplicity, such a machine, being a complicated assembly, is not depicted here. Instead, it is only symbolically shown by a drive motor.

Within the walls 4 and 5 there is located a liquid storage tank to which is attached a pump 7 having an outlet pipe 8 and an actuating button 9. The storage tank, as well as the pump, is schematically represented inasmuch as various types may be employed and they have no bearing on the present invention. The pump preferably employed is a diaphragm type now widely used in diazotype developing apparatus. The amount of liquid delivered when the button 9 is depressed is proportional to the extent of depression within the physical contines of travel of the button. A small depression may deliver but a drop of liquid, whereas full depression may eject several cubic centimeters, depending upon the size of the pump chosen. Of course, the outlet pipe 8 of the pump, partially shown here, connects with the developing chamber of the print processing machine, not illustrated.

A vertically extending lever 11 consisting of a U- shaped bar facing toward the front wall 4 and having sides 12 is pivoted orfulcrumed in the pin 13. As seen in Fig. 2, the bottom end of the lever 11 is forked and there is provided a block 15 having a screw thread 16, over which the forked portion of the lever 11 has a sliding fit. The pin 13 passes through the sides 12 of the lever 11 and also through the block 15, the ends being hammered down for permanent location.

Continuing with Fig. l, it is seen that the screw thread 16 of the block 15 accommodates a lead screw 17 cut in the shaft 1S which is journalled in the front wall 4 and rear wall 5. The front end of the shaft 18 accommodates a manually controlled knob 19.

Above the fulcrum of the lever 11, and in a cutout provided therefor, is located a freely turning disc 21, the shaft 22 of which is attached to the sides 12 of the lever 11. In line with the shaft 22 is the shaft 23 of an electric motor 24 having a base 25 which is attached to the front wall 4. A rotary cam 26 is aliixed to the shaft 23, having four lobes which are adapted to engage the disc 21 and thereby move the lever 11 over the pivot pin 13 to the right. A spring 27 located over a shaft 28 abuts against the lever 11 and rear wall 5 and returns the lever 11 whenever a lobe of the cam 26 is disengaged from the disc 21.

The shaft 28 is journalled in the front wall 4 at one end and in the rear wall 5 at the other end where it terminates in an electric control, such as a rheostat 29, shown merely in outlines, which controls the speed of the drive motor fed from the source shown, by way of example, by the battery 30.

The drive motor represents, as mentioned before, the printing and developing machine to which the apparatus, .in accordance with the invention, supplies developing liquid. This representation is, by way of example, to show that the speed of the developing machine may be controlled by the knob 31 which, as will be seen later, has another important function. It is to be understood,

'of course, that other speed control'means may be employed than the simple rlieostat shown here, such as a variable conical drive, or gear trains, etc.

The shaft 2S also carries a bushing 33 which has a sloping cone face 3e. The latter engages the lever 11 by means of an insert placed in the Aface of lever il so as to form an engaging surface which will resist wear. The top end of the lever il faces the button '9 of the pump 8 and serves to actuate the latter as will be seen from the following description of the operation of the liquid dispensing apparatus.

As shown in Fig. l, the knob 3l is turned fully clockwise so that the cam face 34 has its maximum laterally extending surface in engagement with the insert 35 and positions the lever as far to the right as lthe cam dimension of the bushing 33 permits. in this position the end of the lever 11 does not engage the button 5' and it is assumed that the rheostat breaks the circuit so that the drive motor is standing still. in other words, the print processing machine is not in use and no developing liquid need be supplied.

The motor 24 may or may not be idle at such time, although preferably it will also be disconnected. This motor may be or the synchronous type, such as a shaded pole solid armature motor of small size, since the force required is only to move the lever .l against the spring 27.

Even if the motor 211i is in rotation, it will only oscillate the lever from `the point of abutment against the cam face 34 toward the rear wall 5, without the lever il. touching the button 9 of the pump 7 so that the latter is not actuated. This condition may be altered in two ways:

(l) The fulcrum point or the lever il may be displaced by turning the button i9 so that the lead screw 17 engaging the block l5 moves the latter more toward the rear wall 5, until the lever now pivoting on the insert 35 engages the button 9 of the pump 7. In this manner, pumping action may be had even when the drive motor is idle;

(2) The knob Si may oc turned counterclockwise which will move the cam surface 34 so that the lever 11 will slant toward the button 9 of the pump 7 while, at the same time, it will also turn Ithe rheostat 29 so as to control the speed of the drive motor. Evidently the more the shaft 28 is turned counterclockwise by the knob 31, the greater the stroke of the arm lli, depressing the pump button 9 to a larger extent so that as the tity of liquid than before, at the same time increasing` the speed of the drive motor.

By proper setting of the fulci-um point, the lever l1 may be adjusted to have the optimum stroke for the pump 7 to deliver at each recurrent interval a certain required amount of liquid. As the speed of the drive motor is changed, so is the stroke of the arm il adjusted to the changed speed condition. This balance of adjustment between the strokes in relation to speed of development and the. fulcrum point ot the lever Ill for the proper amount of liquid for each strose lends complete flexibility of operation and provides the right amount of developing liquid under any processing condition.

The chart in Fig. 3 indicates the results of such adjustments. The ordinates represent the setting of the knob 19 and liquid delivery in cubic centimeters per minute. The` abscissae represent the setting of the knob 31 in linear feet of material processed. Curve a indicates the condition when at zero setting, no material being processed, the lever 11 is slanted by adjustment of knob i9 to deliver a small amount, approximately 2.5 cc. of liquid. Now, as the knob Si is turned and the speed is increased, there is a gradual increase of liquid delivery, reaching to somewhat over l5 cc. of liquid delivery at 30 ft. of material being processed per minute.

The condition represented in curve a may be optimum with respect to a certain material, but other materials may require more liquid, in which case thev knob 1 9 isA assedio t... i j

turned to move the fulcrum point of the bar 11 more to the right. Curve b shows that'at'such setting at 30 ft. per minute of material processed, there is a supply of over 20 cc. of liquid per minute. Curve c shows another condition which requires close to 30 cc. of liquid at maximum processing speed..

Whenever the processing speed is reduced Ito zero, liquid delivery may be stopped also by turning the knob 19in a direction to move the fulcrum point of the lever 11 to the lett, should the motor 24 remain energized.

i claim: Y

1. ln an apparatus for dispensing developing liquid in discrete amounts at recurring intervals, particularly for use in diazotype copying machines of variable processing speed which is proportional to the demand of liquid to be used in said machines', a liquid' storage tank,

a pump connected therewith having an outlet, aL lever' for actuating said pump, the stroke of said lever being proportional to the amount of liquid being expelled through said outlet, a rotary cam means for moving said lever at a substantially', uniformly recurrent rate, a rst manual control means for effecting a change in the processing speed of said machine, and simultaneously varying the distance of said lever from .said rotary cam means and thereby determining the effective stroke ot said lever anda second manual control means for varying the extent of its stroke independently from said first control means.

2. In an apparatus for dispensing developing liquid in discrete amounts at recurring intervals, particularly for use in diazotype copying machines of variable processing speed which is .proportional to the demand of'liquid to be used in said machines, a liquid storage tank, a pump connected therewith having an outlet, a lever for actuating said pump, the stroke of said lever being proportional to the amount of liquid being expelled through said outlet, a rotary cam means for moving said lever at a substantially uniformly recurrent rate, a r'irst manual control means for effecting a change in the processing sneed of said machine and simultaneously varying the distance of said lever from said rotary cam means and thereby determining the eective stroke of said lever and a second manual control means for shitting the fulcrum of said lever and thereby changing the exten-t of its stroke independently from said first control means.

3. An apparatus in accordance with claim 2 wherein said lever comprises a vertically extending bar having a forked portion at the bottom, a block over which said forked portion has a sliding iit, said fulcr'um consisting of a pin extending through said forked portion and through said block, and said means for shifting said fulcrum comprising a lead screw threaded at one end into said block and a manually operable knob at the opposite end of said lead screw.

4. An apparatus in accordance with claim l wherein saidvrotary cam means for moving said lever comprises an electric motor, cam wheel attached to the shaft thereof, and a freely rotating disc secured 'to said lever and cooperating with the peripheral surface of said wheel.

l5. An apparatus in accordance with claim l wherein said lever comprises a vertically extending bar, the upper end of which is adapted to engage said pump, and said rst control means comprises a manually rotatable shaft extending perpendicularly through said lever, a cam face attached to `said shaft .havinga sioping surface-facing and engaging said bar, said shaft terminating in an'clectrical controlelement connected to the drive motor -ot` said machine.

References Cited in the file of this patent UNITED STATES PATENTS

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