US2092242A - Duplicating machine - Google Patents

Description

2 Sheets-Sheet 1 Sept. 7, 1937. E. J. BRASSEUR DUPLICAT ING MACHINE 2 Sheets-Sheet 2 Filed April 27, 1936 fiwentor" GTE/"@662 Patented Sept. 7, 1937 PATENT QFFICE DUPLICATING MACmE Ernest J. Brasseur, Winnetka, Ill., assignmto A. B. Dick Company, Chicago, Ill.- a corporation of Illinois Application April 27, 1936, Serial No. 76,650

8 Claims. (01. 101119) This invention relates to duplicating machines, and more particularly to rotary stencil duplicating machines wherein a sheet of paper fed into the machine is passed between a rotatable cylinder and an impression roller to receive an impression from a stencil on the cylinder. The stencil is supplied with duplicating ink from the interior of the cylinder, wherein is disposed a sealed ink chamber or compartment from which ink may permeate through a diaphragm on the cylinder to an ink pad covering the diaphragm, and thence to the stencil sheet which is laid over the pad; and there is within the ink chamber a tiltable ink trough from which the operator may spill ink to replenish the stencil sheet. The weight of line and density ofv the prints produced through any given stencil depends upon the volume and fluidity of the ink in the ink pad, and when this is replenished by the operator the prints are relatively heavy, becoming progressively lighter or thinner as the ink is taken up from the pad.

One of the objects of my invention is to provide means by which the flow of ink to the ink pad and through the stencil may be accurately controlled by the operator and the weight of the prints maintained substantially constant, or varied as desired.

Another object of the invention is to provide means whereby the operator may regulate the supply of ink to the character of the impression paper being usei, and may compensate for variations in the fluidity of the ink such as are caused by changes in temperature and humidity.

-A further object of the invention is to provide means whereby excess ink in the ink pad at the end of a run may be quickly and easilyreturned to the ink chamber, so that it cannot dry and harden in the padand diminish the permeability thereof.

Other objects of the invention will be apparent from the drawings which form a part of this specification, and in which:

Fig. 1 is a plan view, partially broken away and partially in section, of the cylinder of a duplicating machine embodying the invention.

Fig. 2 is a transverse sectional view taken through the cylinder substantially on the line 2-2 of Fig. l.

Fig. 3 is a detail sectional view taken substantially onthe line 3-3 of Fig. 1.

Fig. 4 is a detail sectional view taken substantially on the line 4--4 of Fig. 3.

Fig. 5 is a detail sectional view taken substantially on the line 5-5 of Fig. 3, and

Fig. 6 is a detail perspective view of the cylinder connection to atmosphere.

Referring to these drawings, a cylinder In of a duplicating machine is shown mounted on two upright standards H and I! of a supporting 5 frame. This cylinder it is constructed in the usual manner of end plates i3 and M which are joined and held in position by a perforated diaphragm l6 and suitable rods indicated at H. The end plates l3 and M are provided with bear- 10 ings It on which the cylinder may rotate about its axis on trunnion members or pins l3 secured in the standards I I and I2. Also mounted on one of the trunnigns l9, as by bearings 2|, is a pulley 22 adapted to be driven from any convenient source of power by a belt 23, which may be operatively connected to and disconnected from the cylinder 10 through suitable means such as a slidable clutch pin 24, mounted in the end plate l3 and engagcable with the pulley. Other wellknown parts and features of the duplicating machine are not shown and will not be described except as they are involved in the present invention.

As is usual in machines of this nature the diaphragm I6 is adapted to carry a suitable inking pad 26 and stencil sheet 21, the ends of which are secured to theeylinder by clamps 28 of any convenient construction. 'The diaphragm I6 is fixed and sealed as by solder to flanges 29 and 30 3| of the plates l3 and 14 respectively, and a shield composed of a top portion 32 and side portions 33 is fixed or sealed to the ends and edges of the perforated diaphragm Hi to form a closed ink chamber 34. An opening 36 in this shield pro- 5 vides means for introducing ink into the chamber 34 and a suitable screw cap 31 is employed to seal this opening. Ink may be introduced through the opening 36 onto the perforated diaphragm l6, and thereafter upon rotation of the cylinder 40 will become distributed over the surface of the diaphragm and will pass through the inking pad 26 and the stencil 21. A suitable container or reservoir 38 is preferably provided within the chamber 34, adapted to receive and hold a quantity of ink as introduced through the opening 36, being constructed to tilt and permit the ink to pass to the diaphragm as required. The reservoir 38 is suspended from a shaft 39 mounted in the side walls 33 of the chamber and is provided with suitable tipping means, not shown, which may be actuated by the operator from a point outside the cylinder.

The inking apparatus described is associated with and forms a part of the inking control means of this invention, which comprises means for adjust ably regulating the'pressure within the closed ink compartment 34, either above or below atmospheric pressure, to increase, retard, or reverse the flow of ink through the diaphragm l6 as desired. In the embodiment illustrated it includes a valve device to selectively and regulably connect air pressure means, or suction means, to the compartment 34;

The valve device, indicated generally at M, is mounted on the standard H in any convenient manner and comprises a body portion 42 provided with a cylindrical valve chamber or bore 43 extending from end to end thereof. Communicating with the bore 43 near the ends thereof at ports 44 and 46 are passages 41 and 38, which are respectively connected in any suitable way as by the conduits 49 and 5!, to a source of air under pressure and to suction means. The pressure'means may be an air pump P and the suction means may be an exhaust pump V as diagrammatically shown in Fig. 1, both of which pumps may be driven from the prime mover of the duplicating machine, but as the specific construction of th pressure and exhaust means forms no part of this invention, they will not be further described. The bore 43 is also provided with ports 52 and 53, which lie respectively in the same transverse planes with the ports 44 and 46, and which communicate by passages 54 and 56 with a manifold passage 51 formed in the valve body 42. This manifold 51 is provided with an outlet port 58 by which it is connected to an outlet passage as.

Slidably mounted in the bore 83 is cylindrical valve member 62 provided with spaced cylindrical notches forming annular ports 63 and 6 5, by means of which the port 46 may be connected with port 52, or alternatively, port B6 may be connected to port 53. The spacing of the ports 63 and Se is such, that when ports l4 and 52 are uncovered by the port 63, the ports 46 and 53 are closed by the end portion of the valve member 62. When the member 62 is in its central position, both sets of ports are closed so that neither pressure nor suction is imposed on the manifold. By adjustably moving the valve member 62, the port t3 may be more or less com pletely registered with the ports at and 52 "thus providing a convenient means for throttling the flow of air and accordingly regulating the pressure in the manifold 51. In the same manner the degree of vacuum in the manifold may be regulated by adjustable movement of the suction port t l.

Such adjustable movement of the valve 62 is effected through rack teeth 66 formed on the central portion of the valve and adapted to mesh with a pinion 61 in a recess 68 in the valve body 42. This pinion 51 is mounted on a shaft be suitably journalled in and projecting from the valve body. The end of the shaft 69 is preferably provided with a milled knob 15 for convenience in manual adjustment and the shaft may also carry pointer 12 cooperating with a suitable scale 13 to conveniently indicate the degree of adjustment. Scale 13 may be cali-. brated in any manner desired, being marked in the illustrated embodiment to indicate light or heavy prints from the duplicating machine.

The outlet passage 59 is connected by a suitable conduit 16 to one end of a passage 11 formed in and extending axially through the trunnion pin l9. An axially disposed boss member 18, carried by the side wall 33 of compartment 3 5 is the cylinder.

provided with an annular projecting flange 13 adapted to be received in .and to make a rotatable spigot connection with an annular recess 8| formed in the end of trunnion pin l9. The spigot connection is sufliciently tight to prevent material leakage of air but is no'tso tight as to interfere with the rotation of the cylinder. A passage 82 in the boss member 18 communicates with the passage 11 and also with one end oi" a tube or conduit 83, carried by the cylinder, and which communicates at its other end with a chamber 84 formed in a boss 86 also carried by The chamber 84 terminates in a flared nozzle portion 81 which communicates through an opening 88 in the side wall 33 with the interior of the closed ink chamber 34. The open end of the nozzle 81 is preferably covered with a suitable baflle plate 89 to prevent ink from the chamber 34 being carried into the air connection.

The other side wall 33 of the compartment 34 carries a boss 9| formed with a chamber 92 which is connected to the atmosphere through the wall 33 by an orifice 93 of considerably less diameter than the chamber 92. The boss 9| is provided with a flared portion 94, similar to the nozzle portion 81, which communicates with the interior of the chamber 34 through a suitable opening in the side wall 33. A baffle 96 for this opening is also provided similar'to and for the same purpose as the bafiie 89.

The operation of my device will be apparent from the foregoing description. During ordinary operation, the valve member 62 is set in its central position as that ports 48 and 46 are both closed and the pressure in the chamber 36, by reason of the orifice 93, is substantially the same as atmosphere. During such operation ink is fed through the diaphragm F6 in the wellknown manner, partly by the capillary action of the perforations thereof and partly by the centrifugal force due to rotation of the cylinder, so that the duplicating machine produces medium prints.

If heavier prints are desired for any reason, the operator adjusts the knob 1| to the right, as indicated by the pointer, so that the valve member 62 is moved by the pinion 61 toward the left to partially uncover the ports as and 52. This connects the manifold 51 with the source of air under pressure, which is communicated through conduit 18, passage 11 and conduit 83 .to the interior of the chamber 34, raising the pressure therein above atmosphere. Such increase in pressure causes an increased flow of ink through the perforations of the diaphragm it as will be apparent, increasing the supply of ink to the pad 26 and the stencil 21 and resulting in heavier prints. By adjustably moving the valve 62 to more or less completely uncover the ports id and 52, the increase in pressure and with it the flow of ink can be adjusted as desired. During such forced inking, excess pressure within the chamber 34 is relieved in part through the orifice 93, through which the pressure air flows to atmosphere as indicated by arrows on Fig. 1.

To prevent too heavy a print when the cylinder has been freshly inked, or when for any other reason a lighter than medium print is desired,

the operator adjusts the valve member 62 toward the right to uncover the suction ports 46 and 53. This creates a partial vacuum in the chamber 35, which is in part satisfied by a reverse flow of air through the orifice 93 into the chamber.

The depression within the chamber retards or stops the flow of ink through the pad 26, and the more completely ports 56 and 53 are uncovered, the greater is the depression and the less the flow of ink. It will be readily understood that this vacuum may be raised sufiiciently to permit the superior atmospheric pressure to force ink from the stencil and paid back through the perforations of the diaphragm l6 into the chamber, and this feature of the invention is particularly useful in removing excess ink from the stencil and pad at the close of a run.

It will be understood that the terms heavy and "light, as herein used to describe prints, refer to heaviness or lightness of the lines forming the printed image, which depends upon the volume of ink transmitted to the impression paper through the stencil.

While I have herein described in some detail a specific embodiment of my invention, which I deem to be new and advantageous and may specifically c1a1m,I do not desire it to be understood that my invention is limited to the exact details of the construction, as it will be apparent that changes may be made herein without departing from the spirit or scope of the invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent, is:

1. In a duplicating machine having a printing cylinder provided with an ink-permeable diaphragm and a closed ink chamber adapted to suply ink to said diaphragm, a source of air under pressure, a source of vacuum, and valve means to selectively and adjustably connect said sources to the chamber.

2. In a duplicating machine having printing means including an ink-permeable diaphragm and a closed ink chamber communicating with said diaphragm, means to increase. the pressure within said chamber above atmospheric pressure, means to reduce the pressure in said chamber below atmospheric pressure, and a valve device associated with both said means.

3. In a duplicating machine having a printing cylinder rotatably mounted on trunnions and provided with a closed ink chamber, a source of air pressure, a source of vacuum, a valve device adapted to regulate the flow of either source, and means associated with one of the trunnions connecting the ink chamber to said valve device.

4. In a duplicating machine having a permeable ink feeding and distributing device, pneumatic pressure means to increase the flow of ink through the permeable member and vacuum means to retard the flow of ink therethrough.

5. The combination in a duplicating machine having a printing member and means to supply ink to said member, of pneumatic pressure means to increase the volume of ink supplied to the member and vacuum means to retard the supply of ink thereto.

6. In a duplicating machine having a perforated diaphragm adapted to feed ink to a printing means, a device to control the fed of ink including means to adjustably vary the direction and amount of air pressure on said diaphragm.

7. Inking control means for duplicating machines having an ink-permeable printing element, comprising means to vary the fiow of air through said printing element, and means to reverse the flow of air therethrough.

8. The combination in a duplicating machine having a printing member and a closed chamber adapted to contain ink for supply to said printing member, of a manifold connected to said chamber, a source of air under pressure, a source of vacuum, pressure and suction ports connecting said sources separately to the manifold, and a valve member being movable to variably uncover the pressure ports while the suction ports are covered and to uncover the suction ports while the pressure ports are covered.

ERNEST J. BRASSEUR.

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