US2697397A - Rotary printing drum for duplicating machines - Google Patents

Description

R. W. BAILEY Dec. '21, 1954 ROTARY PRINTING DRUM FOR DUFLICATING MACHINES 4 Shets-Sheet 1 Filed July 21, 1949 INVENOQ" WBAILEY,

Air-702N534 R. W. BAILEY Dec. 21, 1954 ROTARY PRINTING DRUM FOR DUPLICATING MACHINES 4 Sheets-Sheet 2 l Filed July 21, .1949

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R. W. BAILEY Dec. 21, 1954 ROTARY PRINTING DRUM FOR DUPLICATING MACHINES Filed July 21, 1949 4 Sheets-Sheet 4 INVENTOR. W 341L553 .QrToQNEY.

United States Patent 2,697,397 Patented Dec. 21, 1954 ROTARY PRINTING DRUM FOR DUPLICATING MACHINES Richard W. Bailey, Los Angeles, Calif., assignor to Milo Harding Company, a partnership composed of Milo M. Harding and James M. Harding, Los Angeles, Calif.

Application July 21, 1949, Serial No. 105,942 8 Claims. (Cl. 101-119) This invention relates to duplicating machines, mimeographs and the like; more particularly, it relates to the rotatable drum commonly provided in such machines for mounting the stencil.

It is an object of this invention to provide an improved drum of this type.

Such drums commonly comprise a perforated cylindrical shell about which the stencil is wrapped, a thin layer of porous material such as muslin being interposed. Ink within the drum and in contact with the shell feeds outwardly through the stencil as the drum is rotated, printing a form in accordance with the cutting of the stencil on paper urged against the stencil by passing between the drum and an impression roller.

It is another object of this invention to provide a duplicator drum or the like having improved means for supplying ink to the stencil.

It is another object of this invention to provide a duplicator drum or the like having means for supplying ink to the stencil which will deliver automaticallya predetermined quantity of ink.

The perforated cylindrical portion of the shell on which the stencil is mounted is usually substantially less than the entire circumference of the drum and somewhat less than the length of a stencil. The remainder of the circumference being offset inwardly to accommodate the stencil mounting means etc., exteriorly thereof. As the drum rotates, the ink on the inner surface of the shell tends to lag behind the movement of the shell, and furthermore is urged outwardly by centrifugal force. The reduced portion of the shell retards the movement of the ink, so that the ink accumulates adjacent the trailing end of the cylindrical shell, the corresponding end of the stencil thus having too much ink while the head or leading end of the stencil has too little.

It is accordingly another object of this invention to provide a duplicator drum so arranged as to prevent such accumulation of ink.

It is another object of this invention to provide a duplicator drum having means to facilitate transfer of ink bletween the opposite ends of the cylindrical portion of the s el Conventional stencils for duplicating machines are usually made of such size as to accommodate matter filling a legal size sheet; on the other hand, a large proportion of the matter to be printed is readily accommodated on a letter size sheet. Thus, there is frequently a space at the lower or trailing end of the stencil which is not used. As discussed hereinbefore, the ink tends to accumulate in the drum shell over this part of the stencil, and frequently builds up sufiiciently to escape along the opposite edges of the stencil, or to cause the stencil to wrinkle, as well as other difficulties, partly when this part of the stencil is not cut. It is accordingly another object of this invention to provide a duplicator drum or the like arranged to prevent leakage of ink and/or injury to the lower or trailing end of the stencil when printing a letter size form.

It is another object of this invention to provide a duplicator drum or the like, having optionally operable means for diverting the ink from that portion of the drum shell covered by the trailing end of the stencil.

It is another object of this invention to provide a dupli- I cator drum or the like, having optionally operable means for masking that portion of the drum shell covered by the trailing end of the stencil to prevent escape of ink through the shell perforations.

The stencil is usually attached to the drum by the aid of a reenforcing member extending across the head or leading end of the stencil, having laterally spaced keyhole shaped openings respectively engaging hook like fingers provided on the drum. The other end of the stencil usually is unattached since the drum rotates in such a direction as to cause the stencil to hug the drum; further, the ink on the porous layer or pad causes the stencil to adhere thereto. In removing a stencil so arranged, it is necessary to grasp the unattached lower or rear end, pull the stencil from the drum, and then unhook it from the fingers. This is an untidy job due to the ink on the stencil.

It is another object of this invention to provide a dupli- V cator drum having stencil mounting means from which the stencil may be removed by means of the head or leading end which is free of ink.

It is another object of this invention to provide a duplicator drum having means for detachably securing the trailing end of the stencil to the drum.

It is another object of this invention to provide a dupli cator drum having improved means securing the head end of the stencil, optionally operable to release the stencil and permit removal thereof.

It is another object of this invention to provide a duplicator drum having means for detachably securing the head, as well as the trailing end of the stencil, to the drum.

It is still another object to provide a duplicator drum having novel mounting means for securing it in operative relation with the duplicator enabling its removal and replacement in a simple and eflicacious manner.

This invention possesses many other advantages and has other objects which may be made more easily apparent from a consideration of several embodiments of the invention. For this purpose there are shown several forms in the drawings accompanying and forming part of the present specification. These forms will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

In the accompanying drawings:

Figure 1 is a longitudinal sectional view of a duplicating machine, showing in elevation a drum incorporating features of the invention;

Figure 2 is a transverse section on an enlarged scale and partly in elevation, taken substantially as indicated by line 2-2 of Figure 1;

Figure 2-a is a detail section, taken substantially as indicated by line 2a-2-a of Figure 2;

Figure 3 is a top plan view, seen as looking down in Figure 2;

Figure 4 is a sectional view, similar to Figure 2, but on a further enlarged scale and showing a different operating position of the parts;

Figure 5 is a cross section, taken substantially as indicated by line 5-5 of Figure 4;

Figure 6 is a fragmentary section on an enlarged scale, taken substantially as indicated by line 66 of Figure 5;

Figure 7 is a fragmentary cross section on an enlarged scale, taken substantially as indicated by line 77 of Figure 3;

Figure 8 is a fragmentary section on an enlarged scale, taken substantially as indicated by line 88 on Figure 3;

Figure 9 is a fragment of a section similar to Figure 5, but showing a modified form of the invention;

Figure 10 is a view similar to Figure 9 but showing a different operating position of the parts;

Figure 11 is a sectional view, similar to Figure 4, but showing another modified form of the invention;

Figure 12 is a cross section taken substantially as indicated by line 12-12 of Figure 11; and

Figures 13 and 14 are fragmentary sections taken substantially as indicated by the correspondingly numbered lines of Figure 12.

Referring to Figure l, a duplicating machine embodying the present invention is shown schematically and comprises a frame generally indicated by the numeral 1, having upstanding side members 2 and 3 (see also Figures 2 and 3) which cooperate to support the printing drum 5 for rotation about a horizontal axis 6, the drum being driven in a counterclockwise direction by suitable means (not shown). As shown in Figure 2, the drum 5 has a shell 7 covered in part by an ink pad 8 and a stencil sheet 9, a layer of ink (not shown) being provided on the inner surface of the shell 7 for passage through perforations therein to the stencil. Sheets of paper 10 or other suitable material are fed from the stock pile 11 between the drum 5 and the impression roller 12 to be printed in accordance with the cutting of the stencil, the printed sheets 10 being delivered to the magazine 13.

Referring to Figures 2 to 8, the drum 5 comprises a pair of circular heads and 21 joined in spaced relation by the shell 7. As best shown in Figure 5, the shell has a cylindrical perforated portion 22 which is discontinuous, that is, it extends less than a full circumference, the opposite ends thereof being connected by a solid portion 23 spaced radially inwardly from the cylindrical portion 22. The ink pad 8 covers the perforate portion 22 of the shell 7, the opposite or leading and trailing ends 8-11 and S-b thereof being anchored in any suitable manner. Thus, the leading end 8-0 may be attached to a plate 25 extending across the drum, by the aid of a hook formed on the plate 25. The plate 25 has a pair of apertures 26, each of which is engaged by a member 27 slidable on the solid shell portion 23 and urged in a direction to tighten the pad 8 by adjustable spring means 29. The opposite end S-b may be provided with a similar plate which catches behind a short extension 22-a of the cylindrical shell portion 22, or as shown in Figure 5 at 30, the end of the pad 8 may be merely folded over this extension 22-a, since there is very little force acting on the pad.

The stencil 9 is entirely conventional and comprises a paper stiffener or reenforcing strip 31 at its head or leading end with a plurality of key-hole shaped apertures 32 therein, engageable respectively by projections or fingers 33 formed on a bar 34 extending across the drum 5 and supported for angular movement about its axis by reduced portions 34-a and 34-h engaging suitable openings in the heads 20 and 21 respectively.

The arrangement is such that the bar 34 is oscillatable between a position in which the fingers or projections 33 are inclined away from the stencil as shown in Figure 5, and prevent its removal, and a position substantially 90" therefrom permitting ready attachment or removal of a stencil. A light tension spring 35 (Figures 3 and 8) urges the bar 34 to stencil retaining position, a short lever 36 being provided to facilitate operation of the bar 34 to stencil releasing position. For this purpose, the arcuate cover plate 37 must first be moved to permit access to the bar 34, lever 36, etc.. as will be discussed hereinafter. The lever 36 also serves by means of a lug 36-0 engageable with the shell portion 23 to appropriately limit movement of the bar 34 by spring 35.

The opposite or trailing end of the stencil 9 is also secured to the drum 5. Thus, as shown in Figure 5, the length of the stencil sheet 9 is such that the sheet extends beyond the extension 22-a and along the shell portion 23. An elongated member 40 extending across the drum 5 has a forward edge 40-0 adapted to engage the stencil 9 immediately adjacent the extension 22-0 for this purpose being rotatably mounted on the bar 41 by the aid of webs 40-h. A pair of tension springs 42 anchored at 43 on the shell portion 23 (see Figure 7) and connected to a flange 40-1: on the member 40 urge the member 40 about the bar 41 so that the edgeAO-a presses against the stencil 9. For moving the member 40 into and out of engagement with the stencil, bar 41 is pivotally mounted in the heads 20 and 21 by offset pintles 44 and 45, one of which, as 45, extends through the head 21 and has an operating knob 47 secured thereon.

As clearly shown in Figures 5 and 7, the pintles 44 and are so located with respect to the points of attachment of the springs 42 as to form an over center arrangement wherein the member 40 in either stencil engaging position or releasing position is urged about the bar 41 by the springs 42 in a clockwise direction. Thus, in stencil engaging position, the forward edge 40-11 of the member 40 clamps the trailing end of the stencil 9 against the shell portion 23, and in stencil releasing position engages the shell portion 23 at a point spaced from said stencil end, thereby releasably maintaining the member 40 against movement.

.The foregoing manner of mounting the stencil 9 enables removal of the head end of the stencil first, an important advantage since this end has the reenforcing piece 25 and is free of ink. However, if desired, the stencil 9 may be removed in conventional manner by operating the glamping member 40 to release the trailing or rear end rst.

The arcuate plate 37 is provided to form a protection cover for the head of the stencil 9 and the anchoring means therefor, being mounted for movement about the axis of the drum 5 between a closed position covering said head and stencil means and an open position in which they are exposed for manipulation. For this purpose, the opposite edges of the plate 37 are slidingly accommodated respectively in grooves 50 and 51 in the heads 20 and 21. A latch member 53 (Figure 7) is pivotally mounted on the inside of the plate 37 by the aid of cars 54, being urged by a spring 55 so that its inner end 53-a normally engages the shell portion 23. The opposite end of the member 53 has a thumb button 53-b thereon accommodated in an opening 37-a in the plate 37. The inner end 53-(! of the member 53 by engaging a stop lug 56 on the shell portion 23, serves to releasably maintain the plate 37 in closed position. Pressure on the thumb button 53-h disengages the member 53 from the lug 56, so that the plate 37 may be moved to open position.

The ink for the stencil is supplied to the interior of the drum 5 through an opening 60 in the shell portion 23, closed by a threaded plug 61. With the advent of thinner quick drying inks, it is important that the amount of ink in the shell is not excessive; further it is advantageous to be able to replenish the ink supply in an appropriate amount and without the need of removing the plug 61 every time.

Accordingly, means are provided for containing a body of ink in the drum 5 substantially in excess of the amount for use by the stencil, means operable from the exterior of the drum being provided for releasing the ink in appropriate predetermined amounts.

For containing the body of ink, a stationary cradle 62 is rotatably supported within the drum 5 by the aid of a tubular member 63 extending axially of the drum. The cradle 62 comprises an arcuate bottom forming plate 64 concentric with the perforated shell 22 spaced inwardly therefrom and supported by upright end plates 65 and 66 having hubs 65-a and 66-11 which engage the tubular member or axle 63. A tie plate 67 extends between the upper ends of the plates 65 and 66.

The cradle 62 has an elongated opening 68 in the bottom plate 64, as well as an intermediate plate 69 with a similar opening or aperture 70, providing first and second or upper and lower ink containing chambers 71 and 72. A closure member 73 is suspended between the bottom 64 and the intermediate plate 69 by a pivotedlink '74 connected to one arm of a lever member 75 rockably supported between upstanding ears formed on the opposite edges of the bottom plate 64, one of such ears being indicated at 76, Figures 2 and 4. As clearly shown in Figures 4 and 5, the closure member 73 comprises a metal plate 73-a of such size as to overlie the openings 68 or and connected to link 74 by the aid of lug 73-b. A resilient pad 78 is provided on the upper face of plate 73-51 for sealing about the aperture 70 when the closure 73 is in its upper position. A similar pad 79 is provided on the lower face of the plate 73-11 for sealing about the opening 68 when the closure 73 is in its lower position, this pad 79 however being somewhat thicker to allow for the curvature of the bottom plate 64.

The arrangement is such that the closure 73 normally closes the bottom opening 68, the aperture 70 being open, so that the ink chambers 71 and 72 are in free communication but no ink can pass onto the interior surface of the drum 5. However, the closure 73 is optionally operable to uncover the bottom opening 68 and close the aperture 70, thus allowing the ink in the lower chamber 72 to flow onto the interior drum surface. Thus, by making the lower chamber 72 of appropriate size, a predetermined amount of ink is delivered at each operation of the closure 73. After the ink has been released from the lower chamber 72, the closure 73 is returned to its normal position, closing the opening 63 and opening the aperture 70. allowing the lower chamber 72 to refill from the upper ch mber 71. To f cilitate the emptying and filling of t e lower chamber 72. appropriate air vents 77 are provided at each end thereof.

For operating the lever a sleeve 80 is rotatably and slidably mounted on the axial member 63 and has a notched lug 80-a engaging a notch 75-!) in arm 75-a of the lever 75. This prevents rotation of the sleeve 80 as well as constraining the lever 75 to swing in accordance with the axial movement of the sleeve 80, a compression spring 81 confined between the sleeve 80 and the end boss 65a, normally maintaining the parts with closure 73 closing the bottom opening 68.

For moving the sleeve 80 to cause the closure 73 to move to its other operating position, a push rod 82 is slidably mounted in the member 63 extending inwardly from one end and having a transverse pin 83 adjacent its inner end projecting through oppositely disposed slots 63a in the member 63. Rollers 84 are provided on the pin 83 for engaging the sleeve 80, since the push rod 82 and pin 83 rotate with the member 63, while the sleeve 80 remains stationary. The outer end of the rod 82 has a slightly enlarged head 82-a which is sealed against the bore in member 63 as by a conventional O-ring 85 accommodated in a groove in the head 82-a.

The opposite end of the member 63 has an elongated plug 86 secured therein with a through axial opening 86a to be more fully discussed shortly. A compression spring 88 confined between the plug 86 and rod 82 urges the rod 82 outwardly, pin 83 by engagement with the ends of slots 63a serving to limit such movement. Means to be discussed hereinafter are provided for urging the rod 82 inwardly to operate the closure 73.

It will be obvious that the closure 73 must not dwell at an intermediate point with both openings 68 and 70 simultaneously uncovered, since this would prevent proper metering of the ink delivered to the interior of the drum 5. To insure proper operation of the closure 73, it is continually biased by the spring 81 to close the lower opening 68, this force being supplemented by that of a leaf spring 89 confined between arm 75-0 of the lever 75 and the end plate 65. This spring 89 is arranged in a known man er to exert a force opposing movement of the lever 75 from either limiting position and which increases as the lever reaches an intermediate position. Thus, while the force of spring 81 overrides the force of spring 89, exertion of a force on the lever 75 sufficient to move it from a position in which the closure 73 closes the opening 68 to and through an intermediate position, will insure further movement of the lever 75 in response to ri 89 s th t the closure 73 cl ses the aperture 70.

The drum 5 is mounted in the duplicator by the aid of the conical hubs 90 and 91 secured respectively to the drum heads and 21, hub 90 being secured by a special screw 92 threaded into the plug 86. The hubs 90 and 91 respectively engage members 94 and 95 providing conical cups for receiving the conical surfaces of the hubs 90 and 91, and rotatably supported by the upstanding side members 2 and 3 of the frame 1. One of these cup members, as 94, may be power driven, the drum 5 being in driving relation therewith by a pin 96 in the head 20 engaging slot 94-a in the cup member 94.

The screw 92 has a central aperture leading from the aperture 86-0 in the plug 86 to the space between the hub 90 and cup 94 (see Figure 2), communication between this space and the atmosphere being provided by one or more transverse grooves 90a in the surface of the hub 90. The aperture 86-01 opens into the interior of the member 63 which communicates freely with the interior of drum 5 by ports 63-11. In this way, atmospheric pressure within the drum is assured at all times.

The other cup member 95 is rotatably mounted on'the inner end of a short hollow shaft 97, but is restrained against axial movement thereon, and may be optionally driven by means independent of the means driving the member 94, such as a hand crank (not shown) for rotating the drum 5. For this purpose the member 95 includes an integral spur gear 95-0: and a driving pin 98 is provided in the head 21 engaging a slot 954: in the member 95.

The shaft 97 is supported for angular and axial movement in the frame upright 3 by means of a bushing 100 fixed therein, a knob 101 being secured on the outer end of shaft 97 to facilitate its operation. Appropriate movement of the shaft 97 and member 95 thereon to the left (Figure 2) will disengage the member 95 from the hub 91 and allow the drum 5 to be moved to the left to disengage the hub 90 from the other cup 94, freeing the drum 5 for removal from between the uprights 2 and 3. Similarly, movement of the shaft 97 and member 95 to the right will secure the drum 5 after it is replaced.

The shaft 97 is resiliently urged to drum retaining positil tion by a detent arm 102 pivotally mounted at 102-a on a plate 103 secured within the upright 3 about the shaft (Figures 2 and 2-a). The arm 102 inclines from the end 102-11, away from the plate 103 to the free end which is urged inwardly or toward the drum 5 by a compression spring 104, there being a recess 102-b adjacent the free end normally engaged by a pin 105 projecting from the shaft 97. The spring 104 thus serves to maintain the drum 5 in operating position by urging the cups 94. and 95 and their respective hubs into engagement.

When it is desired to remove the drum, the operator, by means of the knob 101 exerts suflicient turning force in a counterclockwise direction, referring to Figure 2-a, on shaft 97, to force the pin 105 out of the recess 102-b, the shaft 97 then being rotated about to align pin 105 with a slot 106 extending through the plate 103 and axially in bushing 100. The shaft 97 together with the cup member is then moved axially t0 the left to disengage the member 95 and hub 91. Inward and clockwise movement of the shaft 97 will cause engagement of pin and detent notch 102b, thus locking drum 5 in place.

An operating rod 107 for actuating the ink feeding mechanism is slidable in the bore of the hollow shaft 97, having a head 107-a projecting from the knob 101 and confining a spring 108 against the end of the shaft 97. The spring 108 urges the rod 107 outwardly, a suitable stop member 107-b on the rod 107 limiting such movement by contact with the inner end of the shaft 97. The inner end of rod 107 is adapted to contact push rod 82 so that suitable pressure exerted on the head 107-a will actuate the closure 73 in the manner previously discussed.

The rotation of the drum 5 causes the ink on the inner surface of the cylindrical shell portion 22 to accumulate adjacent the trailing end of the shell 22 where it joins the inwardly spaced shell portion 23. This is objectionable in any case since it results in an excessive ink supply for the trailing end of the stencil and especially since the last several inches of the stencil are not cut or used in a large proportion of the work. Accordingly, means are provided optionally operable for masking this portion of the shell 22.

Thus, as shown in Figures 4 and 5, a plate 110 is provided extending between the heads 20 and 21 and in spaced relation over the trailing end of the shell portion 22 and the adjacent end of the inwardly spaced shell portion 23. At the leading end of the plate 110, a control flap 111 is provided, secured on a bar 112 extending longitudinally of the drum 5 and rotatably mounted at its opposite ends in the drum heads 20 and 21 respectively. Bar 112 projects through the head 21 having an operating knob 113 secured on its outer end.

The arrangement is such that the flap 111 may be positioned as indicated by full lines to prevent entry of ink between the shell 22 and the masking plate 110 or as indicated by the broken lines to permit ink to enter freely. However, it is to be noted that in the latter case the thickness of the ink layer acting on the trailing end of the shell 22 and the stencil 9 can never exceed the distance by which the masking plate 110 is separated from the shell. As shown in Figure 6, a spring pressed ball 114 maybe provided in the head 21 engageable with either of a pair of recesses 115 in the knob 113 for retaining the flap 111 in adjusted position, appropriate indicia 116 (Figure 1) being provided on the head 21 cooperating with a mark on the knob 113 to indicate the position of the flap 112.

A modified form of means for masking the trailing end of the cylindrical shell portion is shown in Figures 9 and 10. Therein an arcuate plate 119, adapted to closely engage the inner surface of the shell 22, is supported for swinging movement into and out of contact with the shell by a plurality of longitudinally spaced arms such as indicated by 120 pivoted respectively to lugs 121 on the inside of the shell portion 23. A longitudinally extending shaft 122 is rotatably supported at its opposite ends in the heads 20 and 21 respectively, an operating knob 123 being provided on one end thereof as before.

One or more springs 124 tensioned between the shaft 122 and lugs 119-a on the plate 119, urge the plate inwardly of the shell 22, such movement being opposed by the engagement of a cam surface 119b with projecting cam means 122a on the shaft 122, as shown in Figure 9. Upon rotation of the shaft 122 to disengage the cam 122-a and the cam surface 119-b, the plate 119 swings inwardly against shaft 122 as a stop, allowing free passage of ink over the trailing end of the shell 22 (Figure 10). Reverse 7 shaft 122 reengages the cam 122-a and cam surface 119-b and returns the plate 119 to its masking position, an extension 119-c of the cam surface 119-b serving as a stop to appropriately limit rotation of the shaft 122 by engaging the cam 122-a.

In Figures 11 and 12 a modified form of ink cradle is shown in connection with a modified form of printing drum, but it is to be understood that there is no especial cooperation between these modified forms, as'the drum of Figure ll could as well employ the ink cradle of Figures 2 to 5, and the drum of Figure 2 et seq. could equally as well employ the ink cradle of Figures ll and 12.

Referring to Figures 11 and 12, the printing drum shown therein is generally quite similar to the previously described drum comprising circular heads 130 and 131 joined by a shell having a discontinuous cylindrical perforated portion 132' with its ends joined by an inwardly spaced portion 133.

However, to prevent the previously discussed accumulation of ink adjacent the trailing end of the cylindrical shell portion 132, a pair of channels 134 and 135 are provided in the inwardly spaced shell portion 133 connecting said trailing end with the leading end of this portion 132. Thus, the width of the shell portion 133 is less than the space between the heads 130 and 131 so that the opposite edges thereof are spaced from the heads, means 136 and 137 being provided adjacent the heads 130 and 131 respectively forming narrow continuations of the cylindrical shell portion 132 connecting its opposite ends. The means 136 and 137 are connected at their outer edges respectively to the heads 130 and 131 and at their inner edges by upstanding walls 138 and 139 to the shell portion 133. It will be apparent that ink accumulation adjacent the trailing end of the cylindrical shell portion 132 will flow longitudinally along the shell to the channels 134 and 135 and thence via the channels to the leading end of the shell portion 132. Since these channels 134- and 135 form a continuation of the cylindrical shell portion 132, free flow of the ink results.

The described arrangement has important advantages in providing a uniform distribution of ink over the stencil, avoiding excessive inking of the trailing end of the. stencil whil assuming an ample supply of ink for the head end.

The inking pad 8 and the stencil 9 may be secured to the drum in substantially the same manner as in the first described form of the invention. However, as shown in Figure 13, the anchoring means 140 for the trailing end of the stencil 9, similar to that previously described, is rotatably supported by engagement of the pintles 140-a and 14041 with the channel walls 138 and 139 respectively, pintle 1411-17 extending across the channel 135 and through the head 131, an operating knob 1 i1 being fixed on its outer end. Likewise one end of the anchoring bar 142 for the head of the stencil 9, similar to that previously described, is rotatably supported by the channel wall 139 as shown in Figure l4,the other end being similarly supported by the channel wall 133.

An arcuate protective cover 143 is provided as before, slidably mounted in grooves 14-4 and 145 defined respectively by the channel bottoms 136 and 137 and flanges 146 and 147 on the heads 130 and 131.

The stationary cradle 15% for containing the ink is generally quite similar to that of the first described form or the invention and comprises an arcuate bottom wall 151 with an elongated opening 152 and an intermediate apertured wall 153 with an opening 154, a closure member 155 similar to that of the first described form of the invention being provided for controlling the openings. The cradle 150 is rotatably supported with respect to the drum by end plates 156 and 157 secured to hubs 158 and 159 and braced by a top spacer plate 161. This plate 161 has an opening 161-5: for facilitating the passage of ink from the drum opening 162.

The hub 15% is rotatably mounted on a tube 163 fixed in the head 13) and extending inwardly therefrom to provide an air vent for the interior of the drum, a protective cover 164 being provided to prevent accidental entry of ink into the tube 163. The other hub 159 is rotatably supported on the axially extending push rod 165 which operates the closure 155.

A lever member 166 is rockably mounted on the spacer plate 161 by the aid of a bracket 167 and is con nected to the closure by a link 168. The lever member rotation of the 166 has a crank-like lateral extension 169 with a slot 169a for accommodating a reduced neck -a on the push rod 165. The push rod 165 has a packed head 165b at its outer end slidable in a bore 170 provided in the drum head 131, a spring 171 confined between the head 165-b and hub 159 urging the push rod 165 outwardly, to cause the closure 155 to close the bottom opening 152. Appropriate pressure exerted on the push rod 165, as by the operating rod 107 will cause the closure 155 to uncover the bottom opening 152 and close the aperture 154, thus delivering a metered quantity of ink as determined by the volume defined betwen the cradle bottom 151 and the plate 153. Upon release of the push rod 165, the closure 155 returns to its normal position closing the bottom opening 152. A flat spring 172 engages an extension 166-11 of the lever 166 for insuring movement thereof to insure movement of the closure 155 to close either of the openings 152 or 154, in a manner similar to that in the first described form of the invention.

As in the first described form of the invention, it may be desirable to provide optionally operable means for masking the trailing end portion of the shell portion 132, for which purpose, an arrangement substantially identical with that disclosed in Figures 9 and 10 is shown. Thus, an arcuate plate 179 adapted to closely engage the inner surface of shell 132, and corresponding with plate 119 of Figures 9 and 10, is supported for angular movement toward and away from shell 13?. by a pair of arms 180, and is optionally movable into and out of masking position by the aid of a rotatable cam shaft 182 and tension spring 184 all as before.

1 claim:

l. In a. rotatable printing drum for a duplicating machine: a perforate shell adapted to have a stencil sheet secured on its exterior; a stationary cradle rotatably suspended within the drum; said cradle including a horizontal, wall forming upper and lower ink containing chambers in said cradle, there being an opening through said wall for establishing communication between said chambers as well as an opening through the bottom of said cradle for discharging ink into the interior of said shell; a closure adapted to close either of said openings; means including an element extending axially of said drum for operating said closure; means urging said closure to close the opening in said cradle; and means efiective upon movement of said closure to open said cradle opening exerting a force urging said closure to close the opening in said wall.

2. In a printing drum for a duplicating machine: a perforate shell adapted to have a stencil sheet secured on its exterior; means supporting said drum for rotation about its axis and providing an axially extending opening at each end of the drum; a stationary cradle for containing a body of ink, means suspending said cradle in said drum, including opposed members mounted in the openings at the ends of the drum, there being an opening in the bottom of said cradle to pass ink to the interior of the shell; a closure for said opening normally closing said opening; one of said members being slidably supported in the opening in one end of the drum, means responsive to sliding of said one member for operating said closure to open, the other of said members providing a clear passage between the interior and exterior of the drum.

3. In a printing drum for a duplicating machine: a perforate shell adapted to have a stencil sheet secured on its exterior; means supporting said drum for rotation about its axis, a tubular member extending axially through said drum; a cradle suspended from said member within said drum for containing a body of ink, there being an opening in said cradle to pass ink to the interior of the shell; a closure for said opening: lever means pivoted on said cradle for operating said closure to open and to close; a first element slidable on said member and connected to operate said lever; a second element slidable within said member; means movable exteriorly of said member responsive to sliding of said second element for engaging and sliding said first element to operate said lever in closure opening direction; and spring means urging said first element to operate said lever in closure closing direction.

4. In a printing drum for a duplicating machine: a perforate shell adapted to have a stencil sheet secured on its exterior; means supporting said drum for rotation about its axis and providing an axially extending opening, fixed to said drum; a stationary cradle rotatably suspended from said means within said drum for containing a body of ink, there being an opening in said cradle to pass ink to the interior of the shell; an apertured wall in said cradle spaced above the bottom thereof to form upper and lower ink containing chambers; a closure adapted to close either said opening or the aperture in said Wall; lever means pivoted on the cradle for operating said closure; an element slidably supported by said means connected to said lever means; spring means urging said element to move said closure in a direction to close said opening; an element axially movable in said axially extending opening for operating said slidable element in a direction to open said opening and close the aperture in said wall; and a resilient element interposed between said lever means and said cradle opposing movement of said lever means in a direction to move said closure from either closed position.

5. In a printing drum for a duplicating machine: a perforate shell adapted to have a stencil sheet secured on its exterior; means supporting said drum for rotation about its axis a tubular member fixed to said drum; a cradle suspended from said tubular member within said drum for containing a body of ink, there being an opening in said cradle to pass ink to the interior of the shell; a closure for said opening normally urged to closed position; a lever pivoted on said cradle, means connecting said lever with said closure for operating said closure to open and to close responsive to movement of said lever; an element axially movable in said tubular member; a sleeve mounted to slide on the exterior of said tubular member; means operatively connecting said sleeve with said lever; and means movable axially of said tubular member for engaging and sliding said sleeve responsive to axial movement of said element.

6. In a printing drum for a duplicating machine: a perforate shell adapted to have a stencil sheet secured on its exterior; means supporting said drum for rotation about its axis including a pair of members respectively at opposite ends of the drum, at least one of said members having an axially extending opening into the drum; a stationary cradle rotatably supported by said members within said drum for containing a body of ink; a wall in said cradle spaced above the bottom thereof, and forming upper and lower ink containing chambers; there being an opening in said Wall for establishing communication between said chambers, as well as a discharge opening in the bottom chamber; a common closure movable between positions closing one or the other of said openings; means biasing said closure to close one of said openings; and means slidable in said axially extending opening for optionally operating said closure to open said one opening and to close the other openlng.

7. inking apparatus for the rotary printing drum of a duplicating machine, comprising; a cradle for consliding movement relative thereto,

taining a supply of ink, a mounting member for suspending the cradle therefrom in the drum, adapted to rotate with the drum relative to the cradle; said cradle having an opening for passing ink into the drum, a closure for said opening, an operating member mounted on said mounting member for rotation therewith and adapted to be operated from the exterior of the drum; a second member mounted on said supporting member for sliding movement relative thereto, means for moving said second member relative to said supporting member responsive to sliding movement of said operating member, means connecting said second member with said closure for moving the closure to open and close, responsive to movement of said second member, and spring means urging said last named means to close said opening.

8. Inking apparatus adapted to be mounted in the rotary printing drum of a duplicating machine; comprising: a cradle adapted to contain ink, having an opening for passing ink onto the interior of the drum, means for mounting the cradle Within the drum, including a tubular member suspending the cradle therefrom and adapted to rotate relative thereto upon rotation of the drum, a closure for said opening, a slidable member in said tubular member operable from the exterior of said drum; said tubular member having a slot therein, a sleeve surrounding said tubular member for sliding movement thereon, a projection on said slidable member extending through said slot and contacting said sleeve, whereby sliding movement of said slidable member causes corresponding movement of said sleeve, means connecting said sleeve with said closure for moving said closure responsive to sliding movement of said sleeve, and springs on said tubular member urging said slidable member and said sleeve in a direction for holding said closure in position to close said opening.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 628,651 Cummings July 11, 1899 658,037 Dick Sept. 18, 1900 976,704 Smith Nov. 22, 1910 1,095,275 Gibbs et al. May 5, 1914 1,215,310 McCrea Feb. 6, 1917 1,527,783 Brasseur Feb. 24, 1925 1,597,250 Rowley Aug. 24, 1926 1,607,386 Brasseur Nov. 16, 1926 1,625,054 Rosato Apr. 19, 1927 1,687,003 Brasseur Oct. 9, 1928 1,928,233 Simonsen Sept. 26, 1933 2,092,242 Brasseur Sept. 7, 1937 2,169,933 Terrier et al Aug. 15, 1939 2,307,291 Packwood Jan. 5, 1943

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