US2713304A

US2713304A - Stencil printing machine

Info

Publication number: US2713304A
Application number: US284780A
Authority: US
Inventors: James R Thomas
Original assignee: JOSEPH A WEBER
Current assignee: JOSEPH A WEBER
Priority date: 1952-04-28
Filing date: 1952-04-28
Publication date: 1955-07-19
Anticipated expiration: 1972-07-19

Description

July 19, 1955 .1. R. THOMAS STENCIL PRINTING MACHINE Filed April 28, 1952 3 Sheets-Sheet l July 19, 1955 J. R. THOMAS STENCIL PRINTING MACHINE 2 W a /m e T h N 1 I m N 0w 5 w m a f Li k B E 3 I Q /0 I s mdfim g 3 m9 @q \A m u a; M mm mm mum Filed April 28, 1952 July 19, 1955 J. R. THOMAS 2,713,304

STENCIL PRINTING MACHINE Filed April 28, 1952 3 Sheets-Sheet 3 W 0R. @Azz% 2,713,304 Patented July 19, 1955 STENCIL PRINTENG MACHINE James R. Thomas, Deerfieid, 111., assignor to Joseph A. Weber, Mount Prospect, Ii].

Application April 28, 1952, Serial No. 234,780

2 (Ilairns. (Cl. 101-117) This invention relates to a new and improved stencil printing machine.

The imprinting from stencils, and particularly the repetitious imprinting from a single stencil, has been the principal subject of many machines. The unsolved problems of these many machines have been and are presently the imprinting of portions only from a stencil or, in other words, the imprinting of various sizes of stencils with but a single machine without requiring extensive modification. Further, a concurrent problem with such machines is to provide stock or material to be 1 imprinted of the proper size for the various sizes of stencils and the ability of the machine to automatically feed the various sizes of material to be imprinted.

It is therefore a principal object of this invention to provide a stencil printing macihne which is capable of imprinting from a single stencil a plurality of times on material to be imprinted.

An important object of this invention is to accommodate a stencil for repetitious imprinting and having means associated therewith for imprinting any desired portion from the entire stencil.

Another and further important object of this invention is the provision of means for a sheet material to be imprin ed of a size commensirate with the amount of stencil being imprinted.

Another and still further important object of this invention is to supply a continuous sheet material to be imprinted and automatic cut-oil means for cutting the sheet into lengths according to the amount of stencil imprinted thereon.

Still another important object of this invention is to provide a stencil imprinting machine which is adjustable to accommodate the imprinting of any desired portion of the stencil and to automatically and simultaneously feed the material to be imprinted a distance across the im- .1

printing space commensurate with the length of stencil imprinted.

Another and still further important object of this invention is the provision of means in a stencil imprinting machine for regularly and automatically feeding material to be imprinted through the machine, imprinting the stencil or any portion thereof on the material to be imprinted, and finally cutting off the imprinted portion of the material imprinted.

Other and further important objects of this invention will become apparent from the disclosures in the following specification and accompanying drawings.

In the drawings:

Fig. 1 is a top plan view of the stencil printing machine of this invention.

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1. V

Fig. 3 is an end elevational view of the stencil printing machine of Figs. 1 and 2 as viewed from the discharge end thereof.

Fig. 4 is an enlarged fragmentary sectional view taken on the line 4-4 of Fig. 3.

Fig. 5 is a detail view of one of the cam rotors as shown in the device of Fig. 4.

Fig. 6 is another view of the cam rotors employed in the apparatus of Fig. 4.

As shown in the drawings:

The reference numeral 3 indicates generally a frame supporting structure which is preferably a metal casting and including sheet metal portions. The frame supporting structure 8 is mounted on a plurality of spaced apart rubber pads 9 on the bottom thereof to cushion the machine and to insure against the scratching of tables or desks upon which the machine might be placed for operation. The reference numeral 16) indicates a table or inclined top of the supporting structure 8 which is joined by vertically disposed spaced apart

side walls

11 and 12. A vertical wall 13 is provided at the rearward end of the machine and a downwardly curved forward end wall is shown at 14 thus completing the frame support 8 of the stencil printing machine.

A removable bracket 15 is provided at the forward end 14 of the machine and is fixedly attached thereto for the purpose of carrying a roll of paper or other material to be imprinted as designated by the numeral 16. The roll of paper is mounted on a shaft 17 which is equipped with conical end plugs or cores 18 and 19 for holding the roll 16 in centered position on the shaft.

For the purpose of properly feeding the paper from the roll 16 into the operating mechanism of the machine of this invention, there are provided laterally spaced apart

guides

29 and 21 disposed parallel one to the other and extending along the inclined table portion '10 of the support 8. The table top 10 is provided with opposed transversely extending

elongated slots

22 and 23 and a second pair of

elongated slots

24 and 25 opposed and in spaced apart position in the same manner as the

slots

22 and 23. Set

screws

26, 27, 28, and 29 are adapted to pass through the

guide members

29 and 21 and engage longitudinally extending strip members 161 on the underside of the table top 19 by passing through the

elongated slots

22, 23, 24, and 25. It is apparent that with the available lateral spacing of the guides and 21 any desired width of paper stock may be employed on the roll 16 for the purpose of imprinting thereon. The

guides

20 and 21 are adjusted in these

elongated slots

22, 23, 24, and in equal the width of paper stock employed on the roll 16. In cooperation with the

guides

20 and 21 there are also provided spaced apart

fiat springs

38 and 31 in association with the forward ends thereof to cause the paper from the roll 16 to be held down against the table top 10 and to be moved upwardly along the table top 10 between the

guides

20 and 21. Similarly, a transversely disposed plate 32 is positioned at the rear upper ends of the guides or

tracks

20 and 21 and is again for the purpose of directing the paper stock down against the table top 19 and into the imprinting mechanism just rearwardly thereof.

A longitudinally extending and elongated aperture 33 is provided in the paper guiding plate 32 for the passage of a projecting trip finger 34. The purpose of the trip 34 is to prevent the imprinting or the attempted imprinting whenever there is no paper stock in the machine.

A roll structure 35 is for the purpose of carrying a stencil, carrying ink, and eifecting movement of paper to be imprinted through the machine. The strip of paper from the roll 16 is further identified by the numeral 36 and, as previously described, it passes over the curved forward portion 14 of the imprinting machine and thereupon up the inclined table top 10 between the

guide members

20 and 21 and thence over the trip finger 34 and beneath the stencil carrying roll structure 35. A cooperative pressure roll 37 is positioned beneath the roll 35 and cooperates therewith to cause imprinting and feeding of paper stock. The roll 37 is made of rubber or rolls. Similarly the pressure engagement of the roll 37 with the stencil roll 35 causes the advancement of the paper stock within the machine.

A carriage 38 is slidable fore and aft on the frame structure 8. .The carriage 38 is adapted to carry the stencil roll structure 35 and also the pressure roller 37 so that the imprinting mechanism of this machine may be moved forwardly or rearwardly with respect to the inclined table top over which the material to be imprinted is passed. The rearward end of the machine carries a paper cut-off mechanism which is stationary with respect to the frame support 8 and this movable carriage 38 moves with respect to this cut-ofi mechanism. The cut-off mechanism will be later described in detail. The sliding carriage 38 is provided with laterally spaced

side members

39 and 40 and a shaft 41 is mounted for journal support in these spaced side members. The roll structure ismounted on the shaft 41 for rotation therewith.

A hand crank 42 is fastened to the shaft 41 on the outside of the side member 39 of the carriage 38 and rotation thereof causes the shaft 41 to be rotated. Movement of the hand crank 42 occurs in the direction of the arrow 43 and as the stencil on the roll structure 35 7 engages the paper 36 with the pressure roller 37 exerting a force thereagainst, the paper is imprinted from the stencil and the paper is simultaneously moved rearward- 1y. It should be understood that the device. of this invention may be power dn'ven without altering the invention. The pressure roll 37 is carried on a shaft 44 which is supported in the side members 39 and of the shiftable carriage 38. The carrying of the shaft 44 in the carriage side members'is accomplished indirectly by means of spaced apart

arms

45 and 46. The

arms

45 and 46 are hinged respectively on the

sides

39 and 40 of the carriage at 47 and 48. The roll shaft 44 is mounted in the forward ends of the

arms

45 and 46. Springs 49 and 50 spaced apart on the sides of the machine are arranged and constructed to urge the rubber pressure roll 37 upwardly into rolling contact with the roller 35. Oppositely projecting

pins

51 and 52 are disposed on the

side members

39 and 40 respectively for receiving the fit upperends of the springs 49 and 50. The lower ends of the springs are attached at 53 and 54 on the arms 45' and 46respectively. It is therefore apparent that these springs normally urge the pressure roll 37 upwardly toward contact with the stencil carrying roll structure 35. L 7 A shaft 55 extends across the machine and is journaled inthe fixed

side members

11 and 12 of the frame supporting structure 8. The shaft 55 carries spaced spur gears 56 and 57 positioned just inside the spaced

side members

11 and 12. Each of the spur gears 56 and 57 is provided with an

integral collar

58 and 59 disposed on the shaft 55 and extending inwardly toward each other. The

collars

58 and 59 are equipped with set screws for holding the collars and thus also the integral spur gears 56 and 57in fixed position on the shaft 55. The shaft 55 is bent at a right angle outside of and adjacent the side sheet 12 providing a hand gripping portion to effect rotation of the shaft. The extreme outer end of the bent portion 62 is formed as a pointer 63 whereby calibrations (not shown) may be inscribed on the outer side sheet 12 to indicate the position of the carriage 38 with respect to the frame supporting structure 8. Gear racks 64 and 65 are fixedly mounted on. the

carriage side members

39 and 40 respectively for engagement by the spur gears 56 and 57 on the shaft 55. Thus rotation of the spur gears causes movement of the carriage longitudinally with respect to the frame 8. This'movement of the carriage is either forwardly or rearwardly depending on the direction .of rotation of the shaft 55 by the hand gripping portion 62. As shown in Fig. 2, the plate 39 hasa longitudinally extending elongated slot 66 for the passage of the shaft 55. Similarly the plate 40 has an elongated slot (not shown) which is identical to the slot 66. The gear rack 64 is held in position on the side member 39 by spaced screws 67 and 68. As best shown in Fig. 2, elongated slots 126 are formed in the

side members

39 and 40 of the carriage 38 in alignment with the slots 66 adjacent the gear racks. Winged set screws 127 and 128 pass through apertures in the

side members

11 and 12 of the frame 8 and through the elongated slots 126 in the carriage 38 for engagement with a lock nut 129 as shown in Fig. 2. A tightening of the winged set screws 127 and 128 prevents longitudinal movement of the carriage 38 with respect to the frame 8 of the entire stencil printing machine. However, loosening of these set screws permits ready adjustment of the carriage by the operator merely turning the bent end portion 62 of the shaft 55 to any desired position.

As best shown in Figs. 2 and 3, a sprocket 69 is mounted a with a sprocket 71 on a shaft 72. The shaft 72 is jour- Y naled with respect to the supporting structure 8 by means of guide pins 73 and 74 which are positioned'in opposite sides of the frame 8 and extend through the

side members

11 and 12 and into the ends of the shaft 72 to thereupon provide journal bearings for the shaft within the frame 8. Movement of the carriage 38, although occurring on a straight line rather than an arc, does not necessitate a change in the length of the chain 70 as it is a substantial distance from the shaft 72 and the small changes in distance do not afiect operation of the device.

A cam rotor 75 is fixed to the 'shaft 72 and rotates therewith. A bracket 76 is journaled for free hinging movement about a shaft 77 which is fixedly mounted within the

frame side sheets

11 and 12 by means of screws 78 and 79 passing through the side members and into threaded engagement with the ends of the shaft. Spaced collars 8i) and are afiixed to the shaft 77 by means of set

screws

131 and 132 thus maintaining the intermediately disposed bracket 76 in fixed hinging relationship With respect to the shaft 77. a

The bracket 76 includes a pair of vertically spaced apart

arms

81 and 82. Between thearms 81 and 82 there is defined an arcuate surface 133. A roller 83 is journally carried on a stub shaft or pin 84 on the upper arm 81. The roller 83 lies in the same plane with the cam rotor 75. Thus as the high part of the cam 75 engages the roller 83, the bracket 76 is raised about its hinge'mounting on the shaft 77 A second roller 85 is mounted on a stub shaft 86 which is fixed to the cam rotor 75 at the highest point thereon away from the driving shaft 72. The roller 85 projects in the opposite direction from the roller 83 and thus lies in the same plane with the lower arm 82 of the bracket 76. The roller 85 thus acts within the arcuate notch 133 and against the arm 82 to effect a lowering of the bracket 76 about its hinge shaft 77. It is therefore apparent that the bracket 76 is raised by the outer periphery of the cam rotor 75 engaging the roller 83 on the arm 81, and similarly the roller 85 engages the lower arm 82 of the bracket 76 to effect a lowering of the bracket.

A pair of angle guides 87 and 88 are afiixed to the

side walls

11 and 12 respectively of the frame supporting structure 8 through the medium of tubular spacers 134 and 135 and locking screws 136 and 137. The screws pass through the

walls

11 and 12, through the spacers 134 and 135, and

bar 89 extends across the upperrearward end'of the machine between the angle guide supports87 and 88. The

vertical positioning of the stationary shear bar 89 is substantially equal to that of the juncture between the cooperative stencil holding roller and the pressure roller 37. A movable knife 90 is positioned transversely across the end of the stencil printing machine adjacent the stationary shear bar. The knife 90 is inclined at a slight angle so as to insure the shearing of the paper stock as it is fed therethrough. The knife 90 is mounted across the top ends of vertically disposed spaced apart sliding

bars

91 and 92. The knife is attached to the bars by

screws

93 and 94. A cross plate member 95 joins the lower ends of the

vertical bars

91 and 92 making a substantially unitary rectangle along with the knife 90. Vertical translational movement of the knife 90 is caused by rocking movement of the bracket 76. The bracket arm 82 is pivotally attached at 138 to a relatively confined link arm 139 which in turn is pivotally mounted at 140 on a small angle member 141 which is rigidly attached to the cross plate 95. The link arm 139 lies parallel to the member 141 and has only slight pivotal movement thereabout. It is thus possible to transmit the rocking movement of the bracket 76 to vertical movement of the knife 90 with respect to the stationary shear bar 89.

A cross plate 98 is fixed to the stationary angle guides 87 and 88 by means of

screws

99 and 100 and acts to reinforce the stationary part of the structure over and through which the knife mechanism is vertically moved. The plate also acts to carry vertical bars 142 and 143 Which are fastened to the cross plate and thus also the

guides

87 and 88 by means of screws 144 and 145 respectively. These stationary bars 142 and 143 are positioned just inside the vertically moving

bars

91 and 92 which carry the knife means 90 and thus define tracks for the moving knife mechanism. Spaced apart plate means 146 and 147 are similarly attached to the cross plate 98 and the vertical stationary guide bars 142 and 143 by the same screw means 144 and 145. The plates 146 and 147 extend outwardly from the bars 142 and 143 and overlie the vertically shiftable

knife carrying bars

91 and 92.

It is thus apparent that the knife carrying bars 91 and 92 are confined in all directions exceptingvertical movement. It should be explained that the knife structure, including the stationary shear bar 39 and the vertically movable knife 90, is stationary at least longitudinally with respect to the frame 8 while the carriage 38 carrying the stencil printing and feeding rolls moves longitudinally with respect thereto. The purpose of this relative movement is to provide an adjustment for the cut- 011 of the paper stock sheet 36 so that as various portions of the stencil are imprinted the printed stock may be cut ofi to a size commensurate with the amount of printing thereon.

A cross bar or strip 148 extends between the vertical angle guides 87 and 88 at the upper ends thereof and is adapted to carry a countermechanism 101 which is mounted on a supporting bracket 102 and thereupon fastened to the cross bar 148. The countermechanism 101 thus is stationary with respect to the stencil carrying machine and is not subject to movement either by the carriage 33 or the vertically moving knife mechanism. A trip arm 103 is formed as a part of the countermechanism 101 and extends across and into the plane of the vertically movable knife 90. As the paper is imprinted and is moved through the machine and the knife acts to shear off the imprinted portions, the 'countermechanism is arranged and constructed to record the number of operations of the knife. It is therefore possible to have an accurate recording of the number of imprinted and cut pieces of paper stock after operation of the machine is completed.

A removable receiving hopper 104 is provided for the cut and imprinted paper 36 and the means for holding the hopper 104 to the stencil imprinting machine is in the form of hooks 105 on the hopper 104 for hanging over .the vertical wall 13 of the frame supporting structure 8.

6. A rear shield and/or guide 163 forms a paper slide between the cut-otf and the hopper.

A stencil clamp 106 extends across the roll structure 35 and is hingedly mounted by means of spaced

arms

107 and 108 to a cross rod 149 which is hingedly mounted for rotation in the spaced

end members

150 and 151 of the roll structure 35. As best shown in Fig. 1, the cross rod 149 has a bent end portion 152 just outside the end disc 151 of the stencil roll structure 35. As shown in Fig. 4, a locking member 153 is hinged at 154 on the end disc 151 of the roll 35 and lies in the same plane with the bent end portion 152 of the shaft 149. The lock member 153 prevents the rod shaft 149 from having rotation inasmuch as it is engaging and restricting movement of the bent end portion 152 thereof. The stencil 155 is held beneath the clamp 106 of the roll carrying structure 35. In order to release the stencil which is only held at one end or side, the lock member 153 is rotated about its pivotable mounting 1 4 thus permitting an upward swinging of the end portion 152 of the rod 149 which raises the clamp 106 to release the stencil 155. Thus the stencils to be used in this machine may be replaced easily and quite readily merely by clamping them at one end thereof under the clamping member 106.

As shown in Fig. 5, a first cam rotor 1199 is employed in combination with a second cam rotor as shown in Fig. 6. Both of the

cam rotors

109 and 110 are mounted over the shaft 41 which carries the entire roller structure 35. The cam rotor 109 is provided with an arcuate elongated slot 111 disposed concentrically about a circular aperture 112 in the rotor 109. The shaft 41 passes through opening 112. The first cam rotor 109 is further equipped with a plurality of regularly spaced small openings 114 positioned in a path concentric with and spaced outwardly from the arcuate slot 111.

The second cam rotor 110 inciudes an enlarged aperture 115 which is spaced outwardly from a shaft receiving aperture 116. The spacing between the apertures 115 and 116 is equal to the spacing between the arcuate slot 111 and the slot aperture 112 of the earn 109. The

cam rotors

109 and 110 have substantially identical outer peripheries and the various degrees of camming are accomplished in this device by the relative positioning of the cams with respect to each other. Thus various outer cammed surfaces may be accomplished between the two cam rotors to get the desired effective engagement of the

rollers

35 and 37 for the purpose of engaging the rolls at various degrees for various amounts of stencil imprinting and simultaneously various amounts of paper feed therebetween. A single small opening 117 in the rotor 110 is spaced radially outwardly from the shaft opening 116 a distance equal to the spacing between the shaft aperture 112 and the plurality of small openings 114 in the cam rotor 109. The small opening 117 is used for obtaining a registering thereof with any one of the small openings 114. The other end of the roller structure 35 is similarly equipped with adjoining

cam rotors

118 and 119 for the purpose of accomplishing the adjustment of both ends of the roller 35 in the same manner and to the same degree. A spacer member as shown in Figs. 1 and 4 is positioned between the end member 151 of the roller 35 and the cam rotor 110. A screw means 120 passes through the end disc 151 of the roller 35, through the spacer 156, through the enlarged aperture 115' of the cam rotor 110, and thereafter through the eiongated arcuate slot 111 of the cam rotor 109. A nut 157 engages the screw 120 with a milled shoulder portion thereof 158 engaging the elongated arcuate slot 111 preventing rotation of the nut 157. The sleeve spacer passes into the enlarged aperture 115 of the cam rotor 110 thus making the rotor 110 immovable rotationally separately from the shaft 41. However, when the screw means 120 is loosened, the cam rotor 109 may be moved arcuately about the shaft 41 throughout the length of the slot 111. Movement of the cam 109 is, of course, limited by the length of the slot 111 by the passing of the screw means 120 therethrough. When the screw means 126 is tightened, the

cam rotors

109 and 110 no longer are permitted relative movement and the exterior surface of the joint cams is fixed until resetting. For purposes of convenience, the screw means and spacer employed in conjunction with the adjoining

cam rotors

118 and 119 shall be designated by the numeral 121. The details of the screw adjoining means 121 for the

rotors

118 and 119 have not been shown for the reason they are identical to the means employed for the

rotors

109 and 110 as shown in Fig. 4.

The pressure roller '37 mounted on the shaft 44 includes at the outer ends of the shaft spaced

circular rotors

122 and 123. These rotors are of a thickness comparable to the joint thicknesses of the

carn'rotors

109 and 110 and 118 and 119, respectively. The

jointcams

199 and 110 and 118 and 119 thus engage and act against the circular disc rotors 112 and'123 on the shaft 44 causing greater or less separation of the stencil carrying roll 35-with the pressure roll 37. The extended high portion of the joint cams as shown at 164 keeps pressure roll 37 from engaging the periphery of the stencil carrying roll 35 and thus there is no stencil imprinting during this interval of cam engagement. When the lower portions of the cams engage the

rotors

122 and 123, the roller 37 is permitted to be pulled upwardly by the springs 49 and '50 into engagement with the stencil and ink carrying roll structure 35, providing, of course, that there is paper stock to be imprinted within the juncture between the two rolls. In other words, the trip 34 must be depressed from its upright position as shown in Fig. 2 so that the latch 124 fixed to a shaft 159 on which the trip member 34 is carried will be removed from engagement with a ledge 125 formed on the end of the roll carrying arm 45 thus permitting the arm to move upwardly as shown in dashed lines in response to the action of the cams and springs, The paper trip 34 insures that the rolls will be maintained spaced apart and the ink from roll 35 will not be smeared over the pressure and feed roller 37 in case of operation of the machine without a supply of paper therein. A fiat steel bar 1&0 is attached to the trip arm 34 and to the shaft 159. The bar 160 acts as a weight to keep the trip 34 in contact with paper and to cause latch 124 to engage ledge 125 when the machine is operated without paper. I

In the operation of the stencil imprinting machine of this invention, the hand crank 42 is rotated in the direction of the arrow 43 when a supply of roll paper 16 is in'the carrying bracket at the forward end of the machine. The paper strip 36 is delivered upwardly through the spaced guide or

track members

20 and 21 to a position between the vertically spaced rolls and 37 at which point the trip finger 34 has been depressed permitting the roll 37 on the shaft 44 to be swung about the hinged arms 7 and 46 dependent directly upon the peripheral shape of the joint cams 1t39 and 110 and 118 and 119 along with the action of the springs 49 and which maintain the end rollers of the shaft 44 in contact with the cams. The stencil 155 to be reproduced is clamped under the member 166 on the roll structure 35 as previously described, and as the hand crank 42 is rotated that portion of the stenctil which is permitted to engage the'paper stock 36 by reason of the pressure roller 37 pressing upwardly against the paper will be imprinted with the material from the stencil. However, all of the stencil need not be imprinted and this is determined by the relative positioning of the

cam rotors

109 and 110 as determined by the registering of any one of the plurality of small openings'114 with the single small opening 117 of the rotor 116); Simultaneously with the changing in the amount of imprinting there is also a changing in the amount of paper fed by the pressure cooperation of the two

rollers

35 and 37. In order to completely compensate for the change in imprinting amounts of the stencil, there is necessarily the longitudinal shifting adjustment of the carriage 38 for the purpose of cutting the paper stock to the most efficient length. The cutting of the stock can be adjusted to the same degree as the amount of imprinting thereon. The movement of the carriage is alsonecessary for the centering of the imprinted portion of the stencil on the paper stock.

It is thus seen that herein is provided a stencil printing machine wherein various stencils may be readily replaced and various degrees or amounts of stencils may be printed on the paper stock and the changing of the amount of material to be imprinted automatically corrects for amount of paper'stock feed through the machine and whereafter. a manual adjustment of the carriage in the machine will provide for proper centering of the printed portion and cutting'off of paper stock with no waste of paper. a

Numerous details of construction may be varied throughout a wide range without departing from the principles disclosed herein, and I therefore do not propose limiting the patent granted hereon otherwise than as necessitated by the appended claims.

What is claimed is:

l. A stencil printing machine comprising a supporting frame, a supply of material to be imprinted, a stencil holding roll, a shaft for said stencil holding roll carried on said supporting structure, means driving said stencil holding roll shaft, cam rotors carried on both ends of said shaft spaced outwardly from said stencil holding roll, a pressure roll, a shafttfor said pressure roll carried on said supporting structure, spring means normally urging said pressure roll against said stencil holding roll, circular rotor members carried on both ends of said pressure roll shaft spaced outwardly from said pressure roll and in the same planes respectively as each of said cam rotors whereby as the stencil holding roll shaft is driven the cam rotors engage'the circular rotor members to cause engagement or disengagement of the stencil holding roll and pressure roll dependent upon the shape of the cam rotors, said pressure roll shaft mounted on spaced apart arms hinged to said supporting frame, and wherein the spring means urges arcuate swinging of the pressure roll about the hinged arms, and latch means associatedwith said spaced apart arms arranged and constructed for movement betweenttwo positions, said latch means in one of said positions, adapted to maintain the pressure roll spaced from the stencil roll and in the other of said positions adapted to free said pressure roll for uninterrupted contact with said stencil roll, and a hinged actuator for said latch means disposed forwardly of said stencil printing roll whereby when a supply of material to be imprinted is in the machine a the latch means willtbe shifted to a position to permit engagement of the stencil roll by the pressure roll and when there is no material to be imprinted in the machine the latch means will prevent engagement of the stencil roll by the pressure roll.

'2, A stencil printing machine comprising a supporting structure, a fore and aft moving carriage mounted on said supporting structure, a pair of cooperative driven rolls carried on said fore and aft moving carriage, adjustable cam means arranged and constructed to regulate the degree of contact between the, cooperative rolls, a source of material for imprinting thereon, shear type cut-off means mounted on said supporting structure separately from said fore and aft moving carriage, and drive carrying means, directly interconnecting the driven rolls with the shear type cut-off means whereby the cooperative rolls on the fore and aft moving carriage maybe moved toward or away from said cut-off means and rotation of said cooperative rolls causesoperation of the shear type cut-ofi means on the supporting structure.

(References on following page) i 9 References Cited in the file of this patent UNITED STATES PATENTS 934,077 Kunath Sept. 14, 1909 1,050,292 Rafiel Ian. 14, 1913 1,174,414 Hastings Mar. 7, 1916 10 Twomley et a1. Oct. 8, 1918 Cooke May 17, 1932 FOREIGN PATENTS Great Britain Jan. 25, 1909