SELECTIVE PRINTING APPARATUS WITH AN ACTIVATED MASTER
United States Patent 3760725
The heat absorbing text of a printing machine master on a duplicating drum is placed in contact with a dye coating on a sheet or web and irradiated by a first source of radiation so that portions of dye coating in contact with the heat absorbing text melt and adhere to the heat absorbing text while the remainder of the dye coating remains on the sheet when the same is pulled off the master. During the following revolutions of the duplicating drum, copy sheets are fed while a second source of radiation heats the applied coating on the text of the master before the text reaches the printing line. Shielding means are selectively operated to cover the first and second sources of radiation to prevent coating before printing, and dye transfer during printing, so that selected shielded lines of the master are not printed. In another embodiment, coated narrow and wide webs selectively cooperate with corresponding narrow and wise sections of the master sheet.
US Patent References:
Method and apparatus for duplicating text, pictures and the like on unprepared copy receiving sheets
Kuarnegard - December 1968 - 3414724
/3623869.html
Allard - November 1971 - 3623869
APPARATUS FOR THERMOGRAPHIC DUPLICATION OF A RADIATION ABSORBENT PICTURE
Kuarnegard - April 1972 - 3654462
Method and apparatus for duplicating text, pictures and the like on unprepared copy receiving sheets
Kuarnegard - December 1968 - 3414724
/3623869.html
Allard - November 1971 - 3623869
APPARATUS FOR THERMOGRAPHIC DUPLICATION OF A RADIATION ABSORBENT PICTURE
Kuarnegard - April 1972 - 3654462
Application Number:
05/261163
Publication Date:
09/25/1973
Filing Date:
06/09/1972
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
250/330, 250/319
International Classes:
B41L19/00; B41M5/26; B41L19/02
Field of Search:
101/468,470,471 250/65T,83.3HP
Primary Examiner:
Coughenour, Clyde I.
Claims:
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims
1. Selective printing apparatus with an activated master having on one side radiation absorbing means forming text lines, comprising a printing machine including a rotary duplicating drum, a counter pressure roller, supply means for feeding copy sheets to a bight between said drum and said counter pressure roller, and holding means for holding said master on said drum with said radiation absorbing means on the outside; positioning means for placing at least a section of an activating means having on one side a coating of a transferrable dye in a transfer position in which said coating abuts a corresponding section of said master and said radiation absorbing means thereon; a first source of radiation close to said positioning means for irradiating at least said section of said master and said radiation absorbing means thereon so that the radiation absorbing means of consecutive sections of said master are heated during rotation of said drum whereby portions of said coating adhere to said radiation absorbing means and activate the text lines on said master; a second source of radiation located between said supply means and the bight between said drum and said counter pressure roller, for irradiating and heating said portions of said coating on said radiation absorbing means for transferring said text lines to a copy sheet; and a plurality of shielding means selectively movable to a shielding position located between at least said second source and one of the test lines on said master formed by coated radiation absorbing means so that text lines covered by said shielding means are not heated, and not imprinted on the copy sheet.
2. Selective printing apparatus as claimed in claim 1 wherein each of said shielding means includes a shielding member mounted for movement between an inoperative position and a shielding position located between said second source of radiation and said drum with said master; means for shifting each of said shielding members between said positions thereof; and arresting means for arresting each shielding member in said inoperative and operative positions.
3. Selective printing apparatus as claimed in claim 1 further comprising a plurality of other shielding means selectively movable to shielding positions located between said first source of radiation and one of the text lines on said master formed by said radiation absorbing means so that the shielded text lines are not heated whereby no coating adheres to selected shielded text lines.
4. Selective printing apparatus as claimed in claim 3 wherein corresponding text lines of said master are shielded by corresponding shielding means of the two pluralities of shielding means.
5. Selective printing apparatus as claimed in claim 3 wherein each of said other shielding means includes another shielding member mounted for movement between an inoperative position and a shielding position located between said first source of radiation and said master with said heat absorbing means, means for shifting each of said other shielding members between said positions thereof, and arresting means for arresting each of said other shielding members in said inoperative and shielding positions thereof.
6. Selective printing apparatus as claimed in claim 5 wherein said means for shifting include electromagnetic means including a spring biased armature connected with one of said other shielding members.
7. Selective printing apparatus as claimed in claim 3 wherein said shielding means and other shielding means include shielding members and other shielding members, respectively, and shifting means and other shifting means for said shielding members and other shielding members, respectively; and comprising manually operated actuating means for simultaneously operating said shifting means and other shifting means to move said shielding members and other shielding members between said inoperative and shielding positions thereof, respectively.
8. Selective printing machine as claimed in claim 7 comprising bistable dead center spring arresting means for arresting asid acutating means in two positions.
9. Selective printing apparatus with an activated master having on one side radiation absorbing means forming text lines, comprising a printing machine including a rotary duplicating drum having holding means for holding the master on said drum with said radiation absorbing means on the outside; a first takeoff reel and a first windup reel for transporting a narrow web having on one side a coating of a transferable dye confronting the outside of said master along a narrow axial section thereof; a second takeoff reel and a second windup reel for transporting a wide web having on one side a coating of said transferable dye contronting the outsdie of said master along a wide axial section thereof; first positioning means for placing a section of said narrow web in a transfer position abutting said radiation absorbing means of said master along said narrow axial first section thereof; second positioning means for placing a section of said wide web in a transfer position abutting said radiation absorbing means of said master along said wide axial second section thereof; first and second actuating means for selectively actuating said first and second positioning means to place the respective web section in said transfer positions; and a source of radiation for irradiating at least said first and second sections of said master and said radiation absorbing means thereon so that the radiation absorbing means of consecutive first and second sections, respectively, of said master are heated during rotation of said drum whereby portion of said coating adhere to said radiation absorbing means and activate the respective text lines on said master located in the respective first and second sections.
10. Selective printing apparatus as claimed in claim 9 wherein said first positioning means includes a first tubular eccentric member; wherein said second positioning means includes a second tubular eccentric member; comprising a common shaft passing through said first and second eccentric members and supporting the same in end-to-end relation for independent turning movement between first and second inoperative positions spaced from said master, and first and second operative positions pressing the respective web section against said master; and wherein said first and second actuating means are connected with said first and second tubular eccentric members for selectively turning said first and second tubular eccentric members to said first and second operative positons, respectively, to place the respective web section in said transfer position.
1. Selective printing apparatus with an activated master having on one side radiation absorbing means forming text lines, comprising a printing machine including a rotary duplicating drum, a counter pressure roller, supply means for feeding copy sheets to a bight between said drum and said counter pressure roller, and holding means for holding said master on said drum with said radiation absorbing means on the outside; positioning means for placing at least a section of an activating means having on one side a coating of a transferrable dye in a transfer position in which said coating abuts a corresponding section of said master and said radiation absorbing means thereon; a first source of radiation close to said positioning means for irradiating at least said section of said master and said radiation absorbing means thereon so that the radiation absorbing means of consecutive sections of said master are heated during rotation of said drum whereby portions of said coating adhere to said radiation absorbing means and activate the text lines on said master; a second source of radiation located between said supply means and the bight between said drum and said counter pressure roller, for irradiating and heating said portions of said coating on said radiation absorbing means for transferring said text lines to a copy sheet; and a plurality of shielding means selectively movable to a shielding position located between at least said second source and one of the test lines on said master formed by coated radiation absorbing means so that text lines covered by said shielding means are not heated, and not imprinted on the copy sheet.
2. Selective printing apparatus as claimed in claim 1 wherein each of said shielding means includes a shielding member mounted for movement between an inoperative position and a shielding position located between said second source of radiation and said drum with said master; means for shifting each of said shielding members between said positions thereof; and arresting means for arresting each shielding member in said inoperative and operative positions.
3. Selective printing apparatus as claimed in claim 1 further comprising a plurality of other shielding means selectively movable to shielding positions located between said first source of radiation and one of the text lines on said master formed by said radiation absorbing means so that the shielded text lines are not heated whereby no coating adheres to selected shielded text lines.
4. Selective printing apparatus as claimed in claim 3 wherein corresponding text lines of said master are shielded by corresponding shielding means of the two pluralities of shielding means.
5. Selective printing apparatus as claimed in claim 3 wherein each of said other shielding means includes another shielding member mounted for movement between an inoperative position and a shielding position located between said first source of radiation and said master with said heat absorbing means, means for shifting each of said other shielding members between said positions thereof, and arresting means for arresting each of said other shielding members in said inoperative and shielding positions thereof.
6. Selective printing apparatus as claimed in claim 5 wherein said means for shifting include electromagnetic means including a spring biased armature connected with one of said other shielding members.
7. Selective printing apparatus as claimed in claim 3 wherein said shielding means and other shielding means include shielding members and other shielding members, respectively, and shifting means and other shifting means for said shielding members and other shielding members, respectively; and comprising manually operated actuating means for simultaneously operating said shifting means and other shifting means to move said shielding members and other shielding members between said inoperative and shielding positions thereof, respectively.
8. Selective printing machine as claimed in claim 7 comprising bistable dead center spring arresting means for arresting asid acutating means in two positions.
9. Selective printing apparatus with an activated master having on one side radiation absorbing means forming text lines, comprising a printing machine including a rotary duplicating drum having holding means for holding the master on said drum with said radiation absorbing means on the outside; a first takeoff reel and a first windup reel for transporting a narrow web having on one side a coating of a transferable dye confronting the outside of said master along a narrow axial section thereof; a second takeoff reel and a second windup reel for transporting a wide web having on one side a coating of said transferable dye contronting the outsdie of said master along a wide axial section thereof; first positioning means for placing a section of said narrow web in a transfer position abutting said radiation absorbing means of said master along said narrow axial first section thereof; second positioning means for placing a section of said wide web in a transfer position abutting said radiation absorbing means of said master along said wide axial second section thereof; first and second actuating means for selectively actuating said first and second positioning means to place the respective web section in said transfer positions; and a source of radiation for irradiating at least said first and second sections of said master and said radiation absorbing means thereon so that the radiation absorbing means of consecutive first and second sections, respectively, of said master are heated during rotation of said drum whereby portion of said coating adhere to said radiation absorbing means and activate the respective text lines on said master located in the respective first and second sections.
10. Selective printing apparatus as claimed in claim 9 wherein said first positioning means includes a first tubular eccentric member; wherein said second positioning means includes a second tubular eccentric member; comprising a common shaft passing through said first and second eccentric members and supporting the same in end-to-end relation for independent turning movement between first and second inoperative positions spaced from said master, and first and second operative positions pressing the respective web section against said master; and wherein said first and second actuating means are connected with said first and second tubular eccentric members for selectively turning said first and second tubular eccentric members to said first and second operative positons, respectively, to place the respective web section in said transfer position.
Description:
BACKGROUND OF THE INVENTION
The present invention relates to a duplicating machine of the type disclosed in my U. S. Pat. No. 3,648,609, issued Mar. 14, 1972.
The patent discloses an apparatus for activating a printing master of a duplicating machine while the master is mounted on the periphery of the duplicating roller. The master has on the outside mirror script heat absorbing means forming characters and lines, which are brought into contact with a coated web, and when the heat absorbing means are heated by a first source of radiation, the dye coating is transferred to the text lines, and imprint copy sheets during normal duplicating operation. However, the machine disclosed in U.S. Pat. No. 3,648,609, prints the entire text of the master in a thermographic copying process. In this fashion, a disadvantage of water-soluble dyes, as are generally used for alcohol duplication, can be avoided. The disadvantage is that the dye, such as triphenylmethane causes frequently dye deposits on the hands of the operator.
SUMMARY OF THE INVENTION
It is one object of the invention to provide a selective duplicating machine which prints selected lines of the text of a master by a thermographic process.
Another object of the invention is to use for a selective printing operation, a substantially standard duplicating machine, provided with the apparatus of the invention.
With these objects in view, in addition to the first source of radiation, preferably infra-red radiation, which causes the transfer of the dye coating to the text lines of the master, a second source of infra-red radiation or the like is used which acts on the portions of the coating adhering to the characters of the text lines of the master so that the portions of the coating are melted and more easily transferred to the copy sheets. The second source of radiation is located to irradiate the master sheet before its leading edge reaches the printing line between the duplicating drum and the counter pressure roller.
In accordance with the invention, shielding means are provided which are selectively movable to a shielding position located between the second source of radiation and one of the text lines on the master formed by coated radiation absorbing text so that text lines covered by the shielding means are not heated, and not imprinted on a copy sheet.
Preferably, the apparatus further comprises a plurality of other shielding means selectively movable to shielding positions located between the first source of radiation and one of the text lines on the master formed by the radiation absorbing characters and lines, so that shielded text lines are not heated and no coating adheres to the selected shielded text lines.
The shielding means include shiftable shielding members which can be selectively operated under direct or indirect control of manual selector members. For example, a manual member may shift a shielding slide to a position covering a source of radiation, or the manual member may operate a switch to energize an electromagnet to withdraw a shielding member from a shielding position covering the respective source of radiation.
It is also possible to provide a duplicating drum with two relatively displaceable clamping holders for parts of a master, and to adjust the position of the clamping holders so that those parts of the master which are to be printed, are placed adjacent each other so that the effect of the source of radiation is limited to a head lines on one master part and selected text lines on another master part, while the remaining parts of the master are excluded from the effect of radiation.
In a modified embodiment, two coated webs of different width are used one of which is selectively pressed against a corresponding section of the master for transferring portions of the dye coating to the characters of selected lines on the respective sections of the master.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING:
FIG. 1 is a fragmentary schematic side elevation, partially in section illustrating a first embodiment of the apparatus of the invention;
FIG. 2 is a fragmentary schematic plan view of the embodiment of FIG. 1;
FIG. 3 is a plan view, partially in section, illustrating a modified embodiment in which two coated webs of different width are used; and
FIG. 4 is a fragmentary schematic side view of the embodiment of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
Referring first to FIGS. 1 and 2, a duplicating drum of conventional construction is mounted for rotation on a shaft 1a, and cooperates with a counter pressure roller 5 in a printing plane AB passing through the axes of the duplicating drum 1 and counter pressure roller 5. Copy sheets, not snown, can be fed by transporting rollers 1b and 1c to the printing line along which the counter pressure roller 5 is in contact with the printing drum 1. A heat reflecting and insulating cover 2 is fixedly secured to the periphery of the duplicating drum 1, or clamped by a holder. A mirror script master 4 is secured by holding means 3 to the duplicating drum 1 outward of the heat insulating cover sheet 2. Projecting radiation absorbing means 4a which may consist of carbon, form mirror script characters and test lines on the outside of master 4. A web 6 having a coating of a transferrable dye is transported from a takeoff reel 6b to a windup reel 6a, passing over a pressure roller 6c by which the dye coating of web 6 is pressed against the outside of the radiation absorbing text lines 4a. A source of radiation 7, preferably infrared radiation, is partly covered by a reflector 7a to irradiate consecutive sections of the master 4, 4a before the same reach the printing plane CD passing through the axes of duplicating drum 1 and pressure roller 6c. Due to the fact that the radiation absorbing portions 4a are heated by the source of radiation 7, portions of the coating are transferred from web 6 to the outside of the heat absorbing test lines 4a, and these portions, which have the outline of characters, are again heated by a second source of radiation 8 before the master 4 reaches the printing line between counter pressure roller 5 and duplicating drum 1 where an imprint is made on a copy sheet on which the master is superimposed in the printing line.
A similar duplicating machine in which, however, the first source of radiation 7 is different placed, and a second source of radiation 8 is not provided is disclosed in my U.S. Pat. No. 3,648,609 in FIGS. 7 and 8 which disclose details of the apparatus omitted in the drawing of the present application for the sake of simplicity.
The first source of radiation 7 can be covered by first shielding means 11 which include a plurality of parts-circular shielding members 11a provided at the ends of arms 11b which are turnable about a shaft 12. Arm 11b is secured to the armature 18 of an electromagnet 17 which is controlled by a switch 16 in accordance with the position of an actuating lever 14. When lever 14 is in the position illustrated in solid lines, switch 16 is open, and when the respective actuating lever 14 is turned to the position shown in chain lines, projection 14b closes switch 16. A bistable resilient arresting means 15 is provided which passes through a dead center position when actuating lever 14 is shifted, so that actuating lever 14 is resiliently arrested in the inoperative position shown in solid lines, and a shielding position shown in chain lines in which switch 16 is closed so that the respective electromagnet 17 is energized and places the sheilding member 11a in the shielding position shown in broken lines against the action of spring 11c which biases setting means 11 into abutment with a stop 11d.
As best seen in FIG. 2, a series of actuating members 14 is provided of which only one is shown completely to have a projection 14a located in a slot in a shielding means 9 which includes a shielding member 9a. When actuating lever 14 is shifted to the position shown in chain lines, the respective shielding member 9a is also shifted to a shielding position located between the master 4 and the source of radiation 8, so that the text lines 4a cannot be heated by the source of radiation.
As is best seen in FIG. 2, the master 4 has a plurality of circumferential strip-shaped zones 4b, each of which is provided with heat absorbing mirror script text lines only parts of which are shown at 4c. While the sources of radiation 7 and 8 extend along the entire axial length of the master sheet and duplicating drum 1, each of the shielding members 9a has only the axial width of a text line on master 4, and is guided in a slot of a guide bar 10 in a position directly opposite the respective text line 4c and zone 4b, as clearly shown in FIG. 2.
Shielding members 11 of the source of radiation 7 have also a width for covering only one strip-shaped area of the master, and more particularly one text line of the master 4. When any one of the actuating levers 14 is manually shifted to the broken line position shown in FIG. 1, respective shifting member 9a is advanced to the shielding position shown in chain line, and prevent any radiation from source 8 to reach the corresponding text line so that no imprint can be made of the respective text line when the same passes, together with a copy sheet, through the printing plane AB. At the same time, the actuating lever 14 is shifted, and arrested by the bistable spring 15, projection 14b closes switch 16 so that electromagnet 17 shifts the corresponding shielding member 11 to the shielding position shown in chain lines so that the respective text line is not heated by the radiation source 7 before reaching the plane CD where the coating of web 6 is pressed against the respective text line. Since the radiation absorbing text line 4a which is shielded from the radiation source 7 is not heated, no dye coating is transferred to the characters of the respective text line 4a so that it is further assured that no imprint can be made of the respective text line on a copy sheet.
By operating selected actuating levers 14, selected lines are shielded and prevented from making imprints on the copy sheets so that a selective printing operation is obtained in which different copy sheets may have different text lines thereon.
A plurality of copy sheets may be made, however, in each set position so that specific selected lines are printed on a number of copy sheets. When a sufficient number of copy sheets having the same selected text lines has been made, a new selection of lines may be necessary, and in this event, the clearing lever 19 is turned about shaft 20 in the direction of the arrow E out of its initial position of rest abutting a stop 24, to a position in which a cam 21 secured to clearing lever 19 assumes the position shown in chain lines to return actuating levers 14 which were in the chain line position for shielding radiation sources 7 and 8, to the solid line position of rest in which the entire master sheet is irradiated. When clearing lever 19 is released, spring 23 returns clearing lever 19 to the initial position abutting stop 24, but the shifted actuating levers 14 are already resiliently arrested by the dead center spring 15, and remain in the operative position in which also the respective associated electromagnets 17 are deenergized, and permit shielding members 11a, 11b to return to the position of rest abutting stop 11d under the action of spring 11c. The eccentric circular cam 21 extends over the entire axial length of the master 4, and cooperates with all actuating levers 14 so that all levers 14 and shifting means 9, 9a are simultaneously cleared, and switches 16 simultaneously deenergized to permit the shielding members 11 to return to the position of rest.
FIGS. 3 and 4 illustrate a modification in which two adjacent coated webs 39 and 41 of different axial width are used for obtaining coating of selected groups of text lines. On a pair of thin supporting walls 25, 26 of the coating units, a shaft 27, a shaft 31a, and a shaft 28a are mounted. Shaft 31a carries two windup reels 30 and 31, as also shown in FIG. 3, while shaft 28a carries two takeoff reels 28 and 29, and coated webs 39, 41 are wound up on reels 30, 31 and taken off reels 28, 29 after passing between two eccentric tubular members 22, 23 which are mounted on shaft 27 for angular displacement in axially adjacent positions. Eccentric tubular member 32 is fixedly secured to actuating arms 24, 25, respectively, which are operated by links 36, 37 so that each eccentric tubular member 32, 33 can be independently turned between an inoperative position spaced from the master and the printing drum 1, at an operative position pressing the respective web 39, 41 against the master and the duplicating drum so that the coating of the respective web is transferred to a croresponding number of text lines on master 4, not shown in FIG. 4. Due to the fact that the webs 39 and 41 have different axial widths each of which may correspond to a different number of circumferential text lines on the master sheet, a smaller number of text lines or a greater number of text lines can be activated and coated, or the narrower web 41 may cooperate with a part of the master having constantly repeated head lines, while the axially wider web 39 may be used for printing text lines of a separate part of the master. By independently operating the links 36 of the eccentric tubular members 32 and 33, different parts of the master are coated.
The two web arrangements of FIGS. 3 and 4 replaces the one arrangement shown in FIG. 1.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of selective printing apparatus with activated master differing from the types described above.
While the invention has been illustrated and described as embodied in a duplicating machine for making thermocopies of selected lines of a master sheet, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that from the standpoint of prior art fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.
The present invention relates to a duplicating machine of the type disclosed in my U. S. Pat. No. 3,648,609, issued Mar. 14, 1972.
The patent discloses an apparatus for activating a printing master of a duplicating machine while the master is mounted on the periphery of the duplicating roller. The master has on the outside mirror script heat absorbing means forming characters and lines, which are brought into contact with a coated web, and when the heat absorbing means are heated by a first source of radiation, the dye coating is transferred to the text lines, and imprint copy sheets during normal duplicating operation. However, the machine disclosed in U.S. Pat. No. 3,648,609, prints the entire text of the master in a thermographic copying process. In this fashion, a disadvantage of water-soluble dyes, as are generally used for alcohol duplication, can be avoided. The disadvantage is that the dye, such as triphenylmethane causes frequently dye deposits on the hands of the operator.
SUMMARY OF THE INVENTION
It is one object of the invention to provide a selective duplicating machine which prints selected lines of the text of a master by a thermographic process.
Another object of the invention is to use for a selective printing operation, a substantially standard duplicating machine, provided with the apparatus of the invention.
With these objects in view, in addition to the first source of radiation, preferably infra-red radiation, which causes the transfer of the dye coating to the text lines of the master, a second source of infra-red radiation or the like is used which acts on the portions of the coating adhering to the characters of the text lines of the master so that the portions of the coating are melted and more easily transferred to the copy sheets. The second source of radiation is located to irradiate the master sheet before its leading edge reaches the printing line between the duplicating drum and the counter pressure roller.
In accordance with the invention, shielding means are provided which are selectively movable to a shielding position located between the second source of radiation and one of the text lines on the master formed by coated radiation absorbing text so that text lines covered by the shielding means are not heated, and not imprinted on a copy sheet.
Preferably, the apparatus further comprises a plurality of other shielding means selectively movable to shielding positions located between the first source of radiation and one of the text lines on the master formed by the radiation absorbing characters and lines, so that shielded text lines are not heated and no coating adheres to the selected shielded text lines.
The shielding means include shiftable shielding members which can be selectively operated under direct or indirect control of manual selector members. For example, a manual member may shift a shielding slide to a position covering a source of radiation, or the manual member may operate a switch to energize an electromagnet to withdraw a shielding member from a shielding position covering the respective source of radiation.
It is also possible to provide a duplicating drum with two relatively displaceable clamping holders for parts of a master, and to adjust the position of the clamping holders so that those parts of the master which are to be printed, are placed adjacent each other so that the effect of the source of radiation is limited to a head lines on one master part and selected text lines on another master part, while the remaining parts of the master are excluded from the effect of radiation.
In a modified embodiment, two coated webs of different width are used one of which is selectively pressed against a corresponding section of the master for transferring portions of the dye coating to the characters of selected lines on the respective sections of the master.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING:
FIG. 1 is a fragmentary schematic side elevation, partially in section illustrating a first embodiment of the apparatus of the invention;
FIG. 2 is a fragmentary schematic plan view of the embodiment of FIG. 1;
FIG. 3 is a plan view, partially in section, illustrating a modified embodiment in which two coated webs of different width are used; and
FIG. 4 is a fragmentary schematic side view of the embodiment of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
Referring first to FIGS. 1 and 2, a duplicating drum of conventional construction is mounted for rotation on a shaft 1a, and cooperates with a counter pressure roller 5 in a printing plane AB passing through the axes of the duplicating drum 1 and counter pressure roller 5. Copy sheets, not snown, can be fed by transporting rollers 1b and 1c to the printing line along which the counter pressure roller 5 is in contact with the printing drum 1. A heat reflecting and insulating cover 2 is fixedly secured to the periphery of the duplicating drum 1, or clamped by a holder. A mirror script master 4 is secured by holding means 3 to the duplicating drum 1 outward of the heat insulating cover sheet 2. Projecting radiation absorbing means 4a which may consist of carbon, form mirror script characters and test lines on the outside of master 4. A web 6 having a coating of a transferrable dye is transported from a takeoff reel 6b to a windup reel 6a, passing over a pressure roller 6c by which the dye coating of web 6 is pressed against the outside of the radiation absorbing text lines 4a. A source of radiation 7, preferably infrared radiation, is partly covered by a reflector 7a to irradiate consecutive sections of the master 4, 4a before the same reach the printing plane CD passing through the axes of duplicating drum 1 and pressure roller 6c. Due to the fact that the radiation absorbing portions 4a are heated by the source of radiation 7, portions of the coating are transferred from web 6 to the outside of the heat absorbing test lines 4a, and these portions, which have the outline of characters, are again heated by a second source of radiation 8 before the master 4 reaches the printing line between counter pressure roller 5 and duplicating drum 1 where an imprint is made on a copy sheet on which the master is superimposed in the printing line.
A similar duplicating machine in which, however, the first source of radiation 7 is different placed, and a second source of radiation 8 is not provided is disclosed in my U.S. Pat. No. 3,648,609 in FIGS. 7 and 8 which disclose details of the apparatus omitted in the drawing of the present application for the sake of simplicity.
The first source of radiation 7 can be covered by first shielding means 11 which include a plurality of parts-circular shielding members 11a provided at the ends of arms 11b which are turnable about a shaft 12. Arm 11b is secured to the armature 18 of an electromagnet 17 which is controlled by a switch 16 in accordance with the position of an actuating lever 14. When lever 14 is in the position illustrated in solid lines, switch 16 is open, and when the respective actuating lever 14 is turned to the position shown in chain lines, projection 14b closes switch 16. A bistable resilient arresting means 15 is provided which passes through a dead center position when actuating lever 14 is shifted, so that actuating lever 14 is resiliently arrested in the inoperative position shown in solid lines, and a shielding position shown in chain lines in which switch 16 is closed so that the respective electromagnet 17 is energized and places the sheilding member 11a in the shielding position shown in broken lines against the action of spring 11c which biases setting means 11 into abutment with a stop 11d.
As best seen in FIG. 2, a series of actuating members 14 is provided of which only one is shown completely to have a projection 14a located in a slot in a shielding means 9 which includes a shielding member 9a. When actuating lever 14 is shifted to the position shown in chain lines, the respective shielding member 9a is also shifted to a shielding position located between the master 4 and the source of radiation 8, so that the text lines 4a cannot be heated by the source of radiation.
As is best seen in FIG. 2, the master 4 has a plurality of circumferential strip-shaped zones 4b, each of which is provided with heat absorbing mirror script text lines only parts of which are shown at 4c. While the sources of radiation 7 and 8 extend along the entire axial length of the master sheet and duplicating drum 1, each of the shielding members 9a has only the axial width of a text line on master 4, and is guided in a slot of a guide bar 10 in a position directly opposite the respective text line 4c and zone 4b, as clearly shown in FIG. 2.
Shielding members 11 of the source of radiation 7 have also a width for covering only one strip-shaped area of the master, and more particularly one text line of the master 4. When any one of the actuating levers 14 is manually shifted to the broken line position shown in FIG. 1, respective shifting member 9a is advanced to the shielding position shown in chain line, and prevent any radiation from source 8 to reach the corresponding text line so that no imprint can be made of the respective text line when the same passes, together with a copy sheet, through the printing plane AB. At the same time, the actuating lever 14 is shifted, and arrested by the bistable spring 15, projection 14b closes switch 16 so that electromagnet 17 shifts the corresponding shielding member 11 to the shielding position shown in chain lines so that the respective text line is not heated by the radiation source 7 before reaching the plane CD where the coating of web 6 is pressed against the respective text line. Since the radiation absorbing text line 4a which is shielded from the radiation source 7 is not heated, no dye coating is transferred to the characters of the respective text line 4a so that it is further assured that no imprint can be made of the respective text line on a copy sheet.
By operating selected actuating levers 14, selected lines are shielded and prevented from making imprints on the copy sheets so that a selective printing operation is obtained in which different copy sheets may have different text lines thereon.
A plurality of copy sheets may be made, however, in each set position so that specific selected lines are printed on a number of copy sheets. When a sufficient number of copy sheets having the same selected text lines has been made, a new selection of lines may be necessary, and in this event, the clearing lever 19 is turned about shaft 20 in the direction of the arrow E out of its initial position of rest abutting a stop 24, to a position in which a cam 21 secured to clearing lever 19 assumes the position shown in chain lines to return actuating levers 14 which were in the chain line position for shielding radiation sources 7 and 8, to the solid line position of rest in which the entire master sheet is irradiated. When clearing lever 19 is released, spring 23 returns clearing lever 19 to the initial position abutting stop 24, but the shifted actuating levers 14 are already resiliently arrested by the dead center spring 15, and remain in the operative position in which also the respective associated electromagnets 17 are deenergized, and permit shielding members 11a, 11b to return to the position of rest abutting stop 11d under the action of spring 11c. The eccentric circular cam 21 extends over the entire axial length of the master 4, and cooperates with all actuating levers 14 so that all levers 14 and shifting means 9, 9a are simultaneously cleared, and switches 16 simultaneously deenergized to permit the shielding members 11 to return to the position of rest.
FIGS. 3 and 4 illustrate a modification in which two adjacent coated webs 39 and 41 of different axial width are used for obtaining coating of selected groups of text lines. On a pair of thin supporting walls 25, 26 of the coating units, a shaft 27, a shaft 31a, and a shaft 28a are mounted. Shaft 31a carries two windup reels 30 and 31, as also shown in FIG. 3, while shaft 28a carries two takeoff reels 28 and 29, and coated webs 39, 41 are wound up on reels 30, 31 and taken off reels 28, 29 after passing between two eccentric tubular members 22, 23 which are mounted on shaft 27 for angular displacement in axially adjacent positions. Eccentric tubular member 32 is fixedly secured to actuating arms 24, 25, respectively, which are operated by links 36, 37 so that each eccentric tubular member 32, 33 can be independently turned between an inoperative position spaced from the master and the printing drum 1, at an operative position pressing the respective web 39, 41 against the master and the duplicating drum so that the coating of the respective web is transferred to a croresponding number of text lines on master 4, not shown in FIG. 4. Due to the fact that the webs 39 and 41 have different axial widths each of which may correspond to a different number of circumferential text lines on the master sheet, a smaller number of text lines or a greater number of text lines can be activated and coated, or the narrower web 41 may cooperate with a part of the master having constantly repeated head lines, while the axially wider web 39 may be used for printing text lines of a separate part of the master. By independently operating the links 36 of the eccentric tubular members 32 and 33, different parts of the master are coated.
The two web arrangements of FIGS. 3 and 4 replaces the one arrangement shown in FIG. 1.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of selective printing apparatus with activated master differing from the types described above.
While the invention has been illustrated and described as embodied in a duplicating machine for making thermocopies of selected lines of a master sheet, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that from the standpoint of prior art fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.