US3721775A

US3721775A - Device for transferring magnetic signals from a master sheet to magnetic sheets

Info

Publication number: US3721775A
Application number: US00867007A
Authority: US
Inventors: S Fujimoto; S Kato; M Koizumi; T Sue
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 1968-10-20
Filing date: 1969-10-16
Publication date: 1973-03-20
Anticipated expiration: 1990-03-20

Abstract

Device for transferring magnetic signals of a master sheet having a spiral recording track to magnetic sheets wherein a magnetic sheet to be copied (transferred) is intermittently fed so as to be overlaid upon the master sheet held stationary; both of the master and magnetic sheets are pressed against each other by a vertically movable pressure plate; the magnetic fields are applied to both of the sheets for transfer; and the holes for positioning are punched through the magnetic sheet by the punching means fixed to the pressure plate.

Description

United States Patent 1 1 1 1 3,721,775

Fujimoto et a]. 1 51March 20, 1973 [54] DEVICE FORTRANSFERRING [56] References Cited MAGNETIC SIGNALS FROM A MASTER SHEET To MAGNETIC UNUED STATES PATENTS SHEETS 2,926,219 2/1960 Hollmann ..179/100.2 E

2,999,908 9/ I961 Hoshino et al.... [75] Inventors: Sakae Fu unoto, Chofu-shi, Tokyo; 3,037,090 5/1962 Bouzemburgm" sabul'o Km, Koto-ku, Tokyo; 3,052,586 9/1962 Brown ..274/42 Masimi Koizumi, Kawasaki-shi, Kanagawa-ken; Takaji Su FOREIGN PATENTS OR APPLICATIONS 880,570 10/1961 Great Britain ..179/1oo.2 E Japan [73] Assignee: K. K. Ricoh, Tokyo, Japan Examiner-Harry Filed: Oct. 1969 Att0rney-Burgess, Ryan and Hicks 21 Appl. No.: 867,007 ABSTRACT Device for transferring magnetic signals of a master [30] Foreign Appli ti P i it D t sheet having a spiral recording track to magnetic 1 sheets wherein a magnetic sheet to be copied (trans- Oct. 20, 1968 Japan ..43/76057 ferred) i intermittently fed so as to be overlaid p 1968 "43/91034 the master sheet held stationary; both of the master Oct. 20, 1968 Japan ..43/9l035 d magnetic Sheets are p d against each other by Oct. 23, 1968 Japan ..43 3579 a vertically movable pressure plate; the magnetic Nov. 18,1968 Japan .;43/84374 fields are applied to both of the sheets for transfer; U 8 Cl 179/100 2 E 74/3 and the holes for positioning are punched through the u o u 6 I t h t b th h d t [51] Int.Cl. ..G1lb 5/86 magne lc S ee y e punc mg means I e 0 e pressure plate.

4 Claims, 24 Drawing Figures [58] Field of Search ..274/3, 41.4, 42; 179/1002 E PATENTEUmzmm I SHEET 30F 7 FIG. 98

FIG. IOA' FIG. IOB

PATENTEnmsRzolava SHEET 4 OF 7' FIG. II,

PATEr'lTEnnARzoma 3,721,775

n 2n NUMBEBER OF SH FIG; l9

DEVICE FOR TRANSFERRING MAGNETIC SIGNALS FROM A MASTER SHEET TO MAGNETIC SHEETS BACKGROUND OF THE INVENTION The present invention relates to a device for magnetically transferring magnetic signals or information recorded upon a master sheet especially having a spiral recording track to magnetic sheets for duplication.

In the conventional method, the magnetic signals recorded upon a master sheet having a spiral recording track is printed to other magnetic sheets through a reproducer or recording device. Thus there are defects or disadvantages that a large number of recording devices are required for reproducing or printing a large number of magnetic sheets and the duplication or reproduction operation takes a long time.

To eliminate these defects, there has been proposed a method in which the magnetic recording surface of a master sheet is made in close contact with the magnetically coated surface of a magnetic sheet while the magnetic field is applied, thereby printing or reproducing the magnetic sheets. However, the method of the type described above is not suited for mass production.

SUMMARY OF THE INVENTION The present invention provides a device for magnetically transferring magnetic signals recorded upon a master sheet to magnetic sheets. Each of the master sheet and the magnetic sheets consists of a base of paper, plastic, etc. with a coating of a magnetic material having a high permeability such as Fe o -y-Fe O compound ferrite, etc. The coated surfaces of the master sheet and the magnetic sheet are pressed against each other while the magnetic field is applied for transfer or reproduction.

According to one embodiment of the present invention, a rolled magnetic sheet having a relatively long length is utilized while in another embodiment of the present invention, separate magnetic sheets are utilized.

When a magnetic sheet unrolled from the rolled magnetic sheet or fed one by one from a stack of separate magnetic sheets is overlaid upon the master sheet, a pressure plate moves downwardly so as to press both of the master and magnetic sheets against each other while the magnetic fields are applied by one or a plurality of magnets arranged in a plane in parallel with both of thesheets for reproduction or transfer.

According to one aspect of the present invention, one or a plurality of magnets are so arranged as to rotate in said plane. In this case, an angle of rotation is so selected as to be slightly larger than an angle 360ln, where n a number of magnets for preventing the undesired magnetical deterioration of the master sheet and providing a better quality transferred or duplicated magnetic sheet, as will be fully described hereinafter. A stand upon which is stationarily held in position the master sheet is provided with projections which are fitted into the center aperture formed at the center of the spiral recording track of the master sheet and a hole formed at the exterior of this recording track of the master sheet respectively, thereby accurately positioning the master sheet for reproduction.

According to another aspect of the present invention, holes are punched through the magnetic sheets by the punching means fixed to the pressure plate when the plate is moved down. These holes serve to accurately position the duplicated or trans-ferred magnetic sheet upon a suitable reproduction device.

An object of the present invention is to provide a device of the type described above for reproduction of a large number of magnetic sheets having a uniform quality from one master sheet.

A still further object of the present invention is to provide a device for reproduction of a large number of magnetic sheets at high speed by utilizing a rolled magnetic sheet having a relatively long length.

Another object of the present invention is to provide a device for reproduction of a large number of magnetic sheets at high speed by utilizing separate magnetic sheets sheets cut off into a predetermined size Another object of the present invention is to provide a device for reproduction of a large number of high quality magnetic sheets from one master sheet without causing any magnetical or mechanical damage thereto.

Yet another object of the present invention is to punch holes through the magnetic sheets at the same time when the reproduction or transfer is made. These holes serve to position the reproduced magnetic sheet with a high degree of accuracy in case of reproduction.

The above and other objects, features and advantages of the present invention will become more apparent from the following description of some illustrative embodiments thereof with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of one embodiment of the present invention;

FIG. 2 is a plan view thereof illustrating only a magnetic transfer or printing assembly;

FIG. 3 is a perspective view illustrating a pressure plate used therein;

FIGS. 4A and 4B are vertical sectional views illustrating pressure members having drilled holes and being attached to the pressure plate;

FIGS. 5A, B and C are vertical sectional views illustrating the arrangement and relative positions of the pressure member and un-rolled magnetic sheet;

FIG. 6 is a plan view of a plurality of magnets fixed upon a turntable;

FIG. 7 is a plan view illustrating the magnetic sheet immediately after the magnetic recordings have been transferred thereto by the device of the present invention;

FIG. 8 is a perspective view illustrating the essential parts in the driving mechanism incorporated in the magnetic transfer device of the present invention;

FIGS. 9A and B are side and plan views of a connecting rod of the pressure plate respectively;

FIGS. 10A and B are sectional views illustrating the relative positions between a rocking lever and an arm;

FIG. 1 l is a side view of a mechanism for preventing the sagging of the rolled magnetic sheet;

FIG. 12 is a schematic side view illustrating a dust collector used in the transfer device of the present invention;

FIG. 13 is a side view illustrating another emb0diment of the present invention;

FIGS. 14 and 15 are views similar to FIG. 13 for illustrating the operation thereof;

FIG. 16 is a perspective view of a pressure plate thereof;

FIG. 17 is a plan view illustrating a magnetic sheet after the transfer or printing;

FIG. 18 shows the magnetic transfer characteristic curves of a master sheet and a copied sheet; and

FIG. 19 is a plan view of a magnetic sheet.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a sheet stand 1 is made of a nonmagnetic material such as aluminum which can withstand a high pressure and is mounted upon the main body of the magnetic transfer device of the present invention. A master sheet 2 is placed upon the sheet stand 1 with its coated or recorded face being directed upwardly. The master sheet 2 has a spiral magnetic recording track. A rolled magnetic sheet 3 to be copied or recorded is carried by a cylindrical shaft or spool 3a which is loosely journalled by the side walls. A pressure plate 4 is adapted to press the master sheet 2 and the unrolled magnetic sheet portion 3b to be referred to as magnetic sheet 3b hereinafter against the sheet stand 1. Four magnets 5 are fixed to a turntable 7 carried by a shaft 6. (See FIG. 6).

As shown in FIG. 2, the sheet stand 1 has a drilled hole 1a into which is fitted the upper end portion of the spindle 6 in such a manner that the upper end of the spindle 6 may be extended slightly beyond the upper surface of the sheet stand 1. The master sheet 2 has a center aperture formed at the center of the recording track 2a, the aperture having a diameter substantially equal to that of the upper end of the spindle 6. Therefore, the master sheet 2 may be accurately positioned by inserting the upper end of the spindle 6 into the center aperture of the master sheet 2. The master sheet 2 has also an elongated slot 2b extending in the radial direction of and at the exterior of the recording track 2a. A short pin lb extended from the sheet stand 1 has a diameter substantially equal to the width of the elongated slot 2b and is fitted therein. Therefore, the master sheet 2 is further accurately positioned when the upper end of the spindle 6 is fitted into the center aperture and the short pin lb is fitted into the elongated slot 2b. The sheet 3b is wrapped over

rollers

8 and 9 and the surface coated with a magnetic material is made in contact with the master sheet 2. The sheet 3b is further extended toward a pair of feed rollers 10 and 11, which are intermittently driven by a driving mechanism to be described hereinafter every time when one transfer or printing operation is accomplished. Thereafter the sheet 3b is advanced toward a cutting device 12 by a length corresponding to that of one copy sheet every time one transfer operation is accomplished. The pressure plate 4 is adapted to move upwardly and downwardly in response to the intermittent rotation of the feed rollers 10 and 11. As will be described in more detail hereinafter, the pressure plate is moved downwardly when the rollers 10 and 11 are stopped so as to press the sheet 3b and the master sheet 2 against the sheet stand 1.

The turntable 7 is rotated through the engagement of a gear 13 carried by the spindle 6 with a gear 15 carried by a shaft 14 driven by a motor not shown The electromagnets 5 are energized when the master sheet 2 and the sheet 3b are pressed against the sheet stand 1 by the pressure plate 4 so that the magnetic fields are applied to them by the electromagnets 5 rotating together with the turntable 7. Therefore, the spiral magnetic recording track upon the master sheet 2 is transferred magnetically to the sheet 3b. See FIG. 7 The cutting device 12 is also actuated in response to the stop of the rotation of the feed rollers 10 and 11 so that the recorded sheet 3b may be cut off along the cutting line shown by the broken line 3c in FIG. 7 into re-recorded sheets 3d, which are received upon a stand 16.

As shown in FIG. 3, at the undersurface of the pressure plate 4 is formed a projected portion 4a and a resilient member 4b made of a relatively hard yet resilient material such as rubber, etc. is attached to the undersurface of the projected portion 4a. To the resilient member 4b is further attached another resilient member 4c made of a relatively soft resilient material such as urethane rubber. The above

resilient members

4b and 4c constitute a pressure member generally designated by 17 for pressing the magnetic recording track 2a of the master sheet 2. Punch-

like members

18, 19 and 20 depend from the undersurface of the pressure plate 4 in order to punch

holes 3d

3d and 3d through the magnetic sheet 3b. These holes are utilized to accurately position the copied sheet 30 upon a reproduction device. (See FIG. 7 As shown in FIG. 4,

sheet pressing members

21 and 22 are loosely fitted over the punch member 18 and the

punch members

19 and 20 respectively. As shown in FIG. 4A, two

small pins

23 and 24 are vertically movably fixed to the pressure plate 4 in parallel with the punch member 18 and the sheet pressing member 21 is attached to the lower ends of these

pins

23 and 24 with

springs

25 and 26 loaded between the upper surface of the pressing member 21 and the undersurface of the pressure plate 4, so that the pressure member 21 is normally biased downwardly. At the upper ends of the

pins

23 and 24 are formed

stoppers

23a and 24a respectively. The lower surface of the pressure member 21 is so arranged as to slightly extend beyond the lower end surface of the punch member 18. As shown in FIG. 4B, the pressure member 22 is supported by springs 29 30 and pins 27 and 28 in the similar manner as the pressure member 21. It is noted that the undersurface of the resilient member 4a is extended beyond the undersurfaces of the

pressure members

21 and 22. The

punch members

18, 19 and 20 coact with

punch holes

31a, 32a and 32b (See FIG. 2) of die-

like plates

31 and 32 disposed in coplanar relation with the sheet stand 1 so that when the pressure plate 4 is moved down so as to press the

sheets

2 and 36 against the sheet stand 1, the

holes

3d,, 3d and lid (See FIG. 7) are punched. This operation will be described in more detail hereinafter with reference to FIGS. 5A, B and C. When the magnetic sheet 3b is advanced by the feed rollers 10 and 11 and then is stopped (See FIG. 5A), the pressure plate starts to move downwardly so that first the resilient member 4c contacts with the sheet 3b so as to impart a gentle pressure thereto and hold it in position as shown in FIG. 5B. When the pressure plate 4 is further moved down, the resilient member 4c is compressed and the punch member 18 is advanced into the hole 31a, thereby punching the sheet 3b as shown in FIG. 5C. In this case, the pressure member 21 serves to prevent the springback of the sheet 3b. Because of the provision of the resilient member 4c, the sheet 3b is prevented from being applied with the pressure too rapidly and is accurately held in position even if the sheet is waved, so that the holes are punched with an accuracy. The punching by the

punch members

19 and 20 and the

openings

32a and 32b is carried out in the similar manner as described above. A large circular hole 4f is formed through the pressure plate at the position corresponding to the center of the spiral magnetic recording track of the master sheet 2 in order to facilitate the accurate positioning of the master sheet 2 upon the sheet stand 1 by the visual observation.

Referring to FIG. 8, guide posts 33 and 34 for the pressure plate 4 are fixed to the rigid stationary members (not shown) supporting the side members of the sheet stand 1 and the pressure plate 4 is provided with

holes

4d and 4e (See FIG. 3) into which are loosely fitted the guide posts 33 and 34, so that the pressure plate 4 may be slidably moved vertically.

Cam members

35 and 36 are carried by the shaft 14 at both ends thereof respectively and rollers 39a and 40a attached to rocking members 39 and 40 which are biased upwardly by means of

springs

37 and 38 connected to respective ends of the rocking members 39 and 40 are made in contact with these

cam members

35 and 36 respectively. The other ends of the rocking members 39 and 40 are loosely fixed to the side walls (not shown) of the device. The lower ends of the connecting rods 41 and 42 are respectively loosely pivoted at the center portion of the rocking members 39 and 40. At the upper end of each of these connecting rods 41 and 42 is formed a notch 41a or 420 consisting of a V- shaped notch connected with a circular hole through a narrow groove. As shown in FIG. 9, a connecting rod 43 journalled by bearing members 4g and 4h fixed to the pressure plate 4 has the flattened

portions

43a and 43b which are adapted to pass through the narrow communication grooves of the notches 41a and 42a. The stepped

portions

43c and 43d have the sloping surfaces. The connecting rod 43 is connected to the connecting rods 41 and 42 by placing the flattened

portions

43a and 43b into the notches 41a and 42a respectively and thereafter moving in the direction indicated by the arrow a in FIG. 8. The sloping surfaces of the stepped

portions

43c and 43d are provided so that the circular crosssectional shaft portion may be easily fitted into the circular holes of the notches 41a and 420 when the rod 43 is moved in the direction of the arrow 0. Thus, the pressure plate 4 is easily yet securely connected to the connecting rods 41 and 42.

A crank arm 44 is fixed to one end of the shaft 14 and a rocking arm 47 integral with a gear 45 and a rocking lever 46 is rotatably fixed to the side wall in the vicinity of the lower portion of the roller 10. These rocking arm 47 and the crank arm 44 are interconnected with each other by means of a connecting rod 48. The gear 45 is in mesh with a gear 49 carried by a shaft 50 which carries a gear 52 through a onedirection clutch 51 which rotates only in the direction indicated by the arrow b. A gear 54 carried by the shaft 53 of the roller is in mesh with the gear 52. At one end of a shaft 55 of a rotary cutter 12a of the cutting device 12 is fixed one end ofa lever 56 whose the other end has a cylinder 58 into which is loosely fitted an engaging element 57 for slidable movement. As shown in FIG. 111A, the shaft portion of the engaging element 57 is fitted slidably in the cylinder 58 through a spring 59 and a stop 57 a is formed at the rear end of the engaging element 57 so that the element 57 which is pushed by the spring 59 is prevented from being pulled out of the cylinder 53. The leading end 46a of the rocking lever 46 is adapted to engage with the engaging element 57 and is bent outwardly. When the rocking lever 46 is rotated in'the direction indicated by the arrow 0, the engaging element 57 is pushed into the cylinder 58 against the spring 59 by the bent portion 46a as shown in FIG. 10B. Conversely, when the lever 46 is rotated in the direction opposed to that indicated by the arrow c, the side edge opposed to the bent portion 46b of the rocking lever 46 causes the engaging element 57 to move upwardly as shown by the dotted lines in FIG. 10A. Therefore, the arm 56 is rotated so as to rotate the rotary cutter 12a in the direction indicated by the arrow d when the rocking lever 46 is rotated in the direction opposed to that indicated by the arrow c so that the rotary cutter 12a'coacts with a fixed cutter 12b, thereby cutting off the sheet 3b (See FIGS. 1 and 8).

By the continuous rotation of the shaft 14, the

cam members

35 and 36 cause the rocking members 39 and 40 to rock through the rollers 39a and 40a respectively so that the pressure plate 4 is caused to move vertically through the connecting rods 41 and 42. In this case, the crank 44 causes the rocking arm 47 to rock, thereby rotating the gear 45 in the direction indicated by the arrow c while the gear 54 of the roller 10 is rotated in the direction indicated by the arrow e, thereby rotating the roller 10 in the same direction. When the gear 45 is rotated in the direction opposed to that indicated by the arrow 0, the clutch 51 stops the transmissionof the rotation so that the

gears

52 and 54 as well as the roller 10 are not rotated. The

cam members

35 and 36 and the crank arm 44 are so fixed to the shaft 14 that when the rocking members 39 and 40 are moving downwardly, the rocking arm 47 is rocked in the direction opposite to that indicated by the arrow 0 while when the rocking members 39 and 40 are moving upwardly, the rocking arm 47 is rocked in the direction indicated by the arrow c. Therefore, when the pressure plate 4 is moving downwardly the roller 10 is not rotated while the pressure plate 4 is moving upwardly, the roller 10 is rotated.

The numbers of teeth of the

gears

45, 49, 52 and -54 are so selected that upon rotation of the gear 45 in the direction indicated by the arrow 0, the sheet 3b is advanced by a length corresponding to that of one recorded or copy sheet 3d by the pair of feed rollers 10 and l 1. The configuration of each of the

cam members

35 and 36 is so selected that the pressure plate 4 may continuously press the master sheet 2 and the magnetic sheet 3b against the sheet stand 1 while the turntable 7 rotates through an angle of (See FIG. 1 Four electromagnets 5 are fixed to the turntable 7 as best shown in FIG. 6 and each of the electromagnets 5 is adapted to generate the magnetic field having a width in the radial direction slightly larger than that in the same direction of the spiral recording track 2a of the master sheet 2. The magnets 5 are equiangularly spaced apart from each other by 90 so that when the turntable 7 is rotated through an angle of 90, the whole track 20 of the master sheet 2 may be magnetically transferred to the sheet 3b. The arrangement of a plurality of electromagnets 5 described above is advantageous because the angle of rotation of the turntable 7 per operation may be made small as compared with the casein which only one electromagnet is attached to the turntable so that it must be rotated through 360 per operation. Furthermore, the mechanism for driving the pressure plate 4 and the rollers 10 may be designed in a more simplified manner. When it is desired only to improve the transfer or printing speed, the fixed type electromagnets may be utilized. When the feed rollers 10 and 11 are stopped after advancing the sheet 3!; by a length corresponding that of the recorded sheet 3c, the rocking lever 46 causes the arm 56 to move in the direction indicated by the arrow d in FIG. 8. In this case, the sheet 3b is cut off along the broken lines 30 in FIG. 7.

Referring to FIG. 11, the base of a rocking member 60 is pivoted to each of the side walls (not shown) in the vicinity of the rolled magnetic sheet 3 and a roller 8 is rotatably fixed to the leading end of the rocking member 60. A brake shoe 61a at the leading end of a brake member 61 whose base is pivoted to the side wall (not shown) by a pivot 61s is in engagement with the outer periphery of the flange 3e of the spool 3a for the rolled magnetic sheet 3. The trailing end portion of the brake member 61 is bent upwardly in the form of a sickle and the end is further bent inwardly so as to provide a stopper 61b. The upright portion 61c of the brake member 61 is slightly inclined inwardly and a pin 60a which is adapted to engage with the upright portion 610 is fixed to the rocking member 60 so as to be positioned on the right side of the upright portion 61c as shown in FIG. 11. A compression spring 62 has its one end fixed to the horizontal portion 61d of the brake member 61 so that the member 61 is normally biased to rotate in the clockwise direction. When the sheet 3b is advanced in the direction indicated by the arrow f, the rocking member 60 rotates in the counterclockwise direction to a position indicated by the broken lines 60A, thereby displacing the pin 60a to the position designated by the broken line 6011A so as to push the upright portion 61c of the brake member 61. In this case, the displacement of the pin 60a is limited by the stopper 61b of the brake member 61. When the upright portion 610 is pushed toward the position designated by the broken lines 61cA, the brake shoe 61a of the brake member 61 is displaced to the position designated by the broken lines 61aA and released from the flange 3e of the spool 30 so that the rolled magnetic sheet 3 may freely rotate. When the advancement of the sheet 3b is stopped, the rocking member 6D rotates in the clockwise direction by its own weight or by a spring so that the brake member 61 is returned to its normal position so as to retard the rotation of the rolled magnetic sheet 3. Therefore the sheet 3b is imparted with a suitable tension by the rocking member 60 and the brake member 61 which coact with each other through the pin 60a. When the diameter of the roller 8 is made relatively smaller, the curling of the sheet 3b may be suitably corrected or eliminated.

Referring back to FIG. 2, recesses 31b and 320 are formed in the vicinity of the

holes

310, 32a and 32b in the die-

like members

31 and 32 respectively. These recesses 31b and 320 are provided with holes 31c and 32d respectively. As shown in FIG. 12, the hole 31c is intercommunicated with an exhaust fan 64 through a pipe 63 so that the chips or dust produced when the sheet 3b is punched may be discharged through the exhaust fan 64 from the hole 310. The hole 32d is also intercommunicated with an exhaust fan. Thus the chips of the sheet 3b can be prevented from moving into the magnetic transfer portion and adversely affecting the magnetic transfer.

The present invention has been so far described as utilizing the rolled magnetic transfer sheet, but in the embodiment to be described hereinafter with reference to FIGS. 13 to 17, separate sheets are used.

Referring to FIG. 13, reference numeral 101 designates a sheet stand made of a non-magnetic material such as aluminum and capable of withstanding a relatively high pressure; and 102, a member for rigidly supporting the sheet stand 101. A master sheet 103 is accurately positioned by suitable means upon the sheet stand 101 with the recorded surface being directed upwardly.

Two pairs of

feed rollers

104 and 105, and 106 and 107 are disposed on both sides of the sheet stand 101 respectively and are drivingly interconnected with each other by means of a chain 108. Below the sheet stand 101 is disposed a drive shaft 109 having a wheel 111 which has the teeth formed only one semi-circular periphery thereof and is in mesh with an intermediate gear 110 which in turn in mesh with a gear 1050 attached to the roller in coaxial relation therewith. Therefore, upon rotation of the drive shaft 109 in the direction indicated by the arrow a, The roller 105 is rotated in the direction indicated by the arrow b only when the teeth of the wheel 111 is in mesh with the intermediate gear 110. When the gear is in contact with the semi-circular portion of the wheel 111 having no teeth, the roller 105 is not rotated Thus, the roller 105 is intermittently rotated as the wheel 111 rotates. The rotation of the roller 105 is transmitted to the roller 107 through the chain 108.

On the right side of the

feed rollers

104 and 105 is provided a magnetic sheet stand 112 upon which is placed a stack of magnetic recording sheets to be recorded 113 (to be referred to as magnetic sheets" hereinafter) with their surfaces coated with the magnetic material being directed downwardly. These magnetic sheets 1 13 are advanced toward the nip of the

rollers

104 and 105 by a suitable feeding means (not shown) through the

guide plates

114 and 115 from the uppermost one of the stack when the

rollers

104 and 105 are stopped. A pressure plate 116 as shown in FIG. 16 is disposed upon the sheet stand 101 and guided by guide posts (not shown) fitted into

holes

116a and 116b, and connecting

rods

119 and 120 are pivoted by

pins

117 and 118 to the uprightly projected

members

116a and 116d respectively (See FIG. 13). A cam 121 is fixed to the drive shaft 109 and a roller 123 is fixed to the leading end of a rocking member 124 which has its base fixed to a shaft 122 journalled by the stationary members (not shown). The rocking member 124 is normally biased to rotate in the counterclockwise direction by means of a spring 125 so that the roller 123 is made in contact with the cam 121. The other end of the connecting rod 1 19 is pivoted by a pin 126 to the rocking member 124 and the other connecting rod 120 is connected to a rocking member similar to the rocking member 124 and a roller carried by the rocking member is made in contact with a cam similar to the cam 121. Upon rotation of the drive shaft 109 in the direction indicated by the arrow a, the rocking member 124 is rocked so that the pressure plate 116 is intermittently pressed against the sheet stand 101. Another cam 127 is carried by the drive shaft 109 and a rocking member 129 pivoted at 128 is normally biased to rotate in the clockwise direction by means of a spring 130 so that a roller attached to one end of the rocking member 129 is made in contact with the cam 127. A positioning member 132 having two elongated slots 132aa and 132b is positioned on the left side of the support 102. A pin 133 is loosely fitted into the elongated slot 132a and a pin 134 extending from the other end of the rocking member 129 is loosely fitted into the elongated slot l32b. A compression spring 136 is loaded between the pin 134 and a pin 135 extended from the lower end of the positioning member 132 so that the member 132 is caused to move vertically by the rocking member 129 as the cam 127 rotates, thereby moving into and out of the path of the magnet sheets the upper end of the positioning member 132. The gear 1 1 1 and the cam 127 are so arranged that the upper end of the positioning member 132 is moved into the path of the magnetic sheet when both of the

rollers

105 and 107 almost come to the end of the rotation while the upper end is moved away from the path immediately before the rotation of the

rollers

105 and 107.

The roller 105 is rotated only when the teeth of the wheel 111 is in mesh with the intermediate gear 110 so that the sheet 113 is advanced and positioned upon the master sheet 103. In this case, as described hereinabove, the roller 107 is alsodriven in the same direction through the chain 108. The distance between the

rollers

104 and 105 and 106 and 107 is selected so as 'to be shorter than the length of the magnetic sheet 113 so that the leading end of the sheet 113 is held in the nip between the

rollers

106 and 107 even when the trailing end has passed through the

rollers

104 and 105. The numbers of teeth of the wheel 111, the intermediate gear 110 and the gear 105a are so selected that the rollers-104 and 105 may continue their rotation until the leading end of the magnetic sheet 113 advanced by the pair of

feed rollers

106 and 107 is abutted against the upper end portion of the positioning member 131 and thereafter may be stopped. Therefore, the leading end of the magnetic sheet 113 can be accurately positioned by the above described abutment. (See FIG. 14). In this case, it is noted that the

rollers

106 and 107 are stopped while holding therebetween the magnetic sheet 113. The wheel 111 and the cam 121 are so arranged that the magnetic sheet 113 may be acurately positioned by the positioning member 132 as shown in FIG. 14 and that the pressure plate 116 is caused to move downwardly when the

rollers

104, 105, 106 and 107 are stopped. A pressure member 137 made of a rubber or strong rubber is overlaid the entire lower surface of the pressure plate 116 (See FIG. 13) and punch-

like members

138, 139 and 140 (See FIGS. 13 to 16) are fixed to the undersurface of the pressure plate 116 for punching the holes 113a,

11312 and 113s (See FIG. 17) through the magnetic sheet 113 for positioning correctly the same for reproduction.

Holes

102a, 1102b and 102a are drilled in the support 102 for punching the holes in cooperation with the punch member 130, and (See FIG. 13). As shown in FIG. 15, when the rocking member 124 rotates about the pivot 122 in the clockwise direction by the cam 121, the pressure plate 116 is caused to move downwardly by the connecting rod 119 so that the master sheet 103 as well as the magnetic sheet 113 are pressed upon the sheet stand 101 by the pressure member 137 of the pressure plate 116 and the

holes

113a, 113b and 113c (See FIG. 17) are punched.

Below sheet stand 101 are disposed

electromagnets

141 and 142 which are supported by a suitable support (not shown) and whose upper surfaces are arranged in a plane parallel to the surfaces of the

sheets

103 and 113. These

electromagnets

141 and 142 are energized so as to apply the magnetic fields to the

sheets

103 and 113 when the pressure plate 116 is moved to its lowermost position so as to closely contact the sheets with each other, thereby effecting the transfer. The electromagnets may be arranged so as to move in the same plane by a suitable means if required. Upon completion of the punching and magnetic transfer operations, the rocking member 124 rotates about the pivot 122 in the counterclockwise direction as the cam 121 rotates, so that the pressure plate 116 is moved upwardly, thereby releasing the pressure applied to the

sheets

103 and 113. Concurrently, the positioning member 132 is moved away from the passage of the magnetic sheet by the cam 127 and immediately thereafter,

rollers

104, 105, 106 and 107 are rotated again by the toothed wheel 111 through the gear train. Therefore, the transferred magnetic sheet is advanced to the left while the next magnetic sheet 113 is advanced and placed upon the master sheet 103 for magnetic transfer.

FIG. 17 shows schematically the transferred magnetic sheet 113 and the magnetic recording track transferred magnetically from the master sheet 103 is designated by 113d. The reproduction without any distortion is ensured by fitting the positioning holes 113a, 11311 and 1130 over the positioning members of the reproduction device.

So far the electromagnets have been described as being rotated through an angle of 90 in one transfer operation, but in practice they must be rotated through an angle more than 90 because of the reason to be described hereinafter. For the sake of explanation, the number of electromagnets is assumed to be one.

In the magnetic transfer method in which the magnetic field is applied to a magnetic sheet made in close contact with a master sheet, thereby magnetically transferring the recorded signals to the magnetic sheet,

the larger the number of transfers that is, the number of magnetic 'sheets subjected to the magnetic transfer the more the magnetic signals recorded in the master sheet are de-magnetized, so that the output levels of the transferred magnetic sheets are accordingly decreased gradually. To apply the magnetic field to the magnetic sheet made in close contact with the master sheet, an electromagnet is arranged upon'the master sheet so as to move at a constant speed along the magnetic recording zone in the form of a doughnut of the master sheet in a predetermined direction and the exciting current applied to the electromagnet is stopped whenever the electromagnet makes one rotation. However, it is very difficult from the standpoint of the mechanical design and operation to stop the exciting current accurately when the electromagnet makes one rotation. For example, when the electromagnet is de-energized before it returns to its starting position, the magnetic sheet will have a portion to which no magnetic signals have been transferred from the master sheet. Furthermore, when a switch is opened too rapidly, the spark is caused between the contacts, thereby causing the noise and the counter emf is produced in the exciting coil of the magnet, thereby adversely affecting the electromagnet.

In view of the above, in the conventional method the electromagnet is started to rotate from the starting position upon the magnetic recording track zone 202 of the magnetic sheet 201 in FlG. 19, in the direction indicated by the arrow. After one complete rotation, the electromagnet is slightly rotated through a very small angle beyond the starting point 0 while the exciting current is gradually decreased and thereafter the current is completely cut off. Therefore it is seen that the area a is subjected to the magnetic transfer twice in one operation. In this case, when a number of n copy sheets is desired, the area a of the master sheet is subjected to the magnetic field as many as 2n times so that the area a will be inevitably de-magnetized to a large extent as compared with other areas. Therefore, as shown in FIG. 18, the output of the master sheet will vary by M between the area a and the other area so that the output level difference P between the area corresponding to the area a and the other area of the magnetic sheet will be increased larger than the variation M of the master sheet because a magnetic transfer coefficient must be taken into consideration. The variation M will be increased as the number of magnetic copies is increased.

Accordingly the present invention provides a method in which the starting point from which the magnetic field for transfer is applied to the master sheet and the magnetic sheet made in close contact therewith is deviated for each operation, thereby eliminating the defect or disadvantage encountered in the conventional method as described above. According to the method of the present invention, the starting point 0 is deviated in the direction of rotation of the electromagnet by an angle corresponding to the overlapped area a of the master sheet in each operation. Therefore, it is seen that the area a will not be subjected to the magnetic field a number of Zn times as in the case of the conventional method when it is desired to make a number of n copies and that the master sheet is deenergized uniformly over the whole recording track zone thereof, thereby preventing advantageously the excess variation in the output levels.

There will be proposed a wide variety of means and methods for continuously or intermittently displacing the starting points as described hereinabove so that the detailed description will not be made in the specification. But it is noted that the underlying principle of the present invention is to displace or deviate the overlapped area a or the starting point 0 in each operation, thereby uniformly distributing the de-magnetization all over the recording zone of the master sheet.

What is claimed is:

1. A device for magnetically transferring magnetic signals of a master sheet having a spiral recording track to magnetic sheets comprising a master sheet stand fixedly mounted on said device and having projections for accurately holding said master sheet in position,

intermittent feed means for intermittently feeding the magnetic sheet from a rolled magnetic sheet so as to overlay said magnetic sheet upon said master sheet,

means for rotatably supporting said rolled magnetic sheet,

a pressure plate for pressing said magnetic sheet and said master sheet against said sheet stand, thereby pressing both of said sheets against each other,

means for vertically movably supporting said pressure plate so as to move toward and away from said sheet stand,

means for vertically moving said pressure plate in such a manner that said pressure plate is pressed against said sheet stand in correspondence to the intermittent interruption of said intermittent feed means,

punching means interposed between said sheet stand and said pressure plate for punching positioning holes through said magnetic sheet,

a turntable positioned below and in concentric arrangement with said sheet stand,

a plurality of magnets mounted on said turntable and arranged in a plane in parallel with both of said sheets, said magnets each being energized and rotatable with said turntable from a starting point to follow the line of said spiral recording track through an arc of less than 360 for applying magnetic fields to both of said sheets when they are pressed against each other by said pressure plate said magnets being located adjacent a bottom surface of said master sheet, and said magnets being equiangularly spaced from each other in said plane, and

said magnets being de-energized at least beyond the starting points at which the preceding magnets are energized when they are rotated, and the next starting points being displaced from the preceding starting points for every operation.

2. A device for magnetically transferring magnetic signals of a master sheet having a spiral recording track to magnetic sheets comprising a master sheet stand fixedly mounted on said device and having projections for accurately holding said master sheet in position,

intermittent feed means for intermittently feeding separate magnetic sheets one by one so as to overlay said magnetic sheet upon said master sheet,

means for supporting a stack of separate magnetic sheets,

3. A device as set forth in claim 1 wherein said master sheet stand is provided with projections which are adapted to fit into a center aperture located at the center of a spiral recording track of said master sheet and a hole at the exterior of said recording track of said master sheet respectively.

4. A device as set forth in claim 2 wherein said master sheet stand is provided with projections which are adapted to fit into a center aperture located at the center of a spiral recording track of said master sheet and a hole at the exterior of said recording track of said master sheet respectively.

Claims

1. A device for magnetically transferring magnetic signals of a master sheet having a spiral recording track to magnetic sheets comprising a master sheet stand fixedly mounted on said device and having projections for accurately holding said master sheet in position, intermittent feed means for intermittently feeding the magnetic sheet from a rolled magnetic sheet so as to Overlay said magnetic sheet upon said master sheet, means for rotatably supporting said rolled magnetic sheet, a pressure plate for pressing said magnetic sheet and said master sheet against said sheet stand, thereby pressing both of said sheets against each other, means for vertically movably supporting said pressure plate so as to move toward and away from said sheet stand, means for vertically moving said pressure plate in such a manner that said pressure plate is pressed against said sheet stand in correspondence to the intermittent interruption of said intermittent feed means, punching means interposed between said sheet stand and said pressure plate for punching positioning holes through said magnetic sheet, a turntable positioned below and in concentric arrangement with said sheet stand, a plurality of magnets mounted on said turntable and arranged in a plane in parallel with both of said sheets, said magnets each being energized and rotatable with said turntable from a starting point to follow the line of said spiral recording track through an arc of less than 360* for applying magnetic fields to both of said sheets when they are pressed against each other by said pressure plate , said magnets being located adjacent a bottom surface of said master sheet, and said magnets being equiangularly spaced from each other in said plane, and said magnets being de-energized at least beyond the starting points at which the preceding magnets are energized when they are rotated, and the next starting points being displaced from the preceding starting points for every operation.

2. A device for magnetically transferring magnetic signals of a master sheet having a spiral recording track to magnetic sheets comprising a master sheet stand fixedly mounted on said device and having projections for accurately holding said master sheet in position, intermittent feed means for intermittently feeding separate magnetic sheets one by one so as to overlay said magnetic sheet upon said master sheet, means for supporting a stack of separate magnetic sheets, a pressure plate for pressing said magnetic sheet and said master sheet against said sheet stand, thereby pressing both of said sheets against each other, means for vertically movably supporting said pressure plate so as to move toward and away from said sheet stand, means for vertically moving said pressure plate in such a manner that said pressure plate is pressed against said sheet stand in correspondence to the intermittent interruption of said intermittent feed means, punching means interposed between said sheet stand and said pressure plate for punching positioning holes through said magnetic sheet, a turntable positioned below and in concentric arrangement with said sheet stand, a plurality of magnets mounted on said turntable and arranged in a plane in parallel with both of said sheets, said magnets each being energized and rotatable with said turntable from a starting point to follow the line of said spiral recording track through an arc of less than 360* for applying magnetic fields to both of said sheets when they are pressed against each other by said pressure plate , said magnets being located adjacent a bottom surface of said master sheet, and said magnets being equiangularly spaced from each other in said plane, and said magnets being de-energized at least beyond the starting points at which the preceding magnets are energized when they are rotated, and the next starting points being displaced from the preceding starting points for every operation.