JPS6147424B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stripping device for a copying machine.

Blank electrostatographic copiers in which a drum carries a surface coating of photoconductive material, such as selenium, are well known in the art. During operation of such a copying machine, the surface of the drum is sequentially divided into a charged area where a uniform electrostatic charge is applied to the surface of the drum by the corona, and an exposed area where the charged surface is exposed to the image of the original to be copied. Move too far. At this exposure location, the drum surface over the relatively bright areas of the image to be copied loses its charge, but the relatively dark areas of the original retain their charge, forming an electrostatic latent image of the original to be copied. will occur.

Next to the exposure location, the drum surface is moved through the development location. At this development station, the latent image is acted upon by a developer containing toning agent particles that adhere to the charged voltage areas of the image to develop the image. When the surface bearing the developed image leaves the development station, it passes through a drum along with a transfer corona through which a length of copying material, such as ordinary paper, on which the image is to be transferred is fed to a drum. carried on the underside of the This transfer corona causes particles of toning agent to move from the surface of the photoconductor to the surface of the copy paper.

After the image has been transferred to the copy material in this manner, it is necessary to peel the copy material from the surface of the photoconductor, for example on a drum. In the particular structure used to peel off the copy paper that has produced the developed image in the copying machine described above, the drum shape is removed from the area around the drum from where the copy material is fed to the drum to beyond the transfer corona. A matching fixed flexible strip is attached to the edge of the drum such that a narrow strip of copying material extending along the side of the drum is moved from said fixed flexible strip during movement under the transfer corona. It is designed to move above the body.
At the point where copy material is to be removed from the surface of the drum, the raised portion of the flexible strip moves the front corner of the copy material away from the drum and into the nip between the rotating roller and the rubber belt.
A portion of this rubber belt extends around the rotating roller and contacts its surface. The rotating roller is driven in conjunction with the belt to convey the developed copy material away from the photoconductive drum and toward a conveyor roller that delivers the copy material to a user of the copying machine. This stripping device is illustrated and described in detail in U.S. Pat.

After the photoconductive surface exits the stripping station described above, it is then moved through a cleaning station. At this cleaning station, a cancellous roller associated with the surface of the drum is driven in a direction such that the roller and each associated surface portion of the drum move in opposite directions.
This spongy roller is usually moistened with developer material to facilitate cleaning and to prevent the drum surface from being scratched by toning agent particles that remain on the roller when the developer dries.

Although the copiers described above work well in many cases, there are some serious drawbacks to such copiers. First, it is clear from the foregoing description of the stripping device that image transfer to the copy sheet does not take place in the space along the edge of the copy paper that rests above a flexible strip extending through the transfer location. That is, if the original has information or printing in this area, this will not appear on the copy paper. A proposal to prevent this problem by a slight modification to direct this corner of the copy paper into a nip between rotating rollers and a belt without the use of a strip extending through the transfer site has previously been proposed. This was not effective because the developed image inside this blank strip was smeared. Another disadvantage of the copying machine described above arises with respect to the inadvertent double feeding of copy paper from the supply to the drum. The first copy of the two copies is often stripped off by a stripping device, but the second copy is not. In this case, the copy paper continues to move around the drum and wrap around the cleaning roller, eventually becoming saturated with developer and taking on a dark appearance that is not easily discernible. In such a case, if the copier continues to be used, the copy paper wrapped around the cleaning roller will scratch the surface of the photoconductor, eventually requiring replacement of the photoconductor. Moreover, this drum is one of the relatively expensive parts of the copying machine.

SUMMARY OF THE INVENTION An object of the present invention is to provide a stripping device for a copying machine that eliminates the drawbacks of conventional stripping devices.

Another object of the present invention is to provide a stripping device for a copying machine capable of receiving a transferred image on substantially the entire area of a copy sheet.

Another object of the present invention is to provide a stripping device for a copying machine that is reliable in its operation.

A further object of the present invention is to provide a stripping device for a copying machine that prevents double-fed copy paper from wrapping around a copying machine cleaning roller.

It is an object of the present invention to provide a copy paper stripping device that returns the double-fed copy paper to the user along the same path as the copy paper on which the image has been transferred.

Embodiments of the stripping device for a copying machine according to the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, a copying machine 10 using the stripping device of the present invention includes a cabinet 12. As shown in FIGS. The top of the cabinet 12 typically includes a transparent platen 14 covered by a cover (not shown) pivotally attached to the cabinet 12. The cover can be moved away from the platen 14 and the original can be placed face down on the platen 14. A drum 16 carrying a suitable photoconductor on its surface is rotatably supported for movement within the cabinet 12 by any suitable means well known in the art. In FIG. 1, gears are shown in broken lines and sprockets are shown in solid lines for the sake of simplicity. Gear 1 rotating together with drum 16
Reference numeral 8 drives the drum 16 to rotate in the direction of arrow A in FIG. The copying machine 10 is a prime mover 20
It is equipped with A sprocket 22 is attached to the output shaft of the prime mover 20 for driving a pitch chain 24 and a sprocket 26. The chain 24 moves in the direction of the arrow adjacent to it;
A gear 28 attached to the sprocket 26 so as to rotate therewith drives the gear 18 and the drum 16.
is rotated in the direction of arrow A.

Further, as one skilled in the art will appreciate, as drum 16 rotates in the direction of arrow A, its surface successively moves past corona 30. Corona 30 biases the surface of drum 16 to create a uniform electrostatic charge. After exiting the corona 30, the drum surface passes through an exposed location 32. At exposure station 32, a moving optical device scans an original placed face down on platen 14 and transfers a latent image of the original onto the surface of moving drum 16. Details of this optical device itself are not shown since this optical device is outside the scope of the present invention.

After leaving the exposure station 32, the surface of the drum 16 passes through a developer unit 34. In the developing unit 34, the electrostatic latent image on the drum surface is subjected to the action of a developer containing toning agent particles. These toning agent particles adhere to areas of the drum surface that retain a charge after exposure to the image. Further movement of the developed image in the direction of arrow A feeds the drum 16 with a blank sheet at location 36. This piece of paper passes through the transfer corona 38 together with the drum 16. Transfer corona 38
is biased so that the developed image moves from the surface of the drum 16 to the underside of the piece of paper. After the transfer has been performed in this manner, the strip of paper carrying the developed and transferred image is removed from the drum 16 at a stripping station 40.

Gear 42 meshing with drum gear 18 provides input to the copy paper stripping and delivery system. Gear 42 is mounted on a common shaft with sprocket 44, and
2 and sprocket 44 are adapted to rotate around an axis b, which is the axis of a stripping roller, which will be described later. Sprocket 44 is pitch chain 4
6 is driven in the direction of the arrow adjacent to chain 46 in FIG. Chain 46 drives sprocket 48. There is also a gear 50 on the shaft of the sprocket 48.
is installed. The gear 50 meshes with the gear 52 and drives the gear 52 counterclockwise around an axis a of a cleaning roller to be described later.

The chain 46 is also associated with a tension sprocket 54 and a sprocket 56 mounted for rotation about the axis c of the lower roller of a pair of stripping rollers to be described below. The holding roller sprocket 58 is connected to the chain 46 and is driven counterclockwise around the axis d. The pitch chain 46 also drives a lower delivery roller sprocket 60 which is mounted for rotation about axis e. Idle sprocket 62 forms a path for chain 46 back to sprocket 48.

The drive for this copy paper feeder includes a gear 64 which is driven by the drum gear 18. Sprocket 66, mounted on a common shaft with gear 64, is driven about axis f to drive pitch chain 68 in the direction of the adjacent arrow in FIG. The chain 68 has axes g,
The upper and lower paper supply roller sprockets 70 and 72, which are mounted to rotate around h, are driven. Tension sprocket 74 is positioned to provide sufficient tension on chain 68. The gear mentioned above,
The sprocket and pitch chain mechanisms are all located at the rear of the copier 10.

As shown in FIG. 2, a spongy cleaning roller 76 mounted so as to rotate around an axis a
2, causing the surface of the cleaning roller 76 associated with the drum 16 to move in a direction opposite to the direction of movement of the drum surface.

The stripping roller 78, which will be described in detail later, is the roller 8.
0 and sends the peeled sheet to a nip between a pair of intermediate conveyor rollers 82 and 84. Roller 84 is mounted to rotate about axis c. The sheet after coming out from each roller 82, 84 is
It passes through a holding roller 86 mounted so as to rotate around an axis d, and is then subjected to the action of a dryer 88. As the sheet exits the dryer 88, it enters a nip between each delivery roller 90,92. Lower roller 92 is mounted to rotate about axis e. Each roller 90, 92 advances the sheet into a receiving tray 106 or the like.

A copying machine using the stripper of the present invention includes two cassettes holding respective sources 98, 102 of copy paper of different sizes. source 98,
Each paper feed roller 100, 104 cooperates with 102.
are mounted so as to rotate around respective axes g and h. Each supply source 98,1 under the control of the operator
The roller 100 that cooperates with one or the other of 02
Or it can be driven to selectively bring rollers 104 into cooperative relationship. The actuating roller delivers the sheet to a nip between a pair of rollers 94,96. The upper roller of both rollers 94 and 96 is mounted to rotate around the axis f. Each roller 94, 96 delivers a feed sheet onto the surface of drum 16. The structure described above is that of a copying machine to which a book ripping device is applied.

A gear 42 located within a housing 108 supported on the side of the copier as shown in FIGS. 3, 4, 5 and 6 drives a shaft 110 extending from the housing 108. The clutching device 112 of the book stripper includes a clutch member 114 keyed to a shaft 110 by a key 116. The key 116 is connected to the clutch member 11 in relation to the shaft 110.
4 is arranged to allow some radial movement to allow precise positioning relative to axis 110, as will be described below. Clutch member 114 is further adapted to receive a tapered end portion 118 of a rotating roller. This construction allows roller 78 to rotate with clutch member 114 when tapered end portion 118 is inserted into clutch member 114.

Housing 108 is fitted with outwardly extending studs 120, 122, respectively. Each stud 120, 122 receives a bracket 124 attached thereto by any suitable means well known in the art. A pin 12 is attached to the bracket 124 midway between its ends.
6 pivotally supports the arm member 128. Arm member 1
At the end of 28 is a shaft 129 which rotatably supports a metal roller 130 having a knurled outer surface.
is installed. A spring 134 wrapped around the pin 126 has one end applied to the bracket 124 and the other end applied to the arm member 128 and the roller 13
0 is elastically biased and associated with a rubber ring 132 attached to the clutch member 114.

The other clutch member 136 includes a disc-shaped portion attached to an integral axially extending boss portion 138 carried by a bushing 140 carried on the shaft 110. Each ball bearing 142, 144, which has an inner race on the boss portion 138, is held in spaced relationship with one another by a spacer 146 located between the outer races. Each bearing 142, 144 is received within a recess 148 formed within clutch member 114. Each bearing 142, 144 precisely spaces clutch member 114 radially relative to boss portion 138 of clutch member 136. As mentioned above, the key 116 allows some radial movement of the clutch member 114 relative to the shaft 110, with each bearing 142, 144
The function of accurately positioning the clutch member 114 in the radial direction relative to the boss portion 138 of 6 is achieved.

As can be seen from the structure described above, shaft 110 continuously drives clutch member 114 through a key 116 connection therebetween. Furthermore, under the action of friction, the clutch member 136 likewise
Rotates with 0. Clutch assembly 112 is provided with a restraining member that typically restrains clutch member 136 from rotating with shaft 110. Clutch member 136 is formed with a cam 150 having a low point 150a followed by a rising portion 150b in a counterclockwise direction, as shown in FIG. 6, followed by a relatively steep descending portion 150c. The stud 120 rotatably supports a driven arm member 154 that supports a driven member 152 mounted on a cam 150. Spring 156 attached to stud 120
typically biases arm member 154 in a clockwise direction in the drawings. The driven member 152 is located at the lower point 150a of the cam 150 when the components are in the inactive state. In this state, the spring 1 applied to the arm member 154
56 overcomes the frictional action that causes clutch member 136 to rotate with clutch member 114.
Clutch member 136 stops.

The disc-shaped portion of the clutch member 136 is formed with a finger-like portion 158 extending in the axial direction around the periphery.
Finger portion 158 extends a predetermined distance around the disk portion of clutch member 136.
It is apparent that the fingers 158 form a narrow radial clearance with the clutch member 114. The radial dimension of this clearance is for each bearing 142, 144.
more precisely. In practice, the spacing between fingers 158 and clutch member 114 is on the order of 2 mils. Clutch member 11 below fingers 158
A roughened surface portion 160 is provided on the outer surface of 4,
The inner surface 162 of the fingers 158 is highly polished. As will be described in more detail below, during operation of clutch device 112, inner surface 162 cooperates with the image-bearing side of the copy sheet; however, surface portion 16
0 cooperates with the other side of the copy sheet. finger-like part 1
58 and the clutch member 114, the effect of the spring 156 is overcome and the two clutch members are 11
Clutch engagement of fingers 158 and clutch member 114 is provided with sufficient force to move fingers 158 and 136 together. Furthermore, when the two clutch members 114, 136 move together, the driven member 1
52 rides on the rising portion 150b, increasing the force with which it grips the front edge of the seat. As the sheet is thus carried clockwise by the two clutch members 114, 136, the steep drop 150c of the surface of the cam 150 will eventually reach the location of the driven member 152. Further, as the driven member 152 rises along the riser 150, the force stored in the spring 156 increases. That is, when the descender 150c reaches the driven member 152, the spring 156 causes the clutch member 136 and the fingers 158 carried thereon to move clockwise, but faster than the rotational speed of the clutch member 114, so that the clutch member 112 grips the clutch member 112. Release the leading edge of the copy paper sheet. The highly polished inner surface of the fingers 158 facilitates the release action. Furthermore, during this release operation, the leading edge of the sheet has moved forward into the nip between the knurled roller 130 and the rubber ring 132. From this point, the sheet of copy paper is conveyed out of the copier by respective delivery rollers 82,84. Especially cam 150
and finger portion 15 under the action of driven member 152
8 is precisely returned to the same location each time the copying machine is operated.

The front edge of the sheet to be ripped off is attached to the finger-like portion 15.
8 and clutch member 114 using any suitable device. For example, the third
The apparatus of the present invention, illustrated in FIGS. 4, 5, and 6, utilizes thin fingers 164 supported on pivots 166 extending outwardly from housing 108. Fingers 164 are preferably formed from a low friction material such as polytetrafluoroethylene.
has an edge that rests on the surface of the drum 16 and intercepts the leading edge of the sheet of copy material 168 and directs the leading edge into the space between the fingers 158 and the clutch piece 114.

The variation shown in FIG. 7 uses any suitable device (not shown) to curve the leading edge of the sheet to create a raised portion 170. rising part 1
70 represents finger portion 158 and clutch member 114
sufficiently spaced from the surface of drum 16 to automatically enter the space between. Such sheet bending devices are well known in the art, as illustrated, for example, in U.S. Pat.

In the modified book stripping device shown in FIG. An air jet nozzle 172 is used to lift it.

When the front edge of the copy sheet to be removed from the copying machine is ripped off by the clutch mechanism, the copy sheet is not in the position to receive the second sheet until it is delivered to the nip between the roller 130 and the rubber ring 132. It won't happen. When operating an image transfer type electrostatic copying machine,
In one cycle of the copier, two sheets of copy material may be fed from the supply to the drum. That is, while a first of the sheets is being received into the stripping clutch by the book stripping device, the second sheet may not be associated with the clutch and may move with the drum to the cleaning location. At this cleaning location, the second sheet is placed on the cleaning roller 76.
The above-mentioned risk arises as the material gets wrapped around the material. The copying machine 10 is equipped with a device to prevent such a fear. In particular, a shaft 176, optionally supported in the housing of the copier 10, pivotally supports one or more baffle members 174 at or at locations somewhat spaced inwardly of the clutch assembly 112. . Each baffle member 174 includes a shoe portion 178 that rests on the surface of the drum 16. Clutch device 11
The sheet that is not grabbed by 2 is the shoe part 178
Pick up by. The shoe portion 178 directs the leading edge of the sheet to a surface 180 that bends the leading edge of the sheet rearward until it enters the nip between the roller 130 and the rubber ring 132. In this manner, the sheet is conveyed out of the copier along exactly the same path as the copy sheet that would be stripped in the conventional manner.

The operation of the stripping device of the present invention is clear from the above description. As long as drum 16 is being driven, shaft 110 is driven and drives clutch member 114. At the same time, the action of spring 156 prevents rotation of clutch member 136 by clutch member 114. After the image is formed and developed on drum 16, the copy sheet is fed onto drum 16 under transfer corona 38. As the sheet passes transfer corona 38, the developed image is transferred from the surface of drum 16 to the surface of the sheet in contact with drum 16. When the imaged sheet is moved from the transfer location, the leading edge of this sheet is in the fingers 1
58 and into the space between the clutch member 114. This may be due to the action of the stripping fingers 164, or by raised portions 170 formed at the leading edge of the sheet, or by the air jets 1.
72 or any other suitable means. The relationship of the thickness of the sheet 168 to the space between the fingers 158 and the clutch member 114 allows the leading edge of the sheet 168 to mutually engage the fingers 158 and the clutch member 114 as it enters this space. Driven member 152 overcomes the force of spring 156
rides on the cam rising portion 150b. In this case the spring 156 is loaded and pushes the leading edge of the seat into the finger 1
58 and clutch member 114 is increased. The leading edge of the sheet is a roller 130 and a rubber ring 13
Clutch member 1 to the place where it moved to the sandwiching part between 2
After 14 predetermined rotations, the cam lowering portion 150c has reached the location of the driven member 152. At this point, the force of loaded spring 156 causes clutch member 13 to
6 and finger 158 in the same direction at a higher speed than clutch member 114 to release the leading edge of the sheet. The highly polished surface 162 of the fingers 158, as described above, facilitates this release action.

If double feeding occurs on any occasion other than those described above, the second sheet will be blocked by the legs 178 of the member 174, and the nip between the roller 130 and the rubber ring 132 will bring this sheet into a position where it can be picked up. It is then moved and sent to the user of the copying machine in the same way as a normal copy.

It is clear that the objectives of the invention can be achieved in this way. According to the present invention, a stripping device for a copying machine has been obtained which eliminates the drawbacks of conventional stripping devices. The book stripper allows substantially the entire area of the copy sheet to receive the transferred image. The book ripping device is reliable in its operation. The book stripper incorporates a device that prevents double-fed sheets from wrapping around the copier's cleaning rollers. The book stripper returns the double-fed sheet to the user along the same path as the copy sheet on which the image was transferred. The book stripper effectively strips the copy sheet from the drum and delivers it to the user without smearing any portion of the produced image or soiling the copy sheet.

Although the present invention has been described above in detail with reference to its embodiments, it goes without saying that the present invention can be modified in various ways without departing from its spirit.

[Brief explanation of the drawing]

FIG. 1 is a side view of a driving device of an electrostatic copying machine incorporating one embodiment of the stripping device of the present invention, FIG. 2 is an enlarged side view of the copy paper handling device of the copying machine shown in FIG. 1, and FIG. is an enlarged vertical sectional view showing details of the book stripping device of the copying machine shown in FIGS. 1 and 2, FIG. 4 is a front view of the stripping device shown in FIG. 3, and FIG. 5 is an enlarged side view of the book stripping device of the present invention. , Figure 6 is 6- in Figure 5.
6 is a cross-sectional view taken along line 6, FIGS. 7 and 8 are cross-sectional views of different modifications of the essential parts of FIG. 6, and FIG. 9 is a return device for returning double-fed copy sheets to the copier user. FIG. 10... Copying machine, 16... Drum (front), 36...
Transfer location, 40... Stripping location, 42... Drive gear, 78... Stripping roller, 110... Shaft, 112
...Clutch device, 114...First clutch member, 1
16...Key, 136...Second clutch member, 138
...Boss, 140...Butssing, 142,144...
Ball bearing, 150...cam, 152...driven member, 15
6... Spring, 164... Finger piece (directing member), 168
...copy sheet.

Claims (1)

[Scope of Claims] 1. A stripping device for use in an image transfer copying machine which transfers an image developed on a surface to a sheet of copying material which travels with this surface through a transfer location to a stripping location. ) a shaft 110 rotatably supported in a housing 108 mounted on the copier cabinet 12; (b) a first clutch member 114 mounted on the shaft for rotation therewith; (c) a second clutch member 136 attached to the shaft so as to form a narrow space with the first clutch member so as to be rotatable relative to the shaft; and (d) sequentially. a low point 150a and a rising portion 15
0b and a cam surface having at least a relatively steep descending portion 150c, the cam is attached to the second clutch member, and (e) the cam is rotatably attached to the support member 120 attached to the housing. (f) a spring 156 attached to the support member 120 and urging the driven arm member 154 so as to press the driven member 152 against the cam surface; (g) directing a portion of said sheet of copying material from said moving surface into said space between said first and second clutch members; The spatial relationship between the first and second clutch members is defined such that entry of the seat into the space causes the first and second clutch members to engage each other and move as a unit. The shape of the cam surface is determined as follows: (i) When both the clutch members are in a disengaged state, the force of the spring is applied by the contact between the driven member 152 and the low point 150a. Therefore, the second clutch member 136 is stopped, and (ii) under the engaged state of both the clutch members, the driven member 152 and the rising member 150
b forces the driven arm member 154 against the force of the spring, increasing the force stored in the spring to grip a portion of the sheet, causing the driven member 152 and the lowering force to increase. Part 15
0c, the cam surface is configured such that the force stored in the spring drives the second clutch member 136 in the direction of rotation of the shaft to release a portion of the seat; Stripping device. 2. The stripping method of claim 1, wherein the force stored in the spring drives the second clutch member 136 in the same direction as the first clutch member 114 and faster than the first clutch member. Device. 3. Conveyors 82, 84, 86, 8 carrying away the released sheets from the image transfer copying machine.
A stripping device according to claim 1, comprising: 8, 90, 92. 4. Roughening the surface of the first clutch member 114 that engages a portion of the seat, and roughening the surface of the second clutch member 13 that engages a portion of the seat.
6. The stripping device according to claim 1, which polishes the surface of 6. 5. The first clutch member 114 is cylindrical, and the second clutch member 136 has a cylindrical shape.
2. A stripping device according to claim 1, further comprising arcuate fingers 158 radially spaced from a surface of the clutch member. 6. The first clutch member 114 is keyed to the shaft for rotation therewith and limited radial movement, and the arcuate fingers are keyed relative to the first clutch member. 6. The stripping device of claim 5, further comprising rolling bearings (142, 144) between said first and second clutch members for accurate positioning. 7. Claim 1, wherein said guide comprises a finger 164 placed on said surface on which said image is developed.
Stripping device as described in section. 8 A guide for directing the sheet into the space,
2. A stripping device as claimed in claim 1, comprising a nozzle (172) directing a jet of air to the underside of the leading edge of the sheet on the surface on which the image is developed. 9. The stripping device of claim 1, wherein the guide comprises a curved portion 170 formed on the leading edge of the sheet. 10. The stripping device of claim 1, further comprising a shoe portion 178 that obstructs the sheet from being directed from the surface into the space. 11 rollers 82, 84 forming a nip for receiving the released sheet and carrying it away from the image transfer copying machine; a return guide 17 that directs the sheet that has been removed into the nipping section;
4,178. The stripping device according to claim 1, comprising: 4,178. 12 spaced around the first clutch member by a substantially predetermined distance of movement of the clutch member as a unit to receive the released sheet and transport the sheet away from the image transfer copying machine; a roller device 130 for forming a nip at a location;
132. The stripping device according to claim 1, further comprising: 132. 13 a rubber ring 132 supported by the first clutch member 114 and a second rubber ring 132 engaged by a spring 134 such that the roller device rotates together with the first clutch member 114; 13. A stripping device according to claim 12, comprising a roller 130.