Extra Sheet Feeder for Copying Machine

The invention relates to an extra sheet feeder for a copying machine. In general, record sheets having a variety of sizes are provided, and are selectively used to suit a particular use. However, the usual copying machine is provided with a single paper feeder, and hence when it becomes necessary to use a record sheet of a different kind from the kind of record sheets which are already loaded into the copying machine, the loaded sheets must be removed from the machine and a desired record sheet must be loaded anew.

It is pointed out that there is a very strong desire or need to enable a copy to be obtained instantly on a record sheet of a different size from that of record sheets currently loaded in a machine or to obtain dual copies from copying machines which do not have the facility of providing such dual copies.

To accommodate for the need to provide a reduced number of copies of different size or dual copies, a record sheet or sheets are manually loaded into the paper feeder inlet of the machine as an extra sheet or sheets.

There are two types of extra sheet feeding means, one utilizing a devoted feeder which is associated with a separate feeder inlet for receiving an extra sheet or sheets only, and the other receiving the extra sheet into the usual inlet to be fed by the normal feed mechanism.

With feeding means of the former type, a separate feeder inlet must be provided for the extra sheet, which then must be fed by a manual operation, thus unavoidably resulting in a complicated control mechanism of the machine. By contrast, with the latter type, both the construction and the control can be simplified since the existing arrangement can be directly used. As examples of the latter type, U.S. Pat. No. 4,017,181 discloses a copying machine which utilizes a stack of record sheets received in a cassette, but in which when a copying on an extra sheet is desired, the cassette is removed out of the machine with a leading edge of the extra sheet inserted below a separator claw or claws which are provided on the cassette, which is then re-loaded into the machine. On the other hand, British Pat. No. 1,457,117 and U.S. Pat. No. 4,087,178 disclose an arrangement in which the top surface of a cassette which is externally visible when the cassette is loaded is provided with a plurality of indication marks representing a variety of sheet sizes and in which the leading edge of the extra sheet can be aligned with a feed position by aligning the trailing edge of the sheet with one of the indication marks.

In the arrangement of the initially cited U.S. Patent, the cassette must be withdrawn each time an extra sheet is to be loaded, requiring a troublesome operation and preventing an immediate operation. The other or latter PG,4 arrangement suffers from a problem that it cannot be assured that an extra sheet be loaded in place since the alignment with a selected indication mark cannot be achieved unless sheets of standardized sizes are used or a user may not be aware of the size of an extra sheet being used.

Some copying machines of the prior art are provided with a chamber in which a stack of record sheets of a given size is disposed, instead of using a cassette. When a copy on an extra sheet or a dual copy is desired, again the record sheets in the chamber must be removed, or an extra sheet must be engaged with a separator claw or claws which are provided on the chamber, thus resulting in the difficulty of use.

It is an object of the invention to eliminate above difficulties of the prior art by providing an extra sheet feeder having a usual feed mechanism which cooperates with an uppermost record sheet disposed in a stack in a sheet container such as a cassette or a containing chamber for feeding sheets one by one and in which an arrangement is made to enable an extra sheet to be loaded in place in a facilitated manner and fed by the normal feed mechanism.

In accordance with the invention, an extra sheet positioning member is disposed in a path which is formed above a stack of record sheets disposed in a container and into which an extra sheet or sheets are inserted. A manual insertion of an extra sheet through an inlet until it bears against the positioning member is all that is required to load it in place in a positive manner. In this manner, the difficulties of the prior art are removed, enabling a rapidly usable, extra sheet feeder to be provided.

FIG. 1 is a cross section of an extra sheet feeder according to one embodiment of the invention;

FIG. 2 is a perspective view of a sheet cassette which is used in the feeder shown in FIG. 1;

FIGS. 3 and 4 are a perspective view and a front view of the feeder of FIG. 1, illustrating the feeding operation of an extra sheet;

FIG. 5 is a perspective view of the feeder shown in FIG. 1, illustrating an alternative manner which employs an auxiliary placement plate;

FIG. 6 is a fragmentary perspective view of an extra sheet feeder according to another embodiment of the invention;

FIGS. 7 and 8 are cross sections of the feeder shown in FIG. 6, illustrating an extra sheet as it is loaded and as it is being fed;

FIG. 9 is a fragmentary perspective view of an extra sheet feeder according to a further embodiment of the invention;

FIGS. 10 and 11 are cross sections of the feeder of FIG. 9, illustrating an extra sheet as it is loaded and as it is being fed; and

FIG. 12 is a fragmentary cross section of an extra sheet feeder according to still another embodiment of the invention.

Referring to FIG. 1, there is shown an extra sheet feeder for a copying machine which is constructed in accordance with one embodiment of the invention. The feeder is designed to permit an extra sheet (see FIG. 2) to be simply loaded into a given position over the top surface of a sheet cassette 1 in which a stack of record sheets 3 are received and are fed one by one by a feed mechanism to enable a copying operation of a copying machine. Specifically, the cassette 1 includes a body 1A which is in the form of a rectangular box. A top cover 1B is detachably disposed on the top thereof. The front end face of the top cover 1B cooperates with the front wall as well as the upper ends of the both lateral sidewalls of the cassette body 1A to define an opening 4 through which record sheets 3 contained within the body 1A are fed one by one by a feed mechanism to be described later, beginning with an uppermost one. It is to be noted that the top portion of the front wall of the body 1A is centrally notched so as to be slightly lower in elevation than the upper end faces of the sidewalls in order to facilitate a feeding operation of the record sheets 3. A placement plate 5 is disposed within the body 1A and a stack of record sheets 3 is placed thereon. The rear end of the placement plate 5 is pivotally mounted on the both lateral sidewalls of the body 1A at its rear bottom ends, and the plate 5 has its front end urged upward by a compression spring 6 which is disposed between the underside of the front end of the plate and the bottomplate of the body 1A for urging the front end of the stack of record sheets 3 disposed thereon in an upward direction. As a result of such bias, an uppermost one of record sheets 3 in the stack has its both lateral ends at the front end thereof disposed in abutment against the underside of a pair of triangular separator claws 7a, 7b defined at the upper, front corners of the body 1A.

The feed mechanism comprises a pair of rockable roller support arms 9a, 9b having their one end pivotally mounted on support shafts 8a, 8b which are in turn mounted on a stationary member of a copying machine, not shown, a drive shaft 10 extending across the other ends of the support arms 9a, 9b and rotatably supported thereby, and a plurality of feed rollers 11 which are fixedly mounted on the drive shaft 10 in concentric manner therewith. When the drive shaft 10 is driven to rotate the feed rollers 11 counterclockwise while the roller support arms 9a, 9b are simultaneously rocked clockwise, the feed rollers 11 extend into the opening 4 to bear against an uppermost of the record sheets 3 contained in the cassette 1, whereupon the uppermost record sheet is separated from the remainder of the stack by the action of the separator claws 7a, 7b. In this manner, the uppermost sheet can be fed by the rotating feed rollers 11 through the opening 4 into the copying machine.

In the extra sheet feeder of this embodiment, a pair of left- and right-hand stops 12a, 12b are provided at the opposite lateral end of the front end of the cassette body 1A where the claws 7a, 7b are integrally formed, in the form of extensions of the front wall of the body 1A. These stops define positioning members and serve aligning the leading edge of an inserted extra sheet, shown in phantom line, with the leading edge of the copy sheets 3 contained in the body 1A. A guide ledge 15 is secured to the top of the left-hand sidewall of the body 1A to allow the extra sheet to be positioned along its left-hand side and to guide it when it is being inserted. It will be noted that the ledge 15 is contiguous and integral with the left-hand stop 12a.

In use, when the cassette 1 is loaded into a copying machine, not shown, the leading edge of the copy sheets 3 contained in the body 1A is invisible. However, the extra sheet or sheets 2 can be accurately loaded in place by inserting them along the guide ledge 15 until their front edge bears against the stops 12a, 12b. After the extra sheet or sheets 2 are loaded, the roller support arms 9a, 9b may be rocked clockwise to bring the feed rollers 11 into abutment against the extra sheet 2 which covers the opening 4, thereby feeding the extra sheet into the copying machine as the rollers 11 rotate, as shown in FIGS. 3 and 4. It will be noted from FIG. 4 that the both lateral edges of the extra sheet 2 will be turned upwardly by the stops 12a, 12b as the sheet is being fed, but it will be appreciated that the rigidity of a copy sheet is usually sufficient to prevent such sheet from being folded or wrinkled.

In this manner, the described embodiment permits an extra sheet 2 to be loaded in place regardless of its size, by merely inserting it until it bears against the stops 12a, 12b located at the front end of the body 1A which corresponds to the position of the leading edge of normal copy sheets 3 contained in the cassette 1.

As shown in FIG. 5, when an extra sheet 2A has a further reduced size as compared with that of the cassette 1, an auxiliary placement plate 17 may be disposed on top of the cassette 1 so as to extend along the guide ledge 15 and to bear against the stops 12a, 12b. Subsequently, an extra sheet 2A may be inserted onto the placement plate 17 and along the guide ledge 15 until it bears against the front steps 12a, 12b. At positions corresponding to the location of the feed rollers 11, the auxiliary placement plate 17 is formed with a notch 17a and a through-opening 17b to prevent an interference of the plate with these rollers as the latter descend during a normal operation. It is also to be noted that an additional stop 18 is located on the front end of the auxiliary placement plate 17 at a nearly central position, but toward the right-hand side thereof, in order to position the extra sheet 2A by cooperation with the left-hand stop 12a. The use of such auxiliary placement plate 17 permits an extra sheet 2A of a further reduced size to be satisfactorily fed.

FIGS. 6 to 8 show an extra sheet feeder according to another embodiment of the invention. The feeder is designed to assure a smooth sheet feeding operation by preventing an extra sheet from being turned upwardly by stops. This is achieved by causing extra sheet positioning stops 32a, 32b to move inwardly or duck into a body 21A of the cassette as feed rollers 31 descend. Specifically, the feeder of this embodiment is provided with a pair of stop support levers 35a, 35b, each of which is integrally formed with left- and right-hand stop 32a, 32b and which are adapted to be rocked into the body 21A as the rollers 31 move down. In addition to the stops 32a, 32b which are folded from the front end of the levers to extend along the front wall of the body 21A, the stop support levers 35a, 35b include central raised portions 35aA, 35bA toward the both lateral sidewalls of the body 21A, and also include spring abutments 35aB, 35bB located at the rear end of the levers 35a, 35b and which are folded therefrom to extend horizontally toward the both lateral sidewalls of the body 21A. Intermediate its length and toward the rear end, the levers 35a, 35b are pivotally mounted on the inside of the both lateral sidewalls of the body 21A by means of pivots 36a, 36b. It will be seen that a pair of triangular separator claws 27a, 27b as well as a pair of square spring abutments 38a, 38b extend inwardly and horizontally from the both lateral sidewalls of the body 21A. Notches 21a, 21b are formed between the separator claws 27a, 27b and the front wall of the body 21A to receive the stops 32a, 32b therein. It is to be noted that the spring abutments 38a, 38b are located in vertical alignment with the spring abutments 35aB, 35bB formed on the stop support levers 35a, 35b, and coiled compression springs 37a, 37b are interposed between these spring abutments, thus urging the stop support levers 35a, 35b in a direction to drive the stops 32a, 32b upwardly. However, the resulting movement is limited by the abutment of a front portion of the levers 35a, 35b against the underside of the separator claws 27a, 27b, and in this position, the stops 32a, 32b project above the upper surface of the cassette 21.

Feed rollers 31 are fixedly mounted on a drive shaft 30 which is in turn carried by a pair of rollers support arms 29a, 29b. It is to be noted that the free end of the arms 29a, 29b is formed with a downwardly depending bulge 29aA, 29bA which cooperate with the raised portions 35aA, 35bA on the levers 35a, 35b. As the arms 29a, 29b are rocked clockwise, these bulges 29aA, 29bA move into abutment against the raised portions 35aA, 35bA to depress them, thereby rocking the levers 35a, 35b to cause the stops 32a, 32b to duck into the cassette 21.

With the extra sheet feeder thus constructed, when the feed rollers 31 are located in their upper position as shown in FIG. 7, the stops 32a, 32b project above the cassette 21 so that an extra sheet 2 can be easily set in place by inserting it until its leading edge bears against the stops 32a, 32b. Subsequently, when the feed rollers 31 are brought to their feed position (FIG. 8) where they bear against a stack of record sheets 3 through the extra sheet 2 interposed therebetween, the bulges 29aA, 29bA on the roller support arms 29a, 29b cause the stop support levers 35a, 35b to rock to thereby cause the stops 32a, 32b to duck into the body 21A, whereby these stops cannot engage the lateral ends of the extra sheet 2 to turn them upwardly, thus assuring a smooth feeding operation for the extra sheet 2.

In FIGS. 6 to 8, a reference character 21B represents a top cover, 24 an inlet for sheets being fed, 25 a placement plate, 26 a coiled spring, and 28a and 28b pivot pins.

While the feeder shown in FIGS. 6 to 8 is not provided with a guide ledge along the left-hand side of the body 21A for guiding and positioning an extra sheet, it should be understood that such ledge may also be provided in this embodiment. In this instance, it is to be understood that the inner edge of the ledge should be displaced inwardly by an amount corresponding to the thickness of the stop support levers 35a, 35b so that the left-hand edge of an extra sheet 2 being inserted can be aligned with the left-hand edge of the record sheet 3 which are received in a stack within the body 21A. It is also to be noted that the ledge may also be located along the right-hand edge of the cassette 21.

FIGS. 9 to 11 illustrate a further embodiment of the invention where an extra sheet feeder is constructed so that not only stops 52a, 52b but also separator claws 47a, 47b move up and down as feed rollers 51 move vertically. Specifically, in the present embodiment, there are provided a pair of stop support levers 55a, 55b which are constructed in the similar manner as the levers 35a, 35b shown in FIGS. 6 to 8. These levers 55a, 55b are pivotally mounted on pins 56a, 56b on which support arms 60a, 60b which carry the separator claws are also pivotally mounted. The stop support levers 55a, 55b include stops 52a, 52b, raised portions 55aA, 55bA and spring abutments 55aB, 55bB. The both lateral sidewalls of body 41A of the cassette are formed with inwardly projecting spring abutments 58a, 58b, and coiled springs 57a, 57b are interposed between these spring abutments 58a, 58b and the spring abutments 55aB, 55bB to urge the stops 52a, 52b to project above the top level of the cassette 41. The support arms 60a, 60b include separator claws 47a, 47b which comprise a front end of the respective arms folded to extend along the front wall of the body 41A and having a triangular upper projection which is folded back, and also include detent pieces 60aA, 60bA which are folded from the arms, intermediate their length, toward the both lateral sidewalls of the body 41A. At their rear end, the arms 60a, 60b are pivotally mounted on the pins 56a, 56b, on the inside of the stop support levers 55a, 55b. The detent pieces 60aA, 60bA engage the upper end faces of the stop support levers 55a, 55b toward their front end. The upper surface of the detent pieces 60aA, 60bA is engaged by the lower surface of detent pins 61a, 61b which project inwardly from the both lateral sidewalls of the body 41A. These pins represent an abutment against the stop support levers 55a, 55b and the claw support arms 60a, 60b which are resiliently urged by the coiled springs 57a, 57b, and also an abutment against a stack of record sheets 3 disposed within the cassette 41 which is upwardly and resiliently urged by the coiled spring 46 through the placement plate 45 and acting upon the separator claws 47a, 47b and their associated support arms 60a, 60b.

A pair of roller support arms 49a, 49b carrying a drive shaft 50 on which feed rollers 51 are fixedly mounted are formed with bulges 49aA, 49bA on their free end, in the same manner as the roller support arms 29a, 29b shown in FIGS. 6 to 8. Intermediate their length, these support arms 49a, 49b are engaged by one end of coiled tension springs 62a, 62b, which urge the feed rollers 51 to move toward their inoperative position. In response to such bias, the support arms 49a, 49b then bear against the cam surface of oval-shaped disc cams 64a, 64b fixedly mounted on a drive shaft 63, and can be rocked in response to a rotation of the disc cams 64a, 64b as the drive shaft 63 is driven, to thereby move the feed rollers 51 up and down between their operative and inoperative positions.

Considering the arms 60a, 60b which support the separator claws, the arrangement is such that as the roller support arms 49a, 49b rock toward the operative or feed position, the arms 60a, 60b are rocked by the bulges 49aA, 49bA in delayed relationship with respect to the rocking motion of the stop support levers 55a, 55b, thereby depressing the separator claws 49a, 49b slightly against the resilience of the coiled spring 46 which acts thereon through the placement plate 45, the stack of record sheets 3 and the claws 47a, 47b. As the claws 47a, 47b are depressed, an uppermost one or ones of the record sheets 3 will be similarly depressed, but the abutment of the feed rollers 51 against the record sheets 3, through the interposed extra sheet 2, with a suitable pressure assures a normal feeding operation.

It is to be noted that in the feed position of the feed rollers 51, the upper end of the stops 52a, 52b is flush with or below the upper surface of the separator claws 47a, 47b.

The purpose of rocking the separator claws 47a, 47b up and down in response to a vertical movement of the feed rollers 51 is to prevent any likelihood of jamming of an extra sheet 2 which may find its way into a clearance between the topmost level of the record sheets 3 and the separator claws when the stack of record sheets 3 is depressed under the pressure exerted by the feed rollers 51.

With the extra sheet feeder thus constructed, when the feed rollers 51 are in their inoperative position shown in FIG. 10, the stops 52a, 52b project above the upper surface of the cassette 41, so that an extra sheet 2 can be easily loaded in place. On the other hand, when the feed rollers 51 descend to their feed position shown in FIG. 11, the stops 52a, 52b duck into the body 41A of the cassette, followed by a rocking motion of the separator claws 47a, 47b to remove any clearance between them and an uppermost one of the record sheets 3, whereby a smooth feeding operation of the extra sheet 2 is assured.

In FIGS. 9 to 11, reference character 41B represents a top cover, and 48a, 48b pivot pins.

FIG. 12 shows still another embodiment of the invention which is applicable to a copying machine which does not utilize a sheet cassette but in which a stack of record sheets 3 is disposed in a given chamber within the machine. The extra sheet feeder of this embodiment is designed to permit an extra sheet 2 to be easily loaded in place so that its leading edge is aligned with the position of the leading edge of normal copy sheets. Specifically, a copying machine 70 is shown with a chamber 72 receiving copy sheets therein, which is defined by a wall 71 integral with other walls of the machine. A placement plate 75 is slidably disposed within the chamber 72 and is upwardly urged by coiled compression springs 76, and a stack of record sheets 3 is placed on the plate 75. A pair of separator claws 77a, 77b are formed integrally with the upper end of the wall 71, and when the both lateral edges of a front portion of an uppermost record sheet in the stack bear against these claws, a further movement of the stack is prevented. A weight 73 rests on the upper rear end of the stack to impose a suitable load thereon, thus preventing the stack from being collapsed while permitting an uppermost record sheet to be easily removed out of the load imposed by the weight member 73.

It will be noted that in regions corresponding to the both lateral edges of the record sheets 3, the upper end of the wall 71 project upwardly beyond the separator claws 77a, 77b to serve as stops 82a, 82b for an extra sheet 2. An opening 81 for insertion of an extra sheet is formed in the surrounding wall of the machine 70 at a location corresponding to the rear end of the record sheets 3 disposed within the chamber 72.

In the feeder thus constructed, when a feed roller 78 is in its inoperative position, an extra sheet 2 may be inserted through the opening 81 and can be easily loaded in place by feeding it forward until its leading edge bears against the stops 82a, 82b.

With this arrangement, it is unnecessary to load an extra sheet 2 below the separator claws 77a, 77b which bear against an uppermost one of record sheets 3 disposed in the stack, but the extra sheet can be simply loaded in place by inserting it into abutment against the stops 82a, 82b located above the separator claws 77a, 77b.

It should be understood that the invention is not limited to the individual embodiments described above, but that a variety of changes and modifications are possible. By way of example, instead of disposing the stops along the both lateral edges of the copy sheets at a position corresponding to the leading edge thereof as shown in the described embodiments, a single stop may be disposed. The guide ledge which is used to guide and position an extra sheet may be omitted depending on the need of a particular use. Where the rear end of a container which contains record sheets therein is visible as when a cassette is used, such rear end may be provided with a linear array of indication marks along which a lateral side of an extra sheet is to be aligned. However, where a high accuracy is required in the positioning of the leading edge and the lateral side of an extra sheet and a single positioning stop is provided, it is desirable that a guide ledge be provided along the side on which the positioning stop is disposed in combination with an indication mark to assure an accurate positioning of the extra sheet. Means which cause the stops to retract or duck to their inoperative position in response to a feeding operation by the feed rollers may comprise a cam member which is mechanically ganged with a rocking motion of the feed support arms to cause the stops to duck into the cassette. Where the copying machine is provided with a chamber in which to receive record sheets, a solenoid or a linkage may be operated in response to a feeding operation by the feed rollers to retract the stops to a position above the record sheet containing chamber.