Patent Grant
6902162
The present invention is generally directed to the field of document handling and processing technology and, in particular, to improvements relating to the accumulation of material units.
A recurring problem in document handling operations is toner smudging or marking, which most often occurs as the result of the necessary interaction between document handling components and material units containing printed matter being handled by those components. The problem of toner smudging is especially acute and pervasive in document accumulation operations. In conventional accumulation configurations, a single-level accumulator drives material into and over entrance ramps with the use of o-rings (also known as polycords) that are continuously moving in the direction of material flow. These continuously moving o-rings contact each face (i.e., the front and/or the back side) of the material. The material is first driven, as separate pieces or a pair, into the accumulator from an upstream device. The material is then advanced to the exit end of the accumulator by the o-rings that are essentially designed to act as a slip drive and comes to rest as the lead edge of the material contacts a pair of output rollers. Subsequent pages then accumulate over or under each preceding piece until the accumulator's maximum capacity is reached (usually 10-15 sheets) or a full set is satisfied. The o-rings, however, continue to cycle as material comes to rest and as succeeding material enters the accumulator and begins to accumulate. Accordingly, toner smudge occurs as, for example, the bottom set of o-rings becomes impregnated with toner from preceding pieces and transfers this toner to the first page of the set as it rests in the static condition.
Examples of document handling devices such as accumulators that employ pressure-applying belts or o-rings to drive sheets are disclosed in U.S. Pat. Nos. 6,203,006; 5,915,686; 5,794,931; 5,775,689; 5,692,745; 5,655,761; 5,647,587; 5,590,873; 5,484,255; 5,244,200; 5,147,092; and 4,767,115.
Material removal can also be problematic in conventional accumulator devices. Material must be folded and often torn to be removed from between the fixed o-rings of the accumulator. Another problem relates to the stretching of o-rings over time due to wear and material removal. Moreover, material justification can be problematic, particularly when accumulating before a folder. To achieve a high quality fold with minimal shingling, a set of material that is square on all edges (front, back, and both sides) optimizes the fold quality. Other recurring issues include the ease with which an accumulator device can be changed from over-accumulation to under-accumulation, and can be adjusted to accommodate different material sizes, if such switching capabilities are provided at all.
The present invention is provided to address, in whole or in part, these and other problems associated with prior art document handling technology.
The invention disclosed herein provides a sheet accumulating apparatus and method for accumulating sheets. A series of single sheets, or a series of accumulated or stacked subsets of sheets, are inputted into an accumulation section. The apparatus is operable in either an over-accumulation mode or an under-accumulation mode. In the over-accumulation mode, each new sheet of subset of sheets enters the accumulation section on top of the developing stack of sheets in the accumulation section. In the under-accumulation mode, each new sheet of subset of sheets enters the accumulation section underneath the developing stack of sheets in the accumulation section. In either mode, the apparatus is constructed and its components selected and arranged so as to minimize contact or engagement between sheets and physical structure, and to enhance the control of the apparatus over the speed and flow of the sheets through the apparatus. Therefore, smudging of printed matter on the sheets and damage to the sheets are minimized. Moreover, the apparatus facilitates rapid adjustment by the user between the over-accumulation and under-accumulation modes without the need for tools. In addition, the sheets accumulating in the accumulation section are registered on all four sides, i.e., lead edge, trail edge, and lateral edges. Consequently, a predetermined number of sheets are accumulated into a fully registered stack for advancement to a location downstream of the apparatus.
According to one embodiment, a sheet accumulating apparatus comprises an accumulation section defining a sheet feed plane therethrough. An upper ramp is disposed upstream from the accumulation section and is movable into and out of the sheet feed plane. An upper retaining member is linked to the upper ramp and is movable into and out of the sheet feed plane in alternating relation to the upper ramp. A lower ramp is disposed below the upper ramp and is movable into and out of the sheet feed plane in alternating relation to the upper ramp. A lower retaining member is linked to the lower ramp and movable into and out of the sheet feed plane in alternating relation to the upper ramp.
Preferably, the upper ramp, the upper retaining member, the lower ramp, and the lower retaining member are pivotably movable into and out of the sheet feed plane, the upper ramp is pivotable in an opposite direction in relation to the pivoting of the upper retaining member, and the lower ramp is pivotable in an opposite direction in relation to the pivoting of the lower retaining member.
Preferably, the mechanical interface or functional couplings among the corresponding ramps and retaining members are implemented with linkages. Accordingly, in one embodiment, an upper linkage links the upper ramp to the upper retaining member and a lower linkage links the lower ramp to the lower retaining member. The upper linkage comprises a first upper linkage member pivotable with the upper ramp and a second upper linkage member pivotable with the upper retaining member in engagement with the first upper linkage member. The lower linkage comprises a first lower linkage member pivotable with the lower ramp and a second lower linkage member pivotable with the lower retaining member in engagement with the first lower linkage member. Even more preferably, the linkage members include respective toothed portions that engage each other, such that the linkage members can comprise intermeshing gears or gear segments.
In some embodiments, a front stop mechanism is disposed downstream from the upper and lower ramps and is movable into and out of the sheet feed plane.
In some embodiments, a carriage assembly is movably engaged with a frame of the accumulating apparatus and supports the front stop mechanism. Accordingly, the front stop mechanism is movable with the carriage assembly toward and away from the upper and lower ramps, thereby enabling the accumulating apparatus to accommodate different lengths of sheets.
Preferably, the accumulating apparatus comprises a sheet transport device. The sheet transport device comprises one or more sheet-engaging members, such as pusher fingers or lugs, that are movable through the accumulation section along the sheet feed plane. Such a sheet transport device is employed to at least begin transport of a stack of over- or under-accumulated sheets out from the accumulating section of the apparatus. The sheet-engaging members contact only the trail edge of the sheet stack and thus do not cause smudging. Hence, even with the use of the sheet transport device, sheets are still not subject to any moving components while accumulation is occurring.
Preferably, the accumulating apparatus comprises left and right side jogging members disposed at respective lateral sides of the accumulation section. These side jogging members are movable toward and away from each other along a direction transverse to a sheet flow path through the accumulation section. Alternating actuation or other movement of the side jogging members jogs the sheets into side-by-side registration in the accumulation section.
According to another embodiment, a sheet accumulating apparatus comprises an accumulation section defining a sheet feed plane therethrough, and an accumulating assembly disposed upstream from the accumulation section. The accumulating assembly is selectively adjustable to an over-accumulation position and an alternative under-accumulation position. The accumulating assembly comprises a first ramp, a first retaining member, and a first linkage interconnecting the first ramp and the first retaining member, wherein the first ramp is movable with first retaining member. The accumulating assembly also comprises a second ramp, a second retaining member, and a second linkage interconnecting the second ramp and the second retaining member, wherein the second ramp is movable with the second retaining member. At the over-accumulation position, the first ramp and the second retaining member are disposed out of the sheet feed plane, and the second ramp and the first retaining member extend in the sheet feed plane. At the alternative under-accumulation position, the first ramp and the second retaining member extend in the sheet feed plane, and the second ramp and the first retaining member are disposed out of the sheet feed plane. The sheet accumulating apparatus is thus structured so as to be adjustable to either accumulation position, and consequently is capable of either over-accumulating or under-accumulating sheets as desired by the end user.
According to yet another embodiment, a sheet accumulating apparatus comprises upper and lower frame sections, first and second upper rotatable members, upper and lower accumulation ramps, upper and lower sheet guide members, and first and second lower rotatable members. The upper frame section has an upper input end and the lower frame section has a lower input end, such that the upper and lower input ends define an input area and a sheet feed plane therebetween and the sheet feed plane extends through the input area. The first upper rotatable member is disposed in the upper frame section and the second upper rotatable member engages the first upper rotatable member, such that rotation of the first upper rotatable member in one direction corresponds to rotation of the second upper rotatable member in an opposite direction. The upper accumulation ramp is connected to the first upper rotatable member and is rotatable therewith into and out of the sheet feed plane. The upper sheet guide member is connected to the second upper rotatable member and is rotatable therewith into and out of the sheet feed plane. The first lower rotatable member is disposed in the lower frame section and the second lower rotatable member engages the first lower rotatable member, such that rotation of the first lower rotatable member in one direction corresponds to rotation of the second lower rotatable member in an opposite direction. The lower accumulation ramp is connected to the first lower rotatable member and is rotatable therewith into and out of the sheet feed plane. The lower sheet guide member is connected to the second lower rotatable member and is rotatable therewith into and out of the sheet feed plane.
According to still another embodiment, a sheet accumulating apparatus comprises upper and lower frame sections, a plurality of elongate upper and lower sheet guides, and upper and lower accumulation ramps. The upper frame section has an upper end and the lower frame section has a lower end, such that the upper and lower frame sections define an accumulation area therebetween. The upper end pivotably engages the lower end to enable the upper section to pivot away from the lower section and thus to provide access to the accumulation area. The elongate upper sheet guides are supported by the upper frame section and are pivotable therewith, and define an upper boundary of the accumulation area. The elongate lower sheet guides are supported by the lower frame section and define a lower boundary of the accumulation area. The upper accumulation ramp is supported by the upper frame section and is pivotable therewith. The lower accumulation ramp is supported by the lower frame section.
According to a further embodiment, a material accumulating apparatus comprises a frame assembly, an input section, a carriage assembly, and a front stop mechanism. The frame assembly comprises first and second lateral support plates. The input section is disposed at an upstream region of the frame assembly and defines a material flow path running between the first and second lateral support plates. The carriage assembly comprises a front stop support plate extending between the first and second lateral support plates, a first carriage member movably connecting the front stop support plate to the first lateral support plate, and a second carriage member movably connecting the front stop support plate to the second lateral support plate. The front stop mechanism is disposed downstream from the input section and is mounted to the front stop support plate. Translation of the front stop support plate along a general direction of the material flow path varies a distance between the front stop mechanism and the input section.
Preferably, the front stop mechanism comprises a front stop member and an actuator connected to the front stop member, and the front stop member is movable by the actuator into and out of the material flow path. It is also preferable that the front stop member be spring-mounted so as to provide a recoiling action upon contact with an incoming sheet and thus assist in registering sheets from lead edge to trail edge. It is further preferred that the accumulating apparatus comprise a first rack gear mounted to the first lateral support plate, a second rack gear mounted to the second lateral support plate, a first pinion gear fixedly disposed in relation to the first carriage member and engaging the first rack gear, and a second pinion gear fixedly disposed in relation to the second carriage member and engaging the second rack gear. By this configuration, rotation of the first and second pinion gears respectively along the first and second rack gears causes translation of the first and second carriage members respectively along the first and second rack gears.
In some embodiments, the invention comprises upper and lower output rollers fixedly mounted in relation to the front stop mechanism and translatable therewith.
According to a yet further embodiment, a material accumulating apparatus comprises a sheet input device, an accumulation area disposed generally downstream from the sheet input device, a front stop mechanism disposed downstream from the sheet input device, first and second output rollers disposed at a fixed distance downstream from the front stop mechanism, and a material transport device. The sheet input device comprises a first input roller and a second input roller. A material feed plane is defined between the first and second input rollers. The accumulation area comprises a plurality of upper guide rods and a plurality of lower guide rods, such that the material feed plane is disposed between the upper and lower guide rods. The front stop mechanism comprises a front stop member and an actuator connected to the front stop member. The front stop member is movable by the actuator into and out of the material feed plane. The material transport device comprises movable material-engaging lugs between the first and second input rollers and the first and second output rollers.
According to a still further embodiment, a material accumulating apparatus comprises a frame assembly, an input section disposed at an upstream region of the frame assembly, a side jogging mechanism disposed downstream from the input section, and a front stop mechanism disposed downstream from the input section. The frame assembly comprises first and second lateral support plates. The input section defines a material flow path running between the first and second lateral support plates. The side jogging mechanism comprises an upstream support rod extending between the first and second lateral support plates, a downstream support rod extending between the first and second lateral support plates, first and second mounting brackets, first and second side guides respectively linked to the first and second mounting brackets, and first and second actuating devices. Each mounting bracket has an upstream end slidably supported by the upstream support rod and a downstream end slidably supported by the downstream support rod. The first and second actuating devices are respectively adapted to translate the first and second side guides along a direction transverse to the material flow path. The front stop mechanism is mounted to the front stop support plate. Translation of the front stop support plate along a general direction of the material flow path varies a distance between the front stop mechanism and the input section.
According to other embodiments, the accumulating section comprises a plurality of upper elongate members and a plurality of lower elongate members. The sheet feed plane is defined between the upper and lower elongate members. Preferably, the upper and lower elongate members are cylindrical in cross-section so as to provide the minimum possible contact area for sheets that encounter the elongate members.
A method is also provided for registering one or more sheets during or after accumulation of the sheets in an accumulating apparatus, according to the following steps. An accumulation section is provided that defines a sheet feed plane. A front stop is moved into the sheet feed plane. A back stop is moved into the sheet feed plane at a position upstream from the front stop. A sheet is moved along an input path past the back stop into the accumulation section, whereby the sheet contacts the front stop and is recoiled thereby toward the back stop. The sheet is alternately translated along opposing directions transverse to the input path. Preferably, the sheet is moved past the back stop by contacting the sheet with an inclined surface of the back stop, whereby the sheet is at least temporarily diverted away from the sheet feed plane to move around the back stop. The sheet is alternately translated preferably by alternately moving left and right opposing side guides toward and away from a centerline of the accumulation section.
A method is also provided for adjusting an accumulating apparatus between an over-accumulating mode and an under-accumulating mode, according to the following steps. An accumulating section is provided that defines a sheet feed plane extending therethrough. An accumulating assembly is generally disposed upstream from the accumulating section and comprises an upper ramp, an upper retaining member movably linked to the upper ramp, a lower ramp, and a lower retaining member movably linked to the lower ramp. An over-accumulating mode is set by causing the upper ramp to move out of the sheet feed plane whereby the upper retaining member moves into the sheet feed plane, and causing the lower ramp to move into the sheet feed plane whereby the lower retaining member moves out of the sheet feed plane. The under-accumulating mode is an alternative setting. The under-accumulating mode is set by causing the upper ramp to move into the sheet feed plane whereby the upper retaining member moves out of the sheet feed plane, and causing the lower ramp to move out of the sheet feed plane whereby the lower retaining member moves into the sheet feed plane.
According to another method, sheets are over-accumulated according to the following steps. An accumulating section is provided that defines a sheet feed plane extending therethrough. An accumulating assembly is generally disposed upstream from the accumulating section and comprises an upper retaining member and a lower ramp, wherein the upper retaining member and the lower ramp extend into the sheet feed plane. An incoming sheet is moved generally along the sheet feed plane toward the lower ramp. The incoming sheet is caused to contact the lower ramp and move over the lower ramp. The incoming sheet is caused to contact the upper retaining member and be guided downwardly thereby, whereby the incoming sheet enters the accumulating section between the upper retaining member and a preceding sheet residing in the accumulating section.
According to yet another method, sheets are under-accumulated according to the following steps. An accumulating section is provided that defines a sheet feed plane extending therethrough. An accumulating assembly is generally disposed upstream from the accumulating section and comprises an upper ramp and a lower retaining member, wherein the upper ramp and the lower retaining member extend into the sheet feed plane. An incoming sheet is moved generally along the sheet feed plane toward the upper ramp. The incoming sheet is caused to contact the upper ramp and move below the upper ramp. The incoming sheet is caused to contact the lower retaining member and be guided upwardly thereby, whereby the incoming sheet enters the accumulating section between the lower retaining member and a preceding sheet residing in the accumulating section.
According to a further method, sheets are over-accumulated according to the following steps. A first sheet is inputted along a sheet feed plane toward an accumulation area. The first sheet is diverted above the sheet feed plane. The first sheet is urged downwardly as the first sheet moves into the accumulation area, and comes to rest in the accumulation area. A second sheet is inputted along the sheet feed plane toward the accumulation area. The second sheet is diverted above the sheet feed plane. The second sheet is urged downwardly as the second sheet moves into the accumulation area, and comes to rest in the accumulation area on top of the first sheet. The method can be repeated for subsequent sheets to form an accumulated stack of sheets in the accumulation area.
According to an additional method, sheets are under-accumulated according to the following steps. A first sheet is inputted along a sheet feed plane toward an accumulation area. The first sheet is diverted below the sheet feed plane. A trailing edge of the first sheet is urged upwardly as the first sheet moves into the accumulation area, such that the first sheet comes to rest in the accumulation area with its trailing edge elevated above the sheet feed plane. A second sheet is inputted along the sheet feed plane toward the accumulation area. The second sheet is diverted below the sheet feed plane and below the trailing edge of the first sheet. A trailing edge of the second sheet is urged upwardly as the second sheet moves into the accumulation area. The second sheet comes to rest in the accumulation area underneath the first sheet, and the trailing edge of the second sheet is elevated above the sheet feed plane. The method can be repeated for subsequent sheets to form an accumulated stack of sheets in the accumulation area.
It is therefore an object to provide an accumulating apparatus for collecting and advancing sheet articles, and particularly such an apparatus for use in high-speed media processing.
It is another object to provide an accumulating apparatus that permits selection and adjustment of either over-accumulating or under-accumulating of the sheet articles processed thereby, and can also accommodate different sheet sizes.
It is yet another object to provide an accumulating apparatus for improved handling of processed sheet articles that eliminates or at least greatly minimizes toner smudging of smearing of the sheet articles.
It is still another object to provide an accumulating apparatus for improved handling of processed sheet articles wherein the sheet articles are accumulated into a fully registered set of sheets.
Some of the objects having been stated hereinabove and which are achieved in whole or in part by this invention, other objects will become evident as the description proceeds when taken in connection with the accompanying drawings as best described hereinbelow.
Referring now to
In general, accumulating apparatus 10 comprises an input section, generally designated 15; an accumulation area, generally designated 20; and an output section, generally designated 25. Arrow F in
In operation, accumulating apparatus 10 is initially set to perform either over-accumulation or under-accumulation by manipulating outer thumb knobs or levers 41A and 41B and inner thumb knobs or levers 43A and 43B, as described in more detail hereinbelow. An upstream module or other means is used to feed either individual sheets of material or subsets of sheets sequentially into input section 15. Hence, as used hereinafter, the term “sheet” denotes either a single sheet or a subset of sheets, it being understood that accumulating apparatus 10 is capable of producing an accumulated sheet set from either a plurality of individually in-fed sheets or a plurality of in-fed, previously accumulated subsets of sheets. As a general matter, “sheets” can constitute any form of material units capable of being processed by document handling equipment.
As described in more detail hereinbelow, input section 15 controls the speed of the incoming sheets according to a dynamic speed profile as the sheets are being fed into accumulation area 20. Once a sheet enters accumulation area 20, that sheet is held while other sheets are permitted to enter accumulation area 20 either under or over the first sheet. If accumulating apparatus 10 is set to over-accumulate sheets in accumulation area 20, the first sheet entering accumulation area 20 becomes the bottom-most sheet in the resulting stack of accumulated sheets. If, on the other hand, accumulating apparatus 10 is set to under-accumulate sheets, the first sheet becomes the top-most sheet in the resulting stack of accumulated sheets.
As sheets are accumulated in the accumulation area 20, the leading edge, trailing edge, and lateral edges of each sheet are registered or justified, so that all sides of the resulting stack are squared off in preparation for subsequent advancing of the sheet stack to a downstream site (e.g., a downstream sheet set processing module). In at least one embodiment, an adjustable front stop mechanism (described hereinbelow) is utilized to register the leading edge of each incoming sheet. In at least one other embodiment, a jogging mechanism (described hereinbelow) is used to assist in registering the lateral edges of the sheets in the accumulating stack. Once a predetermined number of sheets have accumulated in accumulation area 20, such as by employing conventional sensing or counting means, a transport mechanism (described hereinbelow) generally situated within accumulation area 20 advances the stack into output section 25, from which the sheet set is transported from accumulating apparatus 10 to the downstream site.
As shown in
Referring to
Input section 15 (
The coupling of one of in-feed rollers 53A or 53B to a variable-speed motor (not shown) renders the rollers “dynamic” in the sense that their rotational speed is variable over a given range (for example, approximately 80 ips to approximately 180 ips, where “ips” denotes “inches per second”). For each cycle, defined for the present purpose as a sheet being fed through input section 15 and into accumulation area 20 (and accumulating over or under the pre-existing stack, if any), the dynamic speed profile is characterized by an initial input speed (preferably matched with the output speed of the upstream module) followed by a ramping down of the speed as the sheet enters accumulation area 20 and abuts the front stop mechanism provided. The ramp of deceleration that forms a part of the dynamic speed profile can be associated with a constant rate of deceleration or a non-linear rate. As one example, the initial in-feed speed can be 180 ips, which is thereafter dynamically slowed down according to a predetermined speed profile to a lower speed of 80 ips.
Input section 15 also comprises a switchable over/under accumulating mechanism that comprises the following components. First and second top gears or gear segments 55A and 55B, respectively, are mounted in upper section 10A of accumulating apparatus 10 above central sheet feed plane P, and rotate about respective parallel axes in meshing engagement with each other. Similarly, first and second bottom gears or gear segments 57A and 57B, respectively, are mounted in lower section 10B of accumulating apparatus 10 below central sheet feed plane P, and rotate about respective parallel axes in meshing engagement with each other. Thus, first and second top gear segments 55A and 55B rotate in opposite senses with respect to each other, and first and second bottom gear segments 57A and 57B rotate in opposite senses with respect to each other. In a preferred embodiment, first top gear 55A and top in-feed roller 53A rotate about the same axis, and first bottom gear 57A and bottom in-feed roller 53B rotate about the same axis.
The over/under accumulating mechanism further comprises one or more top accumulation ramps 59 and one or more bottom accumulation ramps 61. Top accumulation ramps 59 are linked in mechanical relation to first top gear segment 55A and rotate therewith, and bottom accumulation ramps 61 are linked in mechanical relation to first bottom gear segment 57A and rotate therewith. As shown in
Preferably, top and bottom hold-down fingers 63 and 65 include respective arcuate sections 63A and 65A as shown in FIG. 4. Each arcuate section 63A and 65A can be constructed as a continuous member or as a contiguous series of differently angled segments. Each of top and bottom hold-down fingers 63 and 65 is constructed of such physical dimensions and material composition as to be capable of storing spring energy. Hence, top and bottom hold-down fingers 63 and 65 are deflectable upon encountering a force and recoverable to an initial profile upon subsequent removal of the force. Inclined surfaces 59A and 61A of respective top and bottom accumulation ramps 59 and 61, and arcuate sections 63A and 65A of respective top and bottom hold-down fingers 63 and 65, selectively interact with incoming sheets as described hereinbelow. The selectivity depends on whether the over-accumulation mode or under-accumulation mode is active. As also described hereinbelow, respective back-stop surfaces 59B and 61B of top and bottom accumulation ramps 59 and 61 assist in selectively registering the trailing edge of the stack of sheets.
Referring to
Referring back to
Referring to
Referring now to
Referring now to
Referring to
A powered drive source adapted for reversible rotary power transfer, such as a rotary solenoid or reversible motor 131, is mounted to support plate 125 through a suitable mounting bracket 133 (see
Referring back to
Referring now to
Output rollers 141A and 141B are driven by an output roller drive motor 161 and associated drive belt 163 and pulleys 165A, 165B and 165C. The position of this motor 161 is also adjustable with output rollers 141A and 141B and front stop mechanism 110. This is accomplished by mounting output roller drive motor 161 to a sliding motor support plate 167. The lateral ends of sliding motor support plate 167 are connected to guide members 169 (only one of which is visible in
Referring back to
As shown in
The jogging movement is effected by a suitable actuator such as a solenoid 207A and 207B mounted to each adjustable mounting bracket 193A and 193B. The moving portion of each solenoid 207A and 207B, for example an actuating arm 209, is able to contact back plate 205A and 205B of each corresponding side guide 191A and 191B. Hence, activation of each solenoid 207A and 207B causes extension of its actuating arm 209, and in turn causes its side guide 191A and 191B to translate inwardly toward the centerline of accumulation area 20 against the biasing force of springs 203A and 203B. Deactivation of each solenoid 207A and 207B causes its side guide 191A and 191B to return to its initial position under the influence of springs 203A and 203B. Alternate activation and deactivation of solenoids 207A and 207B produces the jogging action that results in side-to-side registration of sheets in accumulation area 20. The sheet stack can be jogged each time a new sheet is added to the stack, or can be jogged after the predetermined number of sheets have been added to complete the stack. Preferably, the amount by which each solenoid 207A and 207B causes extension of its respective actuating arm 209 depends on the initial width set between side guides 191A and 191B. For example, if the initial width is set to approximately ¼ inches greater than the actual width of the sheets being processed, the distance by which each actuating arm 209 extends can be ⅛ inches
The operation of accumulating apparatus 10 when positioned in its over-accumulation mode will now be described with reference to
The operation of accumulating apparatus 10 when positioned in its under-accumulation mode will now be described with reference to FIG. 5. Stack S of under-accumulated sheets, or at least the trailing end region thereof, is held against top support rods 45 by bottom hold-down fingers 65. The leading edge of sheet stack S is registered against front stop fingers 113 of front stop mechanism 110, while the trailing edge of sheet stack S is registered against the respective back surfaces of top accumulation ramps 59. Top accumulation ramps 59 are in a lowered position in the material feed plane, such that the leading edge of incoming sheet IS encounters their respective inclined front surfaces and is thereby directed downwardly underneath the bottom side of the bottommost sheet in accumulating stack S. Bottom hold-down fingers 65 are in a raised position in the material feed plane, and thus support sheet stack S in a raised position and guide incoming sheets IS upwardly to allow incoming sheets IS to accumulate underneath sheet stack S. Bottom accumulation ramps 61 are in a lowered position out of the way of the incoming sheets IS. Similarly, top hold-down fingers 63 are in a raised position out of the material feed plane, and thus out of the way of incoming sheets IS and accumulating stack S. Each incoming sheet IS flows along the inclined front surfaces of top accumulation ramps 59 and between stack S and bottom hold-down fingers 65, is jogged by recoiling front stop fingers 113, and comes to rest at the bottom of stack S in registry between front stop fingers 113 and top accumulation ramps 59.
Referring now to
Although not specifically shown in the drawings, it will be understood that an appropriately programmed electronic controller such as a microprocessor, or other conventional means for executing instructions and receiving and/or sending signals, is placed in communication with the variable speed motor driving dynamic infeed rollers 53A and 53B, the motor driving transport belts 81A and 81B, the actuator 131 driving front stop fingers 113, the motor 161 driving output rollers 141A and 141B, the motor driving exit rollers 181A and 181B, and the solenoids 207A and 207B driving the side guides 191A and 191B. The electronic controller can thus maintain synchronization of these various components of accumulating apparatus 10, as well as control the respective operations of specific components. It will be further understood that the electronic controller can receive feedback from upstream and downstream devices in order to determine the proper speeds of the various rollers, and can receive feedback from various sensors situated in accumulating apparatus 10 to determine the location of sheets or to count the number of sheets accumulating in accumulation area 20. Thus, the electronic controller determines the dynamic speed profile of dynamic infeed rollers 53A and 53B, as described hereinabove, in order to feed sheets at an initial input speed and slow the sheets down to a reduced registration speed as the sheets approach front stop fingers 113. In addition, the electronic controller determines the proper time to side jog the sheet stack as sheets enter accumulation area 20. Moreover, the electronic controller determines when the proper number of sheets have accumulated, after which time the electronic controller causes front stop fingers 113 to retract out of the material flow path, transport belts 81A and 81B to move the stack forward into output rollers 141A and 141B, output rollers 141A and 141B to move the stack to exit rollers 181A and 181B, and the exit rollers 181A and 181B to move the stack toward an area or device downstream from accumulating apparatus 10. The provision of independent input, transport, and output drives enables accumulating apparatus 10 to be matched with any upstream and downstream devices.
In one specific but non-limiting embodiment, accumulating apparatus 10 supports sheets that are 5.50 inches (140 mm) to 12.00 inches (305 mm) wide and 3.50 inches (89 mm) to 14.00 inches (356 mm) long. This accumulating apparatus 10 can accumulate 1 to 30 sheets of 18-lb. to 24-lb. paper. Conversion time related to material size and over/under accumulation mode switching is approximately two minutes or less. In addition, this accumulating apparatus 10 can accommodate material skew from 0.5 degrees to 2 degrees, depending on sheet length. Sheets are registered from lead-to-trail edge and side-to-side within a 0.008-inches (0.20-mm) offset.
The operation of accumulating apparatus 10 as described hereinabove will now be summarized with reference being made primarily to
The recoiling reaction of front stop mechanism 110 induces a jogging action that registers incoming sheet IS with the rest of sheet stack S between front stop mechanism 110 and either top accumulation ramp 59 or bottom accumulation ramp 61 (depending on whether accumulating apparatus 10 is set for under-accumulation or over-accumulation as described hereinabove). Dynamic in-feed rollers 53A and 53B increase speed back up to top velocity to advance subsequent incoming sheets IS into accumulation area 20, and the slowdown process again occurs such that the dynamic speed profile is implemented for each cycle of incoming sheets IS being fed into accumulating apparatus 10. Each incoming sheet IS can be fed completely individually, in subsets, or in overlapping relation to other incoming sheets IS.
When a complete set of sheets (sheet stack S) has been over- or under-accumulated, the following exit routine transpires. Spring loaded front stop fingers 113 retract out of the sheet feed path. Side guides 191A and 191B (see
It can be seen from the foregoing that no moving components of accumulating apparatus 10 contact the sheet material during accumulation thereof. Thus, the risk of toner smudging/transfer to the sheet material is significantly reduced or even eliminated. Moreover, the adjustments to accumulating apparatus 10 required to effect a change-over between under-accumulation and over-accumulation, and to effect a change in material size, is quick, easy, and tool-less.
It will be understood that various details of the invention may be changed without departing from the scope of the invention. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation—the invention being defined by the claims.
This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/356,229, filed Feb. 12, 2002; the disclosure of which is incorporated herein by reference in its entirety.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3075630 | Fisk | Jan 1963 | A |
| 4340213 | Jensen | Jul 1982 | A |
| 4640506 | Luperti et al. | Feb 1987 | A |
| 4767115 | Garthe | Aug 1988 | A |
| 4805891 | Luperti et al. | Feb 1989 | A |
| 5131644 | DuBois | Jul 1992 | A |
| 5147092 | Driscoll et al. | Sep 1992 | A |
| 5178379 | Edwards et al. | Jan 1993 | A |
| 5244200 | Manzke | Sep 1993 | A |
| 5375825 | Kennish | Dec 1994 | A |
| 5435534 | Linkowski et al. | Jul 1995 | A |
| 5441244 | Bartoes et al. | Aug 1995 | A |
| 5445368 | Lester et al. | Aug 1995 | A |
| 5472181 | Lowell | Dec 1995 | A |
| 5484255 | Lowell | Jan 1996 | A |
| 5590873 | Smart et al. | Jan 1997 | A |
| 5647587 | Smart et al. | Jul 1997 | A |
| 5655761 | Sanchez | Aug 1997 | A |
| 5692745 | Neifert et al. | Dec 1997 | A |
| 5775689 | Moser et al. | Jul 1998 | A |
| 5794931 | Heilman et al. | Aug 1998 | A |
| 5887864 | Stevens et al. | Mar 1999 | A |
| 5915686 | Neifert et al. | Jun 1999 | A |
| 5954330 | Rabindran et al. | Sep 1999 | A |
| 6010123 | Stevens et al. | Jan 2000 | A |
| 6032953 | Otto et al. | Mar 2000 | A |
| 6203006 | Semanick et al. | Mar 2001 | B1 |
| 6386537 | Howard et al. | May 2002 | B1 |
| 6575457 | Bakoledis | Jun 2003 | B2 |
| 6592114 | Stevens et al. | Jul 2003 | B2 |
| 6644657 | Wright et al. | Nov 2003 | B2 |
| Number | Date | Country |
|---|---|---|
| 0 731 046 | Sep 1996 | EP |
| 0 814 385 | Dec 1997 | EP |
| Number | Date | Country | |
|---|---|---|---|
| 20030151190 A1 | Aug 2003 | US |
| Number | Date | Country | |
|---|---|---|---|
| 60356229 | Feb 2002 | US |
