Patent Application
20200316651
Some embodiments are directed to a cam stacking assembly for a mixed sized mail-piece sorter. In particular, embodiments disclose a cam stacking assembly having a plurality of neighboring cam shafts, each with at least one cam.
Automated equipment is typically employed in industry to process, print, and/or sort sheet material for use in manufacture, fabrication and mail-stream operations. One such device associated with some embodiments described herein is directed is a mail-piece sorter which sorts mail into various sortation bins or trays for delivery.
Mail-piece sorters are often employed by service providers, including delivery agents, e.g., the United States Postal Service (“USPS”), entities which specialize in mail-piece fabrication, and/or companies providing sortation services in accordance with the Mail-piece Manifest System (“MMS”). Regarding the latter, most postal authorities offer large discounts to mailers willing to organize/group mail into batches or trays having a common destination. Typically, discounts are available for batches/trays containing a minimum of two hundred (200) or so mail-pieces.
The sorting equipment organizes large quantities of mail destined for delivery to a multiplicity of destinations, e.g., countries, regions, states, towns, and/or postal codes, into smaller, more manageable, trays or bins of mail for delivery to a common destination. For example, one sorting process may organize mail into bins corresponding to various regions of the U.S., e.g., northeast, southeast, mid-west, southwest and northwest regions, i.e., outbound mail. Subsequently, mail destined for each region may be sorted into bins corresponding to the various states of a particular region e.g., bins corresponding to New York, New Jersey, Pennsylvania, Connecticut, Massachusetts, Rhode Island, Vermont, New Hampshire and Maine, sometimes referred to as inbound mail. Yet another sort may organize the mail destined for a particular state into the various postal codes within the respective state, i.e., a sort to route or delivery sequence.
Note that a service provider might want to process a batch of mail-pieces of varying sizes. For example, a batch might include postcards, standard business envelopes, “full page” envelopes, etc. Typically, a singular tack kick on a tailing edge of a mail-piece might be used to prevent lead edge to trail edge collisions when stacking. This, however, might only be effective when processing mail-pieces of similar size. Moreover, sortation equipment has been made smaller to accommodate the physical limitations of available space, and throughput requirements continuously increase. As the throughput requirements increase, the speed of operation increases commensurately which can increase the frequency of jams or damage to mail-pieces as they are diverted from a high-speed feed path to one of the sortation bins. Damage can occur when a mail-piece comes to an abrupt stop, remains in contact with a high-speed belt or continuously operating roller, collides with a neighboring mail-piece, etc.
Various attempts have been made to control the divert/stacking function and configure the sortation bin such that a jams and damage are mitigated when a mail-piece is collected/accumulated in a sortation bin. In Stephens et al. U.S. Pat. No. 4,903,956, a divert/stacking assembly includes rotating arm which is driven about an axis which is substantially orthogonal to the feed path and in-plane with sheet material at it travels, on-edge, along the feed path. Once the leading edge of the sheet material comes to rest against a registration stop, the arm is activated to urge the trailing edge of the sheet material into the bin, thereby causing the edges of the accumulated sheets to be in register and each of the sheets to be parallel. While systems such as that described in the '956, patent improve the general alignment of sheets within a sortation bin, such divert/stacking assemblies do not account for variable forces which may be required to divert such sheet material or sheet material which may vary in weight or thickness or size. Furthermore, as the rotating arms or urge rollers continue to operate, such divert/stacking assemblies can damage the sheet material.
A need, therefore, exists for a stacking assembly which aligns sheet material, e.g., mail-pieces of various sizes, in a sortation bin while mitigating jams and damage to the sheet material.
According to some embodiments, a stacking assembly accepts mail-pieces traveling from a re-direct mechanism in a first direction and urges a leading edge portion of a mail-piece toward a registration wall of a sortation bin. The stacking assembly may include a plurality of neighboring cam shafts, each with at least one cam, arranged along the first direction, such that rotation of the cam shafts results in synchronized rotation of the cams to guide an incoming mail-piece. Rotation of the cam shafts may also urge a previously stacked mail-piece away from the cams, and into the sortation bin, in a second direction perpendicular to the first direction.
Some technical advantages of some embodiments disclosed herein are improved systems and methods to aligns sheet material, e.g., mail-pieces of various sizes, in a sortation bin while mitigating jams and damage to the sheet material.
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of embodiments. However, it will be understood by those of ordinary skill in the art that the embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the embodiments.
One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
The present invention relates to a new and useful divert/stacking assembly for a sortation device. The divert/stacking assembly is described in the context of a sortation device, however, the invention is equally applicable to any sheet material sorter, e.g., linear, back-to-back, or tiered. The sheet material being sorted is commonly a finished mail-piece, however other sheet material is contemplated, such as the content material used in the fabrication of mail-pieces, i.e., in a mail-piece inserter. In the context used herein, “mail-piece” means any sheet material, sheet stock (postcard), envelope, magazine, folder, parcel, or package, which is substantially “flat” in two dimensions.
In
The sheet feeding apparatus 16 accepts a stack of mail-pieces 14 between a plurality of singulating belts 20 at one end and a support blade 22 at the other end. The support blade 22 holds the mail-pieces 14 in an on-edge, parallel relationship while a central conveyance belt 24 moves the support blade 22, and consequently, the stack of mail-pieces 14, toward the singulation belts 24 in the direction of arrow FP (“Feed Path”).
Once singulated, the mail-pieces 14 are conveyed on-edge, in a direction orthogonal to the original feed path FP of the mail-piece stack. That is, each mail-piece 14 is fed in an on-edge lengthwise orientation across or passed a scanner 30 which identifies and reads specific information on the mail-piece 14 for sorting each mail-piece 14 into a sortation bin A1-A4 (discussed hereinafter when describing the sorter 50). Generally, the scanner 30 reads the postal or ZIP code information to begin a RADIX sorting algorithm. The scanner 30 may also be used to identify the type of mail-piece/parcel, e.g., as a postcard, magazine, which may be indicative of the weight or size of the mail-piece 14 being sorted.
Following the scanning operation, each mail-piece 14 is optionally conveyed to the Level Distribution Unit (“LDU”) wherein, each mail-piece 14 may be routed via a series of diverting flaps/vanes, to an appropriate level or tier A, B, C or D of the multi-tiered sorter. The level A, B, C or D is determined by the controller 60, based upon the information obtained by the scanner 30. For example, if a mail-piece is destined for bin C3, the LDU 40 routes a mail-piece 14 to level C by diverting the input feed path to a lower feed path. It should be appreciated that the LDU may handle and route mail-pieces 14 in a variety of ways to distribute mail-pieces from an input feed path FP to an output feed path, including the use of conventional nip rollers, spiral elastomeric rollers, opposing belts, etc. Furthermore, the orientation may be inverted from an on-edge to a horizontal orientation by a conventional twisted pair of opposing belts and/or visa-versa to reverse the orientation, i.e., from a horizontal to an on-edge orientation (not shown) by the same type of inverting mechanism. While the Linear Feed Path (“LFP”), may be defined by dedicated belt drive mechanisms, the present invention employs elements of an inventive divert/stacking assembly 70 to convey the mail-pieces along the linear feed path LFP and into sortation bins via a cam stacking assembly 80 in accordance with any of the embodiments described herein.
For example,
#6¼ (720) or 3.5″ by 6″,
#7 (730) or 3.75″ by 6.75″,
#9 (740) or 3.875″ by 8.875″,
#10 (750) or 4.125″ by 9.5″, and
#14 (760) or 5″ by 11.5″.
According to some embodiments, a minimum length of 5″ (due to placement of the rightmost cam shaft relative to the registration wall), a maximum length: of 14″ (due to the spacing of each stacker element in the machine), a minimum height of 3.5″ (due to height of the center cam on the rightmost cam shaft), and a maximum height of 10″ (due to height of the guide walls) may be supported along with a maximum thickness of approximately 10 to approximately 13 millimeters (“mm”) (due to the spacing between opposing guides in the transport path).
Referring again to
According to some embodiments, a cam spring arm top finger may be provided to help prevent the leading edge of an incoming mail-piece from colliding with a trailing edge of a previously accepted mail-piece. For example,
As illustrated in
According to some embodiments, a stacking assembly may have the cam shafts linked together so as to rotate in a sequential manner such that: (i) a path into the registration all opens up just in time for the leading edge of a mail-piece to pass through, (ii) the cams continue to rotate to help a tail end of the envelope into place, and (iii) at least one cam then generally provides force in the second direction on a stack of previously accepted mail-pieces in the sortation bin. For example,
As illustrated 1300 in
According to some embodiments, a beam detector may generate a trigger signal when a beam is blocked by a leading edge of an incoming mail-piece. A controller, operatively coupled to cam shafts, may then initiate rotation of the cam shafts upon receipt of the trigger signal. For example, the controller may alter rotation of the cam shafts in accordance with a calculated “intercept motion profile.”
one acceleration and one deceleration;
equal acceleration rate and deceleration rate;
known variables include: initial velocity (measured), final velocity (given), initial position (measured), final position (given), initial time (measured), and final time (given); and
unknown variables include (and thus need to be calculated): acceleration rate (same as deceleration rate), and peak velocity.
According to some embodiments, a nominal cam velocity of 5,200 deg/sec will causes the hooks of each of the four (4) different cams to “hide” behind the wall just before the leading edge of a mail-piece reaches it when the transport is running at 180 in/sec. For slower belt velocities, the nominal cam velocity may scale down linearly with belt speed.
Initial Velocity=1 m/s
Final Velocity=2 m/s
Initial Position=0 m
Final Position=1 m
Initial Time=0 s
Final Time=1 s
The calculated values are:
Acceleration Rate=2.414 m/s2
Peak Velocity=0.293 m/s.
According to some embodiment, a cam stacker may perform different motion profiles depending on the pitch of the incoming mail-pieces. For all of the following examples, two mail-pieces are being stacked at varying pitch. Since the cams are a rotary axis, cycle position will be used to describe their position. This refers to the angle, from 0 to 360 degrees, in which they are at relative to their starting position.
If the mail pitch is large enough, two separate, but same, motion profiles will occur as illustrated by the graph 2700 in
If the mail-pitch is smaller, the motion profiles will be combined. As illustrated by the graph 2800 of
For even smaller mail pitches, the sensor is hit even earlier. Since the first mail-piece isn't done being stacked when the sensor is hit, the intercept profile won't begin until 295 degrees. For example, in the graph 2900 of
This profile occurs at even smaller pitches than previously occurred.
In summary, the divert/stacking assembly may employ a low cost, controllable, and highly accurate positioning device to drive multiple cams for aligning mail-pieces in a sortation bin. Embodiments may be able to stack mail from post cards up to thick flats effectively. Multiple tail cams or kicks may prevent lead edge to trail edge crashes. Since the kicks are close to each other, they may cover a substantial spectrum of mail sizes. According to some embodiments, a stacker may ingest a mix of mail types at any throughput of up to approximately 50,000 pieces per hour. Moreover, the most downstream cam may index out the mail stack by creating a zone for the mail-piece to enter then closing this zone the entire stack will generally be pushed out (e.g., into the sortation bin by a thickness of that mail-piece). That is, the system automatically indexes out the mail stack using the main cam so an external motor for conveying is not needed. Moreover, embodiments do not use any friction elements (which could either wear out or generate heat).
Although specific hardware and data configurations have been described herein, note that any number of other configurations may be provided in accordance with embodiments of the present invention (e.g., in other types of mixed mail cam stackers). Moreover, although some embodiments are focused on particular mail-piece sizes, any of the embodiments described herein could be applied to other types of mail-pieces (e.g., by altering the size, number, and/or location of the cams).
The present invention has been described in terms of several embodiments solely for the purpose of illustration. Persons skilled in the art will recognize from this description that the invention is not limited to the embodiments described but may be practiced with modifications and alterations limited only by the spirit and scope of the appended claims.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16150560 | Oct 2018 | US |
| Child | 16909485 | US |
