Abstract:
A mailpiece transfer system uses a transfer box to unload a plurality of mailpieces from an open tray, while maintaining an orientation alignment of the flat items. The tray is placed in the transfer box, after which the transfer box, holding the tray, is rotated to cause the mailpieces to rest against a cover of the transfer box. The tray is then removed, and the transfer box rotated again, allowing the substantially flat items to rest against a bottom of the transfer box, but without the tray. The mailpieces are then guided to a next workstation. The mailpieces may be edged for delivery to the next workstation.

Description:
RELATED APPLICATION 
     The present Patent Application claims priority to Provisional Patent Application No. 61/216,325 filed May 14, 2009, which is assigned to the assignee hereof and filed by the inventors hereof and which is incorporated by reference herein. 
    
    
     BACKGROUND 
     1. Field 
     This disclosure relates to sheet handling, useful, for example, in the postal sorting industry. The disclosure further relates to receiving and feeding a sheet or object handler with sheets or objects supplied in batch quantities. 
     2. Background 
     In the postal sorting industry, postal mailpieces or letters are supplied from a first machine which performs a first procedure in trays. The letters in the trays are then loaded to a second machine, which performs a subsequent procedure. In a typical example, the first machine is a barcode encoder which reads the address from the mailpieces and applies a corresponding barcode to the mailpiece. The second machine receives the barcoded letters and sorts them for shipment. 
     The barcoding operation requires that an alignment of the letter be selected so as to allow the barcode encoder to read each address. The barcode encoder will typically align the barcode to coincide with the orientation and facing side of the mailpiece. As a result of reading the address and impressing the barcode, the barcode reader knows the directional alignment of the mailpiece. In order to avoid duplicating this alignment operation, the barcode encoder provides its output with the mailpieces in a uniform facing alignment. 
     The letters themselves, however, are not uniform. Those letters which pass the barcode encoder meet requirements regarding standard size limits for letters but those sizes of course vary widely within the requirements. Thus, as objects, the mailpieces are not uniform, which limits options for handling the mailpieces. 
     In one example, it is desired that the sorter receiving the barcoded mailpieces receive the mailpieces in a predetermined alignment. Since this alignment was already established by the barcode encoder, the mail exits the barcode encoder with such alignment. Therefore, if the alignment of the mail as it exits the barcode encoder is maintained, the mail can be fed to the sorter with that alignment. 
     In a typical operation, the processed mail is deposited into mail trays. The trays are open boxes, meaning containers having a bottom and four sides, but no top. In one common configuration, the trays have slanted sides. The processed mailpieces are placed in the trays so as to rest edgewise, with all mailpieces facing in the same direction. 
     In one particular type of operation, the processed mail from the barcode encoder is deposited into mail trays. The trays are open boxes, meaning containers having a bottom and four sides, but no top. In one common configuration, the trays have slanted sides. The majority of mailpieces processed by the bar code encoder are placed in the trays so as to rest edgewise with the barcodes in uniform alignment. This not only pre-positions the barcode or address in proper directional and face-side position, but also positions the barcode at a desired x-y position for efficient reading by the barcode reader. In a typical example, each barcode is about 3.3 cm from the right side and about 0.6 cm from the bottom of the face of the mailpiece; however, it is anticipated that other standards may be used. 
     The present disclosure describes removing the mailpieces from the trays and loading the mailpieces to a piece of equipment such as the sorter, while edging the mailpieces and maintaining the alignment of the mailpieces with respect to their facing sides. 
     It is therefore desirable to automate the unloading of the trays, and automatically present and feed the faced and edged mail to a feeder/singulator for processing. The successful implementation of this technology results in the capability of a single mail processor to monitor the input operations of multiple feeder/singulators. In addition, the successful implementation of this technology offers significant cost savings, from reduced labor costs, as well as increased production efficiency. 
     SUMMARY 
     Transfer of a plurality of items, such as mailpieces, to a transport guideway is achieved while maintaining facing and edging of the plurality of items. The items are provided in a tray, in which each item has a matching directional alignment and rotational alignment. The tray holding the items is received with an open top in a transfer box and the plurality of items are exposed at the open top within the tray. The transfer box is closed to cover the open top of the tray, and rotated to position the open top of the tray in a generally downward facing orientation. The transfer box is opened to expose the tray, with the open top of the tray facing in the generally downward facing orientation. The tray is then removed from the transfer box. The transfer box retains the items for subsequent discharge. Discharged items are conveyed to the feeder/singulator of another piece of equipment such as a sorter. This conveyance uses a plurality of combs to control and deliver the discharged items. The combs provide unit manipulation of items discharged from a single tray. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram showing, a flip unloader open on one end to allow the entrance of the trays. 
         FIG. 2  is a diagram depicting a decline slide. 
         FIG. 3  is a diagram depicting the decline slide and a transition slide. 
         FIG. 4  is a diagram of an edger apparatus. 
         FIGS. 5-7  are diagrams depicting a tray received by a flip unloader box. 
         FIGS. 8 and 9  show the flip unloader box closing over the tray. 
         FIG. 10  is a diagram showing rotation of the flip unloader. 
         FIG. 11  is a diagram depicting the flip unloader rotated past a horizontal position and on a slight incline. 
         FIG. 12  is a diagram depicting the flip unloader box opening to expose the bottom of the tray. 
         FIGS. 13-16  are diagrams showing the use of vacuum to lift the tray clear of a mail slug and move the tray to the empty tray discharge chute. 
         FIG. 17  is a diagram depicting release of the mail tray for discharge. 
         FIG. 18  is a diagram depicting the flip unloader box closing over the mail slug. 
         FIG. 19  is a diagram depicting the flip unloader box rotating prior to alignment with the decline slide. 
         FIG. 20  is a diagram depicting the flip unloader stopped 45 degrees past horizontal, interfacing with the decline slide. 
         FIGS. 21 and 22  are diagrams showing engagement of the comb paddle with the mailpieces in the flip unloader. 
         FIG. 23  is a diagram depicting the lid comb passing through the decline slide comb, transferring the mail slug to the decline slide comb. 
         FIGS. 24-30  are diagrams depicting movement of the mail slug as guided by the combs. 
         FIGS. 31-35  are diagrams depicting the operation of the transition slide and feed table. 
         FIGS. 36 and 37  are diagrams depicting edging of mail within the flip unloader. 
         FIG. 38  is a diagram depicting edging of mail moving down the decline slide from the unloader box. 
         FIG. 39  is a diagram depicting the use of rolling tubes in the flip unloader edging of mail within the flip unloader. 
         FIGS. 40 and 41  are diagrams showing the relationships of the components in plan and side (elevation) views. 
     
    
    
     DETAILED DESCRIPTION 
     Overview 
     The device automatically performs the following functions:
         Confirm proper tray orientation, and reorient or reject improperly orientated trays.   Load the unsleeved tray into the flip unloader.   Remove the mail from the tray.   Automatically edge mail to be presented to the feeder/singulator.   Maintain control of the mail slug.   Transfer the mail slug to the input of the feeder/singulator.   Establish and maintain the integrity of the mail slug facing and edging during and after transfer.       

     The trays are provided at an elevation above the feeder/singulator. A decline slide is used to bring the mail down to the feeder/singulator, and the slide is easily moved to allow operator access to the feeder/singulator when manual processing is required. 
     Physical Description 
     It is desired that the manual feed operations of the feeder/singulator remain accessible. This requires that a flip unloader be easily moved to allow access to the feeder/singulator for manual operations. Placing the flip unloader above the feeder/singulator satisfies this requirement. The trays are transported to the flip unloader by an overhead conveyor, and then the mail slugs are transferred to the feeder/singulator&#39;s operational level. 
       FIG. 1  is a diagram showing a mail transfer apparatus  101 . Mail transfer apparatus  101  includes a flip unloader  111  mounted above a decline slide  115  to transfer the mail in slugs to an in-feed table at a feeder/singulator such as a delivery barcode sorter (not shown). A transition slide ( 316 , shown in  FIG. 3 ) at the bottom of decline slide  115  returns the mail to the horizontal plane for transfer to the feeder/singulator feed table. In addition, because proper edging of the mail is desired for proper feeding of the feeder/singulator, the apparatus  101  is configured to assure that the mail is edged. The apparatus  101  therefore comprises flip unloader  111 , straight decline slide  115  and transition slide  316 . 
     As depicted in  FIG. 1 , flip unloader  111  is a receiver including a box  121  and lid  122 , and is of a size and shape to contain a tray  131 . Flip unloader  111  is open on one end  141  to allow the entrance of the trays. The top of box  121  is covered by lid  122  attached to the box through a hinge  145 . The box is connected to the frame through a pivot shaft on the same end of the box as hinge  145 . While slant edge trays are depicted, it is also possible to use other tray configurations, such as trays having squared edges and trays with hand holes. 
       FIG. 2  depicts decline slide  115  and  FIG. 3  depicts transition slide  316 . Transition slide  316  in turn connects to feed table  321 . As depicted in  FIGS. 2 and 3 , the decline and transition slides  115 ,  316  are modules which are formed from multiple tubes  227 ,  327  placed in the proper configuration to support mail slugs  230  during transfer operations. Decline slide  115  is mounted at an angle of approximately 45 degrees, which provides excellent control of the mail, and gravity provides the motive force to advance the mail slug  230 . Decline slide  115  includes decline slide frame  250  to which are mounted decline support side rails  251 , which assist in edging the mail slug  230 . 
     Support combs, such as leading decline slide comb  237 , leading transition slide comb  337  and trailing transition slide comb  339 , are used to control the transfer of the mail slugs  230 . Combs  237 ,  337  and  339  are shown positioned above the respective decline and transition slides  115 ,  316 ; however, the combs may be mounted below or above the slides  115 ,  316 . Transition slide combs  337 ,  339 , mounted through a common pivot point  341 , control the transfer of the mail slug  230  through transition slide  316 , returning the mail to the horizontal plane defined by a floor plate  352  floor of feed table  321 . 
       FIG. 4  depicts edging rollers  429  forming three lagged rollers. Edging rollers  429  are placed in the bottom of a slide positioned approximately 45 degrees from the horizontal, and mounted perpendicular to the direction of mail travel. A small motor  247  provides power to the tubes, which are interconnected via a belt drive (not shown). As the mail passed over edging rollers  429 , the mail is urged to move against decline support side rails  251 . This urging against side rails  251  assists in edging the mail. 
     The edging can occur at flip unloader  111 , on decline slide  115 , on another portion of the pathway or in any combination of these locations. One advantage of using flip unloader  111  for edging is that the mail is generally able to move more freely within flip unloader  111 , so that edging can take place on a more consistent basis. Providing additional edging on decline slide  115  compensates for a possible tendency for mail in the mail slug  230  to shift away from its edged condition. 
     An advantage of the use of tubes, such as tubes  227  as bottom supports for the mail slugs  230  is that the tubes allow mailpieces to drop through. In the case of mail in slugs  230 , this would not occur, but if a mailpiece becomes separated from the slug  230 , it is likely to drop past the tubes  227  rather than remaining in the operational path of the mail transfer apparatus  101 . This separated mail can include mail which ends up in the trays  131  in the lengthwise orientation of the tray. The ability of improperly oriented mail to fall through the tubes  227  reduces the possibility that such stray mailpieces will get mangled or possibly jam the mail sorting equipment as a result of a misfeed. The stray mailpieces may then be retrieved from the floor or a catch tray (not shown) and placed back in the mail sorting line. 
     Tray Unloading 
     In an example operating environment, the trays  131  are diverted to a feeder/singulator spur. The trays  131  are provided unsleeved and in proper orientation. 
     The apparatus  101  works equally well with full and half trays  131 . Only depictions of processing full trays  131  are included in this section for brevity. 
     As depicted in  FIGS. 5-9 , unsleeved trays  131  enter the flip unloader box  121 . At that time, flip unloader  111  is positioned on an incline to receive trays  131 . As one of the trays  131  enters, the mail is shifted forward, opening a space  611  between the uphill end of tray  131  and the mail slug  230 . 
     As depicted in  FIGS. 9 and 10 , box  121  rotates approaching lid  122 . As flip unloader  111  continues to rotate, a comb paddle  721  mounted to lid  122  enters the space  611  between the tray  131  and the mail. Hand hole  914  can be used to assist by allowing a side prod  916  to press against the mail to establish space  611 . Tray  131  typically is loaded so that space  611  would occur as a result of the tilt of tray  131 ; however, the provision of hand hole  914  allows the prod to press the mail to establish the space  611 . 
     Referring to  FIG. 10 , the closed flip unloader  111  continues to rotate, passing horizontal and stopping on a slight incline, as depicted in  FIG. 11 . At this point, flip unloader box  121  is inverted. 
     As depicted in  FIG. 12 , the flip unloader box  121  opens, exposing the bottom of the tray  131 . In  FIGS. 13 and 14 , a vacuum head  1311  rotates into position on top of the tray  131 . 
     As depicted in  FIGS. 14-16 , the tray  131  is lifted clear of the mail slug  230  and moved to empty tray discharge chute  1613 . The vacuum is disabled releasing mail tray  131 , depicted in  FIG. 17 . 
     As depicted in  FIG. 18 , the flip unloader box  121  closes over the mail slug ( 230 , not shown in  FIG. 18 ). After flip unloader  111  is closed, the tray lid comb ( 721 , not shown in  FIG. 18 ) is indexed, securing the mail slug  230  between comb  721  and the flip unloader box  121 , and also securing the mail in an edged condition. As depicted in  FIGS. 19 and 20 , flip unloader  111  rotates, stopping 45 degrees past horizontal, interfacing with decline slide  115 . Flip unloader  111  at this time is generally in an upright alignment corresponding to the initial alignment, but at a different angle from the horizontal from that of the initial alignment. Thus, if the initial alignment (e.g.,  FIG. 1 ,  6  or  7 ) has the flip unloader box  121  tilted in an incline direction to allow the tray to enter, the alignment of flip unloader  111  interfacing decline slide  115  may be different. This is particularly true if, as depicted, the direction of movement of the tray is opposite that of the direction of movement of the mail when exiting flip unloader  111 . The alignment of flip unloader  111  is also used to provide edging of the mail, so that, on discharge, the edged side of flip unloader  111  may be lower than the side that is not edged. 
     It is alternatively possible to leave the mail slug  230  inverted, in which case, the mail is discharged from the flip unloader  111  after the tray  131  is removed but without flipping the flip unloader  111  back to the upright position. This requires that subsequent handling either re-orient the mail or subsequent processing equipment accept the mail in an inverted orientation. 
     Movement of Mail from Flip Unloader 
       FIGS. 21 and 22  show the engagement of comb paddle  721  with the mailpieces in flip unloader  111 . Referring to  FIG. 23 , as the comb paddle  721  swings upward with lid  122 , mail slug  230  is transferred to decline slide  115 . As depicted in  FIGS. 22 and 23 , comb paddle  721  passes through the decline slide comb  237 , transferring the mail slug  230  to decline slide comb  237 . Decline slide comb  237  permits the mail slug  230  to descend down decline slide  115  in a controlled manner. By descending in a controlled manner, the mailpieces are prevented from scattering. 
       FIGS. 24-29  depict the movement of the mail slug  230  as guided by the combs. In  FIGS. 24 and 25 , after the mail slug  230  is transferred to decline slide comb  237 , lid comb  721  is retracted with lid  122 . In  FIG. 26 , the decline slide comb  237  moves down the decline slide  115  toward second decline slide comb  2637 . The angle of decline slide  115  and gravity maintain the integrity of the slug. Decline slide comb  237  passes through a second decline slide comb  2637  transferring mail slug  230 . In  FIG. 27 , decline slide comb  237  is retracted through the bottom of decline slide  115 . In  FIGS. 27-29 , the mail slug  230  continues down decline slide  115  supported by second decline slide comb  2637 . 
     Transition Slide and Feed Table 
       FIGS. 30-36  depict the operation of transition slide  316  and feed table. As depicted in  FIGS. 31-36 , the mail slug  230  is transferred to leading transition slide comb  337  (also depicted in  FIG. 3 ). Second decline slide comb returns  2637  and moves into position behind mail slug  230 . As can be seen in  FIG. 32 , leading transition slide comb  337  and a trailing decline slide comb  339  move in unison to control mail slug  230 . In  FIG. 31 , trailing transition slide comb  339  replaces second decline slide comb  2637  for the transfer through the curve defined by transition slide  316 . Both transition slide combs  337 ,  339  move in unison to transfer and control mail slug  230 . As can be seen in  FIG. 33 , the leading transition slide comb  337  moves past feed table comb  3341 , transferring control of mail slug  230 . 
     In  FIG. 34 , the lead transition slide comb  337  retracts. As depicted in  FIG. 35 , the feed table comb  3341  and trailing transition slide comb  339  move in unison to control the mail slug  230  and effect the transfer to feed table  321 . 
     Inverting and Edge Alignment 
     Properly edged mail is critical to the performance of the feeder/singulator. It is expected that at times the mail will not be properly edged in the tray. As a result the mail exiting flip unloader  111  will be improperly edged. Automatic mail edging is used to edge the mailpieces. The edging is performed while in the flip unloader box  121 , immediately after discharge from the flip unloader box  121  or as the mail is being transferred through the slides. This may be performed by a number of techniques, including gravity, motion and vibration. 
     The act of inverting the mail in flip unloader  111  back to the upright position after removal of the tray  131  ( FIGS. 18-20 ) has a small but measurable impact on the edge alignment of the mail. It is possible to minimize the edge misalignment during unloading by tuning the apparatus  101 , but it was determined that there will need to be some edge alignment improvement mechanisms incorporated into the system. In one example, edge alignment is established in flip unloader  111  portion of the machine. The result is that the mail is edged along two adjacent edges. Once the mail slug  230  is properly edged and aligned, the slug can be transferred along decline slide  115  without degradation. 
     Occasional mail piece errors may occur in flip unloader  111  and there are designs that will make many of these errors self correcting. For example, mail that is placed sideways in the tray will fall between the tubes of decline slide  115  and be collected and contained in a trough. No operator invention would be required for this error. 
     Mail slug transfers on decline slide  115  work smoothly. The multi-rail design of the decline slide structure has inherent advantages and allows for the slug control combs to pass through the structure and move as required. In one example, the slug support combs will be at a slight angle to aid in controlling the slug as it moves along decline slide  115 . 
       FIGS. 36-39  depict the mail edger operation within the flip unloader  111  and on decline slide  115 . In  FIG. 36 , mail moves down the flip unloader box  121 . In  FIG. 37 , the mail shifts as a result of gravity edge against vertical side  3705  of flip unloader box  121 .  FIG. 39  shows a modified flip unloader box  3921  in which edging is performed. 
       FIG. 38  is a diagram depicting edging of mail moving down decline slide  115  or in flip unloader  121 . As the mail slug  230  moves on decline slide  115 , edging rollers  429  rotate to urge the mail against decline slide support rails  251  on decline slide  115 , as described above in connection with  FIG. 4 . Edging rollers  429  are positioned at a slightly shallower angle than tubes  227 , with the upslope ends of edging rollers  429  slightly below the level of tubes  227 . This allow the mail to smoothly transition onto edging rollers  429 . It is also possible to provide a taper at the lead ends of tubes  227 , which would allow the mail to pass the lead edges of tubes  227  without catching on the lead edges. 
       FIG. 39  is a diagram depicting the use of rolling tubes in the flip unloader box  3921 , used for edging of mail within the flip unloader. A plurality of rollers  3929  are located in the bottom flip unloader box  3929 . When the mail  230  rests against rollers  3929 , the rollers urge the mail to one side of box  3929 . Rollers  3929  are rotationally driven by motor  3947 , either continuously or during a part of the rotational operation of flip unloader when the mail  230  rests against rollers  3929 . 
     Box  3921  may be open between rollers  3929 , leaving open space as depicted at  3951 . The open space  3951  facilitates discharge of mail not in the slug, and the stray mailpieces may then be retrieved from the floor or a catch tray (not shown) and placed back in the mail sorting line. 
     The edging may therefore be performed in flip unloader box  121  against side  3705  or along decline slide  115 , or elsewhere. Alternatively, the edging may take place at multiple locations. 
     As mail slug  230  is transferred along decline slide  115  it has been found that the integrity of the slug is best maintained if the tines of the support combs are at a slight angle. This angle helps maintain the mail slug  230  against the decline slide support rails  251  on decline slide  115 . As mail slug  230  is transferred from decline slide  115  to the horizontal feed table  321 , the tines of the combs (e.g., combs  339 ,  3341 , shown in  FIG. 35 ) work best when perpendicular. 
     Basic Configuration 
     The basic configuration of flip unloader  111  may include
         flip unloader  111  with edging;   decline slide  115  to transition slide  316 ;   transition slide  316  to feed table transfer; and   feed table transfer from transition slide  316  to the feeder/singulator.       

     Modalities 
     In the process of developing any new technology, there is a fair amount of trial and error that leads to further development and retrial. Each step in the maturation of the concept provides a learning experience on what works and what does not work. Overall, there are always some major revelations, or lessons learned, that form the foundation of the design process; those are presented here. 
     In order to automate the unloading and feeding of letter mail in the trays, some standards are enforced to govern the preparation of mail in the tray. As in any process automation, some boundaries need to be defined in regard to the input. Typically product orientation and size are controlled at the input to an automated industrial process. In the case of flip unloader  111 , it is often specified that the letter mail in the tray be of proper orientation (correct facing and standing on edge) and of the proper size (quantity of mail in the tray); this in order to maximize the unloading efficiency. 
     Space Requirements 
     In order to minimize the floor space occupied by mail transfer apparatus  101 , as much of the hardware as possible may be ceiling supported. Floor supports may be tucked against the feeder/singulator machine wherever possible or outriggers are erected without inhibiting machine access. 
       FIGS. 40 and 41  are schematic diagrams showing the relationships of the components in plan and side (elevation) views. In this example configuration, the apparatus  101  is located to receive trays from above the feeder/singulator, with the tray flip unloader  111  located substantially above the floorspace, and decline slide  115  and transition slide  316  feeding down to the feeder/singulator. 
     Also shown is a tray discharge cart  4013  that receives empty trays from tray discharge chute  1613 . In the case of slant edged trays (trays  131 ), the trays, upon dropping into discharge cart  4013  will possibly nest (not shown). If the trays are straight edged, then the trays can be stacked in discharge cart  4013  without nesting. 
     Design Factors 
     Mail manipulation on the feeder/singulator feed table requires overtaking a moving target (the mail already on the feed table moving toward the singulator) with the mail being introduced from the mail transfer apparatus  101 . Presently, the operator performs this function using two hands and the feeder/singulator feed paddle. The design of the present apparatus duplicates the operator&#39;s manipulations with automated comb/paddle replacements. The feed rate is feeder/singulator paced so the automated function is quick, smooth and precise. 
     As was discussed in a previous section, mail that has been unloaded from a tray will almost always require edge alignment. It is expected that this function will be performed in the flip unloader box  121 . Automatic edge alignment is integrated into the design of the mail transfer apparatus  101 . An operator presently utilizes a vibratory device and his hands to jog and align the mail piece edges. In automatic operation, the end over motion coupled with rotational urging will align the mail against the side wall and bottom of the flip unloader box  121  or on the decline slide  115 . 
     In addition to the mail processing requirements for the mail transfer apparatus  101 , there are additional motions associated with jam clearing and tray rejects. The design allows for the feeder/singulator to be operated via manual feed with an operator. This requirement demands that the flip unloader device be moved out of the way for operator access to the sorter. 
     In order for the feeder/singulator to be used for sequencing or other manual sorting, there is the need for the mail transfer apparatus  101  to be stowed or retracted or otherwise moved out of the way for an operator to manual feeding. The motions of the flip unloader box  121  and lid  122  have independent functions that are capable of working in unison. These motions include flip unloader box  121  rotation in both directions with at least six different stop positions and lid open to three different positions and close. The flip unloader  111  may include a full tray or half tray or may be empty so the movements may be smooth with a variable load. In addition, the mass of a lid actuator for lid  122  will be part of the load reflected to the flip unloader&#39;s prime mover. 
     Conclusion 
     It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described and illustrated to explain the nature of the subject matter, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.