Abstract:
Large items such as magazines or large envelopes lie flat upon and are transported by a first conveyor in a first, transverse direction until they sequentially encounter a frustoconical member rotatably mounted to a back wall. A second conveyor is disposed normal to the first conveyor so that it transports the items that have encountered the frustoconical member in a second direction normal to the first. A rotatably mounted barrier has a first, retracted position where it does not interfere with items approaching the frustoconical member and a second, deployed position where it stops the items short of the frustoconical member. The position of the barrier is controlled by information concerning postal routes. The items are sorted into sharply defined groups that are transversely staggered with respect to one another.

Description:
BACKGROUND OF INVENTION 
     1. Field of the Invention 
     This invention relates, generally, to machines that sort envelopes. More particularly, it relates to a high speed flat bed sorter. 
     2. Description of the Prior Art 
     Businesses that mail large quantities of envelopes can save postage expenses by pre-sorting the envelopes by ZIP codes, carrier routes, and so on. 
     One common way to sort envelopes is to momentarily increase the speed of a conveyor belt carrying envelopes after a group of envelopes has been sorted. The momentary increase in speed after each grouping creates a physical separation between grouped envelopes so that a person unloading the envelopes visually observes the physical separation and collects as a unit only those envelopes that are grouped together. 
     This method works in a satisfactory manner at low conveyor belt speeds, but its performance becomes unacceptable at high speeds. Typically, at higher speeds an ambiguity is created by one or more envelopes that lie between contiguous groups. The operator is then unsure as to which group such intermediate envelope or envelopes belongs. Moreover, the repeated speeding up and slowing down of the belt prevents sorting at extremely high speeds. It also wears out the machinery and requires frequent maintenance and adjustment of parts. 
     Business-size envelopes are best sorted while held in a vertical plane, as disclosed in U.S. Pat. No. 6,241,460, entitled “Offset Sorter For Envelopes,” to the present inventor, which disclosure is hereby incorporated by reference into this disclosure. 
     However, large envelopes or magazines cannot easily be maintained in a vertical plane because they lack rigidity and collapse under their own weight. Accordingly, the inventive apparatus disclosed in the incorporated disclosure is not the optimal apparatus for sorting such large envelopes or magazines, even though it can be used for such sorting if necessary. 
     What is needed, then, is an improved apparatus that sorts large envelopes, magazines, and the like, while they are lying flat on a conveyor means. The needed means would eschew the technique of increasing the speed of a conveyor belt between groups of items to physically separate them from one another. Moreover, the needed apparatus would operate at speeds heretofore unattainable yet would have less maintenance requirements than slower devices. 
     However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the identified needs could be fulfilled. 
     SUMMARY OF INVENTION 
     The longstanding but heretofore unfulfilled need for an improved flat bed sorter is now met by a new, useful, and nonobvious apparatus for sorting items to be mailed by grouping them into visually ascertainable distinct groups. The items are disposed in a generally horizontal plane because they are large, flexible items to be mailed such as large envelopes, magazines, and the like. The novel structure includes a first conveyor means for transporting the items along a first path of travel. A back wall is disposed in blocking relation to the first path of travel and a rotating frustoconical member is mounted for rotation to said back wall so that items following the first path of travel encounter the rotating frustoconical member and are constrained against further movement along the first path of travel. A second conveyor means transports the items along a second path of travel normal to the first path of travel. The second conveyor means has a first end disposed in cooperative relation to the back wall so that said items encountering the rotating frustoconical member are transported by the second conveyor means along the second path of travel. 
     A movably mounted barrier means is disposed in alignment with the first conveyor means and in spaced apart relation to the back wall. The barrier means has a first, raised position disposed in vertically spaced apart relation to the first conveyor means so that items following the first path of travel are unimpeded by the barrier means and therefore enter into abutting relation to the frustoconical member mounted for rotation on back wall and are carried along the second path of travel by the second conveyor means. 
     The barrier means has a second, lowered position disposed in blocking relation to items carried by the first conveyor means so that items following the first path of travel encounter said barrier means before reaching the rotating frustoconical member mounted to the back wall and are impeded from reaching the rotating frustoconical member. The items are then transported along the second path of travel by the second conveyor means. A control means alternately raises and lowers the barrier means in response to predetermined input data relating to postal routes. In this way, said items are sorted into transversely staggered groups so that the groups are clearly and unambiguously distinguishable from one another. 
     In a preferred embodiment, the barrier means has a conical shape. Although the barrier means could be provided in the form of a single cone-shaped member, the preferred structure includes a pair of cone-shaped members mounted in longitudinally spaced apart relation to one another so that items abutting such cone-shaped members are positioned substantially squarely relative to the first conveyor means. Where a single cone-shaped member is employed, an auxiliary alignment means such as a fixed position guide rail for aligning the trailing end of each item is employed. 
     The cone-shaped member or members are rotatably mounted to a mounting rod. A pair of transversely disposed, longitudinally spaced apart side walls are secured to opposite ends of the back wall. The mounting rod is disposed in interconnecting relation to the side walls and is supported at its opposite ends by said side walls. The mounting rod is rotatably mounted relative to the side walls so that said mounting rod is rotatable about its longitudinal axis of rotation. The cone-shaped member or members are secured to the mounting rod for conjoint rotation therewith. 
     A computer-controlled control means raises and lowers the barrier means in response to data containing information about postal routes so that the items are sorted into groups where each group includes items that share a predetermined postal designation. The control means may include a cylinder having a plunger that is connected to a linkage that engages the mounting rod so that actuation of the plunger in a first, retracted direction rotates the mounting rod in a first direction, thereby lifting the barrier means and so that actuation of the plunger in a second, extended direction rotates the mounting rod in a second direction opposite to the first direction, thereby lowering the barrier means. 
     A primary object of the invention is to provide a constant conveyor speed apparatus for sorting horizontally disposed large envelopes or magazines into distinctly separate groups. 
     A closely related object is to attain the foregoing object with a device that staggers each group transversely relative to its contiguous groups. 
     Another closely related object is to provide a device that is capable at operating at speeds in excess of twelve thousand items per hour. 
     These and other important objects, advantages, and features of the invention will become clear as this description proceeds. 
     The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts that will be exemplified in the description set forth hereinafter and the scope of the invention will be indicated in the claims. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which: 
     FIG. 1 is a top plan view of the novel flat bed sorter and includes a view of mailable items exiting the sorter in transversely staggered array; 
     FIG. 2 is a side elevational view of the novel sorter when the pivotally mounted barrier means is in its raised position at the beginning of a sorting job; 
     FIG. 3 is a side elevational view of the novel sorter when the pivotally mounted barrier means is in its raised position after having completed at least one operating cycle; 
     FIG. 4 is a side elevational view of the novel sorter when the pivotally mounted barrier means is in its lowered position at the beginning of a sorting job; and 
     FIG. 5 is a side elevational view of the novel sorter when the pivotally mounted barrier means is in its lowered position after having completed at least one operating cycle. 
    
    
     DETAILED DESCRIPTION 
     Referring now to FIG. 1, it will there be seen that the reference numeral  10  denotes an illustrative embodiment of the present invention as a whole. 
     A first conveyor means  12  delivers relatively large items  14  to be sorted to a second conveyor means  16  disposed substantially normal to first conveyor means  12 . For convenience, first conveyor means and all parts of the novel apparatus parallel thereto are deemed to be transversely disposed. Second conveyor means  16  and all parts of the novel apparatus parallel thereto are deemed to be longitudinally disposed. 
     If they are envelopes, items  14  have been filled with inserts, sealed and addressed for delivery by suitable means, not shown. If they are magazines or similar articles, they have been sealed against opening and addressed for delivery. Due to their large size and flexibility, items  14  are lying flat while conveyed on said first and second conveyor means. 
     Novel flat bed sorter  10  is positioned in alignment with the discharge end of first conveyor means  12  and at the side or longitudinal edge of second conveyor means  16 . First conveyor means  12  stops just short of second conveyor means  16 ; items  14  carried by said first conveyor means in the direction indicated by directional arrow  12   a  enter into novel sorter  10  under the momentum imparted to them by first conveyor means  12 . 
     In a first embodiment, sorter  10  includes an upstanding back wall  18  positioned substantially normal to the path of travel  12   a  of items  14  transported by first conveyor means  12  and substantially parallel to the path of travel  16   a  of items  14  transported by second conveyor means  16 . Accordingly, back wall  18  stops items  14  as they are discharged from first conveyor means  12  and prevents them from continuing to travel along path of travel  12   a . Upon encountering back wall  18 , items  14  are transported by second conveyor means  16  along path of travel  16   a  which is substantially perpendicular to the path of travel  12   a  of the first conveyor means  12 . It should therefore be understood that back wall  18  is common to prior art means for changing the direction of travel of items exiting a first conveyor means and entering a second conveyor means where the respective paths of travel of the first and second conveyor means are substantially perpendicular to one another. 
     Sorter  10  further includes a pair of side walls  26 ,  28  that are substantially parallel to one another and substantially perpendicular to back wall  18 . Said side walls  26 ,  28  are secured to opposite ends of back wall  18 . Accordingly, they extend transversely relative to the path of travel  16   a  of second conveyor means  16 . As depicted in FIGS. 2-5, their respective lowermost edges  26   a ,  28   a  are vertically spaced apart from second conveyor means  16  by a distance greater than the highest stack height of items  14  that will be transported by second conveyor means  16  so that said side walls do not interfere with the transportation of items  14 . 
     In FIGS. 2-5, side plate  28  is removed to enable viewing of the remaining parts of sorter  10 . 
     A flexible deflector band  30  is secured as at  31  to each side wall  26 ,  28  and a free distal end thereof extends below lowermost edge  26   a  of side wall  26  into the path of travel  12   a  of items  14  arriving into sorter  10  from first conveyor means  12 . Items  14  encounter said deflector band  30  prior to encountering back wall  18 . Deflector band  30  provides a frictional engagement of each item  14  to slow its speed just prior to its contact with said back wall  18 . This inhibits bouncing of the items off said back wall. 
     In a second, preferred embodiment, frustoconical member  32 , mounted at the lower end of back wall  18 , at the center thereof as indicated in FIG. 1, prevents items  14  from reaching back wall  18  and imparts a small amount of staggering to items  14  as indicated by reference numeral  32   a . The staggering is seen in top view in FIG.  1  and in side elevation in FIGS. 2-5. Frustoconical member  32  rotates in the direction of travel of second conveyor means  16  at an angular velocity equal to the linear velocity of said second conveyor means  16  so that items  14  remain perpendicular to back wall  18  as they travel along second conveyor means  16 . 
     Although only one frustoconical member  32  is depicted, it should be understood that two or more frustoconical members  32  could be provided as may be required by differing size items  14 . 
     If frustoconical member or members  32  are not provided, as in the prior art, items  14  bounce haphazardly from back wall  18  as they are delivered by first conveyor means  12  to second conveyor means  16  and the orderly staggering achieved in this invention is not attained. 
     Each side wall  26 ,  28  is apertured to rotatably receive opposite ends of a mounting rod  34 . As perhaps best understood in connection with FIG. 1, mounting rod  34  is longitudinally disposed, i.e., it is parallel to back wall  18  and to the path of travel  16   a  of second conveyor means  16 . 
     A pair of cones  36 ,  38  (FIG.  1 ), having non-conical bases  36   a ,  38   a , respectively, are tightly secured to mounting rod  34  for conjoint rotation therewith. 
     Rotation of mounting rod  34  about its longitudinal axis of symmetry is under the control of a computerized control means that governs the operation of a pneumatic cylinder  40  having plunger  42 . Plunger  42  is connected to link  44  that is pivotally connected as at  45  to link  46  and said link  46  is clampingly engaged to mounting rod  34 . Accordingly, when plunger  42  is retracted, link  44  lifts link  46  and said link  46  rotates mounting rod in a clockwise direction when viewed in the FIGS. 2-5 position, thereby causing cones  36 ,  38  to rotate in the clockwise direction into their respective “up” or “raised” positions as depicted in FIGS. 2 and 3. 
     When plunger  42  is extended, as depicted in FIGS. 4 and 5, link  44  rotates link  46  and hence mounting rod  34  and cones  36 ,  38  in a counterclockwise direction and cones  36 ,  38  are thus rotated into their respective “down” or “lowered” positions. 
     Deflector band  50  is a flexible member that extends from brake base  52  which is also secured to mounting rod  34  for conjoint rotation therewith. Thus, deflector band  50  is vertically spaced above items  14  in non-interfering relation therewith when brake base  52  is in its “up” or “raised” position as depicted in FIGS. 2 and 3. However, when brake base  50  is in its “down” or “lowered” position as depicted in FIGS. 4 and 5, deflector band  50  interferes with items  14  as they approach cones  36 ,  38 , thereby slowing down said items just before they contact said cones. Thus it is understood that deflector band SO performs the same function for items striking cones  36 ,  38  as deflector band  30  performs for items striking frustoconical member  32 . 
     Cylinder  40  is preferably a pneumatic cylinder as mentioned, but it could also take the form of a hydraulic cylinder or other suitable actuator. Cylinder  40  is controlled by a computer control means, not shown, that includes postal routing data that determines the desired sorting of items  14 . 
     There are numerous ways to mount cylinder  40  in its operable position. In this preferred embodiment, cylinder  40  is pinned as at  39  (FIGS. 2-5) to a “U”-shaped bracket  41 that is secured mid-length of horizontal, longitudinally disposed mounting plate  43  that spans side walls  26 ,  28 , as perhaps best understood in connection with FIG.  1 . 
     When mounting rod  34  is in its first position of rotational adjustment, as depicted in FIGS. 2 and 3, cones  36 ,  38  are positioned in spaced apart relation to second conveyor means  16  and items  14  transported thereby. Thus, they do not influence the position of items  14  as they exit first conveyor means  12  and enter into novel sorter  10 . Items  14  therefore are braked by deflector band  30  and come to rest in abutting relation to back wall  18  (first unillustrated embodiment) or frustoconical member or members  32  (second embodiment). The items are then transported in a longitudinal direction by second conveyor means  16  as perhaps best understood in connection with FIG.  1 . Again, frustoconical member or members  32  rotate at an angular velocity that matches the linear velocity of second conveyor means  16 . 
     When mounting rod  34  is in its second position of rotational adjustment, as depicted in FIG. 4, cones  36 ,  38  are disposed in abutting relation to second conveyor means  16  if the machine is at start-up, i.e., if no items have yet entered sorter  10 . Thus, when the machine commences operation, the first items  14  to enter sorter  10  are braked by flexible braking means  30  and then abut cones  36 ,  38 . Note that the shape of said cones imparts a slightly staggered stacking of items  14 , as denoted by the reference numeral  38   a . After machine operation has begun and at least one group of items  14  has entered sorter  10  when said cones were in their respective raised positions, when cones  36 ,  38  next rotate downwardly they will rest atop said items  14  as depicted in FIG.  5 . 
     Advantageously, cones  36 ,  38  are mounted for rotation about their respective axes of symmetry. Thus, they rotate passively and substantially friction free as items  14  move away from them under the influence of second conveyor means  16 . In this way, as said cones are performing their function of causing items  14  in a group to accumulate against said cones as depicted in FIGS. 4 and 5, they do not interfere with items  14  that have already encountered frustoconical member or members  32  as indicated in FIG.  5 . 
     As the computer-controlled control means positions the cones in their “up” or “down” position, items  14  are sorted into transversely staggered groups as depicted in FIG.  1 . The worker removing each independent group of items is therefore not required to make decisions regarding ambiguous groups as required with prior art systems. Just as importantly, second conveyor means  16  runs at a constant speed whenever it is operating, thereby eliminating the problems associated with variable speed conveyor means. 
     It will thus be seen that the objects set forth above, and those made apparent from the foregoing description, are efficiently attained. Since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 
     It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. 
     Now that the invention has been described,