Abstract:
A conveyor apparatus transports materials along an incline. The apparatus includes an endless base conveyor belt that is tensioned between lower and upper end rollers and is aligned with the incline. A drive means drives the base belt at a selected speed and in a selected direction along the incline. An endless hanging overhead conveyor belt is provided above the base belt, and has a substantially flat conveyance surface for covering materials placed on the base belt. A drive roller of the hanging overhead belt is coupled to the upper end roller of the base belt so as to drive the hanging overhead belt at a speed and direction similar to that of the base belt. The hanging overhead belt extending toward and in proximity to an input transport conveyor for transporting articles at a speed slower than the speed of the hanging belt.

Description:
RELATED APPLICATIONS  
       [0001]    This is a division of a prior patent application having Ser. No. 09/09/594,268 filed on Jun. 15, 2000, entitled, “Inclined Conveyor,” the entirety of which is incorporated herein by reference thereto. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to a conveyor, and specifically to conveyance along an incline.  
         BACKGROUND OF THE INVENTION  
         [0003]    Modern libraries have experienced increased demands from patrons, in terms of needs for larger and larger holdings of books and other tangible materials. Accordingly, it is not uncommon for public libraries, for example, to handle collection and distribution of hundreds of thousands, or even millions, of books and materials. Tasks of librarians in handling these ever increasing volumes are often overwhelming.  
           [0004]    A particularly problematic librarian task involves receiving material returned from patrons. This task, when manually performed by library personnel upon such ever-growing volumes of books and materials, greatly affects time required to repetitively collect and distribute each piece of material, i.e., “turn-around time” is negatively impacted. Moreover, manual performance of this task may lead to repetitive stress-type physical injuries.  
           [0005]    In attempts to minimize these problems, procedures have been developed to provide some degree of automation in the receiving task. For example, some libraries have proposed utilization of a conventional single conveyor belt system for conveying materials returned from patrons at, for example, an extra-library return depository or an intra-library return desk or, to a materials check-in processing station.  
           [0006]    In many libraries, the return depository or return desk is on one floor of a library building, while the check-in processing station is on another floor. Thus, it is desired that a conveyor system transport received library materials upward from one floor to another along an incline. Such an incline is often necessarily steep (greater than about 25 to 30 degrees) due to structural and architectural requirements of the library building.  
           [0007]    It has been observed that in conventional single belt conveyors, materials being conveyed upward tend to slip or tumble down the belt when the incline is steep, due mainly to an insufficient coefficient of friction existing between the belt and the materials. It has also been observed that conveyance along a less-than-steep incline may not even be possible when the single belt surface in contact with the materials becomes contaminated or worn and loses some of its gripping ability. Making the belt “sticky”, for example through use of adhesive-type surface coatings, is not desired in that such coatings may impart unwanted debris to the materials and may therefore be detrimental to the cleanliness of the materials.  
           [0008]    In attempts to solve this steep incline conveyance problem, “cover belt” or “twin belt” conveyors have been proposed as alternatives to conventional single belt conveyors. Examples of these alternative conveyors are disclosed in U.S. Pat. No. 4,425,995 entitled, “Cover Belt Conveyor,” issued to Blattermann, et al., and in U.S. Pat. No. 6,003,659 entitled “Twin Belt Conveyor Apparatus” issued to Uranaka, et al. However, known conveyors of these types are best suited only for conveyance of bulk-type materials in that they commonly incorporate two driven flat belts each tensioned between head and tail pulleys, making for a relatively narrow conveyance space between the-belts. These other conveyors may also utilize meshing, engaging, or mating protrusions of two cooperating belts for conveyance of the material there between. If used for conveyance of library-like materials, the driven and tensioned belts, and in some instances the cooperating protrusions, of these conveyors may damage the materials due to excessive forceful action of the tensioned belts and protrusions.  
           [0009]    Further, it has been observed that bulk-type conveyors utilizing troughs, tubes, flights, or buckets, as disclosed for example in U.S. Pat. No. 4,535,884 entitled “Bulk-Handling Belt Conveyor” issued to Suppan and in U.S. Pat. No. 4,562,918 entitled “En-Mass Conveyor For Vertical Or Steep Delivery Of Bulk Material” issued to Tschernatsch, et al., are unsuitable for library use due to varying sizes of the library-like materials and potential damage caused thereto.  
           [0010]    Thus, there exists a need for a conveyor that performs the task of conveying library-like materials along a steep incline, without damaging the materials.  
         SUMMARY OF THE INVENTION  
         [0011]    An object of the present invention is to provide an inclined conveyor that performs a function of transporting materials along a steep incline angle relative to ground.  
           [0012]    Another object of the present invention is to provide an inclined conveyor that performs a function of transporting, along a steep incline, library-like materials from a receiving station to a check-in station.  
           [0013]    A further object of the present invention is to provide an inclined conveyor that performs a function of transporting, along a steep incline, library-like materials from a receiving station, to a check-in station and to a storage container.  
           [0014]    A yet further object of the present invention is to provide an inclined conveyor that does not damage library-like materials.  
           [0015]    A still further object of the present invention is to provide an inclined conveyor that may be incorporated into an existing library building without a need for extensive remodeling of the building.  
           [0016]    In accordance with the present invention, an inclined conveyor for conveyance of library-like materials from a receiving station to a check-in station includes an endless base belt conveyor. A base or materials support belt is tensioned around a drive roller assembly located closest to a ground plane, and around an upper roller at an opposing end. A tension-less freely hanging overhead endless belt is provided in juxtaposition with and above the base belt, and is driven by a slaved roller drive scheme in proximity to the upper roller of the base belt. A chain coupled to the upper roller of the base belt drives the slaved roller drive scheme. The overhead belt is structured so as to freely cover the base belt and materials placed thereon, and to provide relatively secure containment of materials upon the base belt, thereby allowing transport of the materials on the base belt along an incline, steep or otherwise, without tumbling or slipping. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    [0017]FIG. 1 is a perspective illustration of a material handling system for receipt of library-like materials, including an inclined conveyor of the present invention.  
         [0018]    [0018]FIG. 2 is a partial transparent schematic side view of the inclined conveyor of the material handling system of FIG. 1, constructed in accordance with the present invention, and depicting a non-operative or at rest condition.  
         [0019]    [0019]FIG. 3 is a partial illustration of the side view of FIG. 2, depicting an operative or in-use condition.  
         [0020]    [0020]FIG. 4 is a schematic flow diagram illustrating a material handling system control scheme in accordance with the present invention.  
         [0021]    [0021]FIG. 5 is a magnified cross-sectional illustration of an alternative component of the conveyor depicted in FIG. 3.  
         [0022]    [0022]FIG. 6 is a partial illustration of FIG. 3, depicting a further embodiment of the present invention.  
         [0023]    [0023]FIG. 7 is a magnified illustration of a component of the present invention depicted in FIG. 6. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]    In the following exposition, the words “book”, “material”, and “library-like material” as used herein are synonymous, and are intended to include (i) any conventional library material such as, but not limited to, a bound book, a “paperback” book, a materials container (such as a magazine series receptacle or holder), a diskette cassette, a video tape, or (ii) any other tangible media that may have dimensions or an appearance similar or analogous to a conventional book.  
         [0025]    Referring to FIG. 1, thereshown is a perspective view illustration of an exemplary embodiment of an inclined conveyor  10  of the present invention, incorporated into an overall material handling system for receipt of library-like materials being returned by patrons to a library.  
         [0026]    In this exemplary material handling system, inclined conveyor  10  provides, in part, movement of incoming library materials from a receiving station  20  located in an exterior wall of a library (generally identified by character “L”) to a vicinity of an automated materials identification and check-in apparatus  30 , and finally to a storage container or bin  40  by way of a slide chute  45 . Bin  40  may be as disclosed in U.S. Pat. No. 6,000,770 entitled “A Library Book Bin with a Vertically Adjustable Floor” issued to Frich, and as provided by a SMART BIN™ library storage container available from Tech Logic Corporation of Oakdale, Minn.  
         [0027]    Further in the exemplary embodiment, the material handling system may include a horizontal input belt conveyor  50  for transporting materials received at receiving station  20  to an input or lower end of inclined conveyor  10 . Similarly, the system may also include a horizontal output belt conveyor  60  for transporting materials from an upward or output end of inclined conveyor  10 .  
         [0028]    For simplicity and clarity of the drawings, conveyors  50  and  60  are illustrated in FIG. 1 as motorized belt conveyors (drive motors not shown). However, any type of motorized conveyor may, of course, be employed.  
         [0029]    Illustrated in FIG. 2 is a transparent schematic side view of steep incline conveyor  10  illustrated in FIG. 1. Also depicted in the drawing is receiving station  20  embodying, for example, an automatic patron-activated library material depository designed for “hands-free” operation such as that described in co-pending U.S. patent application Ser. No. 09/507,614 filed on Feb. 21, 2000, and entitled “Access Device For A Materials Depository.” Further depicted is automated materials identification and check-in apparatus  30  embodying, for example, a radio frequency identification (RFID) device such as that also described in the aforementioned co-pending application.  
         [0030]    With reference to FIG. 1 and particularly to FIG. 2, steep incline conveyor  10  includes a conveyor frame  100  having left, right, and bottom side panel members  110 ,  115 , and  120  respectively. As noted above, FIG. 2 is shown in transparent fashion such that left side panel member  110  of frame  100  is not illustrated, so that inner details of conveyor  10  may be readily ascertained. Frame  100  is provided for attachment and support of various components to conveyor  10  that will be described below.  
         [0031]    Similarly, associated with conveyor  50  are panel members  111 ,  116 , and  121 , and with conveyor  60  are panel members  112 ,  117 , and  122 . As may be ascertained from the drawings, the aforementioned panel members of conveyors  50  and  60  may be joined together with the various panel members of frame  100  of conveyor  10  to form an overall complete housing for the material handling system.  
         [0032]    In a particular installation of conveyor  10 , frame  100  may be supported by way of support members  105 . Support members  105 , being structurally similar to conventional jack-type stands, function to support and positionally stabilize frame  100 , particularly when conveyor  10  is in operation and may be experiencing various operational stresses. The aforementioned panel members of frame  100  are preferably fabricated from 14 ga. cold-rolled sheet steel and welded together.  
         [0033]    Additionally in FIG. 1, materials identification and check-in apparatus  30  is shown as being supported above output conveyor  60  by way of brackets  35   a - b  fastened at their opposing ends to upper portions of panel members  110  and  115 .  
         [0034]    With particular reference again to FIG. 2, conveyor  10  includes a lower endless base belt  130  and a tension-less freely hanging endless overhead belt  140 . Endless base belt  130  is tensioned between a head or upper roller  132  and a tail or lower roller  134  by way of a tensioning scheme, e.g., by roller positioning adjustment. Base belt  130  preferably has a durameter rating of 30 to 40, for providing non-slip gripping ability for materials placed thereon as will be further described. Conversely, overhead belt  140  is preferably selected to be relatively smooth. Length and width dimensions of each belt  130  and  140  are, of course, chosen with regard to needs of a particular installation. In a library, for example, belts  130  and  140  are commonly chosen to have widths of about 18 inches each, for adequate transport of a typical variety of material sizes. Lengths of each belt  130  and  140  are largely dependent, however, upon the selected length of conveyor  10 .  
         [0035]    A drive scheme for base belt  130  may be provided by way of a motorized drive drum  136  and a cooperating drive roller  138 . Drive drum  136  may be driven by any suitable technique (not illustrated).  
         [0036]    As may be appreciated with continued reference to FIG. 2, tension-less freely hanging endless overhead belt  140  is, unlike base belt  130 , not tensioned between head and tail rollers. Rather, belt  140  is driven by way of a slaved drive roller  142  and cooperating tensioning rollers  144   a - b  acting collectively as a head roller. The particular absence of a tail roller scheme provides, as will be further described, an ability of belt  140  to conform to and partially encase or envelope materials on base belt  130 . When conveyor  10  is not in operation, it is to be understood that a majority of belt  140  freely lies upon belt  130 . When conveyor  10  is in operation, however, an amount of belt  140  lying on belt  130  is reduced due to partial volumes of materials being transported and “taking up slack” in belt  140  as will be further described.  
         [0037]    Slaved drive roller  142  is motively coupled to upper roller  132  of base belt  130  through a drive chain  150 . It is to be understood that motive force is imparted to drive chain  150  by rotational motion of upper roller  132  through operational movement of base belt  130 , as will be more fully described. The motive coupling of upper roller  132  to drive roller  142  through drive chain  150  may be accomplished by any suitable means such as, for example, providing chain sprockets (not illustrated) on each roller  132  and  142  to accommodate drive chain  150 . It is to be particularly appreciated that slaved drive roller  142  in cooperation with tensioning rollers  144   a - b  collectively provide a “traction motor” scheme for overhead belt  140 .  
         [0038]    Conveyor  10  preferably also includes a base belt support bed  160  and an overhead belt guide panel  170 . Support bed  160  is welded along its lengthwise edges orthogonally to left and right side panel members  110  and  115  (as depicted in FIG. 2), respectively, to provide support to base belt  130  when materials are placed thereon in operation of conveyor  10 . Overhead belt guide panel  170  is structurally similar to support bed  160 , and is similarly welded orthogonally along its lengthwise edges to left and right side panel members  110  and  115  to provide a guide means to overhead belt  140  in operation of conveyor  10 .  
         [0039]    Turning, now, to FIG. 3, there shown is a partial illustration of the side view of the invention shown in FIG. 2, in operation of steep incline conveyor  10 . In FIG. 3, receiving station  20 , check-in apparatus  30 , horizontal conveyors  50  and  60 , and frame  100  have each been removed from the drawing for clarity thereof. Further, FIG. 3 depicts an exemplary conveyance of library-like materials (reference characters “M”) upward along support bed  160  (from a vicinity of drive roller  138  to a vicinity of upper roller  132 ) that have been introduced to conveyor  10  by way of, for example, horizontal conveyor  50  (not illustrated, as aforestated).  
         [0040]    As drive drum  136  and drive roller  138  operate to drive base belt  130 , in a counter-clockwise sense viewed as a whole for upward conveyance of materials M, upper roller  132  responsively rotates in a counter-clockwise sense, thereby driving drive chain  150  and thus slaved drive roller  142  also counter-clockwise. In this manner, overhead belt  140  is caused to be responsively driven in a clockwise sense, viewed as a whole. It is to be appreciated in this exemplary operation of conveyor  10  that belts  130  and  140  move cooperatively to convey materials M upward. Specifically, the cooperation between belts  130  and  140  is achieved upon materials M due to, in part, an addition of an effective weight to each item of material M upon base belt  130  from a weight of overhead belt  140  acting downwardly upon material M toward base belt  130 . Therefore, material M is prevented, to a significant degree, from slipping or tumbling downwardly along base belt  130 . Also, the aforementioned durameter rating of 30 to 40 of base belt  130  provides sufficient gripping ability on materials M. Further, it may be appreciated that since belts  130  and  140  are driven at, or nearly at, the same speed through the aforedescribed slaved traction drive scheme, materials M being transported are acted upon by two cooperatively moving belt surfaces. That is, as may be appreciated by reference again to FIG. 3, overhead belt  140  acts to conform to and partially encase or envelope each item of material M being conveyed along base belt  130 . Such enveloping provides further static stability to material M against slipping or tumbling down base belt  130 .  
         [0041]    Also, it is to be appreciated in the drawing that belt  140  forms a freely hanging tension-less loop (generally outlined by a dotted line and identified by reference character “L”) near lower roller  134 . In operation of conveyor  10 , loop L is diminished or “taken up” as more materials M are added to base belt  130 , and belt  140  conforms to and partially envelops those added materials M.  
         [0042]    Preferably in operation of the overall material handling system, operational speed ratios of horizontal input conveyor  50  to inclined conveyor  10  and to horizontal output conveyor  60  are factors of 1.5 and 2.5, respectively. For example, if input conveyor  50  were selected to run at a speed of 60 ft./min, then inclined conveyor  10  would be selected to run at about 1.5 times that speed, or at about 90 ft./min. In like manner, output conveyor  60  would be chosen to run at a speed of about 2.5 times the speed of input conveyor  50 , or at about 150 ft./min. Such exemplary speed ratios have been found to efficiently operate the material handling system for prevention of “bottlenecks” at input conveyor  50 , for optimized operation of conveyor  10 , and for orderly outflow of materials M from output conveyor  60 .  
         [0043]    [0043]FIG. 4 is a schematic flow diagram of an exemplary control scheme for operation of a materials handling system including steep incline conveyor  10 . In the diagram, materials receiving station  20  (as described in the aforementioned co-pending application) responsively generates a system signal  400  indicative of an in-use or not-in-use condition of receiving station  20 . Start-up signal  400  is then provided as an input to a logical decision gate  405 . Gate  405  determines whether receiving station  20  is in use based upon signal  400 .  
         [0044]    If station  20  is in use, then gate  405  outputs a logical “YES” or “1” signal to a 4-channel device controller or relay  410 . Responsively, device controller  410  allows transfer of sufficient electrical energy to electric motors associated with each conveyor  10 ,  50 , and  60  for operation thereof. Concurrently with the energizing of each conveyor motor, device controller  410  also allows transfer of sufficient electrical energy to materials identification and check-in apparatus  30  (preferably, an RFID device) for operation thereof.  
         [0045]    Conversely, if station  20  is not in use, then gate  405  outputs a logical “NO” or “0” signal to 4-channel device controller or relay  410 . Responsively, device controller  410  stops transfer of electrical energy to the electric motors associated with each conveyor  10 ,  50  and  60 ; and concurrently, device controller  410  then also stops transferring electrical energy to apparatus  30 .  
         [0046]    It should be understood that the aforedescribed control scheme may be controlled by a computerized control system such as a computer workstation or the like. Although the operation and control of the conveyor  10  and overall materials handling system of the present invention has been described herein in simple control terms and concepts, it should be appreciated that alternative or more complex controls and systems are all within the true spirit and scope of the present invention as claimed herein.  
         [0047]    While the present invention has been particularly shown and described with reference to the accompanying figures, it will be understood, however, that other modifications thereto are of course possible, all of which are intended to be within the true spirit and scope of the present invention. It should be appreciated that components of the invention aforedescribed may be substituted for other suitable components for achieving desired similar results. For example, those of ordinary skill in the art will appreciate that the present invention may be selectively adapted for conveyance of materials either up or down an incline (i.e., as an incline or decline conveyor  10  with a corresponding positional change of various elements of the invention, as may be necessary).  
         [0048]    Also, as depicted in magnified cross-section in FIG. 5, overhead belt guide panel  170  together with overhead belt  140  may include a v-guide arrangement for providing longitudinal centering of overhead belt  140  between panels  110  and  115  in operation of conveyor  10 . Specifically, overhead belt  140  could include a longitudinal “v-strip”  149  fixed and centered along belt  140  that would mate with a longitudinally centered “v-channel”  179  in panel  170 . In this arrangement, v-strip  149  runs along and within the v-channel  179  in operation of belt  140 , thereby providing such longitudinal centering of belt  140 .  
         [0049]    Further, support members  105  could be hung from a ceiling installation as an alternative to their jack-stand type of function depicted in the drawings.  
         [0050]    Also illustrated in FIG. 6 is an alternative embodiment of conveyor  10  that is particularly useful when a steep incline conveyor  10  exceeds about 70 degrees. In the drawing, spring loaded bogey wheel arms  600  are coupled to overhead belt guide panel  170  for providing additional pressure to belt  140  as it conforms to and partially encases or envelopes each item of materials being conveyed along base belt  130 . Such additional pressure on belt  140  imparted thereto by arms  600  provides enhanced stability to material M against slippage or tumbling.  
         [0051]    With reference to FIG. 7, an arm  600  is shown in magnified fashion for clarity. Therein, arm  600  includes a bogey wheels  610 , a wheel arm  620  coupled to wheel  610 , and a spring  630  coupled to arm  620  having an attachment loop  640  for the aforesaid coupling of arm  600  to overhead belt guide panel  170 .  
         [0052]    It is to be appreciated that arms  600  particularly provide enhanced conformity of belt  140  to materials M when a large volume of materials are being introduced to conveyor  10 . That is large volumes of materials M tend, in operation of conveyor  10 , to “run together” or form effectively large material M spaces between belts  130  and  140 ; thus, the aforedescribed enveloping of belt  140  may e diminished due to a consequent lack of slack in belt  140  and diminished ability of belt  140  to lie on belt  130 . Arms  600  alleviate this problem by introducing and additional force to belt  140  and, in turn, to materials M on belt  130  so that materials M may be held in place thereon.  
         [0053]    Additionally, each motor for operation of each conveyor  10 ,  50 , and  60 , may be chosen to develop a desired amount of revolutions per minute, for providing the aforementioned operational speed ratios. These RPM choices may be achieved by selection of various horsepower motors, or possibly by a rheostat-like control of identical motors.  
         [0054]    Further, it will be appreciated by those skilled in the art that any suitable conveyance or transport technique may be substituted for base bet  130 . Such techniques include rolling or sliding beds or shuttles, a fixed roller bed, or even simply a low-friction surface for sliding movement of materials M thereupon.  
         [0055]    Lastly, the choice, of course, of mechanical sizes and strengths of various components are all a matter of design choice depending upon intended use and objects intended to be handled by the system of the present invention.  
         [0056]    Accordingly, these and other various changes or modifications in form and detail of the present invention may also be made therein, again without departing from the true spirit and scope of the invention as defined by the appended claims.