Patent Publication Number: US-6655683-B2

Title: Thickness measuring device for use within a mail handling system, and a method of using the same

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to thickness measuring devices, and more particularly to a new and improved thickness measuring device or system, and a method of using the same, which is particularly useful in connection with the measuring or determining the thickness of individual articles, such as, for example, pieces or units of postal mail, wherein the articles may be any combination of envelopes, letters, catalogs, newspapers, magazines, greeting cards, and the like, such that an automatic mail delivery system, which delivers pieces or units of mail into sorting bins that are adapted to have mail pieces or units stacked therein up to a predetermined height or depth dimension, can stop depositing mail pieces or units into a particular sorting bin when the thickness measuring apparatus or system determines that the cumulative thickness dimensions of the detected and measured articles equals the predetermined height of the stack of mail pieces or units to be housed and contained within the particular sorting bin. 
     BACKGROUND OF THE INVENTION 
     Automatic mail delivery or conveying, sorting, and stacking systems are known which deliver pieces or units of mail, such as, for example, envelopes, letters, catalogs, newspapers, magazines, greeting cards, and the like, into sorting bins that are adapted to have pieces or units of mail stacked therein up to a particular height or depth dimension. Since the amount of volume that a particular sorting been could hold, contain, or accommodate would obviously comprise a particular number of pieces or units of mail having predetermined thickness dimensions, then it would be desirable for an automatic delivery or conveying, sorting, and stacking system to predetermine the thickness dimension of each individual unit or piece of mail, as well as to track the number of individual mail pieces or units detected or scanned so that a predetermined stack of mail can in fact be deposited within a particular sorting bin. PRIOR ART automated mail delivery or conveying, sorting, and stacking systems, however, have exhibited several operational drawbacks or deficiencies along these procedural lines. For example, in accordance with a first known type of automated mail delivery or conveying, sorting, and stacking system, while such a system is capable of tracking, ascertaining, or determining the number of pieces or units of mail that have been conveyed, sorted, and delivered to predetermined sorting bins, such a system has nevertheless been unable to accurately determine the thickness of each individual piece or unit of mail and to correlate such information with the total number of detected and counted pieces or units of mail. In particular, the thickness dimension of each individual piece or unit of mail is usually estimated in some manner by some means. In accordance with a second type of automated mail delivery or conveying, sorting, and stacking system, the system does not predetermine the thickness dimension of each individual piece or unit of mail, but to the contrary, the system simply determines or senses the height of the entire stack of mail deposited within each individual sorting bin. For example, each sorting bin is provided or equipped with photocell systems which are accordingly activated when the stack of mail deposited within a particular sorting bin reaches or attains a predetermined height or level. This type of system is relatively expensive, however, in view of the fact that each sorting bin must be equipped with its own photocell detection system. 
     Systems also exist which are capable of determining thickness dimensions of, for example, flat mail pieces or units, however, such systems have not been employed for determining the thickness dimensions of individual pieces or units of mail such that the determined thickness dimensions can then be correlated or used in connection with the counted or detected number of individual pieces or mails so as to correspondingly determine the height of a stack of mail deposited within a particular sorting bin. For example, as disclosed within U.S. Pat. No. 6,123,330 which issued to Schaal on Sep. 26, 2000, a suction separation system is utilized in connection with the conveyance of flat mail pieces, and the system utilizes a rotary potentiometer to determine the thickness dimension of each stack item wherein the thickness dimension is related to, or is a function of, the stack pressure which is suitably monitored, corrected, adjusted, and controlled. In a similar manner, as disclosed within U.S. Pat. No. 5,727,692 which issued to Large et al. on Mar. 17, 1998, the thickness dimensions of envelopes is determined, however, such thickness dimensions are determined as a means for correspondingly determining whether or not any contents are present within a particular envelope. Still further, as disclosed within U.S. Pat. No. 5,704,246 which issued to Kruger on Jan. 6, 1998, a raster gauge is used to determine the thickness dimensions of objects in order to, in turn, determine whether or not such objects can be subsequently handled by means of other machines or equipment located downstream within the overall processing or handling system. As disclosed within U.S. Pat. No. 5,238,123 which issued to Tovini et al. on Aug. 24, 1993, a system is employed to determine thickness and length dimensions or parameters of envelopes whereby those envelopes which do not have length and thickness dimensions which are within a predetermined range of values are removed from the particularly disclosed handling system. Lastly, as disclosed within U.S. Pat. No. 4,953,842 which issued to Tolmie, Jr. et al. on Sep. 4, 1990, there is disclosed a system for determining the thickness dimensions of mail pieces or units such that the mail pieces or units can be properly conveyed by means of a particular handling system in accordance with a predetermined velocity sequence or profile. 
     A need therefore exists in the art for a new and improved thickness measuring device, and a method of using the same, for use within a mail handling system wherein the thickness measuring device can determine the thickness dimension of individual pieces or units of mail as the same are conveyed past the device, and such thickness information or data can be correlated with the number of scanned or detected pieces or units of mail which are being delivered to predetermined sorting bins so as to determine the precise number of mail pieces or units than can be deposited within a particular sorting or storage bin such that the stack of mail disposed, housed, or contained within the particular sorting or storage bin has a predetermined height dimension whereupon further conveyance of mail units or pieces to such sorting or storage bin can be terminated until such sorting or storage bin has been emptied or replaced. 
     OBJECTS OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a new and improved thickness measuring device, and a method of using the same, for determining the thickness dimensions of individual pieces or units of mail, and a mail handling, sorting, and stacking system incorporating the same therein, wherein the mail handling, sorting, and stacking system stacks a predetermined amount of mail within a sorting or storage bin. 
     Another object of the present invention is to provide a new and improved thickness measuring device, and a method of using the same, for determining the thickness dimensions of individual pieces or units of mail, and a mail handling, sorting, and stacking system, having the thickness measuring device incorporated therein, for stacking a predetermined amount of mail within a sorting or storage bin in accordance with techniques which effectively overcome the various operational deficiencies characteristic of PRIOR ART systems. 
     An additional object of the present invention is to provide a new and improved thickness measuring device, and a method of using the same, for determining the thickness dimensions of individual pieces or units of mail, and a mail handling, sorting, and stacking system incorporating the same therein, wherein the thickness dimension data or information for each individual piece or unit of mail can be used in connection with the stacking of a predetermined amount of mail within a particular sorting or storage bin. 
     A further object of the present invention is to provide a new and improved thickness measuring device, and a method of using the same, for determining the thickness dimensions of individual pieces or units of mail, and a mail handling, sorting, and stacking system incorporating the same therein, wherein the thickness dimension data or information for each individual piece or unit of mail can be correlated with the number of detected or scanned pieces or units of mail such that a predetermined number of mail pieces or units can be stacked within a particular sorting or storage bin. 
     A last object of the present invention is to provide a new and improved thickness measuring device, and a method of using the same, for determining the thickness dimensions of individual pieces or units of mail, and a mail handling, sorting, and stacking system incorporating the same therein, wherein the thickness dimension data or information for each individual piece or unit of mail can be correlated with the number of detected or scanned pieces or units of mail such that a predetermined number of mail pieces or units can be stacked within a particular sorting or storage bin such that the stacked mail has a predetermined height dimension whereupon further deposits of mail within such sorting or storage bin are discontinued. 
     SUMMARY OF THE INVENTION 
     The foregoing and other objectives are achieved in accordance with the teachings and principles of the present invention through the provision of a new and improved thickness measuring device, a method of using the same, and a mail handling system in which the thickness measuring device is incorporated, wherein the thickness measuring device comprises a rotary encoder mounted upon a mounting bracket, and wherein further, a movable lever arm is fixedly connected to the rotary shaft of the rotary encoder. A first end of the lever arm has an idler wheel or roller mounted thereon which is adapted to be disposed in contact with, or encounter, mail pieces or units as the mail units or pieces are conveyed along a conveyor path. A hydraulic damper is disposed in contact with the first end of the lever arm, while a second opposite end of the lever arm is fixedly connected to a biasing return spring. As the mail pieces or units respectively encounter the idler wheel or roller of the lever arm, each mail piece or unit will cause deflection of the lever arm a predetermined amount, as controlled by means of the hydraulic damper and biasing return spring, in accordance with the thickness dimension of the particular mail piece or unit, and the deflection of the lever arm will accordingly cause rotation of the rotary shaft of the rotary encoder. The encoder impulse data, corresponding to the rotation of the rotary shaft of the rotary encoder and the deflection amount of the lever arm in accordance with the thickness of the particular piece or unit of mail, will be transmitted to a computer wherein software will effectively convert such impulse data into linear deflection amounts or thickness dimensions or parameters characteristic of the particular unit or piece of mail. 
     The computer software also keeps track of the particular pieces or units of mail, through means of, for example, suitable bar code reader (BCR) or optical character recognition (OCR) apparatus, and correlates the same with the calculated thickness data for each one of the mail pieces or units detected and encountered by means of the rotary encoder lever arm. Stacking storage capacity data for each sorting or storage bin is also pre-entered into the computer, and therefore, the computer can accordingly control the conveyor system such that when a predetermined number of units or pieces of mail, having a cumulative thickness dimension as determined by means of the computer as derived or calculated from the data supplied thereto from the rotary encoder, has been conveyed to a particular sorting or storage bin which has a predetermined mail piece or unit stacking or storage capacity which equals the cumulative thickness dimension or parameter of the predetermined number of detected or encountered pieces or units of mail, the convey- or will terminate further conveyance of mail to such sorting or storage bin until such sorting or storage bin has either been emptied or replaced by means of a correspondingly sized storage or sorting bin. The system is capable of being utilized in connection with the conveyance of substantially all types of mail including, but not limited to, envelopes, letters, catalogs, newspapers, magazines, greeting cards, and the like. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various other objects, features, and attendant advantages of the present invention will be more fully appreciated from the following detailed description when considered in connection with the accompanying drawings in which like reference characters designate like or corresponding parts throughout the several views, and wherein: 
     The SOLE FIGURE is a schematic drawing of a new and improved thickness measuring device, as incorporated within an article handling system, for determining the thickness dimensions of conveyed articles, such as, for example, various pieces or units of mail, such that a predetermined number of articles, or mail pieces or units, can be deposited within a particular storage or sorting bin having a predetermined storage or stacking capacity. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, and more particularly to the SOLE FIGURE thereof, a new and improved article handling system, having a new and improved thickness measuring device incorporated therein, is disclosed and is generally indicated by the reference character  10 . While the article handling system  10  can be adapted for use in connection with the handling or conveyance of substantially different types of articles, for the purposes of the present invention disclosure, the article handling system  10  will be directed toward the handling and conveyance of pieces or units of mail which may, for example, include, but is not necessarily limited to, envelopes, letters, catalogs, newspapers, magazines, greeting cards, and the like. More particularly, it is seen that the new and improved article handling system  10  comprises an article conveyor system as defined by means of a pair of opposed conveyor belts  12  between which articles, such as, for example, various pieces or units of mail, may be conveyed toward a plurality of sorting or storage bins  14 ,  16 ,  18 . In accordance with the particularly novel and unique structure or system which has been developed in accordance with the principles and teachings of the present invention, a central processing unit (CPU)  20  is operatively connected to the article con-veyor belt drive system  12  by means of signal or communication lines schematically illustrated at  22  in order to not only control the operation of the article conveyor system  12 , but in addition, to control various sorting gates, not shown, operatively connected to or comprising the article conveyor system  12  in a well-known manner such that articles being conveyed along article conveyor system  12  may be properly routed to or conducted toward a particular one of the plurality of sorting or storage bins  14 ,  16 ,  18 . It is also to be appreciated at this juncture that while the sorting or storage bins  14 ,  16 ,  18  have been illustrated as being “connected” to the central processing unit  20  by means of lines  24 ,  26 ,  28 , lines  24 ,  26 ,  28  do not actually represent communication or signal lines between the sorting or storage bins  14 ,  16 ,  18  and the central processing unit  20 , but have been illustrated simply as a means for conveying the idea that the central processing unit  20  is aware of the existence of each one of the plurality of sorting or storage bins  14 ,  16 ,  18 , as well as the storage capacity characteristic of each one of the plurality of sorting or storage bins  14 ,  16 ,  18 , and accordingly correlates such existence, disposition, or location of such sorting or storage bins  14 ,  16 ,  18 , and their respective storage capacities, with the article conveyor system  12  along which individual articles are being conveyed. 
     Continuing further, in accordance with the principles and teachings of the present invention, it is to be recalled that the primary objective of the present invention is to predetermine the thickness dimensions or parameters of the articles being conveyed along the article conveyor system  12  such that, knowing the storage capacity of each one of the sorting or storage bins  14 ,  16 ,  18 , the central processing unit  20  can terminate further conveyance of articles to a particular one of the plurality of sorting or storage bins  14 ,  16 ,  18  when the storage capacity of that particular one of the sorting or storage bins  14 ,  16 ,  18  has been reached as a result of having had deposited into such particular one of the plurality of sorting or storage bins  14 ,  16 ,  18  a plurality of articles having a cumulative thickness dimension value which is equal to the storage capacity of that particular one of the sorting or storage bins  14 ,  16 ,  18 . Accordingly, in order to determine the thickness dimension of each article as the same is being conveyed along the article conveyor system  12 , a rotary encoder  30  is located at a position which is located adjacent to the mail flow path of the article conveyor system  12 . A bar code reader/optical character recognition device  32  is also disposed adjacent to the disposition of the rotary encoder  30  and is likewise positioned adjacent to the article conveyor system  12  at a position upstream of the rotary encoder  30  as considered in the direction of conveyance of the articles along the article conveyor system  12 . The bar code reader/optical character recognition device  32  is connected to the central processing unit  20  by means of a signal or communication line  34 , and in this manner, each individual piece or unit of mail conveyed along the article conveyor system  12  is detected and read by means of the bar code reader/optical character recognition device  32 , and such identification information is transmitted to the central processing unit  20  such that the central processing unit  20  can effectively track the particular or individual piece or unit of mail. 
     In addition, it is seen that the rotary encoder  30  is mounted upon a suitable Z-shaped mounting bracket  36 , and that a rotary shaft  38  of the rotary encoder  30  has a lever arm  40  fixedly mounted upon the lower end portion thereof. The lever arm  40  is juxtaposed with respect to the article conveyor system  12  so as to position an idler wheel or idler roller  42 , which is mounted upon one end portion of the lever arm  40 , immediately adjacent to the mail flow path of the article conveyor system  12 . More particularly, the idler wheel or idler roller  42  is adapted to normally be disposed in contact with the outer one of the oppositely disposed or paired conveyor belts  12  as a result of a piston member, not shown, of, for example, a suitable, single-acting hydraulic damper  44  normally being disposed in contact with the end of the lever arm  40  upon which the idler wheel or roller  42  is mounted. The hydraulic damper  44  is fixedly mounted upon the Z-shaped mounting bracket  36 , and the opposite end of the lever arm  40  is operatively connected to a return spring mechanism  46 . As can be seen from the drawing, a first end portion  48  of the return spring mechanism  46  is connected to the lever arm  40 , while a second end portion  50  of the return spring mechanism  46  is connected to a mounting bolt assembly  52  which is fixedly mounted upon the Z-shaped mounting bracket  36 . 
     Accordingly, when a particular piece or unit of mail is conveyed along the article conveyor system  12 , the piece or unit of mail will cause the outer one of the conveyor belts  12 , with which the idler wheel or roller  42  of the lever arm  40  is disposed in contact, to move outwardly and thereby cause counterclockwise deflection of the lever arm  40  against the opposite biases of the return spring  46  and hydraulic damper  44  as denoted by the arrow CCW. Rotation or pivotal movement of the lever arm  40 , in turn, will cause a corresponding rotation or pivotal movement of the rotary encoder shaft  38  such that encoder impulses are generated by the rotary encoder  30 . It is noted that the use of the single-acting hydraulic damper  44  permits the piston rod member, not shown, thereof to be extended out from the hydraulic damper  44  in a faster operative mode than that characterizing the contraction mode of the piston rod member, not shown, into the hydraulic damper  44 . This is important during the pivotal movement of the lever arm  40  in that once a piece or article of mail has passed by the idler roller or wheel  42  whereby the lever arm  40  will then tend to return to its normally undeflected position, the piston rod member, not shown, of the hydraulic damper  44  will tend to prevent any “bounce-back” of the lever arm  40  and effectively ensure maintenance of the lever arm  40  at its normally undeflected position adjacent to the mail article flow path along conveyor system  12  so as to be in an operative position to detect the next piece or article of mail being conveyed along the conveyor system  12 . 
     As is known in the art, a rotary encoder can generate a predetermined number of impulses per a complete revolution, or in other words, for example, one thousand (1000) impulses per 360° of rotation. Therefore, for a predetermined angular movement of the lever arm  40 , and a corresponding angular movement of the rotary encoder shaft  38 , a predetermined number of impulses will be generated by the rotary encoder. The impulses from the rotary encoder  30  are transmitted to the central processing unit  20 , by means of a signal or communication line  54 , in which software can convert or correlate the angular movement of the lever arm  40 , and the corresponding angular movement of the rotary encoder shaft  38 , as signified or indicated by the number of impulses generated by the rotary encoder  30 , to linear values which are therefore indicative of the thickness dimension of the particular piece or unit of mail just detected or sensed by the lever arm  40  and its operatively associated idler wheel or roller  42 . 
     In view of the fact that such detected or sensed particular piece or unit of mail has also just been immediately previously identified by means of the bar code reader/optical character recognition device  32 , and that this mail piece or unit identification information has therefore also been transmitted to the central processing unit  20  by means of signal or communication line  34 , the central processing unit  20  correlates such information to the effect that a particularly identified unit or piece of mail has a particular thickness dimension. In view of the additional fact that the central processing unit  20  not only knows the storage capacity of each one of the storage or sorting bins  14 ,  16 ,  18 , but also knows the routing destination of each previously identified and detected or sense piece or unit of mail, then based upon the cumulative thickness dimensions of a plurality of previously identified and detected or sensed pieces or units of mail which are being routed to a particular destination comprising one of the sorting or storage bins  14 ,  16 ,  18 , the central processing unit  20  will know when the storage or stacking capacity of that particular one of the storage or sorting bins  14 ,  16 ,  18  has been or will be reached. The central processing unit  20  can therefore terminate any further conveyance of pieces or units of mail to such particular destination storage or sorting bin  14 ,  16 , or  18  until such storage or sorting bin  14 ,  16 , or  18  has been emptied or replaced. 
     It is lastly to be appreciated that while the lever arm  40 , and its operatively associated idler wheel or roller  42 , have been disclosed within the article handling system  10  as being disposed in contact with an outer surface of an outer one of the conveyor belts  12  for those conveyor systems  12  within which the articles are conveyed between a pair of oppositely disposed conveyor belts  12 , substantially the same system comprising lever arm  40 , and its operatively associated idler wheel or roller  42 , could likewise be employed in connection with those conveyor systems wherein articles are conveyed along, for example, a single conveyor belt, such as, for example, by means of suction or other implements. In connection with such a conveyor system, it is to be appreciated that the idler wheel or roller  42  of the lever arm  40  will normally be disposed in contact with the surface of the conveyor belt along which the articles are being conveyed and will therefore be directly engaged by the conveyed article such that the lever arm  40  will undergo the corresponding aforenoted deflected movement. In either case or instance, the basic operation of the system  10  is substantially the same, that is, deflection of the lever arm  40 , as detected by means of the rotary encoder  30 , will be indicative of the thickness dimension of the particular unit or piece of mail detected or sensed. 
     Thus, it may be seen that in accordance with the principles and teachings of the present invention, a new and improved article handling system, having a new and improved thickness measuring device incorporated therein, has been developed whereby thickness dimensions of conveyed articles, such as, for example, pieces or units of mail, can be readily determined. In addition, such determined thickness dimensions can be correlated with particular article identification information or data such that the cumulative or total thickness value of a plurality of conveyed articles can be readily determined. This information can, in turn, be utilized in connection with the conveyance of a plurality of articles toward destination storage or sorting bins within which articles are to be stacked to a predetermined height or level. When the system determines that the predetermined height or level within a particular storage or sorting bin has been or will be reached, further conveyance of articles by the article handling system and toward such storage or sorting bin is terminated and is not resumed until the particular sorting or storage bin has been emptied or replaced by means of a new sorting or storage bin. 
     Obviously, many variations and modifications of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.