Abstract:
A disc-type coin sorter for sorting coins of mixed diameters having improved exit slots is set forth. The sorter includes a rotatable disc having a resilient top surface and a stationary sorting head having a lower surface positioned parallel to the upper surface of the disc and spaced slightly therefrom. The lower surface of the sorting head forms a plurality of exit channels for guiding coins of different diameters to different exit stations along the periphery of the sorting head. Each of the plurality of exit channels has two side walls between which the coins are guided and a base across which the coins pass. Each exit channel has a slot in the base and the coin engages a region of the base outside of the slot.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to coin sorting devices and, more particularly, to coin sorters of the type which use a resilient rotating disc and a stationary sorting head for sorting coins of mixed diameters. 
     2. Background Information 
     Although disc-type coin sorters with resilient discs have been used for a number of years, problems are still encountered in applying this technology to certain types of coin sets. Most coins depict individuals, animals, buildings or various other objects which identify a particular coin with the heritage or culture of its country. However, some of these depictions can cause the width of the coin at its center to be greater than at its periphery. An example of such a coin is an older U.S. half dollar in which various facial features of President John. F. Kennedy depicted on the coin project above the face of the coin at its periphery. If such a coin is placed on a surface, the coin will &#34;teeter&#34; back and forth when pressure is applied at opposing edges. 
     Similar problems can occur with coins that are bent. This is a common problem in countries where coins are made from softer materials. As would be expected with a bent coin, a similar type of teetering motion is encountered when pressure is placed on the edges of the coin. 
     The problem with the teetering motion occurs as the coin passes by an electrical or optical sensor. If teetering persists while the coin is being sensed for counting, then the coin may be counted twice due to the teetering motion. Alternatively, sensors which detect the material composition via a magnetic phenomena in an effort to discriminate good coins from counterfeit coins may mistakenly characterize a good coin as a bad coin due to the teetering motion. In summary, the teetering can cause various problems in the sensing of a coin within the coin sorting device. 
     In addition to the specific problem discussed above, there is also an ongoing desire for ever-greater accuracy in the sorting of coins, particularly in disc-type sorters which operate at extremely high speeds. By minimizing the surface contact between the coin and the stationary sorting head, less friction is encountered which can lead to increased speeds. 
     SUMMARY OF THE INVENTION 
     It is a primary object of this invention to provide an improved disc-type coin sorter which can be operated at extremely high speeds and with a high degree of accuracy although some coins being sorted may be bent or have a maximum thickness at the center of the coin. 
     In accordance with the present invention, the foregoing objective is realized by providing a disc-type coin sorter which includes a rotatable disc having a resilient top surface and a stationary sorting head having a lower surface positioned parallel to the upper surface of the disc and spaced slightly therefrom. The lower surface of said sorting head forms a plurality of exit channels for guiding coins of different diameters to different exit stations along the periphery of the sorting head. Each of the plurality of exit channels has two side walls between which the coins are guided and a base across which said coins pass. Each exit channel has a slot in the base wherein the coin guided through the exit channel engages a portion of the base in a region outside of the slot. 
     In one preferred embodiment, the slot has a rectangular cross-section. In another embodiment, the slot has a curved cross-section. In either embodiment, a coin having a maximum middle thickness at its center or a coin that is bent moves through the exit channel without teetering. 
     The above summary of the present invention is not intended to represent each embodiment, or every aspect, of the present invention. This is the purpose of the figures and the detailed description which follow. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which: 
     FIG. 1 is perspective view of a coin sorter embodying the present invention, with portions thereof broken away to show internal structure; 
     FIG. 2 is an enlarged bottom plan view of the sorting head or guide plate in the coin sorter of FIG. 1; 
     FIG. 3A is a cross-sectional view of an exit channel having a rectangular slot; 
     FIG. 3B is a cross-sectional view of an exit channel having a curved slot; 
     FIG. 3C is a cross-sectional view of an exit channel having a triangular slot; 
     FIG. 3D is a cross-sectional view of an exit channel having an enlarged curved slot; and 
     FIG. 3E is a cross-sectional view of an exit channel having multiple slots. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Turning now to the drawings and referring first to FIG. 1, a hopper 10 receives coins of mixed denominations and feeds them through a central feed aperture or opening in an annular sorting head or guide plate 12. As the coins pass through the central opening, they are deposited on the top surface of a rotatable disc 13. This disc 13 is mounted for rotation on a stub shaft (not shown) and driven by an electric AC or DC motor 14 attached to a mounting plate 15. The disc 13 comprises a resilient pad 16, preferably made of a resilient rubber or polymeric material, bonded to the top surface of a solid metal disc 17. 
     As the disc 13 is rotated, the coins deposited on the top surface thereof tend to slide outwardly over the surface of the pad 16 due to centrifugal and frictional forces. As the coins move outwardly, those coins which are lying flat on the pad 16 enter the gap between the pad surface and the sorting head 12 because the underside of the inner periphery of the sorting head 12 is spaced above the pad 16 by a distance which is approximately as great as the thickness of the thickest coin. As further described below, the coins are sorted into their respective denominations, and the coins for each denomination issue from a respective exit channel, such as the channels 20, 21, 22, 23, 24 and 25 of FIG. 2. The particular embodiment illustrated in FIG. 2 was specifically designed for handling six United States coins, i.e., dimes, pennies, nickels, quarters, dollars and half-dollars, respectively. 
     In general, the coins for any given currency are sorted by the variation in diameter for the various denominations, although in many cases it is desirable or necessary to also sort by variation in thickness. The coins circulate between the sorting head 12 and the rotating disc 13 until a single-file stream of coins is obtained. One edge of the coins in this stream of coins is aligned, and possibly adjusted, so that the other edge of the coins is subsequently gaged against gaging surfaces for directing the coins to the exit channels 20-25 for the respective denominations. 
     As can be seen most clearly in FIG. 2, the outwardly moving coins initially enter the entry channel 30 formed in the underside of the sorting head 12 from the central opening that is seen when looking into the hopper 12. It should be kept in mind that the circulation of the coins, which is clockwise in FIG. 1, appears counter-clockwise in FIG. 2 because FIG. 2 is a bottom view. A stripping notch 34 is illustrated for stripping &#34;shingled&#34; or &#34;double&#34; coins (i.e. coins which are stacked on one another). The outer wall 31 of the entry channel 30 extends downwardly to the lowermost surface 32 of the sorting head 12, which is preferably spaced from the top surface of the pad 16 by a distance which is slightly less than the thickness of the thinnest coins. Consequently, the initial outward movement of the coins is terminated when they engage the wall 31 of the entry channel 30, though the coins continue to move circumferentially along the wall 31 by the rotational movement of the pad 16. 
     As the disc 13 rotates, coins in the entry channel 30 that are close enough to the wall 31 engage a ramp 36 leading down to surface 36a. A wall 36b defines an inner border for the surface 36a and extends in an inward arc to a ramp 42 leading down to the lowermost surface 32. The wall 36b tends to strip &#34;shingled&#34; or &#34;double&#34; coins. Preferably, the wall 36b separates the top coin of a pair of &#34;shingled&#34; or &#34;double&#34; coins and guides the top coin towards the ramp 42 for recirculation. Misaligned coins that miss the ramp 36 also require recirculation. The misaligned or stripped top coins engage the wall 36b, and the wall 36b guides these coins to the ramp 42. These coins move down the ramp 42 to the lowermost surface 32, and, as the coins move down the ramp 42, the coins are pressed into the pad 16. Once in a pressed engagement with the pad 16, these coins remain in the same radial position but move circumferentially along the surface 32 until engaging recirculation ramp 44. The recirculation ramp 44 leads back up into the entry channel 30 and recirculates the misaligned or stripped coins back into the entry channel 30. 
     Those coins that reach the surface 36a move circumferentially on the surface 36a, and, similarly, those coins close enough to the wall 31 engage a ramp 38 leading down to a surface 38a. A wall 38b defines the inner border of the surface 38a and extends in an inward arc to the ramp 42. The wall 38b provides another coin stripping mechanism to reduce &#34;shingled&#34; or &#34;double&#34; coins. As described above for the wall 36b, misaligned or stripped coins engage the wall 38b, and the wall 38b guides these coins to the ramp 42 for recirculation. 
     The coins that reach the surface 38a continue moving circumferentially along the surface 38a due to the rotation of the rotating disc 13 and encounter a ramp 46 leading up to a queuing channel 48. An outer wall 50 of the queuing channel 48 extends downwardly to the lowermost surface 32 of the sorting head 12. An inner wall 51 of the queuing channel 48 tends to reduce &#34;shingled&#34; or &#34;double&#34; coins within the queuing channel 48. The inner wall 51 extends downward less than the thickness of the thinnest coin to engage the top coin of &#34;shingled&#34; or &#34;double&#34; coins. For example, in the queuing channel 48, &#34;double&#34; or &#34;shingled&#34; coins are under pad pressure and tend to remain in their radial position. As such, as the &#34;double&#34; or &#34;shingled&#34; coins move circumferentially and maintain their radial position, the inner wall 51 engages the top coin of the &#34;shingled&#34; or &#34;double&#34; coins, tending to separate the coins. While the inner wall 51 separates the coins, the lower coin engages a beveled surface 51a, and, once separated, the lower coin is still under pad pressure with the beveled surface 51a. Consequently, the lower coin retains its radial position while moving circumferentially with the pad 16 and passes under the beveled surface 51a to the lowermost surface 32 for recirculation. 
     In the queuing channel 48, the coins can be pressed into engagement with the sorting head 12. This pad pressure on the coins is sometimes referred to as positive control. If the coins are free from positive control, the coins are free to move outwardly until the coins engage the wall 50 of the queuing channel 48 as the coins continue to move circumferentially due to the rotational movement of the pad 16. If the coins are under positive control, however, the coins maintain their radial position while continuing to move circumferentially along the queuing channel 48 due to the rotational movement of the pad 16. 
     As the coins move circumferentially along the queuing channel 48, the coins under positive control in the queuing channel 48 encounter a ramp 52 leading up into a deep channel 54. The deep channel 54 releases positive control on any thick coins that were under positive control in the queuing channel 48 and, thereby, unable to move outwardly to engage the wall 50 of the queuing channel 48. Therefore, as these coins enter the deep channel 54, the coins are permitted to move outwardly and desirably engage an outside wall 54a of the deep channel 54. The wall 50 of the queuing channel 48 blends into the wall 54a of the deep channel 54. After the coins enter the deep channel 54, the coins are desirably in a single-file stream of coins directed against the outer wall 54a of the deep channel 54. 
     The outer wall 54a guides the stream of coins to a narrow ramp 56. As the coins move circumferentially along the outer wall 54a, the coins engage the narrow ramp 56 leading down to the lowermost surface 32 of the sorting head 12. At the terminal end of the ramp 56, the coins are firmly pressed into the pad 16. As such, the coins are under positive control. Therefore, the radial position of the coins is maintained as the coins move circumferentially towards a gaging channel 58. 
     If any coins in the stream of coins leading up to the narrow ramp 56 is not sufficiently close to the wall 54a so as to engage the narrow ramp 56, then the misaligned coins engage an outer wall 60 of a recirculating channel 61. The recirculating channel 61 includes a beveled surface 62 that is slightly angled (e.g., 5 1/4 degrees) with respect to the pad surface. Such a beveled surface 62 allows misaligned coins to ramp away from pressed engagement with the pad 16. When the leading edges of the misaligned coins hit wall 60, the wall 60 guides the misaligned coins back to the entry channel 30 for recirculation. 
     It can occur that correctly aligned coins passing under the recirculating channel 61 as the coins move circumferentially towards the gaging channel 58 can be slightly shifted in their radial position. To correct this, coins which pass under the recirculating channel 61 encounter a ramp 66 leading into the gaging channel 58. The coins remain under pressure in the gaging channel 58, but the gaging channel 58 tends to urge the coins to be realigned against an outer gaging wall 64 of the gaging channel 58. The gaging channel 58 and the gaging wall 64 allow the coins in the sorting path an opportunity to realign their outer edges at the radial position required for correct sorting. To ensure that every coin engages the wall 64, the radius of the gaging wall 64 from the center of the disc is gradually decreased along the length of the gaging channel 58. 
     The gaging channel 58 preferably includes a beveled surface 68 that angles upward with respect to the pad surface and towards the gaging wall 64 and a deep surface 70. The coins moving into the gaging channel 58 remain under pressure from the sorting head 12, but the beveled surface 68 applies a variable amount of pressure on the coins with a greater amount of pressure on the inside edges of the coins. In this way, the beveled surface 68 helps to prevent the coins from bouncing off the wall 64 as the radial position of the coins is gradually decreased along the length of the gaging channel 58. 
     As the coins move along the gaging wall 64 of the gaging channel 58, the coins engage a gaging ramp 72 leading down to the lowermost surface 32. The gaging ramp 72 causes the coins to be firmly pressed into the pad 16 with their outermost edges aligned with the gaging radius provided by the gaging wall 64. At the terminal end of the gaging ramp 72, the coins are under the positive control of the sorting head 12. This ensures that the coins are held securely in the proper radial position determined by the gaging wall 64 as the coins approach the series of exit channels 20, 21, 22, 23, 24, and 25. 
     Beyond the gaging channel 58, the sorting head 12 forms the series of exit channels 20, 21, 22, 23, 24 and 25 which function as selecting means to discharge coins of different denominations at different circumferential locations around the periphery of the sorting head 12. Thus, the exit channels 20-25 are spaced circumferentially around the outer periphery of the sorting head 12, with the innermost edges of successive channels located progressively farther away from the common radial location of the outer edges of all coins for receiving and ejecting coins in order of increasing diameter. In the particular embodiment illustrated, the six channels 20-25 are positioned to eject successively dimes (channel 20), pennies (channel 21), nickels (channel 22), quarters (channel 23), Susan B. Anthony dollars (channel 24) and half-dollars (channel 25). The innermost edges of the exit channels 20-25 are positioned so that the inner edge of a coin of only one particular denomination can enter each channel; the coins of all other denominations reaching a given exit channel extend inwardly beyond the innermost edge of that particular channel so that those coins cannot enter the channel and, therefore, continue on to the next exit channel. 
     Typically, coin sorters operate by exerting pad pressure onto coins while those coins are within the exit channels of the coin sorter. Pad pressure is obtained because the exit channel is shallower than the thickness of the denomination corresponding to the exit channel. While in the exit channel, a coin under pad pressure is exposed to forces tending to maintain the radial position of the coin and urging the coin to move circumferentially along with the resilient pad. However, coin sorters have been designed such that the exit channel is deeper such that the coin moves freely through the exit channel while not being subjected to pad pressure. The present invention is applicable to either type of coin sorter arrangement. However, it is most useful in a coin sorter that exerts pad pressure on the coin which is more likely to cause the &#34;teetering&#34; effect described above. 
     Each exit channel 20-25 has a corresponding exit opening 20a-25a wherein the coin exits from the periphery of the sorting head 12. Although not shown, the coins then typically enter exit chutes outside the periphery of the sorting head 12 corresponding to the exit channels 20-25. Each exit channel 20-25 is also illustrated with a corresponding exit ramp 20b-25b. The exit ramp 20b bridges the lowermost surface 32 of the sorting head 12 with the exit channel 20 as the coin begins to enter the exit channel 20. In sorters where positive pressure is maintained, the pad 16 still maintains contact with the coin after it has passed the exit ramp 20b. In coin sorters which exert no pressure on the coin in the exit channel 20, the coin slowly is released from pad pressure as it moves along the exit ramp 20b. 
     Accordingly, in the present invention, each of the exit channels 20-25 has a slot 80-85 which provides additional clearance for the central portion of the coin within the exit channel 20-25. Any deviations in the central thickness of the coin due to curvature or features which extend above the periphery of the coin can now extend into the slots 80-85 such that the coin rides along the portions of the exit channels 20-25 outside of the slots 80-85. In essence, the coins ride only on the two rails formed on either side of the slots 80-85. 
     As the coins pass across sensors 90-95 located in the exit channels 20-25, the coins are much less prone to the teetering motion due to the slots 80-85. Thus, the sensors 90-95 sense a coin which is being guided smoothly. This enhances the accuracy of the sensors 90-95 whether their function is to count coins or discriminate between good coins and counterfeit coins. 
     The slots 80-85 are shown in more detail in FIGS. 3A-3E which are cross sections taken along line 3--3 in FIG. 2. FIGS. 3A-3E illustrate a variety of shapes of the slot 80 which can be utilized in exit channel 20. FIG. 3A illustrates a slot 80a which has a length approximately one half of the diameter of coin 100. Clearly, the width of the slot 80a may be much larger such that it is up to 90% of the diameter of coin 100. The slot 80a has a rectangular cross-section which accommodates a protruding portion 101 of the coin 100 as the coin is guided along the exit slot 20. Generally, the slot 80a has a depth equal to approximately the thickness of the coin and is centered within the exit channel 20. The slot 80a may also be configured with multiple, or stepped surfaces, such that one region of the slot is deeper than another region of the slot. 
     FIG. 3B is similar to FIG. 3A except slot 80b has a rounded cross-sectional shape which accommodates the protruding portion 101 of coin 100. 
     FIG. 3C likewise is similar to FIG. 3A except slot 80c has a triangular cross-section shape which accommodates the protruding portion 101 of coin 100. 
     FIG. 3D illustrates a wider slot 80d which is approximately 90% of the diameter of bent coin 102. The slot 80d has a curved cross-section profile similar to the slot 80b in FIG. 3B. However, due to the width of the slot 80d, a severely bent coin 102 can still proceed though the exit channel 20 without the bent coin 102 pressing deeply into the resilient surface 16. Because the bent coin 102 is contacting two points along the corners of the slot 80d, it is less likely to teeter than if only its center contacted the exit channel 20. Slot 80d is preferable since it allows clearance for a protruding middle portion of a coin, and also allows a bent coin 102 to pass as well. 
     FIG. 3E illustrates an alternative embodiment in which three slots 80e are placed into the exit channel 20. The center slot provides clearance for the protruding portion 101 of the coin 100. The outer two slots provide a clearance for the periphery of a bent coin, like the bent coin 102 in FIG. 3D if that bent coin 102 is flipped upside down with respect to the manner in which it is illustrated in FIG. 3D. 
     The coin sorter apparatus of the present invention has been specifically described with reference to the sorting head 12. The stationary sorting head 12 of the present invention, however, can take a variety of different forms. For example, the present invention is useful in a sorting head that utilizes channels with converging walls to guide the coins to the exit channels. Slots may be used in these exit channels of such a coin sorter. 
     Additionally, coin sorters may have sensors which are positioned upstream of the exit channels 20-25 near beveled surface 68 on FIG. 2. A slot may be placed near sensors in this region as well to inhibit any teetering which decreases the accuracy of the counting and/or discriminating. In summary, the slots are useful anywhere a sensor may be placed. 
     While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that it is not intended to limit the invention to the particular forms described, but, on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.