Abstract:
The disclosed invention is a dispensing apparatus and method for dispensing product from a vending machine. The invention employs a motor for bi-directionally rotating a dispenser bucket between two bumpers which physically obstruct and limit the rotational travel, a motor controller for monitoring the current drawn by the motor and signals received from a product vend detection sensor. The motor controller uses monitored information to control the rotational direction and stopping positions of the dispenser bucket. The invention eliminates the need for timing cams and switches and eliminates the need for anti-theft device to prevent product theft from the dispenser bucket.

Description:
TECHNICAL FIELD OF THE INVENTION 
   This invention relates in general to the field of vending machines, and more particularly, to a system and method for controlling a product dispensing mechanism in a vending machine. 
   BACKGROUND OF THE INVENTION 
   Vending machines are widely used to dispense beverages, food, and other perishable and nonperishable goods. Many vending machines, particularly those that dispense beverages, have column walls or partitions between which the individual bottles or cans and the like are stacked in a vertical column. At the bottom of any given stack is a dispensing mechanism that dispenses a selected bottle or can after receipt of payment by the vending machine. One type of dispensing mechanism is known as a bucket type mechanism. Generally, bucket type dispensing mechanisms have a partial cylindrical shape that accommodates within it a row of bottles or cans that is positioned laterally relative to the length of the cylinder. A portion of the circumference of the cylinder, however, is open, therefore allowing the bottles or cans to enter into, and exit from the bucket at various stages of the vend cycle. A motor or other rotational means rotates the bucket about its axis. A gauging means, appropriately located below the bucket, is used to create steps of various sizes, which generally correspond to the length of the individual cans or bottles being dispensed. The opening in the bucket is of a sufficient size so that when rotated to a certain point, the first bottle or can is free to fall out of the bucket dispenser and into the product chute through which it is dispensed to the customer, while the next to vend bottle or can remains in the bucket, held by the next gauging step. During subsequent vends, the bucket rotates to expose the next bottle or can, allowing it to fall. After all products have been dispensed from the bucket, the dispensing mechanism continues through the reload phase of the vend cycle whereby the next row of products enter the bucket in preparation for the subsequent vending cycles. The positions at which the rotation of the bucket stops during the vending cycles are generally controlled by a switch that engages a timing cam mounted on the motor shaft. The switch signals a motor controller to stop the motor at predetermined positions. The timing cam is adjustable to vary the number of stopping positions in order to accommodate the variable number of products in a row. Thus, products are initially seated within the bucket, but are unseated and dispensed as the bucket rotates. 
   Typically, the gauging means must be reconfigured to accommodate the variability of the diameter of the product being dispensed. In this case, the gauging means is created by a series of steps on the lower edge of the partition, and a series of steps on the vending edge of the bucket. The opposite edge of the bucket is straight. In this case, this edge is used to lower a row of products into the bucket during the reload phase of the vend cycle. This is significant in that in most conventional bucket type dispensing mechanisms, the motor rotates the bucket in a constant direction 360° about its axis, therefore the edge of the bucket that is used to lower the product into the bucket during the reload phase of the vend cycle is also used to gauge product out of the bucket during the dispensing phase of the vend cycle. Therefore, if the gauging edge of the bucket is stepped to help control the dispensing of product, it can cause undesirable conditions during the reload phase. Namely, when a row of products is being lowered into the bucket, and if the bucket edge being used to lower these products is stepped, the tendency is that the individual products within a product row enter the bucket at different times. This causes the uniformity of the entire column of product to shift relative to itself front to back. This shifting can result in a number of problems that ultimately can lead to undesirable operation of the vending mechanism. To avoid this undesirable condition, the movement of the bucket can be controlled in a way that results in an oscillating movement, thereby allowing one “straight” edge of the bucket to control the lowering of product into the bucket during the reload phase of the vend cycle, and the other “stepped” edge of the bucket to function as a gauging mean in the dispensing phase of the vend cycle. In the past, this type of oscillating motion has been achieved by use of complex “crank and link” mechanisms that couple the motor to the bucket. 
   Vending machines of this type are vulnerable to various methods to attempt to obtain product without paying. After a product has been dispensed, and additional products remain in the bucket, the opening that was created to free the first product dispensed remains. If the next product in the bucket is caused to move forward into the space previously occupied by the first product, it will be unseated and drop through the opening onto the product chute through which it is dispensed to, in this case, a thief. This forward movement of product can be achieved by rocking or tipping the vending machine, or by some individual reaching their arm, or some device such as a wire, through the product chute. To combat this type of theft, existing vending machines having bucket type dispensing mechanisms have incorporated additional “anti-theft” clips or devices. These devices generally hang down, or spring up in the bucket to create a barrier or obstacle that prevents or discourages product from moving forward in the bucket and thus not allowing the product to drop through the opening through which the first, or previously vended, product passed. Although these clips have added additional cost and complexity to each vending machine, they have not succeeded in eliminating this type of theft. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide an improved method and apparatus for product dispensing in a vending machine. 
   Another object of the present invention is to provide such a method and apparatus that does not require adjustment in order to accommodate and dispense products of various diameters. 
   Another object of the present invention is to provide such a method and apparatus that does not require timing cams and switches to control the stopping positions of the product dispensing mechanism. 
   Another object of the present invention is to provide such a method and apparatus that utilizes a “bucket” type dispensing element that is oscillated without the need of a crank and link mechanism. 
   A further object of the present invention is to provide such a method and apparatus that prevents products from being inappropriately dislodged when the vending machine is rocked or tipped, or pulled forward by other means, without the employment of additional “anti-theft” devices. 
   Thus, the present invention achieves these objects in a method and apparatus for product dispensing. The apparatus includes a motor driven product dispenser having a gauging means that allows multiple products to sequentially be freed one at a time in accordance with the amount of rotation that the product dispenser travels, a motor controller used to control the product dispenser drive motor, a product delivery chute located below the product dispenser for receiving product as they are freed from the product dispenser and transporting them to a product delivery hopper where they are presented to the consumer, a product vend sensor mounted to the delivery chute to detect when a product has been freed from the product dispenser and thereby signal the motor controller to stop rotation of the motor before additional products are freed. Thus, the present invention eliminates the need to adjust the gauging elements of the product dispensing mechanism to accommodate products of various diameters. 
   The invention also includes a set of bumper stops that physically limit the rotation of the product dispenser motor, the motor being bi-directionally operated by the motor controller, and the motor controller having the capability to monitor the current drawn by the motor thereby permitting the controller to recognize when the dispenser has reached predetermined maximum clockwise and counterclockwise rotation stop positions of the motor in accordance with predetermined programmed functions contained therein. The control functions, in conjunction with the ability to detect when a product has been freed from the product dispensing mechanism via input signals from the product vend sensor, eliminate the need for the timing cams and switches that are normally used by prior product dispensing systems. Also, the resulting oscillating movement of the product dispenser is achieved without the use of a traditional crank and link mechanism. 
   The motor controller of the present invention also includes programmed functions that cause the motor to run in a reverse direction after stopping momentarily upon receiving a signal from the product vend sensor that a product has been freed, thereby closing off the opening in the product dispenser through which the recently vended product passed. The duration of this reverse directional rotation may be determined by the motor controller logic such that it is substantially equal to the time that the motor rotated in the original direction in order to move from a “standby” position to the position that allowed the product to pass through. The possibility of products being inappropriately dislodged from the product dispenser in the event that the vending machine is rocked or tipped or pulled forward by other means is eliminated. Thus, there is no need or desire to install additional anti-theft devices. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein: 
       FIG. 1  is an interior view illustrating a vending machine incorporating the disclosed dispensing assembly; 
       FIG. 2  illustrates the bucket type dispenser removed from the vending machine; 
       FIG. 3  is a perspective front view of a dispensing assembly according to the present disclosure removed from a vending machine; 
       FIGS. 4   a – 4   h  are front views of a dispensing assembly according to the present disclosure at different rotational orientations; 
       FIG. 5  is a perspective view of a motor assembly mounted on a front panel of a vending machine; and 
       FIG. 6  is a view of components of a dispensing assembly according to the present disclosure. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Shown in  FIG. 1  is the interior of a vending machine having a housing  101  and a door  102  pivotally coupled to the housing. Within the housing, products  108 , such as beverages, are stored vertically in channels  106  formed between successive partitions  104 . Beverages are typically positioned laterally within the channel and stacked on top of one another to form one or more vertical columns as shown in  FIG. 1 . A rear plate  322  ( FIG. 3 ) extends across behind the rear side of the partitions  104  ( FIG. 1 ), and a front plate  122  ( FIGS. 1 and 5 ) extends across the front side of at least a lower portion of the partitions. A product dispensing chute  130  is positioned below the channel  106  to receive products  108  that are dispensed by the dispensing assembly and to deliver them to a location at which they can be retrieved by a customer through an aperture  132  in the vending machine door. 
   As shown in  FIGS. 2–6 , a dispensing assembly  600  ( FIG. 6 ) is also included for dispensing the products  108  after receipt of payment by the vending machine. As shown in  FIG. 3 , the dispensing assembly includes a dispenser  305  that is positioned substantially horizontally at the bottom of the channel  106  and between partitions  104 , and extends laterally along the channel. The dispenser may extend substantially along the length of the channel, or along the portion of the channel in which products are stacked. The dispenser  305  is mounted to front and rear plates so that it is rotatable about a central axis x—x ( FIG. 2 ). This may be accomplished by any suitable means, such as by shafts  218  and  216  or the like extending through apertures in each of the front and rear panels respectively. 
   The dispenser has a “bucket” type configuration in that, when rotationally oriented as shown in  FIG. 4   a,  it is capable of receiving and holding within it one or more products. This bucket type dispenser has an open portion through which it can receive one or more products, and through which it can dispense or deliver the product when the open portion is facing substantially downward, as shown in  FIGS. 4   c  and  4   d  and as described more fully below. The dispenser has a first edge  236  that is substantially straight. This straight edge is used to control product as they are received into the dispenser from the channels  106  by maintaining the alignment of those product in a single uniform row. The dispenser also has a second edge  237  that has a series of steps that are used to create a gauging means whereby products received into the dispenser can be individually dispensed depending on the amount of rotation induced upon the dispenser by the motor assembly  500  as described below. According to one embodiment, the dispenser is substantially cylindrical in overall shape, but other configurations are also possible. 
   The dispensing assembly  600  ( FIG. 6 ) also includes a motor assembly  500  ( FIG. 5 ) including a motor  505  and a motor controller  150  ( FIG. 1 ) for rotating and controlling the rotational position of the dispenser as will be described further below. The motor assembly is fixedly secured to the vending machine, and in one embodiment is mounted on a front side  502  of the front panel  122 , and rigidly coupled to the dispenser  305  by a coupler cam  420  ( FIGS. 5 and 6 ). A set of bumpers  425  and  426  is formed into the front panel, and is positioned so that it will prevent rotation of the coupling cam past predetermined positions as will be described further below. 
   The motor controller may be programmed to a value that corresponds to the number of products received by the dispenser as previously described. For example, if each row of products  108  stored in channel  106  consists of two beverage containers, then the programmable value of the controller must be set at “2.” In the case that each row of products consists of four beverage containers, the programmable value of the controller must be set to “4.” The controller also has the ability to keep track of the number of products that have been dispensed during a given vend cycle, and thus knows when the dispenser is empty, thereby allowing the dispenser to continue through a reload cycle in order to prepare the next row of products for subsequent dispensing. 
   The dispensing assembly further includes a gate  430  ( FIGS. 4 and 6 ) that extends substantially along the length of the dispenser and prevents products  108   a  from dropping into the dispenser before reloading of the dispenser is desired, as shown in  FIGS. 4   a–e.  The gate is mounted to the front and rear plates by a pair of pivot shafts  640  ( FIG. 6 ) incorporated into the gate, so that it is pivotable about an axis z—z. Attached to the gate is a gate link  435  ( FIGS. 4 and 6 ) that is preferably positioned on the front side of the front panel and pivotably coupled to the gate by a pivot pin  602  or the like so that it is movable between a first position illustrated in  FIG. 4   a  wherein the gate prevents reloading of the dispenser, and a second position illustrated in  FIG. 4   f  wherein the gate does not obstruct products from moving downward within the channel, and thereby allows loading of the dispenser. The pivot pin  602  extends through an aperture  514  ( FIG. 5 ) in the front panel  122  ( FIG. 5 ). Preferably, the aperture  514  is configured so as to guide movement of the gate between the first and second positions in response to movement of the gate link between first and second positions that are described below. 
   In one embodiment, a spring  606  ( FIG. 6 ) or other resistive force is exerted on the gate link to bias the gate link to return to the gate to the first position. 
   The operation of the dispensing assembly are described below in greater detail with reference to  FIGS. 4   a – 4   h.    FIGS. 4   a – 4   h  illustrate the position of several components of the dispensing assembly at different points during the process of dispensing a row of products. Although the front panel is not shown, it is to be understood that the components of the dispensing assembly are positioned relative to the front panel as described above.  FIG. 4   a  illustrates the “home” position of the dispenser, which is where the dispenser remains when the system is idle, or in the stand-by state. As shown, the dispenser is positioned so that its open is facing sufficiently upward so that in this case it will securely hold the row of two products  109  and  110  and so that it is substantially unexposed to the product chute below. The gate and gate link are in their first position in which the gate  430  prevents products from moving downwardly to reload the dispenser. 
   When the vending machine determines that sufficient payment has been received, and a selection has been made, the process of dispensing a product begins. Controller  150  activates the motor  505  to begin rotating clockwise to thereby also rotate the dispenser and coupling cam  420  clockwise as shown in  FIG. 4   b.  As the motor continues to rotate clockwise, the open side of the dispenser becomes oriented such that it is facing significantly downward, allowing the front product  109  to drop out of the dispenser and into the delivery chute  130  ( FIG. 1 ), while allowing the rear product  110  to remain in the dispenser, as shown in  FIG. 4   c.  At this point, the motor controller  150  receives a vend-completed signal from a product vend detector  135  ( FIG. 1 ). Upon receiving this signal, the motor controller will stop the rotation of the motor, and reverse its direction. The motor then rotates counterclockwise until the dispenser returns to the home position as identified by  4   a  earlier. At the next vend cycle, the motor again rotates the dispenser, in the clockwise direction as shown in  FIG. 4   b,  as controlled by the motor controller. As the motor continues to rotate clockwise, the open side of the dispenser becomes orientated such that it is facing significantly downward, allowing the rear product  110  to drop out of the dispenser and into the delivery chute, as shown in  FIG. 4   d.  At this time, the motor continues to rotate in the clockwise direction until the coupling cam  420  contacts the bumper  425  as shown in  FIG. 4   e.  At this point the motor stops and reverses direction. The motor, now rotating in the counterclockwise direction, continues to rotate until the coupling cam engages the gate link, and causes it to pivot the gate  430  counterclockwise about its pivot pin  602 , thereby causing the gate link  435  to move between the first position in which it prevents reloading of the dispenser and the second position shown in  FIG. 4   f  in which it does not rest against a product, allowing products to drop downwardly, until reaching the outer circumference of the dispenser. As the motor continues to rotate counterclockwise, the next row of products  108   a  is gradually lowered into the dispenser bucket. As the row of products lowers into the dispenser, the gate, now under spring tension, follows until it reaches the first position in which it prevents the next row of products  108   b  from lowering beyond a predetermined holding level at which it will not come into contact with the dispenser and therefore will not reload the dispenser when the open side returns to a position facing upwards ( FIG. 4   g ). 
   The motor, dispenser, and coupling cam continue to rotate counterclockwise until the coupling cam contacts the bumper  426  ( FIG. 4   h ), and at this point the motor stops and reverses direction, moving clockwise for a predetermined amount of time until the “home” or standby position is reached. At this point, the motor stops and waits for the next signal from the motor controller to begin another vend cycle. 
   As indicated above, the motor assembly includes a reversible motor  505  and a controller  150  for controlling the rotational direction and position of the dispenser. The controller is electrically coupled to the motor and also monitors the current drawn by the motor. As also indicated above, by interfering with rotational movement of the coupling cam, the bumper physically prevents counterclockwise rotation of the dispenser beyond a predetermined maximum counterclockwise rotation position ( FIG. 4   h ), and clockwise rotation of the dispenser beyond the predetermined maximum clockwise dispensing position shown in  FIG. 4   e.  As the motor tries to rotate further clockwise beyond the position shown in  FIG. 4   e,  it will draw more current, which is sensed by the controller. When the current drawn reaches, or exceeds a predetermined maximum level, for a predetermined amount of time, which in one example may be a maximum of 500 milliamps at 24 volts DC for 500 milliseconds, the controller directs the motor to reverse direction and to rotate counterclockwise. 
   The motor will continue to drive counterclockwise rotation of the dispenser and coupling cam until it reaches a point at which the coupling cam contacts the other bumper as shown in  FIG. 4   h.  As the motor continues to try to drive counterclockwise rotation against the bumper, it again will draw increasingly more current, which will be sensed by the controller. When current draw reaches, or exceeds the predetermined maximum level for the predetermined amount of time, the controller directs the motor to stop rotation. At this point, the motor reverses direction and rotates clockwise for the predetermined time period as previously described. At this point reloading has been completed, and the dispenser has returned to its home position. The dispenser will remain in this home position until further dispensing of products is desired. Thus, the motor assembly is able to easily and efficiently control the rotational direction and position of the dispenser, and ensure that its home position is one in which the open portion of the dispenser is substantially unexposed to the product chute. Further, by using a controller to monitor current and to keep track of the number of vends in a given vend cycle, mechanical switches, timing cams and other mechanical linkages are avoided, reducing the overall complexity of the system. 
   The procedure described above presumes that reloading of the dispenser is required following dispensing of two products, as is true under circumstances where two products are held by the dispenser at a given time. Many dispensers, however, can accommodate one, two, three or more products within the dispenser at one time. It should therefore be understood that variations to the sequences and description above are easily accomplished to accommodate these variations in product numbers. 
   The vending machine includes a product vend detector that senses when product vending has occurred and signals the motor controller accordingly. This detector may be a vibration sensor attached to the product chute, an optical sensor mounted below the product dispenser, or another similar device. 
   Although the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims.