Abstract:
The present invention is a machine for dispensing articles, such as a vending machine, wherein the bottom article in a stack of articles is dispensed. To solve the problem of frictional resistance and excessive weight on the bottom article as it is being dispensed, the present invention provides a lifting mechanism to raise a portion of the stack of articles while the machine dispenses the bottom article. The lifting of the stack of articles above the bottom article relieves the weight of the stack from the bottom article, thereby reducing the frictional force as the machine slides the article out of a gate. In a preferred embodiment, a pair of lifting mechanisms operated by a common driving source cooperate to lift the portion of the stack of articles during the sliding operation and return the stack automatically once the bottom article has been dispensed.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to an automatic dispensing machine such as, for example, a vending machine, and more particularly to a dispensing machine that dispenses the lowermost article from a stack of articles stored in the machine. 
     2. Description of the Related Art 
     In some vending machines, it is a common practice to store the merchandise in a vertical column or stack one on top of the other. When a particular article is to be dispensed from the stack, a pusher mechanism moves the lowermost article from beneath the stack towards a dispensing port. If the articles are short and wide, like for example a compact disc cassette, the number of stacked articles on the lowermost article may be significantly high. The difficulty arises when the height of the stack of merchandise is such that the weight produces substantial friction forces between the lowermost article being dispensed and the surface on which it slides. This phenomena can cause both damage to the article during the dispensing process, as well as jamming of the machine. 
     SUMMARY OF THE INVENTION 
     The present invention includes a carrier that transports a stack of articles to a dispensing station. At the dispensing station, a portion of the stack of articles is lifted by a lifting mechanism that reduces the weight on the lowermost article to be dispensed. The lowermost article in the stack is then dispensed without the undue frictional load that otherwise would accompany the dispensing of the article if the full stack weight was resting on the lowermost article. In a preferred embodiment of the present invention, a pair of lift mechanisms cooperates to lift a portion of the stack of articles prior to the dispensing of the lowermost article. In the preferred embodiment, a pair of linkages driven by a single driving sources achieves the lifting function. The use of a single driving source removes the need for synchronization of multiple driving sources, resulting in a simpler operation. A sensor may be used to signal the disbursement of the article from the automated article dispenser, and the signal may be used as a trigger to return the lifting mechanism to an idle condition. In other words, once the sensor determines that the article has been dispensed from the machine, the lifting mechanism lowers the stack of articles until the time for another article to be dispensed, and the stack of merchandise is returned to a stored position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The exact nature of this invention, as well as its objects and advantages, will become readily apparent upon reference to the following detailed description when considered in conjunction with the accompanied drawings in which like reference numerals designate like parts throughout the figures thereof, and wherein: 
     FIG. 1 is an elevated perspective view of a preferred embodiment of the present invention; 
     FIG. 2 is a front view of the preferred embodiment of FIG. 1; 
     FIG. 3 is a side view in cut away along lines x—x of the preferred embodiment shown in FIG. 2; 
     FIG. 4 is an elevated perspective view of a preferred embodiment of a lifting mechanism of the present invention; 
     FIG. 5 is a front view of the lifting mechanism of FIG. 4; 
     FIG. 6 is a right side view of the lifting mechanism of FIG. 4; 
     FIG. 7 is a left side view of the lifting mechanism of FIG. 4; 
     FIG. 8 is a front view of the lifting mechanism of FIG. 4 cooperating with an article C shown partially in phantom; 
     FIG. 9 is a block diagram of a control device of the present invention; and 
     FIG. 10 is a flow chart of the present invention&#39;s operation. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description is provided to enable any person skilled in the art to make and use the invention, and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the general principles of the present invention have been defined herein specifically to provide a machine for dispensing articles from a stack. 
     Turning to FIG. 1, an elevated perspective view of an automated article dispensing machine is shown. A rectangular U-shaped base is constructed of side plates  1 R,  1 L, and base plate  2 , defining a space S. Projecting towards the interior of the base along the upper portions of side plates  1 R and  1 L are a pair of platforms  4 R,  4 L oriented substantially horizontal. The platforms  4 L and  4 R form a portion of the loading station D. There is a gap between the ends of the platforms  4 L and  4 R, and a pushing mechanism  14  reciprocates in the gap to dispense the lowermost article in a stack of articles on the loading station D. Just below the platforms  4 L,  4 R are a pair of guide plates  5 L,  5 R, each affixed to their respective side plates  1 L,  1 R. 
     A second set of guide plates  6 L,  6 R, are disposed slightly below the guide plates  5 R,  5 L and are mounted to their respective side plates  1 R,  1 L. There is a gap T between the guide plates  5 L and  5 R, and there is a gap U between the second set of guide plates  6 L and  6 R. A sliding mechanism  12  is disposed between the guide plates  5 L,  5 R at gap T, and a rack  16  of the sliding mechanism  12  is located in the gap U between guide plates  6 L and  6 R. In FIGS. 2 and 3, the sliding mechanism  12  can be seen more clearly. The sliding mechanism  12  includes a pushing mechanism  14  that pivots about pin  13 . The pushing mechanism  14  is biased by a spring (not shown) such that pushing mechanism  14  protrudes above the sliding mechanism  12 . The rack  16  is formed in the underside of the sliding mechanism  12  and engages a drive gear  15  which causes the sliding mechanism to be directed laterally in the forward and aft directions according to the direction of the drive gear  15 . 
     A driving motor  19  connected to a speed reducer  18  and shaft  17  drive the drive gear  15 . Hence, the drive motor  19  is responsible for the control over the sliding mechanism  12  in both the forward and rearward directions. The speed reducer  18  is mounted to the side plate  1 L via bracket  18 L. A U-shaped pipe  11  mounted to the base plate  2  serves to guide the flexible rack  16  mounted beneath the sliding mechanism  12 . A sensor F, shown in FIG. 3, detects when the sliding mechanism  12  advances to its forwardmost position. 
     The sensor F will transmit a signal to a microprocessor (not shown) for withdrawing the sliding mechanism  12  as discussed more fully below. Similarly, sensor B detects when the sliding mechanism  12  retreats to its furthest aftward position, and sends a signal indicating this condition to the microprocessor. On the front of the machine is a face plate  20  positioned just above the sliding mechanism  12 . 
     The face plate  20  is located immediately in front of the platforms  4 L,  4 R. The face plate  20  is fixed by bolts in a pair of elongated slots  21 L,  21 R on the side plates  1 L,  1 R, respectively. An opening, or gate G, defined by the platforms  4 L,  4 R and the face plate  20  is sized to permit the particular article to pass through when the pusher mechanism  12  provides the impetus to push the article C through the opening G. The height of the gate G is only slightly larger than the height of the article C. 
     A return prevention member  23  is provided to prevent the inadvertent withdrawal of the partially protruding article C back into the machine. The return prevention member  23  is secured to the face plate  20  by a fitting strip  22 , and partially overlays the gate G from above. The return prevention member  23  is preferably made of a soft and flexible material which will not likely damage the article, such as polyurethane, and includes downward facing projections  23 A,  23 B, and  23 C. The fitting strip  22  is secured to the face plate  20  using wing nuts  26 L and  26 R secured to bolts  24 L and  24 R, respectively, which project from the face plate  20  in a forward facing direction. 
     The fitting strip  22  is then placed over the return prevention member  23  in such a manner as to secure the return prevention member on the face plate  20 . The downward facing projections contact the article C as the article is passing through the gate G, and the downward facing projections  23 A,B,C are deformed thereby. The downward facing projections contact the article C as it begins to pass through the gate G and acts as a one-way valve that deters the article C from returning to the machine due to the resistance of the downward facing polyurethane projections in contact with the article C. In this manner, the return prevention board  23  prevents the article C from being inadvertently withdrawn back into the machine. 
     The upper portion  30  of the machine is the storing repository for the articles to be stacked. The upper portion is formed by side walls  30 L,  30 R and back wall  30 B forming a generally rectangular cross section. A removable front panel  31 , which may include in the observatory window for selecting or observing the articles, encloses the stored reservoir and leaves an opening along the upper portion  32 . Articles may be loaded through the opening  32  into the upper portion  30  with the front panel  31  removed, and the articles can be stacked on the platforms  4 L and  4 R on the loading mount D. 
     FIGS. 4-8 illustrate a preferred lifting mechanism of the present invention. A pair of lifting devices  41 L and  41 R cooperate to form the lifting device  40  of the present invention. Each lifting mechanism is affixed to its respective side walls  30 L,  30 R. The discussion below will refer primarily to the right hand side lifting mechanism  41 R which is symmetric in virtually all respects to the lifting mechanism on the left hand side  41 L. 
     A U-shaped support bracket  42 R is mounted to the right side wall  30 R. Supporting bracket  42 R includes perpendicular flanges  44 R and  45 R with respect to the base of the bracket  43 R. The base  43 R of the bracket  42 R includes a window  46 R through which a lifting mechanism will selectively protrude as provided more fully below. The window  46 R coincides with an opening OR on the side wall  30 R, the opening OR directly adjacent to the window  46 R and provides access to the articles C therein. The position of the opening OR and the window  46 R is preferably in a vertical displacement of approximately  4 - 6  articles C (see FIG. 3) when said articles are stacked on the loading platform D. 
     A first rod  47 R is disposed between the perpendicular flanges  44 R and  45 R. A lifting lever  48 R mounts to the rod  47 R and pivots thereabout. The lever comprises a longitudinal component and supporting legs  49 R and  50 R where supporting legs  49 R and  50 R are seated on the rod  47 R. The lever  48  also includes a second shaft  51 R connecting legs  49  and  50  opposite the longitudinal component. The cylinder  54 R having a rubber ring  53 R in a groove of a guide  52 R is located on shaft  51 R. Similarly, the cylinder  55 R including a rubber ring  57 R in the groove of a guide  56 R is located on shaft  51 R. The rubber rings  53 R,  57 R project through the opening  46 R of the side panel  30 R as shown in FIG.  5 . Further, it can be seen that if the lifting lever  48  is rotated clockwise in FIG. 5 due to a upward movement of bracket  60 R, the subsequent rotation of shaft  51 R about rod  47 R will cause the shaft and the rubber rings  53 R, 57 R to extend through the window  46 R in an upward direction. This condition is described more fully below. 
     Within the bracket  42 R is a slide plate  58 R formed of a base  59 R and flanges  60 R and  61 R forming a U-shaped cross section. Side flanges  60 R and  61 R include elongated slots  62 R and  63 R where a third shaft  65 R is disposed. A claw shaped member defined by open slots  66 R and  67 R are formed at the upper portion of the side flanges  60 R and  61 R. Open slots  66 R and  67 R are elongated in the horizontal direction and open towards the window  46 R. The open slot  66 R holds the guide groove  52 R of the cylinder  55 R. Similarly, the open slot  67 R holds the guide groove  56 R of the cylinder  55 R. Accordingly, when the slide plate  58 R is displaced in the vertical direction, the lever  48 R pivots about the rod  47 R causing the cylinder  67 R with rubber rings  57 R to rotate clockwise in FIG. 5 about rod  47 R through the window  46 R. As will be explained below, the protrusion of the cylinders  67 R and  67 L cooperate to lift the article housed in the mounting structure  30  through windows OR and OL. 
     As shown in FIGS. 5 and 6, an elongated slot  70 R is located in the bracket  42 R below the window  46 R. A pin  72 R located at the upper portion of link member  71 R slides freely in the vertical direction within the elongated slot  70 R, but is fixed rigidly to slide plate  58 R at base  59 R. At the lower end of the link member  71 R is a pin  75 R which connects the link member  71 R with a lever  74 R. The lever  74 R is rotatably connected to a fixed shaft  73  extending between the side plates  1 L and  1 R. Also connected to the shaft  73  is a V-shaped lever  76 . At one end of the V-shaped lever  76  is a cam follower  77  at the end of arm  76 A. The cam follower  77  is biased in contact with the eccentric cam  78  via a spring  84  mounted to a bracket  83 . The spring  84  is preferably selected such that the cam follower  77  exerts no force on the eccentric cam  78  when the distance between the cam follower  77  and the center of the cam is at a minimum. 
     The eccentric cam  78  is fixed on an output shaft  79 D of a speed reducer  79 . The speed reducer  79  in turn is connected to a drive motor  80 . The speed reducer  79  is fixed at the side plate  1 R by the bracket  85 . Mounted adjacent the arm  76 B of the V-shaped lever  76  is a pair of sensors  81 L,  81 U mounted substantially vertical by a bracket  82  which is secured to the base plate  2 . The sensor  81 U outputs a lift signal “U” when the V-shaped lever contacts the sensor  81 U, and the sensor  81 L outputs a release signal “L” when the V-shaped bracket at arm  76 B contacts the sensor  81 L. 
     As can be seen in FIGS. 2 and 3, a shaft  91  is mounted horizontally in side plates  1 L and  1 R. A lever  92  is pivotally mounted on the shaft  91  and rotates in a vertical plane. The length of the lever  92  is selected such that a portion of the lever protrudes above the guide plates  5 R immediately preceding the sliding mechanism  12  for a portion of the arc traced by the lever  92 . The rotation of the shaft  91  is controlled by a pair of levers  93 R and  93 L which are mounted on the outside of the side plates  1 R,  1 L on the shaft  91  (see FIG.  1 ). The lever  93 R has a pin  94 R which is captured in a elongated slot  97 R on bracket  95 R. Brackets  95 R,  95 L and guard plate  95 C cooperate to form a U-shaped formation mounted at side walls  1 R,  1 L, by shafts  96 R and  96 L protruding from the outer side walls  1 L,  1 R. 
     Element  99  (FIG. 3) is an elbow-shaped bracket connected to the driving lever  92 . A sensor  98  adjacent to the element  99  detects the position of the detecting element  95 . The driving lever  92  is biased in the clockwise direction as shown in FIG. 3 by the force of a spring  110 . A bracket BR is mounted in the side wall  1 R and mounts the sensor  98 . 
     FIG. 9 illustrates a schematic of a control device  100  associated with the present invention. Control device  100  comprises an interface  101  which receives the signals from sensors F, B,  81 U,  81 L and  98 , and the dispense signal P; as well as RAM  103  and ROM  104 , and an interface  105  which outputs a rotation and stop signal for the control circuit of the motors  19  and  80 . The control device  100  controls the actuating motors  19  and  80  according to the flow chart of the program stored in ROM  104  based on the signals from sensors F, B,  81 U,  81 L and  98 . 
     The operation of the unit is now explained. In a standby condition, the sliding mechanism  12  resides in its most retracted position (all the way to the right in FIG.  3 ). The pushing mechanism  14  is rotated outward such that it protrudes from the upper surface of the sliding mechanism  12 . The platforms  4 L and  4 R of the loading mount D support the stack of articles C. The cam follower  77  of the lifting devices  40  is in a position adjacent the narrowest width of the cam radius. In FIG. 6, the lever  74 R is rotated in the most clockwise position. Accordingly, the link member  71 R is in its lowest vertical condition and the slide plate  58 R is also in its lowest vertical position. In the standby condition, the cylinders  54 R and  55 R are also in its lower most position because the slide plate  58 R is in the bottom position. Thus, the lifting lever  48 R is in its most vertically rotated position and the rubber rings  53 R and  57 R on the cylinders  54 R and  55 R are in a position that retracts the rings from the opening OR on the side of the storage reservoir  33 . In this manner, the rubber rings  53 R and  57 R (as well as the rubber rings  53 L and  57 L) are not in contact with the article C stored in the reservoir  33 . Also, the lever  92  is rotated in its most clockwise condition by the force of the spring  110 , and the levers  93 L,  93 R are also rotated in their most clockwise rotation position as shown generally in FIG.  1 . The guard plate  95 C is located just in front of the gate G. In this position, the guard plate  95 C prevents access to the gate G and serves as a theft deterrent function. 
     The operation of the automatic disbursal of an article C will now be discussed with reference to the flow chart in FIG.  10 . In step  1  the machine is in the condition where a disposition signal is received for the automatic disbursal of an article C. Prior to receiving the disposition signal P, the apparatus remains in the standby condition described above. Upon receipt of a disposition signal P, in step  2  the rotation signal of the motor  80  is given through the interface  105 . The motor  80  receives the rotation signal and it initiates rotation. By the rotation of the motor  80 , the speed reducer  79  and the eccentric cam  78  is rotated. 
     By the rotation of the eccentric cam  78 , the contact with the eccentric cam  78  and the cam follower  77  causes the v-shaped lever  76  to rotate counter-clockwise as shown in FIG.  3 . Accordingly, the lever  74 R is rotated through the shaft  73  in the counter-clockwise direction. In FIG. 7, the lever  74 L rotates in the clockwise direction. The rotation of the respective levers  74 R,  74 L in turn cause the link members  71 R and  71 L to be translated upward on pins  75 R and  75 L. The link member  71 R pushes up the slide plate  58 R which in turn rotates lever  48 R inward towards the machine. The arms  49 R and  50 R rotate the shaft  51 R center about the shaft  47 R in FIG. 8 in the clockwise direction. This, in turn, causes the shaft  51 R to rotate from a lowest vertical position to a higher position shown in dotted lines on FIG.  8 . The rotation of shaft  51 R causes the rubber rings  53 R and  57 R to extend through the opening OR and contact the article C from the right hand side. Simultaneously, a rotation of shaft  51 L about shaft  47 L causes rubber rings  57 L and  53 L to protrude through the opening OL on the left hand side of the apparatus and contact the article C from the left hand side. Further rotation of the respective shafts  51 R,  51 L result in the cooperating rubber rings lifting the article C off of its adjacent article stacked below it. The two cooperating lift mechanisms  41 R and  41 L lift the retained article C, as well as the stack of articles above the article C, thereby reducing the total weight on the lower most article C to be dispensed. 
     The sensor  81 U detects that the lever  76 A of the V-shaped lever  76  has rotated accordingly and the signal U is output. In step  3 , the signal U is received. On receipt of the signal U in step  4 , the rotation of the motor  80  is stopped. When the motor  80  is stopped, the cooperating lift mechanisms  41 R and  41 L maintain their condition in the above-referenced state. In step  5 , the initiation of the rotation of motor  19  occurs. Rotation of motor  19  causes the drive gear  15  to rotate slowly in the counterclockwise direction as shown in FIG.  3 . The sliding mechanism  12  translates from right to left via the rack  16  cooperating with the drive gear  15 . This process causes the pushing mechanism  14  to contact the back wall of the lower most article C in the stack and advance the article towards the front of the machine. This is shown with dotted lines on FIG.  3 . The pushing mechanism  12  advances the stack of articles C not retained by the cooperating lifting mechanisms  41 L,  41 R, but the height of the gate G permits only the advancement of the lower most article C through the gate G. The pushing mechanism  12  continues to progress until about one-half of the length of the lowermost article C protrudes through the gate G. The weight on the lowermost article C is significantly reduced by the retention of the majority of the stack by the cooperating lifting devices  41 L,  41 R. Accordingly, the frictional force between the platforms  4 A,  4 B and the lower most article C, as well as the frictional force between the lowermost article C and the article immediately above the lowermost article C, is significantly reduced. Therefore, the amount of force needed to eject the lower most article C is reduced. 
     As the sliding mechanism  12  advances to a most forward position, the lever  92  is rotated as shown in FIG. 3 in the counter-clockwise direction. This rotation also causes levers  93 R and  93 L to rotate in the counter-clockwise direction through shaft  91 . Pins  94 R,  94 L rotate accordingly in a counter-clockwise arc. The combination of this circular arc motion and the cam grooves  94 R,  94 L rotate the guard plate  95 C about the shafts  96 R and  96 L in FIGS. 1 and 3, in the clockwise or upward direction. This rotation causes the guard plate  95 C to move away from the opening of gate G. 
     The evacuation of the guard plate allows the article C being pushed by the pushing mechanism  14  to protrude past the guard plate  95 C. The sensor  98  further detects the rotation of the linking lever  99  cooperating with the lever  92 . The sensor F determines that the pushing mechanism  14  has reached the most advanced position shown in dotted lines on FIG.  3 . Step  6  receives the signal from sensor F that the pushing mechanism  14  has reached the most forward position. This leads to step  7  where the rotation of motor  19  is halted. Next, motor  19  is reversed and is driven at step  8 . The drive gear  15  rotates in the counter-clockwise direction withdrawing the sliding mechanism  12  at the rack  16 . This sequence is continued until the sliding mechanism  12  returns to the position shown in solid lines in FIG.  3 . Sensor B detects that the sliding mechanism  12  has returned to its original position and outputs signal B. In step  9 , the output of sensor B is received. 
     In step  10 , upon receipt of signal B in step  9 , the rotation of motor  19  is stopped. With the slider mechanism  12  advanced to the farthest rearward position, the contact between the lever  92  and the sliding mechanism  12  is discontinued. The release of the lever  92  permits the lever to be rotated by the spring  110  in the clockwise direction. Shafts  96 R,  96 L rotate in the counter-clockwise direction, which, in turn, rotates the guard plate  95  downward. The article C which has protruded through the gate G stops the rotation of the guard plate  95 C. The driving lever  92  thus cannot be rotated to the position shown in the continuous line of FIG.  3 . The elbow-shaped member  99  is positioned away from the detection of the sensor  98 . In step  11 , the receipt of the disposition completion signal K from the sensor  98  is accomplished. The article C can now be withdrawn by a user through the gate G. 
     The next lowermost article C is located over the platforms  4 A,  4 B after the lower most article C is withdrawn. The guard plate  95  is no longer supported when the article C is withdrawn from the gate G. The guard plate  95  is therefore rotated further by the motion of the driving lever  92  with the spring  110  in the counterclockwise direction. The guard plate  95  completes the rotation to the position in front of the gate G as shown in the continuous line position of FIG.  3 . By this, the elbow-shaped member  99  contacts the sensor  98  which outputs a disposition completion signal K. In step  12  the disposition signal K is received and rotation of motor  80  is initiated. The rotation of motor  80  causes the rotation of the eccentric cam  78  with the cam follower  77  to return to the original position. This causes the shaft  73 , the lever  74 , the pin  72 R, and the link  71 R to be returned to the lower most position. The lever  76  is rotated by the spring  84  as shown in FIG. 3 to the clockwise most position. As for the lift mechanism  41 R, the slide plate  58 R is returned to the lower most position by the action of the link member  71 R. 
     In step  13 , the signal from sensor  81 L is received. If the signal L is received, step  14  stops the motor  80  and the machine has returned to the standby condition prior to step  1 . This condition is maintained until the disposition signal P is received and the procedure is repeated as outlined above. 
     There can be many alterations to the above discussed embodiments without deviating from the present invention. For example, a set of rollers or a rotating belt can be used to deliver the articles to the loading station D instead of platforms  4 A,B. Similarly, a forklift apparatus can be substituted for the lifting mechanism just discussed to lift a portion of the stack of articles by inserting a fork into the stack. In this embodiment, it is not necessary to have a complimentary lifting component on both sides of the machine since a forklift can achieve the objective from a single side. Finally, the dispensing of the article may be sensed by an optical sensor to determine the completion of the operation and initiate the return to standby  10  condition. Those skilled in the art will appreciate that additional various adaptations and modifications of the just-described preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.