Patent Publication Number: US-7584963-B2

Title: Pre-shuffler for a playing card shuffling machine

Description:
FIELD OF THE INVENTION 
   This invention relates to playing card shufflers and, in particular, to a device for loading cards into a shuffler. 
   BACKGROUND 
   Many types of playing card shufflers are known. One type of known shuffler includes a rotatable wheel having slots, where the wheel is rotated by a stepper motor. One or more decks of cards are placed into an input tray, and rollers forward cards into selected slots in the wheel. A microprocessor controls the stepper motor to align a selected slot with the card path. After the cards are loaded into the wheel, the microprocessor then controls the stepper motor to align randomly selected slots of the wheel with an output mechanism that discharges the cards from the slots into an output tray. The cards in the output tray may be dealt to the players as the cards are output from the wheel, or the dealer may wait until the entire contents of the wheel are discharged and then place the shuffled cards into a shoe for dealing to the players. 
   Another common shuffler randomly removes cards from a vertical stack of cards and places the removed cards in a separate stack. The stacks are then repeatedly combined and separated until the cards are shuffled. Another form of shuffler uses a vertical rack of compartments and places the cards into randomly selected compartments. 
   Additional shufflers are known. Examples of shufflers are described in U.S. patent application Ser. Nos. 10/009,411; 10/256,639; and 10/256,880, all by Ernst Blaha and Peter Krenn; and U.S. Pat. Nos. 6,267,248; 6,149,154; 5,695,189; 6,139,014; 6,068,258; 6,325,373; 6,019,368; and 4,586,712. These U.S. applications and patents are incorporated herein by reference. 
   In these various automatic shufflers, shuffling may not be truly random since the order of cards placed in the shuffler may have some effect on the final order of the shuffled cards. What is needed is a technique for further randomizing the cards output by an automatic card shuffler. 
   SUMMARY 
   In one embodiment, the invention comprises a pre-shuffler that receives a quantity of cards to be shuffled, such as nine decks of cards. Many types of games use multiple decks of cards to deter card counting, such as blackjack, baccarat, punto blanco, and derivatives of such games. 
   One embodiment of the pre-shuffler includes a horizontal moveable box having, for example, nine compartments with vertical walls for separating the cards to be shuffled into groups. Cards are placed into all or some of the compartments in the box, and a shuffling sequence is then commenced. 
   A stepper motor moves the box containing the cards so that the cards in the first compartment are deposited into an input tray of a main card shuffler. The main shuffler then forwards the cards from the input tray one by one, via rollers, to selected compartments in the main shuffler. Any form of main shuffler may be used including those using wheels, a vertical rack of compartments, or vertical stacks of cards, as previously described. The process is then continued for each group of cards in the pre-shuffler until all cards are in the main shuffler. The main shuffler then shuffles (randomizes) the cards in a normal fashion. 
   In one embodiment, the top card in a group of cards deposited by the pre-shuffler into the input tray of the main shuffler was the card adjacent the next compartment in the pre-shuffler, and this top card is the first of the group to be forwarded into the main shuffler. This changes the order of the cards forwarded into the main shuffler as compared to the prior art process of directly placing a stack of all the cards to be shuffled into the main shuffler. 
   In one embodiment, the main shuffler is a wheel having slots (card receptacles). All cards to be shuffled are inserted into the slots in any sequence, with any number of cards placed into each slot. The main shuffler then performs a randomizing procedure on the cards by, for example, randomly selecting a slot and rotating the wheel so that the randomly selected slot is aligned with an output path. The cards are then output from the slot to an output tray. A next slot is then randomly selected, and the cards output from the slot are then placed on top of or underneath the cards that have previously been ejected. When all or a portion of the cards in the main shuffler have been ejected, the dealer may then deal the shuffled cards. The cards output from the main shuffler are in a more random order than had the cards not been pre-shuffled by the pre-shuffler. 
   In one embodiment, the stack of shuffled cards is removed from the shuffler and placed in a conventional dealing shoe for dealing to the players. 
   The pre-shuffler or main shuffler may also be equipped with a playing card reader to detect the rank and suit of each card forwarded to the main shuffler. This may be used to verify that no cards have been removed or added. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
       FIG. 1  is a side view of one embodiment of the pre-shuffler and main shuffler. 
   

   DETAILED DESCRIPTION 
     FIG. 1  illustrates a playing card shuffler  10  comprising, in combination, a pre-shuffler  12  and a main shuffler  14 . 
   The pre-shuffler  12  includes a horizontal support platform  16  connected to the main shuffler  14  by a hinge  18 . Platform  16  is supported in its horizontal position by a tab  20 , extending from the bottom of platform  16 , resting on a tab support  22 , forming part of the main shuffler  14 . The hinge allows the pre-shuffler  12  to be lifted out of its position shown in  FIG. 1  so that the main shuffler  14  may be used in its conventional manner or to gain access to parts for maintenance. 
   A card input box  24  is supported by platform  16  so that box  24  may slide along platform  16 . The bottom of box  24  includes a rack having a linear array of teeth  26  that engage a pinion  28  rotated by a conventional stepper motor (obscured by pinion  28 ). The stepper motor is controlled by a conventional motor control circuit that counts the number of pulses applied to the stepper motor to determine the angular rotation of the stepper motor axle. Such stepper motors and their controls are commercially available and need not be described. Accordingly, the card input box  24  is movable horizontally along platform  16 . 
   Box  24  includes vertical walls  30 , forming card compartments within box  24 . In the embodiment of  FIG. 1 , there are eight vertical walls  30  to form nine card compartments in box  24 . Any number of compartments within box  24  provides a degree of pre-shuffling. For example, the number of compartments may be five or greater. Each compartment may hold 52 cards or any other number of cards. 
   After the dealer has determined that the cards in a game need to be shuffled, the dealer forms a stack of the cards. Generally, there are nine or less card decks used in conventional casino card games, such as blackjack. The dealer then separates the large stack of cards into nine or less groups and places these groups in any order within the compartments in box  24 . In one embodiment, the dealer simply places the cards in the compartments in the order of the unshuffled stack of cards. 
   The cards are now ready to be applied to the main shuffler  14  for complete shuffling. The stepper motor controlling pinion  28  is rotated to align the first compartment of the box  24  with an opening  32  in platform  16 . The walls  30  in box  24  are supported by sidewalls (not shown) of box  24 , and box  24  has no bottom. Thus, the cards  36  slide along the top surface of platform  16 . When a group of cards (e.g., group  38 ) is aligned over opening  32 , the group of cards falls into an input tray  40  of the main shuffler  14 . Although any type of main shuffler  14  may be used, the operation of one type of shuffler  14  is described below for completeness. 
   Once the cards in a compartment have fallen through opening  32  and into the input tray  40 , the cards are supported by a wedge  42 . A cam  44  is rotated to move wedge  42  so that the top card in the group is in contact with rubber roller  48 . Pulley  50  is then rotated such that band  52  rotates roller  48  in a counterclockwise direction to forward the top card in the group of cards to pinch rollers  54  and  55 , also driven by band  52 . 
   This top card is then further forwarded by downstream rollers and to a compartment  60  in rotatable wheel  62 . Wheel  62  is then rotated to align a different wheel compartment with the input card path. To rotate wheel  62 , a stepper motor  70  rotates a pinion  72  that meshes with gears  74  on the periphery of the wheel  62  to align the selected compartment with the input tray  40 . A microprocessor keeps track of the compartments filled and may control the voltage polarity to the stepper motor  70  to rotate the wheel  62  in either direction depending upon the most efficient direction to align a chosen compartment with the input path. The wheel compartments may be filled in sequence or at random. 
   This process of forwarding each of the cards in the input tray  40  one by one is continued until all the cards in the input tray  40  are loaded into selected wheel compartments. As each card is being loaded, a cam  62  pivots a pusher arm  64  to push each card completely into a compartment. 
   A sensor  68  senses each card forwarded past the sensor to detect when the card has completely passed the input portion and has entered a wheel compartment. Sensor  68  may be an optical sensor that simply detects that light has been blocked by a card. After a card has passed sensor  68 , the pusher arm  64  is triggered. If light has not been blocked by a card for a predetermined time, it is assumed that there are no further cards in the input tray  40 , and a next group of cards must be delivered by the pre-shuffler  12 . A microprocessor detects the sensor signal and controls the various stepper motors and other events in accordance with a program stored in a memory. 
   The stepper motor that rotates pinion  28  in the pre-shuffler  12  is energized to move the box  24  so that the next group of cards is aligned with opening  32  and drops through onto wedge  42 . The process of transporting the cards one by one from the input tray  40  into selected compartments of wheel  62  is then performed. 
   Note that the rightmost card in the first group of cards  38  that is adjacent the second group of cards  80  in box  24  is the first card of the group to be forwarded to a compartment in wheel  62 . The separation into card groups by the pre-shuffler effectively flips the order of each group of cards in box  24  around to provide a degree of pre-shuffling before the cards even enter wheel  62 . Thus, the cards are pre-shuffled even before being deposited into the wheel compartments. 
   Once all the cards in the pre-shuffler  12  have been loaded into wheel  62 , a microprocessor determines the random order of compartments to align with the output portion  84  of the main shuffler  14 . When a compartment is aligned with output rollers  86 , a cam  88  is rotated to cause a pusher arm  90  to pivot and push out the entire group of cards  92  in a compartment to pinch rollers  86 . Rollers  86 , being rotated by pulley  94 , forward the group of cards to an output tray  100  of the shuffler  14 . 
   The cards  98  already in the output tray  100  are lifted up by cams  102  and  104 , driven by pulley  94 . The upward-moving cards  98  pivot traps  106  in an upward direction until traps  106  fall back into place in the position shown in  FIG. 1 . As cams  102  and  104  are then removed from the stack of cards  98 , the stack of cards then rests on the top of traps  106 , leaving an opening for a new group of cards  92  to be inserted beneath the stack. 
   This output process is then repeated for all wheel compartments until all the cards have been placed in the output tray  100 . 
   The dealer or other operator may then remove the stack of cards and put them in a conventional dealing shoe for dealing to the players. In another embodiment, each group of cards output from a compartment is deposited in an output shoe for the dealer to deal those cards. 
   Further pre-shuffling may be performed by the stepper motor rotating pinion  28  to randomly align a group of the cards in the pre-shuffler with opening  32 . Opening  32  may include a shutter for only opening when the chosen group is aligned with the opening  32 . Other ways of randomizing the order of the groups of cards deposited into the main shuffler  14  are also envisioned. One embodiment may include a pusher for pushing a selected group of cards through opening  32  when that randomly selected group of cards is aligned with opening  32 . 
   The pre-shuffler portion  12  may be connected to any type of shuffler and can be easily modified to adapt to the input trays of all types of shufflers. 
   Accordingly, the pre-shuffler increases the randomness of the shuffled cards. 
   Having described the invention in detail, those skilled in the art will appreciate that, given the present disclosure, modifications may be made to the invention without departing from the spirit of the inventive concepts described herein. Therefore, it is not intended that the scope of the invention be limited to the specific embodiments illustrated and described.