Patent Description:
Various dispensing cabinets and carts have been developed to assist in the management of medications and other items. However, improvements are still desired in the reliability of dispensing and tracking of items, and it is also desirable to reduce the amount of space required for item storage and dispensing.

According to one aspect, a dispensing mechanism for dispensing elongate items includes at least two helical augers having threads, and at least two channels configured to hold the items to be dispensed with the longitudinal axes of the items to be dispensed being generally perpendicular to the rotational axes of the at least two helical augers. The items to be dispensed are received at least partially within the threads of the augers. The dispensing mechanism also includes a drive mechanism engaged with the at least two augers and configured to rotate the at least two augers to transport the items to be dispensed, driven by the threads of the augers, to dispense the items from the dispensing mechanism.

<FIG> illustrates an example cabinet <NUM> in which the invention may be embodied. Cabinet <NUM> includes various doors <NUM> and drawers <NUM> providing access to compartments for storing items such as medical supplies or medications. For example, supplies such as bandages, swabs, and the like may be stored in unlocked compartments such as may be accessed through one of doors <NUM>. Medications may be stored in individually lockable compartments within drawers such as drawers <NUM>. A computer <NUM> maintains records of the contents of cabinet <NUM>, and may control access to individual compartments. For example, a floor nurse needing to obtain a dose of medication for a hospital patient may enter his or her identification and the medication required into computer <NUM>. Computer <NUM> verifies that the nurse is authorized to remove the medication, and unlocks a particular drawer <NUM> and a particular compartment within the drawer containing the required medication. Computer <NUM> may also control lights that guide the nurse to the correct drawer and compartment, to help ensure that the correct medication is dispensed. In addition, computer <NUM> may communicate with a central computer system that coordinates information from many storage and dispensing devices such as cabinet <NUM>.

While embodiments of the invention are described in the context of stationary cabinet <NUM>, it will be recognized that the invention may be embodied in other kinds of storage devices, for example movable cabinets, carts, storage rooms, and the like. Example dispensing devices are described in the following commonly owned U. Patents and patent applications, the contents of which are hereby incorporated by reference: <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>,, <CIT>, an <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>. Other examples of cabinets are known from <CIT>, <CIT>, <CIT>, and <CIT>.

In the above scenario, the nurse may be given access to a compartment having a large number of doses of the medication, and he or she may simply remove the number immediately required.

Cabinet <NUM> also includes a return bin <NUM>, into which unused items can be placed, for later return to stock by a pharmacy technician.

When further control and tracking accuracy is required, medications may be placed in a dispensing unit such as dispensing unit <NUM>. Dispensing unit <NUM> includes a restock drawer <NUM> and a dispense drawer <NUM>. Restock drawer includes in turn a number of dispensing mechanisms (not visible in <FIG>) that, under control of computer <NUM>, can dispense single items into dispense drawer <NUM>. Dispense drawer <NUM> can then be opened to retrieve the dispensed items. Restock drawer <NUM> is accessible only by specially-authorized persons, for example for restocking by a pharmacy technician.

<FIG> illustrates dispensing unit <NUM> in more detail, including restock drawer <NUM> and dispense drawer <NUM>. A number of dispensing mechanisms may be installed within restock drawer by <NUM> attaching them to rails <NUM>. Only a few dispensing mechanisms <NUM>, <NUM>, <NUM> are shown in <FIG>. Different types of dispensing mechanisms may be present, depending on the kinds of items to be dispensed, as is discussed in more detail below. The different kinds of dispensing mechanisms may be of differing sizes, and rails <NUM> may be configured as necessary to accommodate a particular mix of dispensing mechanisms, by fixing rails <NUM> to different sets of hangers <NUM>.

For example, dispensing mechanism <NUM> is a double width mechanism, placed between rails that are two bays wide, while dispensing mechanisms <NUM> and <NUM> are single width mechanisms, placed between rails <NUM> that are connected to adjacent sets of hangers <NUM>. Other sizes of dispensers, for example triple and quadruple widths are also possible.

<FIG> also illustrates that dispense drawer <NUM> and restock drawer <NUM> form a nested pair of drawers. That is, restock drawer <NUM> can slide out of cabinet <NUM> on guides <NUM> for restocking, maintenance, and the like, carrying dispense drawer <NUM> with restock drawer <NUM>. Similarly, dispense drawer <NUM> can slide in and out of restock drawer <NUM> on similar guides not easily visible in <FIG>.

Dispense drawer <NUM> may conveniently serve as a work surface for the user of cabinet <NUM> or a similar device. For example, once an item has been dispensed into dispense drawer <NUM> and the user has opened dispense drawer <NUM> to retrieve the item, the user may use the flat bottom of dispense drawer <NUM> to rest a note pad, computer, or other item he or she may use to document or make notes about the transaction. Dispensing unit <NUM> may include features to facilitate the use of dispense drawer <NUM> as a work surface. For example, the guides or other slide mechanism by which dispense drawer opens may include a detent at the openmost position of dispense drawer <NUM>, to lend stability to dispense drawer <NUM> while it is used as a work surface.

<FIG> is a detail view of a portion of <FIG>, showing that at each hanger <NUM> is an electrical connector <NUM>. Each connector <NUM> connects with a mating connector attached to wiring within a rail <NUM> positioned at the respective hanger <NUM>, supplying power and signals coming from other systems within cabinet <NUM>. Other connectors <NUM> are spaced along the rails, for making electrical connections with the dispensing mechanisms such as dispensing mechanisms <NUM>, <NUM>, and <NUM>. To accomplish the required electrical connections, each rail <NUM> may house a wiring harness, a printed circuit board assembly (PCBA), or the like. Thus, computer <NUM> can communicate individually with any dispensing mechanism within restock drawer <NUM>. Cabling from all of the connectors converges at a circuit board (not visible) at the back of dispensing unit <NUM>, which in turn connects to other electronics within cabinet <NUM> via one or more flexible cables (not visible in <FIG>), which permits dispensing unit <NUM> to slide out of cabinet <NUM> for restocking, maintenance, and the like.

<FIG> illustrates dispensing unit <NUM> fully loaded with seven dispensing mechanisms <NUM>, <NUM> dispensing mechanisms <NUM>, and seven dispensing mechanisms <NUM>, fully populating the available spaces on rails <NUM>. It will be recognized that this arrangement of dispensing units is but one example of many, many arrangements of dispensing units that could be employed. For example, restock drawer <NUM> may not be fully populated with dispensing units. Only one or two different kinds of dispensing mechanisms may be present, or four or more kinds of dispensing units may be present. Different kinds of dispensing units may be present in any workable proportions, and like dispensing units need not be installed next to each other. Example dispensing unit <NUM> can hold up to <NUM> single width dispensing mechanisms (with two additional rails <NUM> installed). One example of this is shown in <FIG>, in which dispensing unit is loaded with <NUM> dispensing mechanisms <NUM>.

Preferably, each dispensing unit can identify itself through its respective connector <NUM>, and computer <NUM> can create a map of the particular arrangement of dispensing units that are installed. Computer <NUM> can also preferably detect the presence of a dispensing unit at any one of the bay positions, through the respective connector <NUM> or via a separate sensor. In addition, each dispensing unit can preferably also communicate to computer <NUM> the kind and quantity of items it contains and stands ready to dispense.

<FIG> is a reverse angle view of a portion of the fully-loaded dispensing unit <NUM> of <FIG>, showing a back panel <NUM> of restock drawer <NUM>. Preferably, both restock drawer <NUM> and dispense drawer <NUM> include latching mechanisms operable by computer <NUM>, to prevent the opening of the drawers at improper times. For example, computer <NUM> may permit restock drawer <NUM> to be opened only when computer <NUM> has received a proper security code from a restocking technician, and may permit dispense drawer <NUM> to be opened only after an item has been dispensed from one of dispensing mechanisms <NUM>, <NUM>, <NUM>. A latching mechanism <NUM> for locking and unlocking restock drawer <NUM> is visible in <FIG>. A similar latching mechanism may be provided inside restock drawer <NUM> for locking and unlocking dispense drawer <NUM>. Also visible in <FIG> are various connectors <NUM> for connecting to other electronics within cabinet <NUM>, for example a power supply, computer <NUM>, or other electronic components through one or more flexible cables (not shown).

A wide variety of dispensing mechanisms has been developed for dispensing different kinds of items, for example syringes, vials, single medicine doses in blister packs, and the like. A number of such dispensing mechanisms are described in <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; and <CIT>.

However, the dispensing mechanisms described in those documents may not be suitable for dispensing certain other items having other shapes. For example, some medications are available in pre-filled syringes. <FIG> illustrates two pre-filled syringes <NUM> and <NUM>, in different sizes. Although other sizes are possible, syringe <NUM> may be a "one milliliter" (<NUM>) syringe, carrying a <NUM> dose of previously prepared medication, and syringe <NUM> may be a "two milliliter" (<NUM>) syringe, carrying a <NUM> dose of medication. Each of syringes <NUM> and <NUM> has a body <NUM> containing the medication, a luer connector <NUM> for connecting the syringe to an infusion port or a needle, and a plunger <NUM>. As is apparent, the body <NUM> of <NUM> syringe <NUM> is longer than the body <NUM> of <NUM> syringe <NUM>, so as to store more medication. Accordingly, the plunger <NUM> of <NUM> syringe <NUM> is longer than the plunger <NUM> of <NUM> syringe <NUM>, so as to permit expelling all of the medication from the longer body. Preferably, syringes usable in embodiments of the invention are the same or similar in diameter.

Prefilled syringes may simplify medication management in a hospital or other health care facility. Because medications can be purchased already in the appropriate syringe, there is no need to compound the medication or fill the syringe at the health care facility, saving time and avoiding potential errors. Syringes may be available holding a variety of medications in a variety of doses. Prefilled syringes may be especially attractive for controlled substances such as narcotics, for which it is especially important to simplify medication tracking and avoid medication errors.

For protection during dispensing, a syringe such as syringe <NUM> or syringe <NUM> may be placed in a protective capsule. <FIG> shows a body cap <NUM> and a plunger cap <NUM> sized to snap together to enclose syringe <NUM>. Body cap <NUM> and plunger cap <NUM> may preferably be made of an inexpensive, sterilizable polymer such as polypropylene, although any suitable material may be used. Body cap <NUM> and plunger cap <NUM> may be disposable and used only once, or may be reusable. <FIG> shows the completed assembly of a syringe capsule <NUM>. A similar (but longer) capsule may be provided for larger syringe <NUM>.

In the discussion below, the term "syringe" or the term "capsule" may sometimes be used to refer to the combination of a syringe and its protective capsule. For example, when a syringe in a capsule is dispensed, this may be referred to as simply dispensing a syringe or dispensing a capsule.

<FIG> illustrate upper and lower views of a dispensing mechanism <NUM> for dispensing prefilled syringes and other similarly-shaped items, in accordance with embodiments of the invention.

As is visible in <FIG>, a button <NUM> at the top of dispensing mechanism <NUM> allows a user authorized to access the interior of restock drawer <NUM> to signal computer <NUM>, for example to record the fact that dispensing mechanism <NUM> has been refilled. A light <NUM> may be present to enable computer <NUM> to communicate to the user, for example flashing the light to direct the user to restock this particular dispensing mechanism.

As is visible in <FIG>, a connector <NUM>, compatible with connectors <NUM> on rails <NUM>, is positioned to engage one of connectors <NUM> when dispensing mechanism <NUM> is installed in restock drawer <NUM>. Various parts of dispensing mechanism <NUM> collectively constitute a housing that defines an opening <NUM> at the bottom of dispensing mechanism <NUM>, through which items are dispensed. Dispensing mechanism <NUM> may be removably secured to one of rails <NUM> using a snap mechanism, one or more screws, or by another method.

As is shown in <FIG>, example dispensing mechanism <NUM> comprises a dispenser <NUM> and a cassette <NUM>, which are separable. For example, dispenser <NUM> and cassette <NUM> may snap together, may be separable with the removal of one or a small number of screws, or may be reasonably separable in some other way without damage to either dispenser <NUM> or cassette <NUM>. In this way, restocking may be accomplished by replacing a depleted cassette <NUM> with a full cassette <NUM>. A gear <NUM> in cassette <NUM> engages a driving gear <NUM> within dispenser <NUM> when cassette <NUM> is assembled to dispenser <NUM>.

Preferably, as will be discussed in more detail below, cassette <NUM> does not contain any active electrical components. All of the active components of example dispensing mechanism <NUM> may reside in dispenser <NUM>. For example, an antenna <NUM> can excite a passive memory chip <NUM> in cassette <NUM>, to determine the contents of cassette <NUM> (written into passive memory chip <NUM> when cassette <NUM> was filled at a remote location). If desired, antenna <NUM> can also be used to update the data in passive memory chip <NUM>. This wireless data exchange may use any suitable wireless protocol, for example Near Field Communications (NFC), radio frequency identification (RFID), or another wireless protocol.

Dispenser <NUM> can preferably automatically detect the installation and removal of cassette <NUM>. This automatic detection may facilitate the inventory and tracking of items, and also can help prevent illicit diversion of items. The detection may be accomplished in any suitable way, for example periodic polling using antenna <NUM>, a contact sensor (not shown) that can detect the presence of cassette <NUM> electromechanically, or by another technique.

In other embodiments, which are not part of the claimed invention, a dispensing mechanism in accordance with embodiments of the invention may not have the separable architecture of dispensing mechanism <NUM>, but may be a single unit including space for storing items to be dispense and including an actuator and other components for dispensing items. In other embodiments that do include a cassette, the cassette includes active components, for example a motor or other actuator, light emitters for sensing, or other components.

As are visible in <FIG>, a light emitter <NUM> and one or more light receivers <NUM> are positioned near the bottom of dispenser <NUM>. In operation, light from light emitter <NUM> reflects from reflective surface <NUM> (visible in <FIG>) and returns to light receivers <NUM>, so long as it is not interrupted by an item being dispensed and falling through the "light curtain" formed across opening <NUM>. When an item is dispensed through opening <NUM>, it interrupts the light received by either or both of light receivers <NUM>, and dispenser <NUM> can note that an item has in fact been dispensed. If no light interruption is detected despite a command to dispense an item, computer <NUM> may assume that a misfeed or other problem has occurred, or that cassette <NUM> is empty. By using more sophisticated monitoring strategies, accidental dispensing of multiple items may be detected. For example, if two interruptions of the light curtain are detected closely spaced in time, a double feed may be indicated. Emitter <NUM> may be of any suitable type of emitter, and may emit light in any suitable wavelength or combinations of wavelengths. For example, light emitter <NUM> may be a light emitting diode, a laser such as a vertical cavity semiconductor emitting laser (VCSEL) or another kind of light source, and may emit visible light, infrared light, or light in other suitable wavelength bands or combinations of wavelength bands.

In other embodiments, light emitter <NUM> and receivers <NUM> may be on opposite sides of opening <NUM>, so that receivers <NUM> receive light directly from light emitter <NUM> until the light is interrupted by the dispensing of an item.

<FIG> shows a partially exploded oblique view of dispenser <NUM>, revealing some internal details of dispenser <NUM>. A motor <NUM> is mounted on a printed circuit board <NUM>, and turns driving gear <NUM>, which engages gear <NUM> on cassette <NUM> to actuate cassette <NUM>. Motor <NUM> may be, for example, a stepper motor whose angular position can be readily moved incrementally and held. In that case, an item may be dispensed by advancing motor <NUM> by a number of steps known to correspond to one dispensing operation. If the light curtain does not detect that an item is dispensed, motor <NUM> may be advanced further, and if no dispensing is yet detected, an error message may be generated, or it may be assumed that cassette <NUM> is empty. Alternatively, motor <NUM> may be a simple DC or AC motor, in which case dispensing may be accomplished by simply running motor <NUM> until the dispensing of an item is detected, and then shutting off the motor so that motor <NUM> is advanced incrementally as far as is needed. A time limit may be imposed, such that if no dispensing is detected within the time limit with motor <NUM> running, the motor may be shut off and an error message generated. In other embodiments, an encoder may be provided on the motor or another component, and may provide feedback as to the rotational position of the motor or the state of the dispensing mechanism.

In other embodiments, an actuator other than a motor may be used. For example, a solenoid or memory metal actuator may provide a reciprocating motion that is used to drive the driving gear within dispenser <NUM> using a ratchet or ratchet-like arrangement. Other kinds of actuators and driving arrangements are possible.

A microprocessor, microcontroller, or similar controlling circuitry may reside within dispenser <NUM>, and may operate the various active components and sensors of dispenser <NUM> in response to high-level commands from a supervisory controller elsewhere within restock drawer <NUM>, or from computer <NUM>. In that case, dispenser <NUM> is considered a "smart" dispenser, because it includes some processing intelligence. However, other architectures are possible. For example, logic signals from a supervisory controller elsewhere within restock drawer <NUM> may operate dispenser <NUM>.

As was discussed above, dispensing mechanism <NUM> may be especially useful for dispensing prefilled syringes, which preferably are enclosed in protective capsules such as capsule <NUM>.

<FIG> shows an oblique view of a cassette <NUM> in accordance with embodiments of the invention, partially cutaway, to reveal a number of syringe capsules <NUM> stored inside. For visibility of the internal arrangement, cassette <NUM> is shown only partially filled with syringe capsules <NUM>. The capsules <NUM> shown in <FIG> hold <NUM> syringes <NUM>. A removable spacer <NUM> is attached to door <NUM> of cassette <NUM>, to constrain the shorter capsules <NUM> longitudinally. When it is desired to dispense <NUM> syringes <NUM>, spacer <NUM> can be removed.

Cassette <NUM> includes four augers in a parallel vertical arrangement. In <FIG> a right front auger <NUM>, a right rear auger <NUM>, and a left front auger <NUM> are visible. A left rear auger <NUM> is also present, but not visible in <FIG>. Three vertical channels for storing three columns of capsules <NUM> are formed by one or more of the augers, cassette inserts <NUM>, and part dividers <NUM> formed in the housing of cassette <NUM>. Capsules <NUM> are stored with their longigudinal axes generally perpendicular to the axes of the augers.

A set of gears <NUM> includes a right front auger gear <NUM> fixed to right front auger <NUM>, such that right front auger <NUM> turns when right front auger gear <NUM> is turned. Similarly, right rear auger gear <NUM> is fixed to right rear auger <NUM>, left front auger gear <NUM> is fixed to left front auger <NUM>, and left rear auger gear <NUM> is fixed to left rear auger <NUM>. Left rear auger gear <NUM> is engaged with gear <NUM> and left rear auger gear <NUM>. Right and left idler gears <NUM> and <NUM> couple to the respective front and rear auger gears. Thus, when gear <NUM> is driven by driving gear <NUM> of dispenser <NUM>, all four augers in cassette <NUM> turn in synchronization, as is explained in more detail below, to move capsules <NUM> downward toward the bottom of cassette <NUM>.

It will be recognized that the terms "left", "right", "front", and "back" are arbitrarily assigned, and may be assigned differently in other embodiments. Similarly, the terms "up", "down", "top", "bottom", "vertical", "horizontal" and the like refer to the positions of the dispensing mechanisms in the figures. Dispensing mechanisms embodying the invention may be used in other orientations.

<FIG> show orthogonal views of the augers, gears, and capsules of cassette <NUM>, from the directions indicated in <FIG>. Right rear auger <NUM> and left rear auger <NUM> are visible in <FIG>, while the front augers are not. Right rear auger <NUM> and right front auger <NUM> are visible in <FIG>, while the left augers are not.

As is shown in <FIG>, the left and right augers have different handedness. Left rear auger <NUM> has left handed threads, while right rear auger <NUM> has right handed threads. However, as is shown in <FIG>, right front auger <NUM> and right rear auger <NUM> have right handed threads.

<FIG> shows the operation of gears <NUM>. When gear <NUM> is driven counterclockwise (as viewed from the top of cassette <NUM>) by driving gear <NUM> and motor <NUM>, left rear auger gear <NUM> and left rear auger <NUM> are driven clockwise. And because left rear auger gear <NUM> engages with right rear auger gear <NUM>, right rear auger gear and right rear auger <NUM> turn counterclockwise. Because left rear auger <NUM> has left handed threads (as shown in <FIG>), turning it clockwise drives capsules <NUM> downward. And because right rear auger <NUM> has right handed threads, turning it counterclockwise also drives capsules <NUM> downward.

Right and left idler gears <NUM> and <NUM> translate the rotation of rear auger gears <NUM> and <NUM> to front auger gears <NUM> and <NUM>, ensuring that the augers on the right side of cassette <NUM> (augers <NUM> and <NUM>) turn in the same direction, and the augers on the left side of cassette <NUM> (augers <NUM> and <NUM>) also turn in the same direction, but opposite the direction of the augers on the other side. Because the handedness of the augers on the two sides of cassette <NUM> differs and the rotation direction differs, both sets of augers drive capsules <NUM> downward.

It will be understood that the direction of rotation of gear <NUM> could be reversed, and the handedness of all of the augers reversed, to achieve the same effect.

Referring again to <FIG>, the three columns of capsules <NUM> thus progress downwardly in parallel and at the same rate. The flat faces <NUM> at the bottom thread of the left and right augers are out of phase, so that a passage is formed, permitting a capsule <NUM> to drop by gravity from one of the columns out of cassette <NUM> at intervals of <NUM>, <NUM>, and <NUM> degrees of the rotation of gear <NUM>. In other embodiments, a dispensing mechanism embodying the invention may be used in another orientation, such that the augers force the items from the cassette.

<FIG> shows an oblique view of a cassette <NUM> in accordance with other embodiments of the invention, partially cutaway to reveal a number of syringe capsules <NUM> stored inside. As compared with cassette <NUM>, cassette <NUM> has the same external dimensions, but uses different augers and gears to accomplish the downward motion of the capsules <NUM> inside. For example, as is visible in <FIG>, gear set <NUM> differs from gear set <NUM> shown in <FIG>. In addition right rear auger <NUM> has a different handedness than right front auger <NUM>, as is explained in more detail below.

As is shown in <FIG>, the left and right rear augers have different handedness. Left rear auger <NUM> has right handed threads, while right rear auger <NUM> has left handed threads. Also, as is shown in <FIG>, right front auger <NUM> also has right handed threads, differing from right rear auger <NUM>. Although not visible, the left front auger also has left handed threads, so that opposing corner augers have like threads.

Augers with the handedness arrangement of <FIG> work in concert with gears <NUM>, as shown in more detail in <FIG>. Gear <NUM> is similar to gear <NUM>, and is positioned to be driven by gear <NUM> of dispenser <NUM>. Gear <NUM> engages with left rear auger gear <NUM>, which is coupled with left rear auger <NUM>, which has right handed threads. When gear <NUM> is turned clockwise (as viewed from above) as shown, left rear auger <NUM> turns counterclockwise.

Left rear auger gear <NUM> is coupled to central idler gear <NUM>, which in turn drives right front auger gear <NUM>, turning right front auger <NUM> in the same direction as left rear auger <NUM>. Because diagonal augers have the same handedness in this embodiment, they both drive any capsules <NUM> downward.

Left front auger gear <NUM> engages and is driven by right front auger gear <NUM>, and thus turns in the opposite direction. Left front auger <NUM> thus turns clockwise, and having left handed threads, drives capsules <NUM> downward.

Similarly, right rear auger gear <NUM> engages and is driven by left rear auger gear <NUM>, and turns the same direction as diagonally-opposed left front auger <NUM>. Idler gear <NUM> has teeth only in the upper portion of its height, and auger gears <NUM> and <NUM> have teeth only in the lower portion of their heights, so that they do not interfere with idler gear <NUM>.

In the embodiment of <FIG>, syringes are also dispensed at intervals of <NUM>, <NUM>, and <NUM> degrees of the rotation of gear <NUM>. Unitary dispensing may be accomplished in any suitable way. For example, motor <NUM> may be a stepper motor, and may be driven by the number of steps needed to turn the augers <NUM> or <NUM> degrees, as needed for the next dispensing. Or motor <NUM> may be driven until the dispensing of a syringe is detected by the light curtain at the bottom of dispenser <NUM>.

A component of a cassette in accordance with embodiments of the invention is fitted with an encoder, so that the positions of the augers are known.

<FIG>, and <FIG> illustrate the operation of the encoder, in accordance with embodiments of the invention. <FIG> shows an upper oblique rear view of a portion of cassette <NUM>. An opening <NUM> is formed in rear wall <NUM> of cassette <NUM>. Rear wall <NUM> is the wall that mates with dispenser <NUM> when cassette <NUM> is coupled with dispenser <NUM>. Opening <NUM> is just below gear <NUM>. An optical sensor (not shown) may be present in dispenser <NUM>, aligned with opening <NUM>.

<FIG> shows a lower oblique rear view of a portion of cassette <NUM>. Gear <NUM> has a number of ramped pockets <NUM> in its underside. In this example, pockets <NUM> are rotationally spaced, <NUM>, <NUM>, and <NUM> degrees apart, and correspond to positions of gear <NUM> at which items are dispensed from cassette <NUM>. A spring-loaded plunger <NUM> rides against the bottom side of gear <NUM>, "falling" (upward) into pockets <NUM> as they pass plunger <NUM>. Plunger <NUM> carries a reflective target <NUM>, but the part of plunger <NUM> surrounding target <NUM> is otherwise relatively non-reflective, for example molded of a black plastic. Whenever plunger <NUM> falls into one of pockets <NUM>, target <NUM> becomes visible through opening <NUM>.

<FIG> shows plunger <NUM> in its upward position, such that target <NUM> is visible through opening <NUM>. <FIG> shows plunger <NUM> in its downward position, such that target <NUM> is not visible through opening <NUM>.

A light source and sensor within dispenser <NUM> (not shown) can detect target <NUM>, to detect when cassette <NUM> has reached a position in which a syringe can be dispensed. When gear <NUM> is not in such a position, plunger <NUM> is pushed downward by the ramps at the trailing edges of pockets <NUM>, so that reflective target <NUM> is no longer visible through opening <NUM>. The sensor reading the position of target <NUM> thus provides feedback as to the configuration of cassette <NUM>. To dispense a syringe item, motor <NUM> may be driven until target <NUM> is seen by dispenser <NUM>, and then motor <NUM> may be stopped. The dispensing of a syringe may be confirmed by signals from the light curtain at the bottom of cassette <NUM>. If not dispensed item is detected by the light curtain, gear <NUM> may be advanced to the next dispensing position.

It will be recognized that other kinds of encoders may be used, but would not fall under the scope of the claimed invention. For example rotary optical encoders, linear encoders, or other kinds of encoders, on any suitable component of a dispensing mechanism. In the type of encoder of <FIG> and <FIG>, the sense of the detections may be reversed. For example, a reflective target may be detectable when the mechanism is not at a dispensing location.

While the encoder arrangement is described in relation to cassette <NUM>, it may be used in other cassette arrangements as well, for example in cassette <NUM>.

In some embodiments, a cassette such as cassette <NUM> may include a brake that is automatically engaged when the cassette is removed from its dispenser. In this way, inadvertent loss of items from the cassette may be prevented during transport and storage of the cassette.

<FIG> shows an upper oblique view of cassette <NUM>, including a braking arrangement according to embodiments of the invention. In this example arrangement, a torsion spring <NUM> biases a wedge <NUM> into the teeth of right rear auger gear <NUM>. So long as cassette <NUM> is not attached to a dispenser, wedge <NUM> prevents motion of the gears of cassette <NUM>.

<FIG> shows a partially cutaway view of cassette <NUM>, revealing additional details of the brake. Wedge <NUM> is integrally formed with a lever <NUM>, which can pivot about axle <NUM>. At the bottom of lever <NUM> is a protrusion <NUM>, which extends outside the envelope of cassette <NUM> when wedge <NUM> is engaged with gear <NUM>, by the action of torsion spring <NUM>.

<FIG> shows a partially cutaway view of cassette <NUM>, with lever <NUM> in a position as if cassette <NUM> were engaged with a dispenser such as dispenser <NUM> (not shown). The front wall of the dispenser has pushed protrusion <NUM> of lever <NUM> into cassette <NUM>, causing lever <NUM> to rotate about axle <NUM>, drawing wedge <NUM> out of engagement with gear <NUM>, against the action of torsion spring <NUM>. Thus, once cassette <NUM> is installed in the dispenser, the gears are free to turn in response to motor <NUM> (not shown). When cassette <NUM> is disengaged from the dispenser, the gears of cassette <NUM> are automatically locked.

It will be understood that the encoder and braking systems of <FIG> may be used in cassettes of other embodiments, for example cassette <NUM>. In addition, other kinds of encoder and braking systems may be used, but would not fall under the scope of the claimed invention.

<FIG> shows a cassette <NUM> in accordance with other embodiments of the invention. The width W of cassette <NUM> is approximately double the width of cassettes <NUM> and <NUM>, but cassette <NUM> may be of comparable size in the other orthogonal dimensions. Cassette <NUM> can hold six columns of syringe capsules <NUM>, and thus has a higher capacity than the other cassette embodiments described above. In <FIG>, cassette <NUM> is shown loaded with capsules for <NUM> syringes <NUM>. A spacer (not shown) may be mounted to door <NUM> when it is desired to use cassette <NUM> to dispense <NUM> syringes <NUM>, similar to spacer <NUM> shown in <FIG>.

<FIG> shows cassette <NUM> with some enclosure parts removed, to reveal internal details. Three augers <NUM> (only one of which is visible in <FIG>) hold capsules in columns. Each of augers <NUM> is preferably wide enough to substantially span two columns of capsules, one column on each side of each auger. A set of gears <NUM> is positioned to be engaged by a driving gear in an attached dispenser (not shown), through drive and encoder gear <NUM>.

<FIG> show side and end views of cassette <NUM> respectively, and illustrate the packing of syringe capsules <NUM> within augers <NUM> of cassette <NUM>. Note that the left and right sides of cassette <NUM> are defined as viewed from the rear, as in <FIG>. Because cassette <NUM> is viewed from the front in <FIG>, left and right appear to be reversed in <FIG>. Augers <NUM> all have the same handedness (left or right handed threads), and are mounted "in phase" with each other. In some embodiments, all of augers <NUM> are identical with each other.

Gears <NUM> are designed such that as gear <NUM> is turned, the augers <NUM> "take turns" rotating intermittently to dispense syringes, as is explained in more detail below.

<FIG> is an upper oblique view of gears <NUM>, including drive and encoder gear <NUM>. Two of augers <NUM> are also shown, but one has been removed for clarity. A first idler gear <NUM> engages with drive and encoder gear <NUM>, and also engages with a first timing gear <NUM>. In this example, first timing gear <NUM> has the same pitch diameter and same number of teeth as drive and encoder gear <NUM>, and thus first timing gear <NUM> turns by the same amount and in the same direction as drive and encoder gear <NUM>. Similarly, additional timing gears <NUM> and <NUM> are driven from first timing gear <NUM>, through additional idler gears <NUM> and <NUM>. All of drive and encoder gear <NUM>, idler gears <NUM>, <NUM>, and <NUM>, and timing gears <NUM>, <NUM>, and <NUM> are thus geared together and turn together when drive and encoder gear <NUM> is turned.

Each auger <NUM> is fixed to a respective auger gear 3007a, 3007b, or 3007c, each corresponding to one of timing gears <NUM>, <NUM>, or <NUM>.

<FIG> is a lower oblique view of gears <NUM>, and showing the operation of auger gears 3007a, 3007b, and 3007c, in accordance with embodiments which do not fall under the scope of the claimed invention. Only one auger <NUM> is shown in <FIG>, for clarity.

As is visible in <FIG>, timing gears <NUM>, <NUM>, and <NUM> have teeth around their entire perimeters only in the upper portion of their heights. In their lower portions, timing gears <NUM>, <NUM>, and <NUM> have teeth around only a portion of their perimeters. For example, timing gear <NUM> has <NUM> teeth around its upper portion, but only five teeth <NUM> partially around its lower portion, and gaps between and adjacent the five teeth, for a total of six gaps. The remainder of the lower portion of timing gear <NUM> is a smooth cylindrical surface <NUM>, preferably having a diameter of approximately the pitch diameter of timing gear <NUM>.

In addition, auger gear 3007b (corresponding to timing gear <NUM>) has a pitch diameter sufficient for <NUM> teeth, but has only <NUM> teeth, with two teeth missing at locations <NUM>, spaced <NUM> degrees apart around the perimeter of auger gear 3007b. In the position shown, auger gear 3007b does not turn with timing gear <NUM>, because their teeth are not engaged. Only when the lower teeth <NUM> of timing gear <NUM> reach the location of auger gear 3007b do the teeth of auger gear 3007b and timing gear <NUM> engage. However, the engagement is temporary. Lower teeth <NUM> will cause auger gear 3007b to rotate only <NUM> degrees, and then the two gears will disengage for the rest of the rotation of timing gear <NUM>.

Similar relationships exist between timing gear <NUM> and auger gear <NUM>, and between timing gear <NUM> and auger gear 3007c. Timing gears <NUM>, <NUM>, and <NUM> are mounted out of phase with each other by <NUM> degrees. Thus, for every <NUM> degrees of rotation of drive and encoder gear <NUM> (and of timing gears <NUM>-<NUM>), one and only one of auger gears 3007a-3007c rotates <NUM> degrees. Auger gears 3007a-3007c "take turns" rotating <NUM> degrees. That is, the augers turn incrementally (pausing between rotations) and sequentially (one after the other, no two at the same time). Each <NUM> degree rotation of an auger dispenses one syringe. In <FIG>, the rotation directions of the augers are shown in dashed lines, to indicate the incremental motion.

As is visible in <FIG>, auger gear 3007c is finishing its <NUM> degree rotation, and its teeth are just coming out of engagement with timing gear <NUM> at location <NUM>. But at the other side of the gear set, timing gear <NUM> is just coming into engagement with auger gear 3007a at location <NUM>, and auger gear 3007a is about to start its <NUM> degree rotation. Auger gear 3007b remains stationary for the time being as one of its missing teeth is adjacent smooth cylindrical surface <NUM> of timing gear <NUM>.

Drive and encoder gear <NUM> may include flat encoder faces <NUM>, angled at <NUM> degrees to each other. Encoder faces <NUM> may be coated with a reflective material, and may be visible to a detector within a dispenser such as dispenser <NUM>. Whenever one of encoder faces <NUM> is seen by the detector, it can be assumed that the currently moving auger has rotated <NUM> degrees, and that an item has been dispensed. To dispense an item, the dispenser may simply rotate its motor until the next encoder face <NUM> is seen, and then stop the motor.

Claim 1:
A dispensing mechanism (<NUM>, <NUM>, <NUM>) for dispensing elongate items, the dispensing mechanism comprising:
at least two helical augers (<NUM>, <NUM>) having threads, wherein each of the items to be dispensed is received at least partially within the threads of two of the augers; at least two channels configured to hold the items to be dispensed with the longitudinal axes of the items to be dispensed being generally perpendicular to the rotational axes of the at least two helical augers, and
a cassette (<NUM>) including
an opening (<NUM>), the at least two augers, the at least two channels, and
an encoder configured to indicate a rotational position of a component of the drive mechanism, wherein the encoder comprises a spring loaded plunger (<NUM>), the spring loaded plunger comprising a reflective target and being configured to sequentially fall into and be driven out of pockets (<NUM>) in a gear; and
a drive mechanism engaged with the at least two augers and configured to rotate the at least two augers to transport the items to be dispensed, driven by the threads of the augers, to dispense the items from the dispensing mechanism;
a dispenser including
an actuator,
a connector (<NUM>) for receiving electrical power and control signals from a cabinet in which the dispensing mechanism is installed,
an optical sensor aligned with the opening in the cassette and configured to detect the reflective target through the opening of the cassette whenever the plunger falls into one of the pockets, and
an opening (<NUM>) at the bottom of the dispenser through which the dispensing mechanism is configured to dispense the items; and
wherein the dispenser and the cassette are mateable such that the actuator can drive the drive mechanism, and wherein the dispenser and cassette are separable.