1. Field of the Invention
The present invention pertains to the art of vending machines and, more particularly, to a dispensing system for a vending machine.
2. Discussion of the Prior Art
Vending machines are commonly utilized in dispensing a wide range of products, including canned and bottled beverages, edible food items, and other consumer products. In the case of dispensing beverage products, it is desirable to configure a vending machine such that it is capable of dispensing various different sized and configured beverage containers. That is, as manufacturers of beverage products alter their container designs, it is desirable to not require the vending machine itself to be reconfigured, at least substantially, to accommodate a new product. Of course, the reliability of the overall dispensing system of the vending machine must be maintained.
For use in connection with dispensing canned and bottled beverage products, there is typically employed either a vend rotor or oscillator which is driven by a vend motor to sequentially dispense the beverage containers. In the case of the rotor, this arrangement generally takes the form of a cradle which initially receives one or more of the beverage products to be dispensed. Such cradles are typically semi-cylindrical in shape and mounted for rotation about a fore-to-aft extending axis under a column or stack of stored products. As the cradle rotates, the product(s) carried therein is dispensed. Typically, the cradle will be compartmentalized such that two or more fore-to-aft spaced products can be supported at any given time, with each product being sequentially dropped from the cradle as the cradle performs a complete 360° rotation, whereupon the cradle receives one or more additional products for dispensing. Known oscillator-type dispensing arrangements work on a generally similar principal, except that the corresponding product support or retention structure is driven to oscillate back and forth through a predetermined angle for dispensing sequential containers from a stack.
Therefore, in connection with these conventional can and bottle vending machines, motors are employed to establish the required rotation or oscillation which, in turn, functions to release stored products from within a storage rack. Whether the motor is coupled to a rotating (rotor) or oscillating (oscillator or bale) vending device, the overall system design must be configured to accommodate the particular product parameters. To this end, vendors typically employ a variety of shims, bottle rods, rod sleeves or the like to adjust the vending geometry as needed. Obviously, requiring these additional components to provide vending flexibility is undesirable, costly to manufacture, and increases overall assembly time.
In order to establish the desired rotation or oscillation, vending machines also utilize the various motors to move mechanisms in the form of cams and the like. In turn, the mechanisms release stored product from within a stack or storage rack arranged within the vending machine. In order to properly execute a vending operation each and every time a selection is made, motor shaft position must be controlled. In general, prior art vending machines typically use either AC or DC motors mounted to a plate within the vending machine. The motors are coupled to a cam and switch system which, in turn, controls the position of either the rotating or oscillating bail vending device. Furthermore, the vend motor must include an anti-pilferage mechanism as required to meet UL standards.
In operation, the cams and switches, when actuated by the motor, operate the rotating or oscillating bail device to dispense a product. Once the product vends, the cam interrupts power to the motor. Alternatively, the cam might interrupt power to a controller which, in turn, interrupts power to the motor. In any event, through a rather complicated arrangement of cams, switches and associated linkages, once a vending operation is complete, power to the motor is interrupted. In this manner, pilferage from the machine is limited.
Certainly these systems have proven themselves effective over the years, however, the overall complexity of the mechanisms has resulted in numerous failures. Cam mechanisms wear, switches fail, and bottles and cans jam in the stacks. Vending machines require constant maintenance in order to ensure the proper vending of product. Naturally, in order to remain profitable, the maintenance costs are passed on to the consumer through elevated prices of the vended product.
Still another concern is wear and tear on vend motor components. In typical fashion, upon receipt of an electrical signal, the vend motor activates instantaneously. That is, the output shaft moves from a state of rest to a dynamic state almost immediately. This abrupt change in state places a great deal of stress on gears, shafts and other components in the drive train. Over time, these stresses will cause a failure in the vending operation.
Based on the above, there exists a need in the art for an improved product delivery system for a vending machine which is designed to flexibly accommodate future package configurations, such as the length and/or diameter of various beverage containers, without requiring an undue number of components. In addition, there exists a need to more accurately control a vend motor by simplifying the overall cam and/or switch arrangement. Furthermore, there exists a need to operate a dispensing system in a manner so as to minimize stresses on motor components. In general, there exists a need to enhance the versatility and reliability of a vending machine dispensing assembly.
The present invention is directed to a dispensing system for a vending machine. In accordance with the most preferred form of the invention, the dispensing system includes a vend motor, a notched rotor, a push arm member, a return spring and a load bar. The vend motor is carried by a motor housing attached to support structure of the vending machine. An output of the vend motor is utilized to rotate an output cam member which, in turn, drives the notched rotor. The push arm member includes a first end portion rotatably mounted to a boss provided as part of the motor housing, while a second end portion of the push arm member is positioned along a peripheral portion of the output cam. In this fashion, as the cam rotates, the push arm member glides along the peripheral portion. The push arm is also connected to the load bar, retained by the return spring, and pivoted when engaged by a projection or lifting arm provided about a portion of the output cam.
With this arrangement, the vend motor functions to rotate the rotor to a series of controlled, dispensing positions. These positions actually correspond to spacing required in connection with properly dispensing a given product. In a hold position, the rotor is positioned to prevent pilferage. The notches provided as part of the rotor establish the vending geometry required for a wide variety of packages, without the need for additional components such as shims, bottle rods and the like. The rotor can actually be configured to any combination of notch length, depth and quantity to vend a variety of products. Therefore, a single rotor configuration will accommodate an abundance of present and future package designs. A corresponding arrangement can be established employing an oscillator.
In accordance with one embodiment of the present invention, the vend motor includes a main body housing, a DC motor, a plurality of sensors, an electronic controller, e.g., a I/O control board, and an actuating member. Each motor assembly is mounted to internal structure of the vending machine below an associated bottle stack. In the preferred form of the invention, each respective motor assembly is interconnected to a main, programmable controller which functions to operate a particular vend motor based on a consumer selection.
Specifically, a 24-volt DC motor having an input shaft and an output shaft is mounted to a top portion of the main body housing. More specifically, the output shaft is connected to a rotator or oscillator device through a gear system contained in the main body housing. Preferably, an input shaft rotation sensor is secured to the motor assembly and positioned to measure the angular rotation of the input shaft. In addition to the rotation sensor, a position sensor is mounted to the motor housing and positioned to measure the angular position of the output shaft. Preferably, the rotation and position sensors constitute magnetic sensor devices. However, other sensors, e.g., optical, hall-effect, detent and the like, are acceptable. Preferably, the position sensor is accurate to within ⅓° of rotation.
In accordance with the present invention, each of the rotation and position sensors interconnect with the electronic controller mounted to the motor housing. In this manner, a main controller can operate the vend motor to efficiently accomplish a desired vending operation. By mounting the sensors and motor to a housing having a profile which fits within the profile of the DC motor, a compact vending motor package is created which improves product delivery efficiency. With this overall arrangement, the combination of the input and output sensors and the electronic controller allow for very accurate, programmed motor position control preferably to within ⅓° of shaft rotation. In this preferred form of the invention, the sensors and controller eliminate the need for position sensing cams and switches and simplify the overall wiring of the machine. Additionally, through simple programming of the main controller, the rotator or oscillator vend position can be adjusted so as to eliminate the need for shims, bottle rods, and bottle rod sleeves.
In further accordance with the present invention, use of the 24-volt DC motor enables bi-directional movement of the rotator or oscillator device. With this arrangement, by simply controlling the polarity of power supplied to the motor, forward and reverse operation of the output shaft is possible. Accordingly, once the vending operation is complete, the motor output shaft can be reversed or backed-up to a “hold” position which prevents pilferage from the machine. In this manner, the DC vend motor of the present invention meets the requirements established by Underwriter's Laboratories.
In accordance with another aspect of the present invention, the dispensing system includes a soft start control. The soft start control utilizes a memory module in which is stored a software program for generating a start signal for the vend motor. The software program creates a dynamic pulse width modulated (PWM) signal for starting the motor. Preferably, the program's PWM signal starts with a low pulse width ratio that doubles with each successive pulse until a 100% duty cycle is achieved. In this manner, current is gradually applied to the motor such that the transition from a state of rest to a dynamic state is buffered. With this arrangement, the gears, shafts and other drive components will realize extended operational life.
The PWM signal of the present invention can easily be varied through manipulation of the software code such that a wide range of frequencies can be achieved. In this fashion, a particular PWM train can be implemented for each motor type, or design requirement. Further in accordance with the present invention, the soft start control is designed to be a “start and forget” system. Accordingly, once a 100% duty cycle is achieved, the software program terminates. In this manner, additional monitoring and termination of the signal is no longer required.
Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of a preferred embodiment when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
With initial reference to
Central cavity 14 includes a storage section 21, a dispensing section 22, a delivery section 24 and a lower section 26. Storage section 21 is provided to hold products in escrow until a vending operation is performed. Towards that end, storage section 21 is provided with a plurality of vertically extending column walls 32-36 which, together with side walls 8 and 9, form a plurality of column or stack areas 40-45. In the embodiment shown in
As further shown in
Referring to
In accordance with the depicted embodiment of the present invention, the overall vend motor unit 65 includes a motor housing 120 that supports a motor 122. Preferably, motor 122 is a 24-volt DC electric motor having an output shaft 124 interconnected to a vend motor unit output shaft 125 through a gear mechanism (not shown). More specifically, vend motor unit output shaft 125 includes a first hub portion 128 having a cam surface 130 provided with a lifting arm 131. Vend motor unit output shaft 125 also includes a second hub portion 134 that projects from first hub portion 128. When mounted to frontal support wall 60, second hub portion 134 projects through an opening 136 having a bushing 137. Bushing 137 limits the wear on hub 134 as motor 122 rotates vend motor unit output shaft 125 through various vend positions. As shown, second hub portion 134 includes a plurality of lands and grooves (not separately labeled) which, as will be discussed more fully below, operatively engage with cradle 106 through opening 136.
As best shown in
Referring to
As further illustrated in
During select portions of a vend operation, load bar 108 is moved between a first position wherein intermediate portion 188 supports a column of product containers, to a second position enabling a lowermost container(s) to be carried into cradle 106. Toward that end, push arm 110 is provided with a first end 202 having a hub 203 adapted to matingly engage with guide member 190 of load bar 108. First end 202 of push arm 110 is also provided with an ear element 204 having a central opening (not separately labeled) for connecting with return spring 112. First end 202 leads to a second end 206 adapted to ride along cam surface 130 of first hub portion 128 during the vend operation. In addition, second end 206 is provided with a guide element 208 adapted to travel in a guide opening 210 located in frontal support wall 60. With this construction, rotation of vend motor unit output shaft 125 will cause lifting arm 131 to engage with second end 206 of push arm 110. Lifting arm 131 causes push arm 110 to translate upward, moving load bar 108 from a first or support position to a second or loading position, thus enabling product containers 49 to fall into cradle 106. As lifting arm 131 continues to translate upward, guide element 208 travels within guide opening 210, whereupon push arm 110 will eventually return to an initial set position under the force of return spring 112.
The manner in which vending system 100 carries out a vend operation will now be described. In a manner known in the art, to initiate the vend operation, a consumer inserts currency into a designated opening provided on vending machine 2. At this point, the consumer selects one of a plurality of products through various control elements (not shown) generally arranged on an outer surface of door 18. After product selection, main control 152 signals the I/O controller 144 to activate a vend motor unit 65 corresponding to a particular stack area 40-45 in which the selected product is located. Actuation of vend motor unit 65 causes vend motor unit output shaft 125 to begin to rotate cradle 106 to a particular vend angle. Following each vend operation, controller 144 stores an angle value or position corresponding to a previously vended product. I/O controller 144 will rotate cradle 106 a predetermined amount in order to cause the selected product container to fall passed the associated one of the plurality of grooves 176 into product delivery chute 70. After a predetermined number of vending operations, generally corresponding to the storage capacity of cradle 106, lift arm 131 causes push arm 110 to travel within opening 191, causing load bar 108 to deflect or move to its second position in order to allow additional product containers 49 to be replenished or reloaded in cradle 106. During the entire operation, I/O controller 144 senses, through inputs received from rotation sensor 140 and position sensor 142, the rotational angle of cradle 106.
In accordance with the most preferred form of the present invention, I/O controller 144 supplies motor 122 with a pulse width modulated (PWM) signal to control a speed at which vend motor unit output shaft 125 rotates. I/O controller 144 includes a program, stored in memory 145, for generating a particular start signal for vend motor unit 65. That is, a ramped PWM signal is sent to motor 122 so as to gradually increase the rotational speed of vend motor unit 65. Preferably, the PWM signal starts with a low pulse width ratio that doubles with each successive pulse until a 100% duty-cycle is attained. In this manner, electrical current is gradually applied to motor 122 such that a transition from a state of rest to a dynamic state is buffered. The PWM signal of the present invention can be easily varied, such as through a manipulation of software code, such that a wide range of frequencies can be achieved. In this manner, a particular PWM train can be developed for each application. In further accordance with the present invention, the soft start control is designed to be a “start and forget” system. That is, once initiated, additional monitoring is not required. With this construction, rapid starts and stops that typically wear motor components are eliminated. In further accordance with the most preferred form of the invention, I/O controller 144, rotation sensor 140 and position sensor 142 are all carried by motor housing 120 and arranged in a manner to maintain a thin profile for vend motor unit 65.
In any event, it should be recognized that the vending system of the present invention provides an accurate product dispensing control, preferably to within approximately ⅓° of rotation, thereby eliminating the need for mechanical position sensing components. Moreover, by incorporating the controller and various sensors into vend motor unit 65, the overall wiring of vending machine 2 is simplified. The vending system also eliminates the need for shims or bottle rods to adjust for various product container sizes. Furthermore, vend motor unit 65 prevents pilfering from vending machine 2 as required by U.L. standards.
Although described with reference to a preferred embodiment of the present invention, it should be readily apparent to one of ordinary skill in the art that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, it should be recognized that the cradle could be in the form of an oscillator or rotor and that various cradles could be used to accommodate different product container sizes. Also, it should be noted that the vend motor can be made operable in both forward and reverse rotational directions. Most preferably, after a vend operation, the vend motor is partially reversed so as to prevent unauthorized removal or pilfering of product containers from the vending machine. In any event, the invention is only intended to be limited to the scope of the following claims.
The present application claims benefit to U.S. Provisional Patent Application Ser. No. 60/415,767 entitled “VENDING MACHINE ROTOR DISPENSING SYSTEM” filed on Oct. 4, 2002; U.S. Provisional Patent Application Ser. No. 60/415,761 entitled “COMPACT DC VEND MOTOR ASSEMBLY” filed on Oct. 4, 2002; and U.S. Provisional Patent Application Ser. No. 60/415,773 entitled “VEND MOTOR SOFT START” filed on Oct. 4, 2002.
Number | Date | Country | |
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60415761 | Oct 2002 | US | |
60415767 | Oct 2002 | US | |
60415773 | Oct 2002 | US |
Number | Date | Country | |
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Parent | 10678154 | Oct 2003 | US |
Child | 12220069 | US |