Abstract:
The present invention is an improved method to grind coffee where grinding speed can be adjusted either on demand or according to a programmed profile. By lowering the rotational speed of the grinding burrs, the user can insure more consistent particle size for types of coffee or methods of brewing where it is desirable, or dramatically increase speed for greater productivity. By incorporating a load cell, the grinder is able to identify coffee brewing device and deliver portioned ground coffee according to program settings or user input. The device also features an improved hopper design to reduce waste and ease whole bean removal. More importantly is a new method to calibrate the distance between the grinder mills and to automatically adjust grinder particle size so that a given numerical value is consistent for each grinder and every user.

Description:
[0001]    This application for a Utility patent claims benefit of a prior application for provisional patent No. 62/109,856 filed Jan. 30, 2015. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    It is commonly understood in the coffee industry that different varieties of roasted coffee and methods of brewing coffee require a specific particle size of ground coffee and specific ration of ground coffee to water and to achieve optimal results. The precision required for some coffees requires a slower grinding speed than is customary to ensure that the coffee beans are cut rather than crushed by the grinding mechanism. Existing coffee grinders are not able to vary the speed on demand for each kind of coffee being ground or accurately adjust the quantity of coffee delivered to accommodate different brewing methods. Grinders that are able to grind coffee to order use time as a method of measurement must be continuously be adjusted when grind settings are changed. Using time as a means of measuring ground coffee is impossible if a grinder is to be used for anything other than a single type of coffee brewing method. 
         [0003]    Historically, coffee grinders are comprised of a container to hold whole coffee beans above the grinding mechanism. In order to facilitate cleaning of this container, removing or replacing the coffee beans, a closing mechanism is required to stop the flow of coffee and the container is removed. Fragile bean containers often break when being handled once removed from the machine and excess quantity of coffee beans remain in the grinder and must be ground and discarded. 
         [0004]    Coffee Shop owners and roasters have long sought viable methods to track coffee consumption and record usage data in order to properly schedule maintenance of their machines and manage inventory. Previous attempts to record data include simple counters on coffee grinder dosing lever, but these grinders often require more than one pulls on the dispensing lever to deliver the correct amount of coffee. Espresso coffee machines are often equipped with devices to count the number of times a button is pushed to dispense coffee, but these machines are unable to differentiate between a button pressed deliver coffee and one simply to rinse between servings. This inaccurate data is kept on the machine itself and there is no facility to automatically collect and analyze usage information. Grinders used to prepare coffee for methods other than espresso have no means of gathering coffee consumption data either by quantity or brewing method. 
         [0005]    Existing systems that attempt to control the delivery of food product in food preparation have used time for portion control cannot accurately measure consumption and no means to log or deliver usage data to coffee roasters or store managers. 
         [0006]    Most importantly, no accurate means exists to calibrate the distance between the grinding mills so that the numeric indicator of the grind setting on one grinder is consistent with any other grinder. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is an improved method and apparatus to grind coffee where grinding speed can be adjusted either on demand or according to a programmed profile. By lowering the rotational speed of the grinding burrs, the user can insure more consistent particle size for types of coffee or methods of brewing where it is desirable. When a more diverse coffee particle size is desired or when speed of operation is more important than consistent particle size, the grinder can operate at a much higher rotational speed. Because programming a variety of settings can be time consuming, pre-programmed settings can be entered remotely using an internet connection and delivered to any number of grinders at one time. The grinder is optionally accessible remotely via the internet for programming and accessing usage data. 
         [0008]    Using an integrated load cell and platform provide the user the ability to portion ground coffee by weight. Additionally, using a load cell allows the grinder to identify the type of brewing device placed upon the platform by the weight of the device, preloading the program tailored to that device and the type of coffee selected. The grinder is then able to adjust the speed of the motor and the particle size of the ground coffee automatically. 
         [0009]    To simplify handling of unground coffee beans, the whole bean hopper is designed to slide towards the user to remove unground coffee beans from the device without removing the bean coffee container from the grinding apparatus. This also reduces the distance between the outlet of the hopper and the grinding burrs to minimize the amount of coffee left in the machine and reduce waste. 
         [0010]    The ability via motorized mechanism to automatically adjust the distance between the two grinding mills according to pre-programmed settings, manually entered values or in response to data collected from external devices. More importantly, the ability to calibrate the adjustment mechanism by moving the grinding mills towards each other until they come together and stop, thereby establishing a zero set point from which all grinder settings will be calculated. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a side view of one embodiment of the variable speed grinder; 
           [0012]      FIG. 2  is a top view of the drive mechanism for the variable speed grinder; 
           [0013]      FIG. 3  is a detailed side view of the sliding bean hopper mechanism in its closed position; 
           [0014]      FIG. 4  is a side view of the sliding hopper mechanism in its open position; 
           [0015]      FIG. 5  is a side view of the grinder detailing the activation switch and operation; 
           [0016]      FIG. 6  is a top view of the base of the grinder; 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]      FIG. 1  shows a side view of one embodiment of a coffee grinder  100  with receptacle for whole coffee beans  1 , a flexible drive belt  2  to convey power from the motor  3  and drive gear  20  to the grinder burr carrier  21  to rotate the outer portion of a grinding mechanism  22 . A cooling fan  4  is fixed to the base of the drive motor  3 . A toroidal transformer  5  and bridge rectifier  24  to power the drive motor  3 . A computer circuit board  16  controls the speed and torque profile to the drive motor  3 . A capacitor  6  to regulate the power coming from the transformer  5 . A load cell  9  to measure the weight of dispensed product on platform  7 . A digital encoder  8  to adjust values and parameters controlled by a circuit board  16 . An adjustment dial  10  to adjust the height the grinding burr  35  along fixed shaft  11 . Two bearings  12  provide support for the grinding mechanism  22 , allowing it to rotate around the center shaft  11 . A drive belt  2  situated above the two support bearings  12 . A chute  13  is attached to the front of the grinder  100  and below the hopper  1 . A guide bar  14  supports the fixed shaft  11  and aligns the hopper  1  to the grinder  100 . Finger guards  15  are molded into hopper  1 . 
         [0018]    A coffee grinder with a variable speed motor  3  can grind finely ground coffee more precisely and consistently at lower speeds than conventional high-speed grinders. Different methods of brewing coffee such as espresso coffee require that coffee beans be cut into consistent particles of even distribution. Existing coffee grinders spinning at high rates of speed tend to crush the coffee beans rather than cut them, especially when the motor starts resulting in an inconsistent particle size. Shown in  FIG. 100  is an embodiment of a coffee grinder that overcomes the challenges of consistent coffee particle size by using a variable speed motor whose speed and starting torque characteristics can be adjusted via a programmable controller  16  to accommodate a variety of coffee preparation methods or coffee bean types while retaining the ability to grind at high speeds when precision is unnecessary. 
         [0019]    Additionally, once coffee is ground it begins to oxidize rapidly and lose much of its flavor and aroma. A grinder that processes only as much coffee as is required and dispenses it directly from the grinding mill  22  unobstructed into a brewing device or filter holder eliminates waste and provides for the immediate consumption of ground coffee. The ability to grind coffee as needed and in the precise quantity required is key to ensuring quality. While some grinders use time to portion coffee, the rate at which coffee is ground varies with the particle size required and the hardness of the bean. Using a load cell  9  and platform  7  to portion the coffee allows for a wide variety of coffee types and brewing methods to be accurately ground and portioned for each application. The ability to program these values via a programmable controller  16  ensures consistency regardless of user and speeds the delivery of a variety of coffees custom tailored to each customer&#39;s needs. 
         [0020]    Coffee mills of a conical design  22  allow the coffee to be ground and dispensed directly from the bottom of the mill  10  and into a filter holder or receptacle. In order to facilitate an unobstructed flow of coffee in to the mill, the outer grinding surface must be rotated against a fixed internal grinding cone. The placement of the drive belt  2  above the two bearings  12  improves upon existing designs by allowing the belt  2  to be replaced without removing the grinder burr carrier assembly  21 . 
         [0021]    The exemplified embodiment further improves upon existing designs by using a DC motor drive  3  that adjusts torque in response to the load on the burr carrier assembly  21  eliminating the need to use additional gear reduction assemblies the previously were required to maintain burr speed. Reducing the number of parts needed improves reliability and eases future service to the internal components. 
         [0022]    The variety of grind settings and weights required for different brewing methods and coffee types can generate hundreds of combinations. The exemplified embodiment of this invention stores these different combinations as preset values in circuit board  16  and connects wirelessly to external devices so that these values can be programmed remotely and downloaded to one or a multitude of coffee grinders at one time. The programmed values are accessible by the user via the rotary encoder  8 . 
         [0023]    In the exemplified embodiment of the invention, coffee beans are stored in the hopper  1  and flow towards the grinding burrs  22 , whose outer section rotates around an axially fixed center burr secured to center shaft  11 . The adjustment dial  10  moves the center burr up and down along center shaft  11  adjusting the distance between the center burr and the rotating outer burr  22 , resulting in fine or more coarsely ground coffee. The ground coffee passes through tapered openings in the adjustment ring  10  onto coffee tray  7 . All ground coffee is dispensed and no residual coffee remains ensuring freshness and eliminating waste. 
         [0024]    An electronic position encoder  72  is attached to an electric stepper or servo motor  71  which in turn drives two pinch rollers  70  to cause the adjustment dial  10  to rotate, thereby adjusting the particle size of the ground coffee. The rotary encoder  72  is always under power to monitor the position of the adjustment dial  10  even if said dial is manually rotated without the use of the stepper motor  71  or the two pinch rollers  70 . 
         [0025]    Coffee is the second largest internationally traded commodity after oil and monitoring consumption and inventory levels for both retailers and roasters is important. The electronic circuit board  16  monitors usage data for all programmed functions of the grinder and uploads that data on demand or in real time to the Internet. In addition to usage data, the system can send text alerts or emails regarding inventory levels or call for service either automatically or when initiated by the user via text message, email or other electronic means. 
         [0026]    The height of the grinder  100  is designed to accommodate the most common filter holders and brewing devices, but can manufactured with varying heights to accommodate coffee bags or large containers according to a customer&#39;s needs. 
         [0027]      FIG. 2  is a top view of the drive mechanism for the variable speed grinder showing the motor driven primary pulley gear  20  driving the flexible belt  2  and passing power to the larger gear driven grinding mill carrier assembly  21  and grinder burr  22 . A supporting bar  14  is mounted to the assembly and supports the center non-rotating portion of the burr assembly. Magnet  43  is positioned along the support bar to index the position of a sliding coffee bean hopper along with a reed switch  41  or similar sensor to remove power from the motor assembly when the coffee bean hopper has been removed or slid out of operating position. A molded chute  31  is attached to one side of the grinder to facilitate the removal of un-ground whole coffee beans from the grinder. 
         [0028]    Using high torque DC motor allows for a larger primary drive gear  20  to drive the burr carrier  21  with more contact between the gears  20  and  21  and the belt  2 . It also allows for an approximate three-fold increase in torque without additional gear reduction assemblies. 
         [0029]      FIG. 3  is a detailed side view of the sliding bean hopper mechanism  1 , holding whole coffee beans  17  and bean chute  13 . Magnets  40  and  43  secure the hopper  1  into position and reed switch  41  detects the position of magnet  42 . 
         [0030]    A coffee grinder that is capable of grinding a variety of coffee types needs to facilitate the removal of unground coffee beans with a minimum of waste. Prior embodiments of coffee grinders require the removal of the bean holder from the machine. A stopping device in a bean holder, commonly known as a hopper, interrupted the flow of beans to facilitate removal from the machine, but a significant amount of coffee beans remain in the space above the coffee mills which have to be ground in order to remove resulting in a significant amount of waste. Hoppers are typically plastic or glass and handling them away from the machine provides an opportunity for the operator to drop the hopper, which are easily broken and rendered unusable. Index magnets  40  and  43  attract to each other and force the alignment of the hopper opening with the grinding mechanism. Index magnet  42  activates the reed switch  41  when the hopper is in proper position and signals the electronic board to allow the grinder to activate. 
         [0031]      FIG. 4  shows the side view of the hopper mechanism  1  slid forward  19  to allow the coffee to flow from the bottom of the hopper via chute  13  into a container  18 . 
         [0032]    The current embodiment of the grinder  100  improves on existing designs using a sliding hopper design  1  with a gliding motion  19  to allow the coffee to be removed from the grinder without removing said hopper from the machine. 
         [0033]    To remove coffee beans, the hopper is slid forward until index magnet  42  aligns with magnet  43  and stops the hopper in the correct position to remove unused coffee beans via chute  13 . Index magnet  42  moves away from reed switch  41  and prevents the motor from operating while the hopper is either out of position or removed. The sliding action  19  also eliminates the need for a neck or support structure found on existing grinder hoppers reducing the amount of unground beans left in the grinder. 
         [0034]      FIG. 5  shows a side view of the grinder mechanism with switch  50  of a capacitive, micro or similar construction. A graphical display is shown  51  with three different selections  52 ,  54  and  56  and three input methods for making said selections  53 ,  55  and  57 . 
         [0035]    In a busy retail environment, small selector switches that require the visual attention of the operator slow the process of preparing coffee beverages and are prone to error. The proposed invention simplifies the selection process with a single large switch  50  on the side of the grinder mechanism. Touching the switch in a pattern activates the grinder&#39;s preset values to deliver the desired amount of coffee. Touching the switch a single time indicated by action  53  initiates the grinding process indicated on display  51  and value in the first position  52 . Touching the switch twice indicated by action  55  initiates the grinding process for the value in the second position  54 . Touching the switch twice indicated by action  57  initiates the grinding process for the value in the second position  56 . 
         [0036]    Other programs can be entered in a similar fashion, for example continuously touching the switch  50  for more than a preset amount of time, for example two seconds, allows the grinder to run continuously until the switch is touched a subsequent time. The addition of a second switch on the opposite side of the grinder allows for more program options, for example touching both switches at the same time operates the grinder in reverse rotation so that the grinder can be adjusted without wasting coffee beans. 
         [0037]      FIG. 6  shows a top view of the base of the grinder with a display  60 , encoder  8  and load cell  6 . A removable scale platform  7  is shown that will index onto load cell  8 . Use of a load cell  8  allows the device to determine, by weight, the type of brewing device that has been placed on the platform  7  and automatically load the program that brewing device requires, adjusting the grind settings and motor speed upon selection by the operator. Automating this process allows a variety of preprogrammed portion settings using a touch sensitive display a single touch sensitive input device, including but not limited to a sequence of taps or a using one or more fingers. The operator can activate the grinding process and program without looking at the display or identifying a specific button to push. 
         [0038]    When grinding coffee for espresso, the operator may often prefer to hold the coffee filter with their hand and bypass the load cell  6  and platform  7 . When the device is activated without anything placed on the platform  7 , the grinder can initiate a programmed delivery based upon time instead of weight. Because the grinder is able to use a rotary encoder to determine particle size and receives speed data from the grinder motor, the grind time can be adjusted to accommodate any change to better insure consistent timed coffee delivery. 
         [0039]    The advantages of the present invention include, without limitation, the ability to program preset values via a remote device including but not limited to wifi, Bluetooth or the internet for access on the device; the ability to call for service from the device itself either by staff or initiated by the device itself when self diagnostics register a problem with the device; the ability to track consumption of coffee and wear on components remotely either in batches or in real time and to analyze captured data for inventory and accounting purposes; the ability to grind a variety of coffees for a variety of brewing methods and store the templates for each for ready access by the user; the ability to reverse grinder rotation so that the particle size of the ground coffee can be adjusted without grinding the coffee present in the mill; the ability to accurately weigh each delivery of ground coffee regardless of receptacle employed and the ability to remove unground coffee from the device without removing the bean hopper thereby minimizing the retention of unused coffee in the grinder and minimizing waste. 
         [0040]    In broad embodiment, the present invention is more efficient and precise method of delivering coffee on demand than those currently available with data collection and analysis capabilities not currently available in any available coffee grinder. 
         [0041]    While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention.