Patent Application
20070187534
This disclosure relates to a grinding apparatus for grinding material, such as coffee beans.
Grinding apparatuses are well-known in the art. Machines have been developed to convert roasted coffee beans into a ground substance suitable for brewing. Additionally, differing tastes in coffee have fostered the need to have differing grinds. For example, if one desires an espresso type of coffee, a fine grind of coffee may be needed for the espresso brewing process. However, some may desire the taste of freshly-ground coffee, but desire the flavors associated with a drip brewing process. A more coarse grind may suit this coffee drinker. Consequently, the prior art developed apparatuses that were adjustable and could provide differing grinds of coffee.
U.S. Pat. No. 5,201,474 to Midden shows a coffee grinder which enables one to select a desired grind of coffee. Midden teaches that unground coffee beans may be fed between two grinding elements commonly referred to as grinding burrs in order to produce a desired grind. The grinding elements were of differing shapes and sizes, and had differing surface configurations in order to alter the type of grind. Therefore, in order to obtain differing grinds, one had to change the grinding elements.
U.S. Pat. No. 5,558,283 to Fisher et al. shows a grinder having the ability to provide differing levels of grind. Using the Fisher apparatus, one could selectively adjust the space between spaced apart grinding elements in order to adjust the grind of coffee. The Fisher apparatus utilized a pair of grinding burrs, one of which rotated and the other of which was substantially stationary. However, the Fisher et al. apparatus biased the two grinding elements toward one another, which allowed the gap to expand or contract during the grinding process; therefore, the gap could vary, resulting in a potentially uneven grind over time.
The current disclosure improves on the prior art. The apparatus and method as disclosed includes a housing with an inlet and an outlet positioned near opposite ends of a longitudinal axis. A generally stationary grinding element or non-rotatable burr is retained in the housing. The non-rotatable burr is selectively movable along the longitudinal axis, but will does not rotate during the grinding process.
A rotating grinding element or rotatable burr is also positioned within the housing, and held at a fixed point on the longitudinal axis. A drive motor rotates the rotatable burr about the longitudinal axis. The non-rotatable burr is selectively movable between an idle position where the burrs engage one another and a grinding position where a gap exists between the burrs.
An adjusting device positioned within the housing enables selective movement of the non-rotatable burr along the longitudinal axis. In one embodiment, the adjusting device includes a controllable motor is connected to a worm gear positioned to engage gear teeth extending from a lateral edge of the non-rotatable burr. As the worm gear turns, it urges rotation of the non-rotatable burr about the longitudinal axis.
The non-rotatable burr includes a collar extending in a direction away from the rotatable burr. The collar and the inner surface of the housing are cooperatively threaded to enable movement of the non-rotatable burr along the longitudinal axis. There is a hole in the grinding surface of the non-rotatable burr. The collar has a hollow interior positioned around the hole; thus, the interior of the collar is connected with the inlet to provide a passage for material to pass from the inlet toward the gap between the burrs. A feeding auger urges unground material from the inlet toward the gap. The feeding auger is coupled to the drive motor at a first end and coupled to the rotatable burr at a second end.
The housing has a second outlet sufficiently sized to allow a clearance between an outer diameter of the rotatable burr and a corresponding inner surface of the housing. The clearance is too small to allow unground material to pass through, but large enough to allow ground material to escape. After passing through the gap, the ground material is expelled from the housing via the outlet.
The disclosed method includes the steps of providing a housing having an inlet and an outlet, providing a non-rotatable burr, and providing a rotatable burr. The method further includes providing an adjuster to selectively and controllably position the non-rotatable burr with respect to the rotatable burr, and bringing the burrs into contact with one another during a calibration or adjustment event. The method maintains a desired, pre-determined dimension in the gap between the burrs. The method allows for calibration of the gap to produce a desired type of grind from the grinder.
The method also includes the operation of the adjuster to selectively move the non-rotatable burr with respect to the rotatable burr to provide or set a gap of a desired dimension between the burrs. Additionally, a preselected amount of unground material is introduced into the inlet. A rotator turns the rotatable burr in order to grind the material, and then is expelled from the outlet. Preferably, the method also includes the step of moving the non-rotatable burr back into contact with one another once the preselected material has been expelled from the outlet.
The method may also include the providing of a pair of actuators: a first actuator to selectively operate the adjuster, and a second actuator in communication with the drive motor that delivers torque to the rotatable burr. The method may further include the step of placing the first and second actuators in communication with one another, so that when the first actuator finally locates the non-rotatable burr to its selected position, the second actuator automatically activates the rotator.
Other objects, advantages and novel features of the present disclosure will become apparent from the following detailed description when considered in conjunction with the accompanying drawings.
To operate, the user turns on the grinder assembly 24 at a control switch 28 and grinds a predetermined time related volume of ground coffee which is collected in a container 30 positioned below. The container 30 may be a coffee brewing funnel, coffee retaining bag, French press coffee brewing pot, or any other type of container which might be used to collect and brew, store or otherwise retain ground coffee. A variety of control functions can be incorporated in an appropriately configured control panel or control interface. For example, batch size or type of grind can be controlled using selectable control elements such as dials or dedicated switches. In the interest of clarity in this disclosure, reference will be made to the switch with the understanding that any and all other control elements or interfaces are contemplated.
The first and second burrs 38, 40 define a grinding burr assembly 52. A controllable burr adjuster 54 is operatively coupled to the grinding burr assembly 52 for controllably adjusting at least one of the grinding burrs. As shown in
The burr adjuster 54 shown in
With further reference to
As can be seen in
Having described the general structures and functions of the grinding 20 disclosed herein we now move on to the methods of operation and adjustment of the grinder 20 and grinder assembly 24. The grinder assembly 24 operates in the general manner described above for grinding beans. Further, the present disclosure provides a method of adjusting the grinder 20 to help assure and produce ground particles of a generally consistent size or range of sizes. The consistency of the particles is achieved regardless of the size of the particles selected, for example espresso grind versus drip grind. In other words, the present system helps to maintain consistent grinding of particles to a desired size or range of sizes. The consistency and repeatability of the grind size is achieved by the controllable grinder assembly 24. For example, the general structure of the grinding burrs 38, 40 and the burr adjuster 54 is provided. However, additionally shown are system components shown in diagrammatic form which provide sensing, control, information storage and operation of grinder assembly 24.
The system as shown in
Further, it will be appreciated that the threads 62 on the barrel 64 are generally relatively fine or narrowly spaced so as to further enhance the degree of precision with which the grinding burrs 38, 40 can be adjusted. Additionally, the increased number of threads and the relatively flat pitch of the threads as a result of being narrowly spaced apart can enhance the retention of the adjustment by reducing the possibility of rotation during the grinding operation which may occur as a result of vibration or friction between the beans being ground and the surfaces 32, 34 of the burrs 38, 40.
With further reference to
The sensors 90, 92 may be provided in a form such that they detect the positioning of the grinding burrs 80, 40 or the gap between the burrs through a variety of techniques. The sensors may be physical sensors that actually contact respective burrs or the gap to sense the physical dimensions relative to the burrs. Also, the sensors may be in the form of electrical, magnetic or optical sensors which sense the characteristics of the burrs and, in relation, the gap defined between the burrs. The sensors may also take the form of sonic detectors which sonically detect the relative position of a corresponding burr or of both burrs so as to provide a signal which can be processed to determine the gap between the burrs. It is envisioned that any form of sensing, including those noted above, but not limited to such sensors, may be used to determine the relationship of the burrs 38, 40, the position of each or both burrs, or the spacing of the gap between the burrs in any form possible. The interpretation of the embodiment of these sensors and the detecting of the gap between the burrs is envisioned to be broadly interpreted in the context of the present disclosure and is not intended to be limiting.
The controller 82 controls the motor 68 of the embodiment of the burr adjuster 54 shown in the figures. The controller 82 can control the motor 58 to operate the worm gear 64 a desired number of rotations or to a desired degree of load resistance. In this regard, a feedback sensor 102 can be coupled to the motor 68 and controller 82 over control lines 104.
During a calibration cycle, the burr adjuster 54 is operated to bring the generally non-rotatable burr 40 into a position in which the corresponding surface 34 contacts the surface 32 of the first burr 38. The engagement of the surfaces 32, 34 will be sensed by the load sensor 102 providing feedback to the controller 82. Once the contact is detected, sensed as an increased load on the motor 68, the controller 82 can operate the motor 68 to back off the burr 40 a desired amount. By backing off the surfaces 32, 34 based on the number of rotations of the worm gear 64, generally high precision dimensions can be maintained in the gap 74. This is true even if there is some wear on the surfaces 32, 34. In this regard, if a portion of the surface tends to wear over time, bringing the surfaces 32, 34 together for purposes of calibration and backing off a predetermined number of rotations at the worm gear 64 will still produce the desired gap 74. The gap 74 is consistent regardless of the dimensional wear on the surfaces 32, 34 as a result of being able to repeatedly recalibrate the relationship of the burrs.
It should be noted that there can be a variety of configurations of the burr adjuster 54 and that only one embodiment of the burr adjuster 54 is disclosed. Further, while the worm gear 64 is shown as being generally tangential to the corresponding teeth 56, it is envisioned that the adjuster 54 could be rotated 90 degrees to mesh with an appropriately configured gear such as a pinion gear, being attached to the drive 68. Such a rotated configuration may provide a longer range of axial movement of the non-rotatable burr 38. It is within the scope of the present disclosure that other forms of adjuster 54 could be included such as by way of hydraulics, pneumatics, spring biasing or any other form of adjuster which are currently available or may be provided in the future.
With the foregoing in mind, it should also be noted that the input device 84 is intended to be broadly interpreted. In this regard the input device 84 could be embodied in a keyboard, electrical information, inductive or conductive communication as well as, perhaps manual adjustment of rotary dials or other devices provided in the grinder 20. The input device 84 could also be a programmable chip or other device which is inserted into or otherwise coupled to the controller 82 to provide relevant information to the controller 82 for use in adjusting the burrs 38, 40.
In one use of the present disclosure, only one type of bean 27 is placed in the hopper 26 and only one type or grind of bean is desired. However, the present grinder 20 still provides for calibration of the burrs 38, 40 upon each grinding event, periodic programmed periods of a predetermined number of grinding events or other such occurrence as well as calibration upon selection by the user such as by requesting a calibration cycle using the input device 84. Regardless of the motivation for the calibration, the grinder assembly 24 as described can be calibrated to maintain a desired dimension 74 between the burrs 38, 40.
Before initiation of a grinding cycle, the controller 82 can operate the adjuster 54 to bring the surfaces 32, 34 of the burrs 38, 40 together. The load sensor 102 will sense a resistance which occurs when the two surfaces 32, 34 contact each other. Upon sensing this condition, the controller 82 stops advancement of the burr 38 towards the burr 40 by deactivating the motor or actuator 68. The controller 82 then controls the adjuster 54 in the opposite direction to back off the burr 38 from the burr 40 a desired dimension 74 to provide a desired gap between the surfaces 32, 34. Once the controller 82 deactivates the adjuster 54 the engagement of the gear 64 with the teeth 56 and the threads 62 with the chamber 42 wall helps to maintain, retain or otherwise hold or lock the desired adjustment between the burrs 38, 40. With this in mind, while a threaded barrel 64 has been shown and described, it is possible that the barrel 64 may not include the threads 62. This may result if the configuration of the adjuster 54 with the burr 38 is sufficient so as to not require the additional benefit of the precision adjustment of the thread 62.
Once the desired calibration is achieved, the grinder drive or motor 44 is operated thereby rotating the shaft 48 and driving the generally rotatable burr 40. A controllable slide gate mechanism of known construction may be provided between the hopper 26 and the grinding chamber 42 thereby facilitating controller introduction of beans into the gap 74 between the burrs 38, 40.
In another embodiment of the grinder 20, the input device 84 may allow for selection of a variety of grinds or even custom selection of a desired grind. In this regard, the input device would be controllable by the user or passive such that the information is pre-programmed into a memory device such as a card, inductive or conductive device, a bar code presented to a bar code reader type of input device 84 or other devices or systems for inputting the information. The selection of a desired grind at the input device 84 is provided to the controller 82. Before grinding beans, the controller 82 can operate the adjuster 54 to controllably adjust the gap 74 between the burrs 38, 40. The adjustment is carried out in much the same manner as described above. However, the adjuster 54 backs off the burr 38 from the burr 40 dimension which corresponds to the selected grind. Such information may be stored in the memory 98 such that a desired grind corresponds to, a gap dimension 74. Once again, the present disclosure provides a desirably consistent adjustment such that the gap dimension 74 is generally a fixed amount and does not depend upon the degree of wear on the burr surfaces 32, 34.
With the foregoing in mind, however, it is envisioned that the present disclosure can also compensate for wear on the burrs 38, 40. In this regard, the burrs generally are expected to have a predetermined life of some number of grinding operations. Information could be provided to the controller 82 or otherwise programmed into the system 80 to make minor adjustments to account for regular and ordinary wear on the surfaces 32, 34. For example, if the burrs 38, 40 are expected to maintain a sufficiently honed surface after ordinary grinding of coffee bean of, perhaps, 5000 cycles, the information can be provided to the controller 82. Knowing that there will be some wear of the honed surfaces 32, 34, minor incremental adjustments can be made to gap 74 to slightly decrease the gap 74, for example, at a point half-way through the life of the burrs and three-quarters of the way through the life of the burrs.
In yet another embodiment, the system 80 may include the sensors 90, 92. It should be noted that the above descriptions may or may not include the sensors 90, 92. In the presently discussed additional embodiment, the sensors 90, 92 monitor the gap 74. When the controller 82 detects that the sensors 90, 92 indicate that the gap has fallen outside of a desired range, either too large or too small, the controller 82 can operate the adjuster 54. In this regard, it may not be necessary to bring the surfaces 32, 34 into engagement and then back off the burr 38. In other words, the sensors 90, 92 can provide feedback to the controller and provide information to operate the burr adjuster 54. Continued feedback from the sensors 90, 92 through the controller in relation to the operation of the burr adjuster 54 results in obtaining and maintaining a desired gap 74 between the surfaces 32, 34. Such monitoring can be used to monitor and adjust the gap 74 to be smaller or larger to obtain a desired gap spacing. While it may be preferable to make such adjustments when the rotating burr 40 is not in operation, it is within the scope of the present disclosure to allow the adjustment by way of the adjuster 54 to occur during a grinding cycle.
An additional embodiment of a grinder assembly 24a is shown in
As shown in
While embodiments have been illustrated and described in the drawings and foregoing description, such illustrations and descriptions are considered to be exemplary and not restrictive in character, it being understood that only illustrative embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. The applicants have provided description and figures which are intended as illustrations of embodiments of the disclosure, and are not intended to be construed as containing or implying limitation of the disclosure to those embodiments. There are a plurality of advantages of the present disclosure arising from various features set forth in the description. It will be noted that alternative embodiments of the disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations of the disclosure and associated methods, without undue experimentation, that incorporate one or more of the features of the disclosure and fall within the spirit and scope of the present disclosure and the appended claims.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US04/11741 | 4/16/2004 | WO | 1/25/2007 |
| Number | Date | Country | |
|---|---|---|---|
| 60463307 | Apr 2003 | US |
