U.S. patent application number 11/566419 was filed with the patent office on 2007-03-22 for beverage making apparatus.
This patent application is currently assigned to APPLIANCE DEVELOPMENT CORPORATION. Invention is credited to Dov Z. Glucksman, Gary P. McGonagle, Laura J. Nickerson, John P. Oliver.
Application Number | 20070062378 11/566419 |
Document ID | / |
Family ID | 37417828 |
Filed Date | 2007-03-22 |
United States Patent
Application |
20070062378 |
Kind Code |
A1 |
Glucksman; Dov Z. ; et
al. |
March 22, 2007 |
BEVERAGE MAKING APPARATUS
Abstract
A brewing apparatus for infusing compacted ground coffee in a
grounds cup at a brewing station with heated water under pressure.
At a brewing station, a piston head with an active seal that is
spaced from the grounds cup wall during motion, extends into the
grounds cup. When the piston head begins to compact the ground
coffee it activates the seal to form a sealed upper end of a
brewing chamber. Hot water is admitted to the brewing chamber to
produce the coffee. When the brewing cycle is completed, the piston
head displaces further to force additional coffee from the grounds.
Then the piston head retracts to allow the infusion chamber
assembly to be removed for cleaning.
Inventors: |
Glucksman; Dov Z.; (Danvers,
MA) ; McGonagle; Gary P.; (Lynn, MA) ;
Nickerson; Laura J.; (FItchburg, MA) ; Oliver; John
P.; (Gulf Breeze, FL) |
Correspondence
Address: |
GEORGE A. HERBSTER
40 BEACH STREET
SUITE 303
MANCHESTER
MA
01944
US
|
Assignee: |
APPLIANCE DEVELOPMENT
CORPORATION
130 Centre Street
Danvers
MA
01923
|
Family ID: |
37417828 |
Appl. No.: |
11/566419 |
Filed: |
December 4, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11129041 |
May 14, 2005 |
|
|
|
11566419 |
Dec 4, 2006 |
|
|
|
Current U.S.
Class: |
99/279 |
Current CPC
Class: |
A47J 31/3623 20130101;
A47J 31/4403 20130101; A47J 31/4421 20130101; A47J 31/52 20130101;
A47J 31/3609 20130101; A47J 31/5253 20180801; A47J 31/5255
20180801; A47J 31/3614 20130101; A47J 31/525 20180801 |
Class at
Publication: |
099/279 |
International
Class: |
A47J 31/00 20060101
A47J031/00 |
Claims
1. Apparatus for brewing beverages by supplying a liquid under
pressure to an infusible material, said apparatus comprising: A)
infusion chamber means for receiving the infusible material
including a side wall, an open top and a perforated bottom, and B)
piston means for compacting the infusible material and dispersing
the liquid, said piston means including piston head means for
forming a brewing chamber in said infusion chamber means and piston
rod means for moving said piston head means past said open top,
said piston head means having an active peripheral sealing means
including: i) first means fixed to said piston rod means for
forming a rigid structure, ii) second means for compacting the
infusible material and dispersing the liquid and including: a)
means for forming a labyrinth facing said brewing chamber, and b)
perforated disk means overlying said labyrinth for distributing the
liquid under pressure evenly over the infusible material during
brewing, iii) sealing means attached to each of said first and
second means for suspending said second means from said first
means, and iv) spring means intermediate said first and second
means for separating said first and second means when said piston
head means is spaced from the infusible material whereby said seal
means contracts from said side wall of said infusion chamber means,
said second means overcoming the bias of said spring means during
compaction of the infusible material whereupon said seal means
expands into a sealing engagement with the side wall and said
piston head means and said infusion chamber means form the brewing
chamber.
2. Apparatus as recited in claim 1 wherein said sealing means
includes a peripheral sealing portion for sealing the periphery of
said perforated disk means and said labyrinth forming means whereby
liquid emerges from said piston head means into the infusible
material only through said perforated disk means.
3. Apparatus as recited in claim 1 wherein said sealing means
includes an annular flexible body portion with first and second lip
means for attachment to said first and second means.
4. Apparatus as recited in claim 3 wherein said first and second
means include first and second attachment means for attaching to
said first and second lip means, respectively.
5. Apparatus as recited in claim 1 wherein said sealing means
includes skirt means for forming a seal with said side wall when
said active sealing means is in its expanded state.
6. Apparatus as recited in claim 5 wherein said skirt means extends
from the periphery of said annular flexible body portion.
7. Apparatus as recited in claim 6 wherein said second means
additionally includes guiding means for aligning said piston head
means with said infusion chamber means thereby to protect said
skirt means from damage when said piston head means moves in said
infusion chamber means.
8. Apparatus for brewing beverages by supplying a liquid under
pressure to an infusible material wherein said apparatus includes
an infusion chamber including a side wall, an open top and a
perforated bottom and a piston including a piston head that forms a
brewing chamber in said infusion chamber and a piston rod that
moves said piston head past said open top, said piston head having
an active peripheral seal comprising: A) a first rigid disk fixed
to said piston rod, B) a second disk including a labyrinth facing
said brewing chamber and a perforated disk overlying said labyrinth
that distributes the liquid under pressure evenly over the
infusible material during brewing, C) a seal captured by each of
said first and second disks that suspends said second disk from
said first disk, and D) a spring intermediate said first and second
disks that separates said first and second disks when said piston
head is spaced from the infusible material whereby said seal
contracts from said infusion chamber side wall, said second disk
overcoming the spring bias during compaction of the infusible
material whereupon said seal expands into a sealing engagement with
the side wall and said piston head and said infusion chamber form
the brewing chamber.
9. Apparatus as recited in claim 8 wherein said seal includes a
peripheral sealing portion that seals the periphery of said
perforated disk and said second disk whereby liquid emerges from
said piston head means into the infusible material only through
said perforated disk.
10. Apparatus as recited in claim 8 wherein said seal includes an
annular flexible body portion with first and second lips attached
to said first and second disks, respectively.
11. Apparatus as recited in claim 10 wherein said first and second
disks include first and second attachment means for attaching to
said first and second lips, respectively.
12. Apparatus as recited in claim 10 wherein said seal includes a
skirt attached to said body portion forming a seal with said
infusion chamber when said active peripheral seal expands.
13. Apparatus as recited in claim 12 wherein said skirt extends
from the periphery of said annular flexible body portion.
14. Apparatus as recited in claim 13 wherein said second disk
additionally includes a guide that aligns said piston head with
said infusion chamber thereby to protect said skirt from damage
when said piston head moves into said infusion chamber.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of co-pending U.S. patent
application Ser. No. 11/129,041 filed May 14, 2005 for a coffee
making apparatus.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention generally relates to apparatus for brewing
beverages by directing a liquid, such as hot water, across a
compacted infusible material, such as ground coffee beans, in a
sealed infusion chamber.
[0004] 2. Description of Related Art
[0005] A large number of commercial devices are available for
brewing beverages, particularly coffee, by infusing material with a
liquid. Prior art coffee makers have incorporated a variety of
percolating, drip, steeping and other brewing approaches. A large
number of these coffee makers were also designed to brew coffee in
batches, for example, 4-cup to 12-cup batches. Such devices,
however, were characterized by difficulties in maintaining coffee
flavor over time, in controlling waste as occurred by making
excessive coffee that was then discarded, and in cleaning and
maintenance of the coffee makers.
[0006] The advent of espresso machines introduced new coffee
brewing concepts. Espresso machines produce a small quantity of
coffee at any given time, such as a cup of cappuccino or espresso.
Espresso was brewed and continues to be brewed by placing an
appropriate quantity of ground espresso coffee into an infusion
chamber, compacting the ground coffee and closing that chamber. Hot
water under pressure infuses the compacted coffee to extract its
essence and directs the beverage to a cup.
[0007] This process has become very popular, and there are a
variety of implementations primarily for use in espresso machines,
but also for machines for brewing coffee. For example, U.S. Pat.
No. 4,457,216 to Dremmel discloses an infusion chamber with
hydraulically operated upper and lower pistons that close a
scalding chamber. The scalding chamber contains coffee grounds and
receives hot water. During the brewing process the loose coffee
swells. When brewing is complete, the lower piston rises to
compress the swollen grounds extract the brewed coffee that passes
through the lower piston to a cup or other serving receptacle.
After the brewing cycle is complete, the upper piston retracts.
Then the lower piston can elevate to position the used compressed
coffee grounds above the infusion chamber for removal.
[0008] U.S. Pat. Nos. 4,796,521 and 5,255,594 to Grossi disclose
infusion chambers with a piston that delivers hot water by means of
a metering unit. The piston is operated to allow the introduction
of a filter carrier element and for compressing the coffee powder.
U.S. Pat. No. 4,796,521 discloses a direct introduction of ground
coffee from a coffee grinder into the infusion chamber. U.S. Pat.
No. 5,255,594 discloses a motor drive.
[0009] U.S. Pat. No. 5,230,277 to Bianco discloses two pistons
mounted on circulating ball screw actuators for closing the top and
bottom of an infusion chamber. The pistons are brought together to
compact ground coffee after which hot water is introduced for
infusion. After the brewing cycle, both pistons can be raised so
the lower piston can eject the used coffee grounds.
[0010] In U.S. Pat. No. 5,237,911 to Aebi a piston moves into an
infusion chamber to compress ground coffee. The bottom of the
piston comes into direct contact with the compressed ground coffee.
There is no specific disclosure of a seal for preventing the escape
of water from the infusion chamber past the piston.
[0011] U.S. Pat. No. 5,277,102 to Martinez discloses a vending
machine with a lower piston. The lower piston rises to compact
ground coffee against a fixed upper plunger or piston.
[0012] In U.S. Pat. No. 5,280,747 to Bonneville an espresso machine
has a vertically movable snout for supplying hot water under
pressure to ground coffee held in a filter. A cylinder or piston
moves against the action of an antagonist spring to cause the snout
to penetrate the package and compress the ground coffee.
[0013] U.S. Pat. No. 5,302,407 to Vetterli discloses a brewing or
infusion chamber with a movable piston. The brewing chamber has an
open top. A closure piston opens and closes the brewing chamber.
Pressurized hot water causes the movable piston to move upward to
compress the ground coffee.
[0014] In U.S. Pat. No. 5,402,706 to Locati an infusion chamber has
a lower filter piston and an upper, two-part infuser piston. The
infuser piston has a seal. One part of the upper piston slides into
the other part against an opposing spring resistance. The seal
remains in a contracted condition at a narrow diameter of a conical
seat while the infusion piston enters the infusion chamber. During
an operating stage, however, the distance between the two portions
of the piston decreases causing the seal to shift upward to a
maximum diameter of a conical seat. This process provides a seal
and eliminates brushing and scraping of the packing to minimize
wear and tear.
[0015] U.S. Pat. No. 5,911,810 to Kawabata discloses a coffee
brewing system in which a vertically movable cylinder receives
ground coffee and has a top opening. A vertically movable, upwardly
urged plunger compacts grounds after second cylinder is
elevated.
[0016] U.S. Pat. No. 6,035,762 to Ruckstuhl discloses an espresso
machine with a brewing chamber in which two brewing chamber parts
can be displaced relative to one another. In a closed position they
form a brewing chamber for filter capsules. One of the members has
multiple nozzles for directing hot water across the coffee. This
approach allows the use of coffee pods of different sizes.
[0017] In U.S. Pat. No. 6,606,938 to Taylor, a beverage brewing
apparatus includes a disposable cartridge that is initially pierced
and vented by a tubular outlet probe when an arm pivots a water
disposing head into a sealing relationship with the top of the
removable cartridge.
[0018] U.S. Pat. No. 6,711,988 discloses an espresso machine with a
variable volume infusion chamber. A piston with a static seal,
shown as an O-ring, seals against and moves relative to an infusion
cylinder. During brewing the piston elevates underwater pressure to
allow swirling. When a predetermined pressure is obtained, a
frothing valve opens. The piston moves toward the frothing valve to
press the coffee grounds under a spring-generated force.
[0019] These and other features have been incorporated in a number
of single-cup coffee makers, particularly for espresso machines for
commercial use, as in restaurants, coffee shops and the like.
However, such machines are expensive and not economically
attractive to most consumers even though they may make the best
coffee.
[0020] Recently several manufactures have introduced so-called
"cup-at-a-time" coffee makers. They replace such pistons with
hinged top units that latch to a base. A consumer must manually
unlatch the hinged top unit, open it to expose a container for
receiving either proprietary coffee pods or loose coffee. Then the
consumer must manually close and latch the top unit to compact the
coffee and form the sealed infusion chamber.
[0021] With cup-at-a-time coffee makers clean up requires the top
to be reopened. If the coffee is made with loose grounds, the
grounds cup must be removed so the used grounds can be discarded.
If a pod is used, it can be lifted from a grounds cup without
having to remove the grounds cup.
[0022] In many applications consumers desire automatic systems that
incorporate coffee grinders. Such systems are characterized by
locating the brewing chamber at an inaccessible location so it
becomes impossible or, at best, very difficult, to clean the
brewing chamber. Cleaning the brewing chamber in any such coffee
maker is very important. If regular cleaning is not undertaken,
oils and organic acids present in coffee attack the seal materials
used to define the brewing chamber. Such substances also accumulate
on the walls of the brewing chamber. If the seal slides over the
walls, this material produces a rough surface that can damage the
seals with use.
[0023] Some commercially available consumer-oriented coffee makers
limit the consumer to proprietary prepackaged coffee filter pods.
This can limit consumer choices. Also some consumer-oriented coffee
makers are limited to making espresso. These factors and expense
limit their market to consumers.
[0024] What is needed is apparatus for brewing a beverage, such as
coffee, that is economical and easy to use. Specifically, what is
needed is an economical coffee brewing apparatus that eliminates
manual operation of latches, facilitates the incorporation of a
grinder, simplifies cleaning and maintenance and is adapted for
accepting ground coffee in a variety of forms.
SUMMARY
[0025] Therefore it is an object of this invention to provide
brewing apparatus for the consumers that has many of the advantages
of more expensive commercial systems and that is economical,
convenient to use and easy to maintain.
[0026] Another object of this invention is to provide brewing
apparatus that eliminates manual latching mechanisms.
[0027] Still another object of this invention is to provide brewing
apparatus that is adapted for use with a grinder while maintaining
separation between their respective functions in order to
facilitate use and maintenance.
[0028] Still another object of this invention is to provide a
coffee brewing system that is adaptable for receiving coffee
grounds in a variety of forms.
[0029] Yet still another object of this invention is to provide a
coffee brewing system in which a grounds cup can be withdrawn for
filling or cleaning without the need for releasing manual latches
or breaking seals.
[0030] Yet another object of this invention is to provide a coffee
brewing apparatus that can be used for brewing regular coffee or
espresso.
[0031] In accordance with this invention, beverage brewing
apparatus includes a supply for liquid under pressure for
application to an infusible material. An infusion chamber receives
the infusible material and includes a side wall, an open top and a
perforated bottom. A piston compacts the infusible material and
disperses the liquid. A piston head is adapted to close the
infusion chamber to define a brewing chamber. A piston rod moves
the piston head past the open top. The piston head has an active
peripheral seal with a first structure fixed to the piston rod to
form a rigid support. A second structure is adapted for compacting
the infusible material and dispersing the liquid. A sealing
structure attaches to each of the first and second structures for
suspending the second structure from the first structure. A spring,
intermediate the first and second structures, separates them when
the piston head is spaced from the infusible material whereby the
seal contracts from the side wall of the infusion chamber. When the
second structure overcomes the spring bias during compaction of the
infusible material, the seal expands into a sealing engagement with
the side wall. The piston head and the infusion chamber form the
brewing chamber.
[0032] In accordance with another aspect of this invention, a
beverage brewing apparatus includes a supply for liquid under
pressure to be directed to an infusible material. The apparatus
includes an infusion chamber with a side wall, an open top and a
perforated bottom. A piston includes a a piston rod and a piston
head that form a brewing chamber in the infusion chamber. The
piston rod moves the piston head past the open top, The piston head
has an active peripheral seal comprising a first disk fixed to the
piston rod for forming a rigid support, a second disk, a seal
captured by each of the first and second disks for suspending the
second disk from the first disk, and a spring intermediate the
first and second disks. The spring separates the first and second
disks when the piston head is spaced from the infusible material
whereby the seal contracts from the infusion chamber side wall. The
second disk overcomes the spring bias during compaction of the
infusible material whereupon the seal expands into a sealing
engagement with the side wall and the piston head and the infusion
chamber form the brewing chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The appended claims particularly point out and distinctly
claim the subject matter of this invention. The various objects,
advantages and novel features of this invention will be more fully
apparent from a reading of the following detailed description in
conjunction with the accompanying drawings in which like reference
numerals refer to like parts, and in which:
[0034] FIG. 1 is a perspective view of an espresso machine
incorporating this invention;
[0035] FIG. 2 is a perspective view of the interior portions of the
espresso machine shown in FIG. 1 taken from the right front;
[0036] FIG. 3 is a perspective view of the espresso machine shown
in FIG. 1 taken from the left rear;
[0037] FIG. 4 is an exploded view of a compacting structure used in
the espresso machine of FIGS. 1 through 3;
[0038] FIG. 5 is a detail of a top disk shown in FIG. 4;
[0039] FIG. 6 is a view in section of a portion of the espresso
machine taken along lines 6-6 in FIG. 3;
[0040] FIG. 7 is a section view of the portion of the infusion
chamber taken along lines 7-7 in FIG. 6;
[0041] FIG. 8 is an exploded perspective view of a infusion chamber
assembly that receives ground coffee;
[0042] FIG. 9 is a cross section of the infusion chamber assembly
of FIG. 8;
[0043] FIG. 10 is a cross section of an active seal shown in FIG.
4;
[0044] FIG. 11A is a cross section that depicts the compacting
structure of FIG. 4 in an intermediate position with the compacting
structure located within the infusion chamber assembly;
[0045] FIG. 11B is an enlarged detailed portion of the structure
shown in FIG. 12A;
[0046] FIG. 12A is a cross section that depicts the compacting
structure of FIG. 4 in a position that compacts the ground coffee
in the infusion chamber assembly;
[0047] FIG. 12B is an enlarged detailed portion of the structure
shown in FIG. 12A;
[0048] FIG. 13 is a cross section that depicts the compacting
structure of FIG. 4 in a fully extended position that facilitates
cleaning;
[0049] FIG. 14 is a simplified schematic view of a control system
for operating the espresso machine shown in FIG. 1; and
[0050] FIG. 15 is a flow chart depicting one embodiment of the
operation of the control system in FIG. 14.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0051] FIG. 1 depicts one embodiment of an apparatus of this
invention for brewing beverages, such as coffee, by supplying a
heated liquid, such as hot water, under pressure to an infusible
material in an infusion chamber. Specifically, FIG. 1 depicts such
apparatus in the form of an espresso machine 20 with a housing 21
with and on a base 22. The housing 21 includes a cup warmer 23 for
cups, such as the cup 24, so cups can be preheated before being
filled with espresso. The housing includes a control panel 25, a
brewing/steam control knob 26 and a grind fineness adjustment knob
27 for any included coffee grinder. A water reservoir or tank 30 on
the base 22 has an integral handle 31 to facilitate removal and
filling.
[0052] FIG. 1 depicts a removable, reusable, infusion chamber 32 at
a brewing station 33 that includes a grounds cup holder 34 with an
integral handle 35.
[0053] A removable drip tray assembly 36 resting on the base 22
provides a facility for supporting one or two cups 37L or 37R or
both. The housing 21 also supports a steam nozzle 38 and a coffee
bean hopper door 39 that covers a hopper 39A in FIG. 2 that directs
coffee beans into any included grinder. A fill station 40 is
located at a fill station door 41
[0054] In use a consumer brews one or two cups of coffee by
activating a power-on switch 42 and by checking the water reservoir
30 for a sufficient water level. Then the individual grasps the
handle 35 to withdraw the infusion chamber assembly 32 from the
brewing station 33 in a straight-forward motion to deposit
preground coffee or prepackaged ground coffee into the infusion
chamber assembly 32.
[0055] If freshly ground coffee is desired, the individual inserts
the infusion chamber assembly 32 into the fill station 40 through
the fill station door 41 again with a straight-forward motion. If
the fill station 40 has a coffee grinder, the individual moves the
fineness adjustment knob 27 to a desired position and selects
either a one-cup or two-cup quantity by means of a one-cup switch
43 or a two-cup switch 44. Activating the switch 45 initiates the
grinding operation that deposits the appropriate quantity of ground
coffee into the infusion chamber assembly 32. Alternatively the
fill station would comprise a container for ground coffee and a
dispenser for depositing pre-measured quantities of coffee into the
infusion chamber assembly 32.
[0056] When the filling operation is completed, the individual
merely withdraws the infusion chamber assembly 32 from the fill
station 40, whereupon the fill chamber door 41 closes. Then the
individual inserts the infusion chamber assembly back into the
brewing station 33. These operations are achieved without any need
to manipulate latches or other mechanisms.
[0057] When various visual annunciators, such as LEDs or like light
sources 46, indicate brewing can begin and the brew/steam control
selector 26 is in the brewing position, depressing a brewing switch
47 initiates the brewing operation. The consumer sees the result
when brewed coffee begins to fill the coffee cups 37L and 37R. If
only one cup is to be brewed, it is merely necessary to remove the
cup 37R and center the cup 37L below the handle 35, or vice
versa.
[0058] Emptying the used coffee grounds requires the individual to
withdraw the infusion chamber assembly 32 from the brewing station
33 to dispose of the used coffee grounds and to clean the grounds
cup. Periodically an individual can initiate a cleaning cycle
whereby a compacting structure becomes readily accessible, as
described later. The control 27 can include an access ring 50 that
can be used to remove the front burr of the grinder for
cleaning.
[0059] When it is desired to apply steam for foaming milk or for
preheating a cup the consumer merely shifts the BREW/STEAM control
26 to a steam position. Steam will be dispensed from the bottom of
the steam nozzle 38.
[0060] FIGS. 2 and 3 depict the espresso machine 20 with the
housing 21 removed to view the major components including the base
22, the water reservoir 30, the removable drip tray assembly 36 and
the cup warmer 23. FIG. 2 additionally discloses the BREW/STEAM
control valve 26, the grind fineness adjustment knob 27 and the
steam nozzle 38.
[0061] The water reservoir 30 has a hinged top 51 and rear wall 52
with a connector 53. The connector 53 includes a check valve (not
shown) that closes when the water reservoir 30 is removed from the
espresso machine 20 for filling. When a full water reservoir 30 is
inserted and seated in the espresso machine 20, a connector on the
apparatus, not shown but well known in the art, interacts with the
connector 33 to open the check valve. Water is then available to a
pump 54 shown in FIG. 3.
[0062] The pump 54, when active, pumps cold water into a boiler 55
through a conventional flow meter 56. Tubing, not shown for purpose
of clarity, conveys hot water from the boiler 55 to an inlet hose
57 on a compacting assembly 60 that forms a brewing chamber in
cooperation with the infusion chamber assembly 32 that is inserted
into the brewing station 33. Heat from the boiler 55 elevates the
temperature of the cup warmer 23.
[0063] As shown in FIG. 2, at the brewing station 33 the espresso
machine includes a semi-cylindrical support portion 61 and two
tangential planar wall extensions 62 that carry a shelf 63. The
shelf 63 acts as a support for the infusion chamber assembly 32,
particularly the grounds cup holder 34. An interlock 64 provides an
enabling input to a brewing controller when the infusion chamber
assembly 32 is fully seated and properly aligned in the brewing
station 33.
[0064] The fill station 40 has a similar structure with a
semi-cylindrical support portion 65 and two tangential planar wall
portions 66. A shelf 67, similar to the shelf 63, supports the
infusion chamber assembly 32 for receiving ground coffee. An
interlock 68 provides an enabling signal to a controller when the
infusion chamber assembly 32 is fully seated and aligned in the
fill station 40.
[0065] Still referring to FIGS. 2 and 3, the compacting assembly 60
includes a piston assembly 70 driven, in this embodiment, by a
motor 71 through a speed reduction gear mechanism 72. In this
specific embodiment the apparatus 20 also includes a coffee grinder
73 at the fill station 40 that grinds beans to ground coffee of a
selected coarseness or fineness.
[0066] FIG. 4 depicts the piston assembly 70. It includes a
threaded piston rod 74 characterized by an axially extending slot
75 that engages a stationary base plate for preventing rotation. A
radial arm 76 serves as a switch actuator for limit switches as
described later. A threaded rod retainer 77, overlying an upper end
80 of the threaded piston rod 74, includes a plurality of clips 81.
The clips 81 engage corresponding apertures 82 in a top disk 83 as
more specifically disclosed in FIG. 5.
[0067] FIG. 5 is a perspective view taken from above the top disk
83. The top surface of the top disk 83 has a plurality of
circumferential lands and grooves that provide a rigid structure
while minimizing its weight and material. The top disk 83
additionally includes a passage 84 for enabling a connection to the
inlet hose 57 in FIG. 3 that connects to the boiler 55.
[0068] Referring again to FIG. 4, a bottom disk 85 includes an
axial shoulder 86 and a bottom labyrinth 87. The labyrinth 87
facilitates the dispersal of water exiting a nipple 90 across the
extent of and through a supported perforated disk 91 as described
later. A guide ring 92 is axially coextensive with the axial
shoulder 86 and provides peripheral support for the perforated disk
91. A screw 93 engages a central threaded aperture 94 accessible
from the bottom of the bottom disk 85 thereby to fasten the bottom
disk 85, the perforated disk 91 and guide ring 92 into a
subassembly. In this assembly the free ends of axially extending
walls forming the labyrinth 87 support the perforated disk 91 so it
does not deform when it engages ground coffee in the infusion
chamber assembly 32.
[0069] A wavy spring 95 lies intermediate the top disk 83 and
bottom disk 85. The top disk 83 and bottom disk 85 sandwich a seal
96 characterized by a radially contracted state and a radially
expanded state. The top disk 83, bottom disk 85, perforated disk
91, guide ring 92, screw 93, wavy spring 95 and seal 96 thereby
form a piston head 97 that attaches to the threaded piston rod 74
and provides an active peripheral seal structure. As described in
more detail later, the seal 96 attaches to the bottom disk 85 and
to the top disk 83. When the threaded piston rod 74 is in a
retracted position, the wavy spring 96 exerts a force that tends to
separate the top disk 83 from the bottom disk 85. Under these
conditions the seal 96 relaxes, has a minimum diameter and is
radially contracted. When the axial distance between the top disk
83 and bottom disk 85 decreases, the wavy spring 95 compresses and
the diameter of the seal 96 increases so the seal 96 moves to the
radially expanded state.
[0070] The seal 96 performs several functions. First, the seal 96
engages the cylindrical wall 112 of the grounds cup 102 to confine
any water or brewed coffee to the brewing chamber 98. Second, the
seal 96 assures that all the hot water admitted to the labyrinth in
FIG. 4 passes through the perforated disk 91 and into the ground
coffee in the brewing chamber 98. As a third function, the seal 96
acts as a flexible coupling that supports the bottom disk 85 on the
piston head 97. The specific construction of the seal 96 and its
performance of these functions are described later.
[0071] FIGS. 6 and 7 are useful in understanding the mechanical
arrangements of the compacting assembly 60 and the infusion chamber
assembly 32. When the piston head 97 is positioned in the grounds
cup 102 at a position shown by dashed line 99 and sealed by the
seal 96, the area below the piston head 97 bounded by the infusion
chamber assembly 32, specifically the grounds cup 102, becomes a
brewing chamber.
[0072] In these views, however, the motor 71 and gear train 72 have
retracted the threaded piston rod 74 and the piston head 97 to an
upper limit or fully retracted position as defined when the radial
arm 76 on the threaded piston rod 74 engages an upper limit
microswitch 100. A lower limit microswitch 101 defines a lower-most
position or range of travel. When the piston is fully retracted,
the infusion chamber assembly 32 is easily removed from the brewing
station 33.
[0073] FIGS. 8 and 9 depict the infusion chamber assembly 32 with
the grounds cup holder 34 and a grounds cup 102. The grounds cup
holder 34 includes a face plate 103 with the integral handle 35 and
an integral cylinder 104. Spaced circumferential ribs 105 on the
cylinder 104 form a channel that engages the shelf 63 that acts as
a supporting track at the brewing station 33 shown in FIG. 2 to
position the infusion chamber assembly 34 below the compacting
assembly 60. The ribs 105 also engage the shelf 67 in FIG. 2 that
acts as a track at the fill station 40.
[0074] Still referring to FIGS. 8 and 9, the grounds cup holder 34
has a concave bottom 106, a right dispensing port 107 and a left
dispensing port 110. During brewing, coffee exits from both of
these ports. When two coffee cups, such as the coffee cups 37L and
37R are arranged as shown in FIG. 1, coffee is dispensed into the
two cups simultaneously. However, the spacing between the ports 107
and 110 is such that when a single cup is centered about the handle
35, coffee from both dispensing ports 107 and 110 will be directed
into a single cup.
[0075] Referring again to FIGS. 8 and 9, the grounds cup 102 has a
cylindrical wall 112 that extends from an open top with a lip 113
that engages a top edge 114 of the cylinder 104, so the grounds cup
102 essentially rests in the grounds cup holder 34 for support. At
the bottom, the grounds cup 102 has two tapered annular portions
115 and 116 that terminate with a perforated bottom or sieve
portion 117.
[0076] In accordance with one aspect of this invention, the depth
of the cylindrical wall 112 is at least equal to the depth of the
grounds in the grounds cup 102 plus an amount that enables the
piston head 97 to achieve a sealing relationship with the
cylindrical wall 112 of the grounds cup 102. This depth provides
flexibility to a consumer because a single grounds cup 102 will
accommodate coffee in different packages or in different
quantities. There is no need to inventory different grounds cups.
Further, the grounds cup 102 easily separates from the grounds cup
holder 34 for cleaning. This structure also allows an accessory
element, such as a crema insert, to be located intermediate the
grounds cup 102 and the grounds cup holder 34.
[0077] FIG. 10 depicts the annular seal 96 that is a component of
the active seal. The structures in phantom at the right of FIG. 10
are useful in conjunction with other drawings for understanding the
relationship of the seal 96 with components of the piston head 97
and its functions. Specifically, the seal 96 has an annular body
120 that has a C-shaped cross section to form a channel 121 with an
opening facing a center axis 122. An annular upper lip 123 extends
axially and upward to be captured in a groove 124 in the top disk
83. An annular lower lip 124 extends downward axially to terminate
with a free end 125. This end is captured between the axial
shoulder 86 of the bottom disk 85 and the guide ring 92. The free
end 125 bears against the perforated disk 91. An integral obliquely
extending exterior skirt 126 can flex radially with respect to the
axis 122.
[0078] In the relaxed or radially contracted state shown in FIG.
10, the upper lip 123, annular body 120 and lower lip 124 form a
flexible coupling that suspends the bottom disk 85 from the top
disk 83. The lower lip 124, particularly the surface at the free
end 125, forms a seal to confine the hot water under pressure to
the volume between the perforated disk 91 and the lower disk 85
including the labyrinth 87. This prevents any water from escaping
at the periphery of the piston head 97, particularly at the guide
ring 92. When the seal 96 assumes a radially expanded state due to
the compression of the wavy spring 95 and movement of the bottom
disk 85 toward the top disk 83, the skirt 126 expands into the
cylindrical wall 122 thereby to form of peripheral seal that
defines an upper limit of the brewing chamber 98 and that confines
all the hot water under pressure and brewing coffee to the brewing
chamber 98.
[0079] FIG. 6 and 7 depict the espresso machine 20 with the piston
97 and threaded piston rod 74 retracted to an open position, the
arm 76 having activated the upper limit micro switch 100. In this
fully retracted position, the compacting apparatus 60 has retracted
the piston head 97 to a position that allows the infusion chamber
assembly 32 to be inserted into the brewing station 33 with coffee
130. The circumferential ribs 105 engage the support provided by
the shelf 63 in FIG. 2. When fully seated, the grounds cup holder
34 engages the interlock 64. When the structures are oriented as
shown in FIGS. 6 and 7, the wavy spring 95 separates the top and
bottom disks 83 and 85 by a maximum distance so that the seal 96 is
in its radially contracted state.
[0080] As described later, when water temperature and other
conditions are satisfied, the consumer pushes the brewing switch 47
in FIG. 1. The motor 71 displaces the threaded piston rod 74 and
piston head 97 toward the infusion chamber assembly 32. FIGS. 11A
and 11B depict the piston head 97 as it first enters the grounds
cup 102. The seal 96, particularly the seal skirt 126, is spaced
from the grounds cup cylinder 112.
[0081] As will be apparent, the position of the grounds cup 102
relative to the piston head 97 will not be held to close
tolerances. Thus, it is possible for a misalignment to exist during
normal operations. In contemplation of this possibility, the guide
ring 92 shown in FIGS. 4, 11A and 11B serves to prevent any damage
to the seal 96. Specifically, the guide ring 92 has an annular body
131 and angularly spaced, radially extending tabs 132 with outer,
downwardly located chamfers 133. Should there be any misalignment,
a chamfer 133 will contact the lip 113 and center the piston head
97 within the grounds cup 102. Thus the wall 112 does not contact
the skirt 126 as the piston head 97 enters the brewing chamber 98
Consequently the guide ring 92 protects the seal 96 from damage.
Moreover there is no wear on the seal 96 during this downward
motion.
[0082] The motor 71 continues to drive the threaded piston rod 74
and piston head 97 downward with the configuration shown in FIGS.
11A and 11B, until the perforated disk 91 contacts the ground
coffee 130. Further downward motion of the piston head 97 begins to
compact the ground coffee 130. In addition at some point the force
exerted on the peripheral disk 91 will be greater than the force
exerted by the wavy spring 95. As a result, the distance between
the top and bottom disks 83 and 85 decreases. Consequently the seal
96 moves to the radially expanded state and drives the skirt 126
against the cylinder wall to form the seal.
[0083] As the ground coffee compacts, the load on the motor 71
increases. When the current reaches a first specified threshold,
the motor 71 is de-energized. The gear ratios lock the piston head
97 in its vertical position. The seal formed by the skirt 126 now
defines the top of the brewing chamber 98. This event enables hot
water to pass from the boiler 55 through the hose 57 and the piston
97 and to permeate the coffee 130 under pressure.
[0084] As can be seen from FIG. 4, the heated water under pressure
from the liquid supply including the water reservoir 30, pump 54,
boiler 55, flow meter 56 and inlet hose 57 travels through the
nipple 90 to emerge in the labyrinth 87. The pressure required to
displace the water into the labyrinth 87 is less than that needed
to force the water through the perforated disk 91 and the compacted
coffee grounds 134 in FIGS. 12A and 12B. Thus, the water initially
fills the labyrinth 87 and then passes through the entire surface
of the perforated disk 91 bounded by the lower lip 124 of the seal
97 thereby to permeate the ground coffee 130 uniformly.
[0085] Referring to FIG. 12B, the brewed coffee 134 in the brewing
chamber 98 above the ground coffee 130 may be under pressure. To
the extent such pressure exists, it does not detract from the
sealing force that drives the skirt 126 against the cylindrical
wall 122. Although such brewed coffee 134 enters a gap 135 between
the seal body 120 and skirt 126, it produces an additive pressure
component that further perfects the seal. Consequently the
compacting apparatus 60 provides both compacting force and a
mechanism for controlling the active seal.
[0086] In one embodiment of this invention, the brewing cycle has
another step. After the brewing cycle is completed the motor 71 is
energized again to drive the threaded piston rod 74 downwardly
thereby over compacting the coffee grounds 130 to extract
additional beverage. This downward force increases motor current to
a next higher threshold. When the threshold is reached, the motor
71 reverses to retract the threaded piston rod 74 and piston head
97 back to the position shown in 11A.
[0087] During the processes of compression and over compression and
initial retraction, the seal 96, primarily the skirt 126, undergoes
only minimal sliding against the cylindrical wall 112. As soon as
the motor 71 produces any significant upward displacement during
retraction, the wavy spring 95 begins to expand to separate the top
and bottom disks 83 and 85 so the seal 96 with its skirt 126
retracts radially from the cylindrical wall 112. Consequently, the
seal 96 will not wear and have a long life.
[0088] When the motor 71 fully retracts the threaded piston rod 74
and the piston head 97, the radial arm 76 again engages the upper
limit microswitch 100 to de-energize the motor 71 and conclude the
brewing cycle, so a consumer can remove a cup and drink the
beverage. Also in this position, the consumer can easily remove the
infusion chamber assembly 32 from the brewing station 33 for
cleaning after each use and for filling with fresh ground
coffee.
[0089] Generally this per use cleaning of the infusion chamber
assembly 32 will be sufficient. Cleaning the piston head 97 can be
done less frequently because during brewing the only elements in
contact with brewed coffee and coffee grounds are the infusion
chamber assembly 32 and the bottom surface of the piston head 97,
that is, the perforated disk 90 and guide ring 92 and the surface
of the seal 96 at a gap 135. The water under pressure prevents the
bottom disk 85 including the labyrinth 87, upper disk 83 and
internal surfaces of the seal 96 from accumulating any residue.
[0090] When it is desired to clean the piston head 97, the consumer
initiates a cleaning cycle by activating a "clean" switch 136 in
FIG. 1 while the infusion chamber assembly 32 is removed. This
operation energizes the motor 71 and drives the threaded piston 74
downwardly until the arm 76 strikes the lower limit microswitch
101. As shown in FIG. 13, the entire piston assembly 97 is then
accessible for cleaning in the brewing station 33. Generally it is
merely necessary to wipe the surface of the perforated disk 91 and
guide ring 92 with a damp cloth or sponge. A more thorough cleaning
might be achieved by means of a special cleaning cycle, like a brew
cycle, with an infusion chamber assembly 32 inserted at the brewing
station 33.
[0091] FIG. 14 is a block schematic that summarizes the various
control inputs and outputs that can be utilized in the espresso
machine 20 of FIG. 1. In this specific embodiment, a controller 140
has connections to the water pump 54, the boiler 55, the flow meter
56, the piston motor 71 and the grinder 56. The flow meter 56
produces a FLOW input signal for the controller 140. A temperature
sensing circuit 141 generates a TEMP input signal. A current sensor
142 provides a CURRENT signal to a threshold level circuit 143. The
threshold level circuit produces one of two outputs to a control
unit 144. The first is from a LEVEL 1 detector 145 that represents
the current that exists as compacting assembly 60 compacts the
coffee grounds to an appropriate level. A LEVEL 2 detector 146 is
set at a higher level and serves to provide a reversing signal for
the post brewing over compression sequence. A water level sensor
147 indicates the presence of a sufficient quantity of water for a
brewing operation.
[0092] The upper limit microswitch 100 and the lower limit
microswitch 101 provide two other control inputs to the controller
140. Still other control inputs are provided by the interlock 64
that indicates the proper alignment of the infusion chamber
assembly 32 in the brewing station 33. The interlock 68 indicates
the proper positioning of the infusion chamber assembly 32 in the
fill station 40. Other inputs include the power-on switch 42, the
one-cup and two-cup switches 43 and 44, the brewing switch 47 and
the grind switch 136.
[0093] FIG. 15 is a basic flow diagram for outlining the logical
operations that can occur within a controller 140, including the
control unit 144. When the apparatus 20 is plugged into an outlet,
control unit 144 is enabled and step 150 senses the existence of a
full power status. When that condition is realized, step 151
transfers control to step 152 and may at that point also energize a
power-on annunciator.
[0094] Step 152 reads the input signal from the water level sensor
147 in FIG. 14. If insufficient water exists, step 152 waits for
water to be added by the consumer in step 153. When that test is
completed, step 154 determines whether the water temperature is
above a first operating threshold, typically set at the bottom of
an acceptable brewing temperature range. On initialization this
typically will not be the situation, so control passes from step
154 to step 155 to energize the boiler 55. Steps 156 and 157 also
monitor the water temperatures for values in excess of an upper
limit of an acceptable range for de-energizing the boiler in step
157. As shown this control sensor enters into a loop including
steps 154 through 157 thereby to constantly control the temperature
of the water during the brewing cycle
[0095] Once the water temperature is in an appropriate range, the
consumer receives a notification as the illumination of a ready to
brew light. This may initiate a time-out to limit the maximum
interval before the brew button 47 in FIGS. 1 and 14 is actuated.
The time-out interval terminates the operation of the boiler
55.
[0096] Once the brew button 47 is actuated, control passes to step
162 to determine whether the infusion chamber assembly 32 is
properly aligned by monitoring the interlock switch 64 shown in
FIGS. 2 and 14. When both the conditions of steps 160 and 162 are
met within the time-out interval, step 163 energizes the motor 71
to extend the piston head 97. When the piston head 97 begins to
compact the ground coffee as shown in FIG. 12A, the signal from the
motor current sensor 142 increases until the current reaches the
first threshold established by the Level 1 detector 145. When this
occurs, step 156 de-energizes the motor 71. Now the system is ready
to infuse the compacted ground coffee.
[0097] Next the control unit 144 determines whether the one-cup
switch 43 or the two-cup switch 44 has been actuated. As will be
apparent, such switches should be ganged so only one of the two
switches can be depressed at any time. Step 166 establishes the
amount of water that must transfer through the brewing chamber 98
in response to the selection of one or two cups. Step 167 energizes
the pump 154 so heated water flows to the brewing chamber 98 until
the flow meter 56 records the specified quantity. When this occurs
step 171 turns off the water.
[0098] Step 172 then energizes the motor to produce
over-compacting. Step 173 monitors the current from the current
sensor 142 until the Level 2 detector 146 indicates that second
threshold has been reached. At that point step 174 reverses the
motor and begins the retraction process. When the radial arm 76
engages the upper limit microswitch 100, step 175 transfers control
to de-energize the motor at step 176. As will be apparent, when
step 176 de-energizes the motor, the brewing cycle has been
completed.
[0099] In summary, the espresso machine 20 of FIG. 1, specifically
the structure that forms the brewing chamber 98 including the
infusion chamber assembly 32 with its grounds cup 102 and the
piston head 97 with its seal 96, facilitates and simplifies an
operation by which coffee grounds are compacted and then infused
under pressure. Sealing is enhanced because the water pressure acts
to increase, rather than decrease, the sealing force. Further, as
the seal is radially contracted for most discrete piston head
motion, it will have a long life. As a result it is possible to
construct a brewing chamber that is sealed across the top with a
single piston and that enables the infusion chamber assembly 32 to
be removed for cleaning and to be transferred to a remote site for
receiving ground coffee, such as at the fill station 40 or even
some separate filling position remote from the apparatus 20.
[0100] The simplicity of this design allows the espresso machine 20
to be available for consumers with many of the advantages of the
more expensive commercial systems. Yet this espresso machine 20 is
easy to use because there is no need for a consumer to manipulate
manual latching mechanisms. Moreover, owing to the fact that the
seal 96 seals against the side wall 112 of the grounds cup 102 the
machine can accommodate ground coffee or a variety of coffee pods
of different diameters and in differing amounts and quantities up
to some arbitrary maximum depending on the depth of the grounds cup
102. As a result, the espresso machine 20 in FIG. 1 is readily
adapted for accommodating a wide range of infusible materials.
[0101] This invention has been disclosed in the form of a
particular espresso machine 20. It will be apparent, however, that
variations could be incorporated or applied to the specifically
enclosed embodiment without departing from the invention. For
example, the compacting assembly 60 of FIGS. 4, 6 and 7 utilizes a
particular motor and drive means for producing the vertical
displacement of the piston head 97. Mechanical, hydraulic,
pneumatic or other mechanisms and driving structures might be
utilized for displacing the piston head 97 to its various
positions. The piston head 97 is disclosed with a particular
arrangement of top and bottom disks, an intermediate spring and a
sealing structure. Alternate implementations of each of those
elements could provide equivalent functions. For example, the
specifically disclosed structure of the seal 96 with the skirt 126
is particularly suited for the high-pressure environment associated
with espresso brewing applications. The pressure required to brew
regular coffee is considerably less. In such an application a
variation of the active seal 96 with the skirt removed may be
substituted. As another alternative, the active seal could be
replaced by a passive seal, such as an O-ring. The grounds cup 102
is disclosed as a deep drawn element; shallower grounds cup could
be substituted. Accessory devices might be interposed between
bottoms of the grounds cup 102 and the grounds cup holder 32, all
while still realizing some, if not all, the advantages of this
invention. The specifically disclosed control sequence could be
altered while still achieving the advantages of this invention.
[0102] Therefore, it is the intent of the appended claims to cover
all such variations and modifications as come within the true
spirit and scope of this invention.
* * * * *