Moisture prevention valve in an apparatus for the preparation of liquid beverage from solid and liquid components

The present invention involves an improvement to a beverage making apparatus in which a slide valve assembly for preventing moisture from seeping into an area holding the solid component of a beverage mix is provided with a finger tab. The tab serves as a grasping device to manipulate the slide valve between open and shut positions and as a deflector of the solid material ejected from the holding area.

FIELD OF THE INVENTION 
This invention relates to a beverage preparation apparatus in which a 
liquid component and a solid component such as a powder or coffee grounds 
are mixed to form a beverage and, more particularly, an apparatus in which 
a slide valve is used to protect the solid component from moisture 
emanating from the mixture of liquid and solid such as in a combination 
coffee bean grinder and brewing apparatus. 
BACKGROUND OF THE INVENTION 
Apparatus used to make beverages from a solid component and a liquid 
component for distributing directly to the consumer are legion in number. 
One example is machines which meter a predetermined amount of powder and 
water to a mixing area. Another example is combination coffee grinders and 
brewers that are finding great acceptance from restaurants and the like. 
Brewing coffee directly from freshly ground beans in the same apparatus 
has considerable appeal. A typical combination grinding and brewing 
apparatus employs a hopper which upon a signal discharges beans into a 
proportioning device which measures the desired quantity of beans. The 
beans are then transferred to a grinder that grinds the beans to a desired 
consistency after which the ground coffee is delivered to a filter within 
the brewing basket immediately before hot water is sprayed over the 
grounds. A common feature in most apparatus of this type is the use of a 
sealing structure which prevents moisture emanating from the hot water 
tank and brewing basket from reaching the interior of the grinder 
assembly. Wetting of the grounds prior to reaching the brewing basket is 
undesirable, particularly when the grounds are still in the grinder 
itself. It causes problems with the proper distribution of the ground 
coffee to the brew basket and is difficult to clean. 
A number of structures have been devised to prevent the egress of unwanted 
moisture into the grinder. An example may be found in U.S. Pat. No. 
4,913,037 issued to Brian D. Newnan and assigned to the same assignee as 
the present invention. In the patent, the passage between the grinder and 
the brew basket is conveniently sealed by a solenoid operated valve which 
is open during the grinding operation but closes when the grinder motor 
shuts down. The valve is a flap of material which is pivotally mounted, 
biased into a closed position and responsive to the movement of a solenoid 
plunger for opening the passageway. The valve can also be manually opened 
by use of a finger tab thus allowing access into the passageway for 
cleaning when required. The passageway itself is defined by an elbow 
shaped hood which serves to guide the coffee grounds when ejected from the 
grinder through the valve opening into the brew basket. 
The aforementioned prior art valve is extremely suitable for the purpose 
intended, but does not meet the requirements of combination grinder 
brewers in which space is severely restricted. The pivoting action of the 
prior art valve and the linkage to the solenoid plunger require valuable 
space as does the passageway defined by the elbow shaped hood. It 
therefore would be desirable to have an apparatus having a valve assembly 
in which the moisture of the brewing operation could be sealed off during 
the brewing cycle without the sacrifice of valuable space while 
simultaneously maintaining good coffee ground dispersal across the filter 
paper within the brew basket. Additionally, the valve assembly should 
allow for easy manual access into the valve interior for cleaning and 
maintenance. 
SUMMARY OF THE INVENTION 
The present invention provides for a coffee grinding and brewing apparatus 
in which the passageway communicating with the grinder and brewing area is 
selectively opened when the grinder motor is activated and closed when 
not. Thus, moisture emanating from the brewing cycle cannot reach the 
grinder as the passageway there between is sealed shut. The invention 
contemplates the use of a slide plate or shutter that is directly 
connected to a solenoid by a solenoid plunger. The shutter plate also has 
an opening. When the grinder is activated, the solenoid is activated and 
moves the shutter into an open position in which the opening of the 
shutter is in registry with the opening of the grinder head. The movement 
of the solenoid plunger and plate are essentially coplanar which reduces 
the number of working and moving parts. Moreover, the shutter is provided 
with a tab finger which extends into the brewing area a sufficient 
distance to deflect at least a portion of the stream of coffee grounds 
ejected from the grinder thereby ensuring the coffee grounds are properly 
distributed prior to brewing. The timing of operation sequence is such 
that the solenoid valve remains operational for a predetermined time 
period after the grinder ceases operation. Once the predetermined time 
period has elapsed, the solenoid shuts off and a biasing element closes 
the shutter just prior to the brewing cycle so that moisture therefrom 
does not proceed into the grinding head.

The above and other features and advantages of this invention and the 
manner of realizing them will become more apparent, and the invention 
itself will best be understood, from a study of the following and appended 
claims, with reference being made to the attached drawings showing some 
preferred embodiments of the invention. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The perspective of FIG. 1 illustrates the front and side exterior of a dual 
hopper grinder brewer apparatus described in greater detail in commonly 
assigned and copending applications U.S. Ser. Nos. 07/816,749 filed Jan. 
2, 1992 and concurrently filed U.S. Application Ser. No. 07/951,674, filed 
Sep. 25, 1992. The details of the auger-grinder-brewer assembly of the 
referenced application are not essential for the understanding of the 
present invention. Generally, as depicted the dual hopper, grinding and 
brewing apparatus can be visualized best by being comprised in three 
sections: a hopper section 10 comprising a pair of hoppers 12 separated by 
an interior wall 14; a panel section 16 containing the front control panel 
18; and a lower section 20. Positioned in each hopper 12 is an agitator 
wheel 22 serving to break up clumps of coffee beans and move the coffee 
beans within each hopper. A pair of electrically heated plates 24 and 26 
ar respectively mounted on the top surface of panel section 16 and 
extension 20a of the lower section 20 function to maintain coffee in 
coffee decanters warm. The control panel 18 is provided with the various 
manual controls needed to operate the apparatus including a hot water 
spigot 28 for obtaining hot water for other beverage needs. A brew basket 
30 for holding the filter paper and coffee grounds is mounted beneath the 
underside of the panel section 16 between a pair of brew basket arms 32 
and 34 as seen in FIGS. 5 and 6. As seen in the front view of FIG. 2, 
grinder 36 is mounted in the panel section 16 beneath the hoppers 12 to 
receive the coffee beans that are transferred from a selected hopper by an 
auger mechanism 38 shown in dashed lines. 
Referring now to FIGS. 3 and 4, a solenoid support plate bracket 44 is 
secured directly to the grinder 36. Solenoid valve housing 46 is mounted 
on bracket 44 by any appropriate fastener element such as metal screws or 
rivets. Slide valve spacing bracket 45 has a pair of legs 45a and 45b 
mounted beneath grinder 36 and are spaced sufficiently far apart to 
register with the edges of the opening into the grinder 36. One end of 
bracket 45 is crimped to fit about grinder head 36 to help prevent any 
slippage caused by vibrations and the like and to maintain the flatness of 
the spacer plate. 
Mounted within housing 46 is a solenoid 48 having a solenoid plunger 50 
which extends through an opening (not shown) in housing 46. The distal end 
50a of plunger 50 is provided with a slot for receiving shutter plate 52 
which is secured to the end of plunger 50 by a pin (not shown). Shutter 
plate 52 has a width which allows it to slide freely between but in close 
tolerance with the interior edges of legs 47. A finger tab 54 extends 
downwardly from the left side of shutter plate 52 as viewed in FIG. 4. A 
helical spring 56 is coiled about plunger 5 and abuts the end of shutter 
plate 52 and the facing wall of solenoid housing 46. Shutter plate 52 
further defines an opening 58 which is essentially the same size as the 
opening in grinder head 36 and registers therewith when shutter plate 52 
is in its open position. However, spring 56 biases shutter plate 52 is a 
closed position when solenoid 48 is not operative. 
A bearing surface for shutter plate 52 is provided by a sheet 60 of low 
friction wear resistant material secured to the underside of legs 45a and 
45b by seal keeper 62 and seal 64. Shutter plate 52 is made slightly 
thinner than bracket 45 to ensure that plate 52 can slide freely over 
sheet 60 when in operation. Sheet 60, keeper 62, and seal 64 collectively 
define an opening which is longer than the opening in shutter plate 52, 
thus allowing tab finger 54 to extend downwardly there through as shown in 
FIG. 3. As best seen in FIGS. 5 and 6, this larger opening as defined 
above allows movement of the finger tab into the various positions as 
shown. Components 60, 62 and 64 have legs similar in shape to legs 45a and 
45b, but with greater width, to provide a support and bearing surface for 
shutter plate 52. Sheet 60 may be made of any low friction and wear 
resistant material such as, for example, sheets of Teflon (registered 
trademark of the Du Pont Company). Using low friction material greatly 
reduces the coffee and other residue build up between the shutter plate 
and bearing surface. Cleaning and maintenance are greatly facilitated. 
From FIGS. 3 and 4, it can clearly be seen that shutter plate 52 and 
solenoid plunger 50 are directly connected and in line, i.e., essentially 
co-planar. The advantages of the co-planar positioning is that 
misalignment (as found in prior art shutter mechanisms) is minimized. 
Additionally, fewer working parts are needed which reduces mechanical 
problems and increases service life. 
An alternate construction may be employed for the placement of the spring 
as shown in FIG. 10. Instead of using the spring in compression to 
maintain the bias of the shutter plate in a closed position, the spring 
may be used to provide a bias from an extended position. To accomplish 
this the bracket would be extended as illustrated by bracket 102 to form 
an inverted U-shape. One end of spring 104 is connected to bracket 102 and 
the other end secured to a tab extension 106a of shutter plate 106. 
Shutter plate 106 slides between legs 102a and 102b of bracket 102 as 
described above with respect to shutter plate 52. Shutter plate 106 is 
coupled to solenoid plunger 108 of solenoid (not shown) and functions in 
an almost identical manner as shutter plate 52, the difference being that 
plunger 108 pulls plate 106 into a closed position and extends spring 104. 
Reference is now made to FIG. 7 which illustrates one of the functions of 
finger tab 54 which takes place during grinder operation. During the 
grinder cycle the shutter plate 52 is moved against the biasing force of 
spring 56 by action of solenoid plunger 50 so that opening 58 registers 
with opening 66 in grinder head 36. In the plane of FIG. 7, the grinding 
burrs of grinder head 36 spin in a clock-wise motion causing the coffee 
grounds 68 to be thrown toward the left side of the brew basket 30 lined 
with a filter 70. Ordinarily, the distribution of the coffee grounds 
within filter 70 would be skewed to one side which could deleteriously 
effect the quality of the brewed coffee. However, finger tab 54, which 
extends down through the opening defined by keeper 62 and seal 64, 
deflects grounds 68 to provide a more even distribution of the coffee 
grounds over filter 70. The tangential flow of the coffee allows for 
higher exit velocity which aids distribution and also cleaning of the 
grinder head. It should be noted, however, that the opening 66 is not 
centered in relationship to the passageway defined by the various valve 
components in order to ensure that the coffee stream impacts further down 
the passageway and against tab 54. 
Additionally, finger tab 54 also permits shutter 52 to be manually opened 
as shown in FIG. 4 against the bias of shutter spring 56. Manual opening 
of the shutter plate greatly assists the cleaning and maintenance of the 
shutter mechanism. 
Reference is now made to FIG. 8 wherein it can be seen that a 120 volt ac 
power source 71 is connected to grinder 36, solenoid 48 and voltage input 
terminals of grinder timer 72 and solenoid timer 74. Timer 72 is 
preferably a single shot timer such as a Model Q2 Serials solid state 
timer available from National Controls Corporation. Timer 74 is preferably 
a "delay-on-break" timer such as a Model Q3 Series timer available from 
National Controls Corporation. The duration of timer intervals may be 
adjusted for each timer by potentiometer 72a and 74a respectively. 
When the normally open start switch 76 is momentarily closed, the loads of 
timer 72 and 74 (that are respectively grinder 36 and solenoid 48) are 
energized. This sequence is apparent from the timing diagram of FIG. 9. 
Grinding of the coffee beans transported to grinder 36 from the hoppers by 
auger mechanisms 38 commences. Simultaneously, shutter plate 52 is moved 
to its open position, allowing coffee grounds to be ejected through 
registered openings 58 and 66 and evenly distributed by deflection against 
tab finger 54 over the brew basket 30. When timer 72 goes into its off 
state, it de-energizes grinder 36 and signals timer 74. Timer 74 then 
delays for a short time interval the de-energization of solenoid 48. 
Following the lapsing of the time interval, solenoid 48 is de-energized 
and shutter plate 52 is retracted into its closed position, thereby 
preventing moisture from the brewing cycle from entering into grinder head 
36. 
As is readily inferred from a reading of the detailed description and the 
appended drawing, the present invention is not only suitable for use with 
combination coffee grinders and brewers, but with any beverage making 
apparatus where it is desirable that the solid component be distributed 
evenly in the region of mixture and that excess moisture be prevented from 
moving into the solid component holding area. Thus, while the invention 
has been described in detail with respect to the preferred embodiment, it 
is not intended that the scope of the invention be limited other than set 
forth in the following claims.