Patent Application
20060021930
This is a continuation-in-part application of the application titled “coffee filter paper and method of use” that was filed on Jul. 20, 2004.
Coffee filter papers, such as cup-like paper filters or cone-like filters, have an open top for receiving coffee grounds and for allowing hot water to drip into the filter to extract the grounds therein. Such filters tends to cause coffee grounds to overflow the rim of the filter paper into a cup or carafe when too much or too fine grounds is used or when the paper filter collapsed during brewing.
Numerous efforts have been made in the prior art to address the grounds overflow problem above. Sandvig [U.S. Pat. No. 4,728,425], Bielfeldt et al [U.S. Pat. No. 6,189,438], Katapka [U.S. Pat. No. 6,705,471] and Spiteri Antonio [U.S. Pat. application Ser. No. 20020185010] taught a retainer, a filter support, a blind-end frame and a set of longitudinal folds, respectively, to prevent filter collapse. Rainer and Dolfel in U.S. Pat. applications Ser. Nos. 20020066700 and 20020189461 taught to use higher permeability material in upper region of the filter and perforations on the filter, respectively, to prevent coffee grounds overflow. Hugentobler [U.S. Pat. No. 5,582,730] taught a distribution cover for a filter basket to obtain more uniform water distribution and limit coffee grounds overflow. The improved coffee filters, however, require a large filter size, which in turn requires the brew station to be large and bulky. In addition, the improved filters are still prone to coffee grounds overflow, especially when the hot water is delivered to the filter under pressure at high flow.
Rehman et al. in U.S. Pat. No. 5,012,629, Gruenbacher in U.S. Pat. No. 5,633,026, Black & Decker in its Home Café® machines and Philips in its Senseo® machines taught various coffee pods comprised of a predetermined amount of coffee grounds pre-packaged between two paper filters, thus preventing any overflow of coffee grounds out of the filter during brewing. The coffee pod, however, disallows consumers to use different amounts of coffee grounds to brew their desired strength of coffee. It also prevents consumers from being able to use their favorite coffee beans from their preferred coffee roasters. Moreover, the grounds in the coffee pods are not freshly ground and roasted.
The present invention is to provide consumers a new coffee filter paper to resolve the grounds overflow problem without the drawbacks and limitations of the prior art.
The invention provides a pack of paper filters to enable consumers to use various amounts of fresh ground coffee beans from their preferred roasters to brew coffee in coffeemakers designed to use pre-packaged, not as fresh coffee pods. The filter pack comprises a stack of pan-shaped paper filters and a stack of overflow prevention sheets in a container covered by a lid film with a tab. The pan-shaped paper filter comprises a rim and a chamber to receive the fresh ground coffee beans. The rim of the pan-shaped paper filter comprises a plurality of folds where the adjacent paper layers in each fold are attached to each other via either an adhesive coating or embedded adhesive fibers to maintain the shape of the pan-shaped filter.
The overflow prevention sheet comprises one or more overflow stoppers spaced apart from the sheet by two or more line spaces and connected to the sheet by two or more breakable bridges, four sufficiently stiff sides for accurate positioning and alignment, and line spaces around the overflow stopper. The overflow stopper has a water permeable center portion, a rim, an adhesive ring at the rim for forming adhesive bonds to the rim of the pan-shaped filter, and four breakable bridges to connect to the sheet. To prevent the breaking of the resulting pods during the removal of the resulting pod attached to the sheet, the outer periphery of the overflow stopper is made at least 0.01 inches larger, preferably at least 0.04 inches larger than that of the pan-shaped filter. To prevent delamination of the pod during the brewing process or handling, the rim for the overflow stopper may be made substantially more flexible than the center portion.
The container comprises a chamber to precisely position the stack of pan-shaped filters, a guide chamber for guiding and aligning a seal presser with the rim of the pan-shaped filter in the chamber, and a seal platform for supporting the rim of the pan-shaped filter. The sealing presser has a handle, a body plate and a sealing ring protruding out of the lower surface of the body plate. One or more heating elements, controlled by a pressure sensitive micro-switch, are incorporated in either the seal platform of the container or the sealing ring of the sealing presser for activating the adhesive ring on the overflow stopper after proper alignment has been obtained among the seal platform, the sealing ring, the rim of the pan-shaped filter and the rim of the overflow stopper in the container by the guiding chamber.
To use the filter pack to brew coffee with fresh ground coffee beans, one removes the lid film for the container and measures with a spoon or scooper a desired amount of fresh ground coffee beans, which may vary from about 4 to 10 grams, into the top pan-shaped filter in the stack in the container. After placing one overflow prevention sheet into the container, one inserts the sealing presser into container to press the overflow prevention sheet against the top pan-shaped paper filter for several seconds. The guide chamber automatically positions the overflow prevention sheet and the sealing presser to cause alignment of the rim for the overflow stopper and the sealing ring of the presser with the rim of the pan-shaped paper filter. The sealing presser is then removed from and the sheet containing one pod is lifted out of the container. To remove the coffee pod from the pod sheet, one may simply push the pod downward to break the bridges between the overflow stopper and the overflow prevention sheet.
In another embodiment of the invention, the filter pack comprises a plurality of stacks of pan-shaped filters received in a plurality of chambers in the container. Each of the overflow prevention sheets comprises a plurality of overflow stoppers. The sealing presser has a plurality of sealing rings. In use, one fills all the top pan-shaped filters in the stacks of pan-shaped filters with various amounts of fresh ground coffee beans, places one overflow prevention sheet into the container, and insert the seal presser into the container as described above. The resulting pod sheet will contain a plurality of coffee pods attached to it, thus allowing one to make a plurality of coffee pods at a time.
In another embodiment of the invention, the pan-shaped filters and overflow stoppers are adapted to make a coffee pod directly in the holder of the coffeemaker during the brewing process. The rims for the pan-shaped filter and overflow stopper are so dimensioned that the brew heads of the coffeemakers act as the sealing presser. The adhesive ring is made from an adhesive material that is or can become adhesive at a temperature at or below the brewing temperature for the coffee beans. The adhesive material is a pressure sensitive adhesive that is sufficiently hydrophobic to survive the brewing process during which the adhesive ring in close contact with nearly boiling water, and the rims are rendered hydrophobic by coating with a hydrophobic polymer such as poly (ethylene vinyl acetate) or linear low density polyethylene or by embedding hydrophobic polymer fibers such as polyethylene or polypropylene fibers with the paper fibers. To brew, one places a pan-shaped filter into the pod holder for the coffeemaker, adds to the pan-shaped filter a desired amount of freshly ground coffee beans for a desired coffee strength, places and aligns an overflow stopper on to the pan-shaped filter, closes the brew head of the coffeemaker to seal the rim of the overflow stopper to the rim of the pan-shaped filter to form a closed coffee pod, and pump hot water through the pod. The extracted pod is then removed from the holder for disposal just like a pre-packaged coffee pod. In a further embodiment of the invention, the rims for both the pan-shaped filter and overflow stopper are sloped to achieve self alignment between the rims when the overflow stopper is placed onto the pan-shaped filter.
It is an object of the present invention to provide a pack of paper filters to enable consumers to use fresh ground coffee beans to brew coffee in the coffee makers designed to use coffee pods.
It is a further object of the present invention to provide a pack of paper filters to enable consumers to use their favorite coffee beans from their favorite roasters in the coffee makers designed to use coffee pods.
It is a further object of the present invention to provide a pack of paper filters to enable consumers to vary the amount of ground coffee beans to obtain their desired coffee strength in the coffee makers designed to use coffee pods.
It is a further object of the present invention to provide a pack of paper filters to enable consumers to make coffee pods directly in the pod holder of the coffee makers designed to use coffee pods during a brewing process.
It is an object of the present invention to provide a pack of paper filters to prevent any overflow of coffee grounds over the filter paper when the coffee grounds are too fine or the water is delivered too fast to the filter.
These and other objectives and advantages of the present invention will become apparent from the following description of the preferred embodiments, taken together with the accompanying drawings.
The accompanying drawing illustrates diagrammatically non-limitative embodiment of the invention, as follows:
a is a section view of the pack of coffee paper filters along line A-A of
b is a sectional view of the pack of coffee paper filters along line B-B of
c is a section view of one pan-shaped filter 29 of
d is a sectional view of one overflow stopper sheet 25 of
e is the section view of a modified pan-shaped filter;
e are section views showing a process of making coffee pods by consumers or end users using the pack of coffee paper filters of
a is a sectional view of the sheet of pan-shaped filters along line A-A of
d are a section views showing a process of making coffee pods by consumers or end users using the sheet of pan-shaped filters of
a-5d are sections of four alternative overflow stoppers;
b are section views showing a process of making coffee pods by consumers or end users using the pack of coffee filters of
a is a section view of a stack of three modified pan-shaped filters;
b is a section view of a stack of two modified overflow stoppers.
a is a section view of the stack of six combined sheets along A-A of
d illustrate a pack of coffee paper filters 10 comprising four stacks 43, 43a, 43b and 43c of pan-shaped paper filters 29, as best viewed in
Each of the pan-shaped paper filters (
The container 18 comprises four chambers 15 to precisely position the four stacks 43, 43a, 43b and 43c to restrict their movement. Each chamber 15 has a bottom 16 and a side wall 14 for supporting the bottom and side wall of the pan-shaped filters 29, and a seal platform 13 for supporting the rim 21 for enabling the sealing operation. The container 18 also has a guiding chamber 12 defined by side walls 11 for guiding and positioning a seal presser 37, to be discussed in more details in
Each overflow prevention sheet 25 comprises four overflow stoppers 49 spaced apart from the sheet by cuts or line spaces 26 and connected to the sheet by breakable bridges 71. Each overflow stopper comprises a water permeable center portion 24, a rim 20, and an adhesive ring 30 at the rim 20 (
e show the process of using the filter pack 10 to make fresh coffee pods containing various amounts of freshly ground coffee beans of one's favorite brands at one's homes. After removing lid film 23 and the stack 50 of the overflow stoppers 29 from container 18, one measures four desired amounts of fresh ground coffee beans 35, 35a, 35b and 35c, which may vary from about 4 to 10 grams, with a spoon or scooper to the four pan-shaped filters 29 on top of the stacks 43 to 43c (
One then inserts a sealing presser 37 into container 18 to attach the overflow prevention sheet 25 to the top pan-shaped paper filters 29 (
The pod sheet 46, which has four coffee pods 45-45c containing different amountss of fresh ground coffee beans 35-35c, respectively, can be lifted out of the container by picking the upward-bent corner 31 of the overflow prevention sheet 50 (
To prevent the breaking and delamination of pods 45-45c during their removal from pod sheet 46, the outer diameter for rim 20 should be at least 0.01 inches larger, preferably at least 0.04 inches larger, than the outer diameter for rim 21. Such difference in diameter for rims 20 and 21 is especially important in any of the following situations when
1) there is adhesive material outside the overflow stoppers 49 in the overflow prevention sheet 25;
2) the pan-shaped filter 29 contains adhesive materials such as adhesive fibers or coatings made from poly(vinyl acetate), polyethylene or other adhesive polymers; and
3) At least one of the overflow prevention sheet 25 and pan-shaped filter 29 is made from a filter paper that already comprises adhesive or hot melt fibers mixed with the paper fibers or an adhesive coating. It is appreciated that in this case the adhesive ring 30 on the overflow stopper 49 may not be needed.
In the cases that the pan-shaped filter 29 contains materials that can become adhesive under the conditions when presser 37 is used to seal the rim 20 to rim 21, a ring-shaped release sheet or layer (e.g. release paper) should be placed between the rims 21 of the pan-shaped filters 29 or be coated on the lower surface of the rims 21. Without such a release layer, the pan-shaped filters near the top end of the stacks 43-43c may stick to the pod sheet 46, causing not only waste of pan-shaped filters but also undesirably high water flow resistance for the resulting pods 45-45c.
It is appreciated that it is also possible to prevent the breaking and delamination of pods 45-45c during their removal from pod sheet 46 by selecting the appropriate filter paper for pan-shaped filters 29. It was found that if the selected filter paper for the pan-shaped filters contains no material that can become adhesive under the conditions when the presser 37 is used to seal the rim 20 to rim 21, the removal of the coffee pods from pod sheet 46 can be successfully performed even if the rim 20 of the overflow stopper has a smaller outer diameter than the rim 21 of the pan-shaped filters 29. It is also appreciated that it is possible to prevent pods 45-45c from breaking during their removal from pod sheet 46 by making the outer peripheries for the overflow stopper 49 and pan-shaped filter 29 larger than the outer periphery of the sealing ring 36 for the presser 37.
In
c show a process of using overflow prevention sheet 25 of
In operation, one places a filter sheet 27 into container 18. The guiding chamber 12 aligns the sheet so that the four pan-shaped filters are received by the four chambers 15 and the rims 21 rest on sealing platforms 13. Four desired amounts of fresh ground coffee beans 35-35c, varying from 4 to 10 grams, are added to pan-shaped filters 29 with a spoon or scooper (
After inserting presser 37 into container 18 and pressing it for ˜5 seconds, the rims 20 for the four overflow stoppers are sealed to the rims 21 for the four pan-shaped paper filters (
To prevent the breaking and delamination of pods 45-45c during their removal from pod sheet 46, the adhesive should be confined within the overflow stoppers in the overflow prevention sheet 25 and the outer diameter for the rim 20 of each overflow stopper should be smaller, preferably at least about 0.02 inches smaller, than the outer diameter for the rim 21 of the pan-shaped filter 29. It is appreciated, however, that by making the outer diameters for both the rim 20 and rim 21 larger than the outer diameter for the heating bar 32 or the sealing ring 36, the removal of pods 45-45c becomes less or in-sensitive to the relative size of the rims 20 and 21. It is also appreciated that four separate pan-shaped filters 29 such as those described in
In
a shows the cross-section of one of the overflow stopper s 49 of
To achieve improved bonding to rim 21, the thickness of the pressure sensitive adhesive ring 56 should be at least half the diameter of the fibers constituting the pan-shaped filters 29. To achieve instant bonding between the rim 21 and the adhesive ring 56 on rim 20, an adhesion enhancing layer (not shown) may be coated on the upper surface of the rim 21 of the pan-shaped filters. The enhancing coating may be applied to rim 21 by either spraying or printing a polymeric product comprising polyacrylate, poly(ethylene vinyl acetate) or other polymers.
A method of using filter pack 10 of
With the hydrophobic pressure sensitive adhesive ring 56 on the rim 20, it was also found that the coffee pod 45 can be made from a pan-shaped filter 29 and overflow stopper 49 during the brewing process. Here, one removes a pan-shaped filter from the container 18 and places it into the pod holder for the coffeemaker. A desired amount of freshly ground coffee beans 35 is added to the pan-shaped filter in the pod holder. After placing and aligning an overflow stopper 49 on to the pan-shaped filter, the brew head of the coffeemaker is closed to cause the brew head to press the rims 21 and 20 on the pod holder, causing the adhesive ring 56 to bond the rims 20 and 21 to form coffee pod 45 right in the pod holder prior to the introduction of hot water to the brew head.
To make the coffee pod 45 during the brewing process in the pod holder, it was also discovered that the pressure sensitive adhesive ring 56 can be replaced by a heat activable adhesive ring such as a hot melt ring that can be activated by the brewing temperature. In this case, the adhesion bonds 42 between the adhesive ring on rim 20 and the rim 21 are formed when the hot water is introduced to the brew head to extract the ground coffee beans.
b shows a square-shaped overflow prevention sheet 25 with one overflow stopper 29 on it. The overflow stopper is separated from the sheet by four line spacers 26 (not shown) and connected to the sheet by four bridges 71 just like that shown in
In
d shows another alternative overflow stopper 49. This alternative comprises a highly flexible film 79 having an ring-shaped edge section functioning as the rim 20 for the overflow stopper and a center portion 24 with openings 67, a filter paper disc 58 attached to the center portion of the flexible film, and a pressure sensitive adhesive layer 56 on the lower surface of the rim. It was discovered that the high flexibility of the film 79 made the seal between the rims 20 and 21 significantly less prone to delamination or de-sealing during handling or accidental drop of the coffee pods 45. Besides preventing any overflowing of coffee grounds during discovered that by making the paper disc 79 thicker or more rigid than the rims 20 and 21, the seal between the rims became significantly less prone to delamination or de-sealing during handling or accidental drop of the pods.
The highly flexible film 79 is a soft plastic film (e.g. a low density polyethylene film or a polyethylene vinyl acetate film) of a thickness less than about 0.002 inches, preferably less than 0.0005 inches. It was found that by replacing the plastic film 79 with a thin elastomer film, the seal between the rims 20 and 21 became even less prone to delamination or de-sealing uring handling or accidental drop of the coffee pods. Examples of such elastomer films are butyl rubber film, thermal plastic elastomer polyethylene film and polyurethane film. To obtain the similar high resistance to delamination, the elastomer film can be made thicker than the plastic film, but it should not be thicker than about 0.01 inches, preferably not thicker than 0.002 inches. It is appreciated that by having the rims 20 and 21 of the overflow stopper and pan-shaped filter in
a and 7b show one stack 43 of three pan-shaped filters 29 and a stack 50 of overflow stoppers 49, respectively. Both the overflow stoppers 49 and pan-shaped filters 49 are made from filter paper. Unlike in the earlier exemplar embodiments where the rims 20 and 21 are horizontal, the rims 20 and 21 here are sloped, which was found to cause self alignment between the rims 20 and 21 when an overflow stopper 49 is placed onto the pan-shaped filters 29. Adhesive layers 59a and 59b are provided on the rim 20 and 21, respectively, and are adapted to cause adhesion only when they are pressed together. Adhesive layer 59a on a top overflow stopper does not stick to the overflow stopper below, and adhesive layer 59b on top pan-shaped filter does not stick to the pan-shaped filter below, thereby facilitating the removal of an overflow stopper from stack 50 and a pan-shaped filter from stack 43.
The adhesives 59a and 59b can be a loop/hook type adhesive where adhesive layer 59a comprises numerous microscopic loops coated on the rim 20 and adhesive layer 59b comprises numerous microscopic hooks coated on the rim 21. When pressed together, the microscopic loops and hooks form numerous microscopic loop-hook bonds to seal the rim 21 to rim 20. One example of such loop/hook adhesives is the reclosable fastners from 3M under its Scotchmate brand. The adhesives 59a and 59b can also be a two-part adhesive with the adhesive layer 59a comprises the activator or curing agents and the adhesive layer 59b comprises an adhesive that quickly solidifies when in contact with the curing agents. For example, the adhesive layer 59b is a curable silicone compound such as RTV 11 or RTV 77 and the layer 59a comprises curing agent such as dibutyl tin dilaurate or stannous tin octoate, all of which are available from General Electric Company. It is appreciated that the adhesive layers 59a and 59b can be replaced by heat activable adhesive fibers mixed with the paper fibers in the filter paper, a heat activable adhesive coating on the paper, or by a hydrophobic pressure sensitive adhesive ring on the rim 20.
It was discovered that the self alignment between the rims 20 and 21 significantly improves the preparation of the coffee pod 45 when the pod is made directly in the pod holder of a coffeemaker from the pan-shaped filter 29 and overflow stopper 49. Similar to the method of using the filter pack 10 of
a show a pack of coffee filters 10 that comprises six combined sheets 82. Each combined sheet comprises a pan-shaped filter 29 that is identical to those of
The folding line 78 may be a perforated or thinned line to enable one to readily fold the overflow stopper over on top of the pan-shaped filter after one has added a desired amount of fresh ground coffee beans to the pan-shaped filter. The folding line should be sufficiently long to enable automatic alignment of the rim 20 to rim 21 when the overflow stopper 49 is folded over to cover the pan-shaped filter 29 on the combined sheet 82. The section at the folding line 78 is preferred to be significantly more flexible or to be rendered significantly more flexible than the overflow stopper 49 to prevent movement of the pan-shaped filter 29 of the combined sheet 82 and the ground coffee beans in it when one folds the overflow stopper 49 to cover the pan-shaped filter 29. In this and other embodiments above, it is appreciated that the release sheet 55 may not be needed if the adhesive ring 56 is a hot melt adhesive or other adhesive that is adhesive at ambient environment and the adhesive may be distributed uniformly in or on the overflow stopper, that such hot melt adhesive may be located at the pan-shaped filter or at both the overflow stopper and pan-shaped filter, and that a cavity may be formed on the center portion 24 of the overflow stopper 49.
Like the pan-shaped filters and overflow stoppers of
The scope of the invention is obviously not restricted or limited to the embodiments described by way of examples and depicted in the drawings, there being numerous changes, modifications, additions, and applications thereof imaginable within the purview of the claims.
