Patent Application
20150135967
The field relates to cartridges for beverage brewing and, more particularly, to cartridges and cartridge components which provide for improved beverage flavor and quality.
Single-serve beverage brewers are well-known devices used to brew a cup of coffee, tea, hot chocolate, or other beverage. One such example of a single-serve beverage brewer is the Keurig® Single Cup Brewing System available from Green Mountain Coffee Roasters, Inc. of Waterbury, Vt. The Keurig Single Cup Brewing System includes an automatic brewer which injects hot water under pressure into a sealed cartridge containing ground coffee or other particulate beverage medium. The hot water mixes with the ground coffee in the cartridge to brew the coffee. The freshly-brewed coffee is subsequently delivered by the brewer to the user's cup. Importantly, hot water used to brew the coffee and the liquid coffee must not leak from the cartridge during this process because any liquid leakage would interfere with the brewing process and operation of the brewer and could create an unacceptable mess requiring clean up by the user. A further problem associated with water leakage is that any water which escapes from the cartridge can flow down and into the user's cup diluting the coffee or other beverage in the cup.
The cartridge used with the Keurig Single Cup Brewing System is known as a K-Cup®.
A problem confronting coffee roasters which package ground coffee 5 in K-Cup-type cartridges 1 is that the roaster must make a compromise between the integrity and performance of the cartridge 1 and the freshness and quality of the coffee packaged in the cartridge 1. This integrity and performance problem arises because coffee produces carbon dioxide gas after it is roasted, ground and packaged. The positive gas pressure can build within the cartridge 1, causing the cartridge 1 to swell and become distorted.
The pressure build up within the K-Cup-type cartridge 1 and the resultant expansion and distortion can adversely affect the cartridge 1 by potentially preventing the cartridge 1 from being properly seated within the brewer. Distortion and swelling of cartridge 1, or multiple cartridges 1, can also damage or rupture the carton or secondary package (not shown) in which a plurality of cartridges 1 are packaged. This carton or secondary package can, for example, be made of cardboard which closely encloses the cartridges 1. The carton or secondary package can be broken open by expansion of plural cartridges 1. The carton or secondary package may not be salable at retail if it is broken. Moreover, a case containing many cartons or secondary packages can similarly be broken open by expanding cartridges and delivery may be refused by the wholesaler. Cartridge 1 distortion is also undesirable from a performance standpoint because a customer could perceive a swollen K-Cup-type cartridge 1 as being defective and potentially unsafe because of microorganism contamination.
In extreme circumstances, the swelling and distortion can cause the cartridge 1 to rupture and fail compromising package integrity. A K-Cup-type cartridge 1 could fail if the K-Cup lid 7 became detached from the cartridge 1. Any failure of the K-Cup-type cartridge 1 would result in damage or loss of the ground coffee 5 within the cartridge 1.
A compromise can be made to minimize risk of K-Cup-type cartridge 1 distortion and failure by “degassing” the ground coffee before packaging in the cartridge 1. Degassing represents a compromise because degassing reduces the risk of package distortion and failure, but can also degrade the freshness and quality of the degassed ground coffee 5. Degassing involves spreading the ground coffee 5 on a surface for between 24 to 48 hours after roasting and grinding so that carbon dioxide gas can be released. Ground coffee is particularly active in carbon dioxide production within this period of degassing. Because the ground coffee will produce relatively less carbon dioxide gas after degassing, the roasted and ground coffee can be packaged with a reduced risk of cartridge 1 distortion or failure.
The loss of ground coffee 5 freshness and quality which occurs during degassing may degrade the flavor of the ground coffee. Ground coffee 5 packaged in a K-Cup-type cartridge 1 or other cartridge type following degassing is not optimally fresh and flavorful. This is a particular disadvantage for the Keurig Single Cup Brewing System and ground coffee 5 packaged in K-Cup-type cartridges 1 because users of these premium coffee-brewing products are discerning and expect a superior coffee experience with optimal coffee freshness and flavor.
Thus, the roaster must attempt to strike the appropriate balance between packaging performance, appearance and integrity and the quality of the coffee or other beverage brewed by means of the K-Cup-type cartridge 1 or other cartridge type. Striking the appropriate balance can result in a less-than-optimal coffee experience for the consumer.
It would be an improvement in the art to provide a single-serve cartridge and cartridge components compatible for use with the Keurig Single Cup Brewing System and similar brewing systems, which would permit proper operation of the brewer in which the cartridge is loaded, which would avoid liquid leakage during brewing, which would optimize the freshness and flavor of the coffee or other particulate beverage medium packaged in the cartridge, which would avoid gas build up within the cartridge and cartridge distortion and which would provide an optimal experience for the consumer.
Certain embodiments of the present invention are concerned with providing a single-serve beverage cartridge into which liquid, typically hot water, is injected under pressure by a brewer, such as a Keurig brand Single Cup Brewing System. One highly preferred type of cartridge is a K-cup cartridge. The cartridges are ideal for the brewing of coffee from particulate beverage medium within the cartridge, although the cartridges may be used with beverages other than coffee. Cartridge embodiments of the types described herein restrict air entry into the cartridge, allow gas generated by the coffee to be vented from the cartridge before brewing and yet limit liquid flow out of the cartridge during the brewing process. The result is that the coffee roaster can package roasted, ground coffee in the cartridge while optimally flavorful without risk of compromising package quality or integrity.
In embodiments, a single-serve beverage cartridge comprises the combination of a single-serve cartridge and a one-way pressure relief valve. In an embodiment, the cartridge comprises a cup, a lid and a granular beverage medium within the cup. The cup has a shape and is preferably of a gas-and-liquid impermeable material. The cup preferably includes a rim defining an opening. A lid which is preferably of a gas-and-liquid impermeable material is sealed to the rim entirely around the opening and covering the opening. The cartridge further includes a vent, a puncture zone and a separate valve placement zone. In embodiments, a brewer needle can inject the liquid into the cartridge through the puncture zone. The granular beverage generates gas creating pressure within the cartridge before the liquid injection.
In embodiments, the preferred one-way gas pressure relief valve vents gas from the cartridge yet is liquid-tight to injected liquid. A preferred valve comprises a base layer and a flexible seal. The base layer is preferably affixed over the vent in the cartridge entirely within the valve placement zone. It is most highly preferred that the lid includes the vent, the valve placement zone and the puncture zone. Preferably, the valve is attached to the lid in gas flow communication with the vent and in the valve placement zone. Such placement can avoid interference with insertion of a brewer entrance needle into the cartridge. In embodiments, the vent has a cross-sectional area of less than about 0.00019 in2. Such a relatively small vent size contributes to restriction of liquid flow out of the cartridge during the brewing process.
In embodiments, the base layer includes a first side, a second side, at least one hole entirely through the base layer and adhesive on the second side affixing the base layer to the cartridge and most preferably to the lid. In the embodiment, the at least one hole has a total cross-sectional area of less than about 0.000314 in2. In other embodiments, the base layer of the valve can include plural holes. In such embodiments, the plural holes have a total cross-sectional area of less than about 0.000314 in2.
A liquid flow-restricting baffle is formed by an inner edge of the adhesive surrounding the at least one hole. The baffle is positioned over the vent and in gas-flow communication with the at least one hole. It is preferred that the inner edge of the adhesive defining the baffle is spaced entirely from the at least one hole in the base layer. The baffle contributes to limit and prevent leakage of liquid from the cartridge by reducing force of the liquid injected into the cartridge by the brewer.
In embodiments, the flexible seal includes a first region joined to the base layer first side spaced at least partially from the at least one hole and a second region unjoined to the base layer first side covering the at least one hole. The regions define, together with the base layer first side, a gas flow path from the at least one hole to a periphery of the flexible seal. The flexible seal flexes responsive to the gas pressure to at least partially open the gas flow path and permit gas outflow from the cartridge. Such gas flow path also preferably includes a path from the baffle and through the at least one hole. The valve relieves the gas pressure before the liquid injection thereby maintaining the cup shape and the gas seal while permitting the beverage medium to be packaged in the cartridge without substantial degassing and limits flow of the injected liquid out of the cartridge.
It is preferred that the flexible seal first region is joined to the base layer first side by an adhesive. In embodiments, the flexible seal flexes to allow gas to flow along the gas flow path when cartridge internal gas pressure exceeds ambient air pressure by about 0.2 psig.
In certain embodiments, a wetting agent may be provided between the base layer and flexible seal. A wetting agent facilitates air-tight closure of the valve and cartridge.
In other embodiments, first and second layers which are releasably held together are utilized to facilitate air-tight closure of the valve and cartridge. The first and second layers can comprise a first layer atop the base layer first side around the base layer hole, a flexible cover layer over the first layer and the base layer hole and a second layer supported by the flexible cover layer facing the first layer and covering the base layer hole. In such embodiments, the first and second layers are releasably held together to form a seal blocking passage of gas into the cartridge. Flexing of the flexible seal separates the first and second layers sufficiently to allow gas to flow along the gas flow path.
In embodiments, the valve is sized to have a footprint area of less than about 0.25 in2.
In embodiments in which the lid is circular in shape, the lid defines a circle with a center and the puncture zone comprises a circle concentric with the center. In such embodiments, the valve placement zone is concentric with both the center and the puncture zone. The lid may have a radius of less than about 1 inch and the puncture zone may have a radius of about 0.5 inch.
In embodiments, the invention may be implemented as a lid component for closure of a single-serve beverage cartridge. The lid may be supplied as a component separate from other components of the cartridge and may be attached to the cartridge at any suitable point of the manufacturing process.
Other features and embodiments are described in the drawings and detailed description which follows.
Exemplary single-serve cartridges and components with a one-way gas pressure relief valve may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements throughout the different views. For convenience and brevity, like reference numbers are used for like parts amongst the embodiments. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the accompanying drawings:
Before describing exemplary cartridge embodiments 10, 10a, an expanded description of the problems inherent in a representative prior art K-Cup-type cartridge 1 is provided. Referring then to
As illustrated in the section views of
The Keurig Single Cup Brewer (not shown) injects hot water under pressure into the K-Cup-type cartridge 1 loaded in a holder (not shown) within the brewer. The hot water is injected under pressure by means of an entrance needle 26 (example shown in
The entrance and exit needles 26, 28 are inserted automatically by the brewer when the brewer handle is lowered with a K-Cup-type cartridge 1 properly seated in the holder. The entrance needle 26 is inserted through lid 7 and into head space 25 and exit needle 28 is inserted through bottom 17 of K-Cup-type cartridge 1 and into lower space 27.
Entrance needle 26 is a hollow cannula-like tube with a sharpened end facing lid 7 and which pierces lid 7. Entrance needle 26 may be a stainless steel needle having a cylindrical bore, a length of approximately 10 mm and a diameter of approximately 4 mm. Lid 7 is of a material which can be pierced by the entrance needle. A gasket (not shown) around entrance needle 26 forms a liquid-tight seal against lid 7 and prevents liquid from exiting K-Cup-type cartridge 1 between entrance needle 26 and lid 7.
Exit needle 28 may be a stainless steel cannula-like needle having a cylindrical bore, a length of approximately 5 mm and a diameter of approximately 4 mm.
In the examples, hot water is injected into head space 25 above filter element 3 and into contact with ground coffee 5 (or other particulate beverage medium). Filtrate (i.e., liquid coffee) from ground coffee 5 passes through filter 3, through exit needle 28 and to a coffee cup (not shown) placed in the brewer.
The problem resulting from carbon dioxide gas released from the ground coffee 5 or other particulate beverage medium can be easily understood by reference to
Referring next to
The distortion and swelling of cartridge 1, or multiple cartridges 1, can damage or rupture the carton or secondary package (not shown) in which a plurality of cartridges 1 are packaged rendering the carton, or case in which multiple cartons are packed, unsalable as previously described. Also as previously described, swelling of a K-Cup-type cartridge 1 can interfere with seating of cartridge 1 in the brewer and can render cartridge 1 visually unattractive and unsalable as being potentially contaminated with bacteria or microorganisms.
Referring now to
As previously described, cartridges 10, 10a illustrated in
Referring then to
Referring next to FIGS. 13 and 16-17, exemplary cartridges 10, 10a, may include a filter element 45 within cup 33. Filter element 45 may be made of a suitable material such as cellulosic material or polypropylene. Filter element 45 may be joined circumferentially to cup sidewall 43 inner surface 49. In the examples, filter element 45 provides a type of “basket” for holding ground coffee 51 or other particulate beverage medium therein.
Persons of skill in the art will appreciate that a filter element with a structure other than filter element 45 may be implemented for use with cartridge 10, 10a. And, certain cartridge 10, 10a embodiments may not include a filter element 45, for example if the beverage medium is a water-soluble material.
A head space 53, above filter element 45 in the examples, is preferably provided. A lower space 54, below filter element 45 in the examples, is also preferably provided. As illustrated in FIGS. 13 and 16-17, ground coffee 51 produces carbon dioxide and other gases as represented schematically by wavy lines 55 originating from ground coffee 51.
While the improvement is described in connection with ground coffee 51, it is to be understood that the improvement is applicable to any particulate beverage medium which produces gas.
Referring further to
Valve 11 may be affixed directly to a lid 35 of a sealed cartridge 10, 10a over vent 57 following loading of roasted and ground coffee 51 into the cartridge 10, 10a. In other embodiments, valve 11 may be applied to lid 35 before lid 35 is attached to cup 33 providing a combined lid 35 and valve 11 which may be supplied as a cartridge component.
An advantage of providing lids 35-35b as pre-manufactured components is that the valve manufacturer can better control quality of the valves 11 and attachment to the lids 35-35b. A further advantage of providing lids 35-35b as pre-manufactured components is that the lids 35-35b can be supplied to the roaster as finished components. The roaster can then apply lids 35-35b to cups 33 using the roaster's conventional packaging equipment without any need for specialized equipment to apply the valve 11 to lid 35.
As discussed below, valve 11 is constructed to prevent air and contaminants outside of cartridge 10, 10a from entering valve 11 and cartridge 10, 10a. Valve 11 also allows positive pressure from within cartridge 10, 10a to escape, thereby preventing cartridge 10, 10a from swelling and becoming distorted. And, valve 11 is constructed to prevent hot water 40 injected through entrance needle 26 and any pressurized liquid coffee or beverage filtrate from leaking through valve 11, potentially spilling onto the brewer and surfaces surrounding the brewer causing a mess which must be cleaned up. Escape of such hot water 40 and/or liquid coffee through pressure relief valve 11 could also cause the brewer to malfunction or could flow into the user's cup beneath cartridge 10, 10a diluting the coffee or other beverage.
Valve 11 is preferably affixed to lid 35 because lid 35 provides a relatively smooth and generally flat surface which facilitates adhesion and attachment of valve 11 to lid 35. In other embodiments, valve 11 may be affixed to bottom 41 of cup 33, or to any other part of cartridge 10, 10a which does not interfere with operation of the brewer.
In the examples, valve 11 is mounted on cartridge 10, 10a at a location which will not interfere with penetration of brewer entrance needle 26 or brewer exit needle 28 into cartridge 10, 10a. Entrance needle 26 of a Keurig brewer can puncture a hole in lid 35 which is as large as about 0.25 inches in diameter. Given the large size of the puncture, it is desirable that there be no contact between entrance needle 26 and valve 11. In certain embodiments, it may be important that valve 11 is spaced from entrance and exit needles 26, 28 because the material used to manufacture valve 11 may be tougher than the material used to manufacture lid 35 and cup 33. Consequently, the brewer entrance 26 and exit needles 28 might not be capable of piercing through valve 11. As a further example, force applied to valve 11 might separate lid 35 from cup 33 around rim 37 or tear lid 35 before entrance needle 26 were to penetrate valve 11 and lid 35. This could cause cartridge 10, 10a to leak during the brewing process.
For embodiments in which valve 11 is affixed to lid 35, it has been determined that the attachment position should be offset, preferably entirely offset, from the location of lid 35 where the brewer entrance needle 26 pierces lid 35 to inject hot water into cartridge 10, 10a for brewing the coffee or other beverage as described previously. By entirely offsetting valve 11 from lid 35 contacted by the entrance needle 26, it is ensured that entrance needle 26 will be able to easily penetrate through lid 35 as presently occurs with cartridges 1.
An exemplary location of valve 11 on lid 35 entirely offset from the location where entrance needle 26 penetrates lid 35 may be understood by reference to
By way of non-limiting example and as illustrated in
In such an example, valve 11 may have a generally rectangular footprint, or land area, as illustrated in
The foregoing examples are merely representative. Persons of skill in the art will appreciate that puncture zone 59 may be located other than as illustrated in
Referring again to
Referring to
In the example, vent 57 is a single hole in lid 35. In embodiments, the single hole of vent may be punched in lid 35 during die cutting of lid 35. In other embodiments, vent 57 includes plural openings entirely through lid 35. In embodiments, vent 57 has a total cross-sectional area (in a plane defined by lid 35) of less than about 0.00019 in2. Such cross-sectional area could be the area of a single vent 57 or the total area of a plurality of vents 57. A smaller cross-sectional area of vent 57 is preferred because a relatively small vent 57 will restrict flow of hot water 40 injected into cartridge 10, 10a and restrict liquid coffee. While such a small vent 57 will restrict flow of hot water 40 and/or liquid coffee, it will allow carbon dioxide gas flow therethrough because gas is less dense than liquid such as hot water 40 or liquid coffee.
Base layer 65 includes first and second sides 71, 73, a periphery 75, a body 77 between sides 71, 73 and at least one hole 81 entirely through body 77. Base layer 65 is generally flat, or planar, and may be made of materials that will not degrade during momentary contact with hot water 40, liquid coffee or beverage filtrate during the brewing process. Base layer 65 should be impervious to gas flow. Representative materials for use in base layer 65 include polyethylene, polypropylene, polyethylene terephthalate, biodegradable polylactic acid, cellulose acetate, or any other suitable material or materials. Base layer 65 may have a thickness in the range of about 0.25 mils to about 50 mils depending on the application.
Referring to
Referring to
Referring FIGS. 14 and 16-17, adhesive layer 69 is provided on base layer 65 second side 73 to removably mount base layer 65 on a release liner (not shown) after manufacture and to permanently attach base layer 65 and valve 11 to lid 35 of cartridge 10, 10a. In the example, adhesive layer 69 may be about 0.25 mils to about 15 mils in thickness. Adhesive layer 69 should be impervious to gas flow and sufficiently impervious to liquid (i.e., hot water 40, liquid coffee) to prevent gas and liquid leakage between base layer 65 and lid 35. Suitable adhesives for adhesive layer 69 may include pressure-sensitive and heat-activated adhesives. Rubber-based, silicone and acrylic adhesives may be utilized as adhesive layer 69.
Referring further to FIGS. 14 and 16-17 and 19A, adhesive layer 69 is deposited across base layer 65 second side 73. Adhesive layer 69 has an inner edge 83 surrounding hole 81, or plural holes 81, 81a, 81b, to define with base layer 65 second side 71, a liquid flow-restricting baffle 85. Baffle 85 is in gas-flow communication with hole 81. When valve 11 is attached to lid 35, baffle 85 is positioned over vent 57.
Baffle 85 provides a space, or buffer, which holds and stores hot water 40 injected into cartridge 10, 10a by the brewer through entrance needle 26 and any liquid coffee which may enter baffle 85 through vent 57. Baffle 85 limits hot water 40 and/or liquid coffee flow through hole 81 by reducing the pressure of hot water 40 and/or liquid coffee which may enter baffle through vent 57. Baffle 85 is particularly effective at minimizing or modulating the momentary high pressure of hot water 40 (i.e., a type of water hammer) as such water fills cartridge 10, 10a after injection into cartridge 10, 10a through entrance needle 26 as described below.
Referring again to
Valve 11 opens and closes to allow carbon dioxide gas outflow from cartridge 10, 10a based on pressure differential between pressure inside cartridge 10, 10a and pressure outside cartridge 10, 10a. Valve 11 may be designed to open with any desired target pressure differential. Selection of materials with appropriate resiliency is one manner of engineering valve 11 to open at a desired pressure differential. An opening target pressure differential may be less than about 0.2 psig greater pressure inside cartridge 10, 10a than outside cartridge 10, 10a. Valve 11 may be designed to close when pressure inside cartridge 10, 10a exceeds pressure outside cartridge 10, 10a by about 0.008 psig or less. Other target opening and closing pressures may be utilized and the foregoing are merely non-restrictive examples.
Referring to the exploded view of
In the example, flexible seal 67 includes closure 91 (also referred to in industry as a “dry strap” or simply “strap”), cover membrane 93, and an adhesive layer 95 joining cover membrane 93, or layer, to closure 91 and selectively joining cover membrane 93 shoulders 97 (outer regions of cover membrane 91 in the example) to attachment regions 99, 101 of base layer 65 first side 75. As previously described, “selective joining” means or refers to joining of cover membrane 93 only to attachment regions 99, 101 of base layer 65 and not to base layer 65 between such attachment regions 99, 101. Because cover membrane 93 is unjoined to base filter layer 65 where closure 91 is secured to cover membrane 93 between attachment regions 99, 101, cover membrane 93 is permitted to flex and move slightly away from base layer 65 (caused by the pressure differential) along the unjoined regions when in the open state to permit gas flow out of valve 11. When the unjoined portion of cover membrane 93 moves away from base layer 65, closure 91 also moves at least partially away from base layer 65. Accordingly, cover membrane 93 of the example is a type of flexible cover membrane 93. This opening of valve 11 can be understood by comparing
Flexible seal 67 also applies a force which closes hole 81 to prevent ambient air from entering hole 81, valve 11 and cartridge 10, 10a when in the closed state. Such force also contributes to closure of hole 81 to prevent hot water 40 injected into cartridge 10, 10a by the brewer and liquid coffee from leaking out of cartridge 10, 10a through hole 81. Wetting fluid 89 enhances securement of closure 91 across hole 81.
In the examples, gas flow path 87 extends through baffle 85 and hole 81 through base layer 65 body 77. Along base layer 65 first side 71, gas flow path 87 is bounded by base layer 65 first side 71, closure 91 (adhered to cover membrane 93 by adhesive 95 in the example), and shoulders 97 of cover membrane 93 selectively joined to base layer 65 by adhesive 95 along attachment regions 99, 101. Exemplary gas flow path 87 permits gas outflow from cartridge 10, 10a and through valve 11.
As is illustrated in
Closure 91 is secured to cover membrane 93 by adhesive layer 95. Closure 91 prevents adhesive layer 95 from contacting filter layer 65 where it is unjoined with cover membrane 93 between attachment regions 99, 101. Adhesive layer 95 joins cover membrane 93 to base layer 65 attachment regions 99, 101. Exemplary adhesive layer 95 is a gas-impervious pressure-sensitive adhesive layer 95 which may be about 0.25 mils to about 15 mils in thickness. Adhesive layer 95 may be of the same adhesive used for adhesive layer 69.
Cover membrane 93 may be selectively joined to base layer 65 by means other than adhesive layer 95. For example, cover membrane 93 could be selectively joined to base layer 65 by means of sonic welding.
Representative materials for use in closure 91 and cover membrane 93 may include polyethylene, polypropylene, polyethylene terephthalate, biodegradable polylactic acid, cellulose acetate, or any other suitable material or materials. Closure 91 and cover membrane of flexible seal 67 should be impervious to gas flow and sufficiently impervious to liquid (i.e., hot water 40, liquid coffee) to prevent gas and liquid leakage therethrough. Closure 91 and cover membrane 93 may each have a thickness of about 0.25 mils to about 50 mils.
Referring to FIGS. 14 and 16-17, optional bumpers (also referred to as rails) 103, 105 may be joined to cover membrane 93 by an adhesive 107. If provided, bumpers 103, 105 are useful to provide separation between the unjoined portion of cover membrane 93 and any adjacent object such as another cartridge (e.g., cartridge 10, 10a) or the carton or secondary package in which a cartridge 10, 10a is packaged so that closure 91 can freely move away from base layer 65 permitting valve 11 gas flow path 87 to open. Bumpers 103, 105 may be of polyethylene, polypropylene, polyethylene terephthalate, biodegradable polylactic acid, cellulose acetate, or any other suitable material or materials and may have a thickness of about 0.25 mils to about 50 mils. Adhesive 107 may be of the same material as adhesives 69 and 95.
Referring then to
In the example of
Base layer 265 is not limited to a single hole 281 and plural holes could be used in place of single hole 281, for example in the same manner as holes 81, 81a, 81b described in connection with
Referring again to
In the example, adhesive layer 269 is deposited across base layer 265 second side 273. Adhesive layer 269 has an inner edge 283 surrounding hole 281 (or plural holes such as holes 81, 81a, 81b), to define, with base layer 265 second side 273, a liquid flow-restricting baffle 285. Baffle 285 is in gas-flow communication with hole 281. When valve 211 is attached to lid 35, baffle 285 is positioned over vent 57 through lid 35.
Baffle 285 provides a space, or buffer, which holds and stores hot liquid coffee 40 which may pass through vent 57 during the brewing process. Accordingly, baffle 285 contributes to restriction of liquid coffee 40 in the same manner as baffle 85 and the description of baffle 85 structure and operation is incorporated herein by reference.
In the example, flexible seal 267 comprises a first layer 311 on base layer first side 271, a second layer 313 on membrane 315, a cover membrane, or layer, 293 and an adhesive layer 295 joining membrane 315 to cover membrane 293. Adhesive layer 295 also selectively joins cover membrane 293 shoulders 297 (i.e., outer regions of cover membrane 293 in the example) to attachment regions 299, 301 of base layer 265. As with valve 11, “selective joining” means or refers to joining of cover membrane 293 only to attachment regions 299, 301 of base layer 265 and not to base layer 265 between attachment regions 299, 301. Because cover membrane 293 is unjoined to base layer 265 between attachment regions 299, 301, cover membrane 293 is permitted to flex and move sufficiently away from base layer 265 along the unjoined region when in the open state to permit gas flow out of pressure relief valve along gas flow path 287. Accordingly, cover membrane 293 can be characterized as a flexible cover membrane 293.
In the example of
Cover membrane 293 and membrane 315 secured to cover membrane 293 are over first layer 311 and holes 281, 317. In the example, second layer 313 is a coating deposited on a surface of membrane 315 facing first layer 311. Membrane 315 with second layer 313 facing first layer 311 covers holes 281, 317 to block gas and liquid coffee 40 flow through holes 281, 317, when valve 211 is in the closed state. Therefore, second layer 315 on membrane is supported by cover layer 293 in the example. And, first layer 311 and second layer 313 are in abutment when valve 211 is in the closed state.
First and second layers 311, 313 may be releasably held together by means of various systems. For example, first and second layers 311, 313 could separately comprise an adhesive layer and a release layer. By way of further example, first and second layers 311, 313 could separately comprise layers having an affinity of an ionic type in which opposite charges attract first and second layers 311, 313 together. Holding together of first and second layers 311, 313 whether by adhesive or ionic affinity provides a more complete closure against entry of air into valve 211 and cartridge 10, 10a.
In certain embodiments, first layer 311 is generally referred to as a no tack, ultra low tack, cling film, self wetting, removable adhesive, or cohesive substrate. In embodiments, the material for use in first layer 311 may also be characterized as a pressure-sensitive adhesive. First layer 311 should be of a material which does not permit gas flow therethrough and which is sufficiently impervious to liquid to prevent leakage. Copolymers of polyisobutylene and poly methyl methacrylate are illustrative materials for use as a first layer 311. First layer 311 may be about 0.25 mils to about 15 mils in thickness.
Second layer 313 may be a gas-impervious silicone or other dry release film layer. Membrane 315 with second layer 313 deposited thereon may be about 0.25 mils to about 15 mils in thickness. An example of a silicone material which may be used as a second layer 313 is polydimethysiloxane.
By way of example only, the affinity of first layer 311 for second layer 313 can be described in quantitative terms as a bond strength in the range of 0.25 grams/inch to 10 grams/inch when measured with a tensile tester in accordance with ASTM F-88. With the appropriate selection of materials and/or inherent surface energies of first and second layers 311, 313, the ability to form seals of controlled bond strength is established. The implementation of first layer 311 and second layer 313 provides a means for keeping membrane 315 in place against base layer 265 and achieving a gas-tight seal that enables valve 211 to function as a one-way pressure relief valve.
Persons of skill in the art will appreciate that either the first layer 311 or the second layer 313 could be an adhesive layer or a release layer or that either first layer 311 or second layer 313 could have an opposite charge and affinity of the ionic type.
As is illustrated in
Bumpers 303, 305 may be secured to cover membrane 293 by adhesive 307 which may be the same as adhesive 107. Bumpers 303, 305 serve the same purpose as bumpers 103, 105 previously described. Operation of cartridge 10, 10a and valve 211 are described below.
Operation of the improved cartridges 10, 10a will now be described in connection with cartridge 10 of
Referring first to the example of
Valve 11 is initially in its closed state. Closure 91 is forced against base layer 65 by flexible cover layer 93 across hole 81 closing hole 81 and preventing gas flow therethrough preserving the freshness of ground coffee 51 or other particulate beverage material inside cartridge 10, 10a. Wetting agent 89, which may be provided between base filter layer 65 and closure 91, facilitates gas-tight abutment of closure 91 against base layer 65 and across hole 81.
Referring to
When the differential pressure is decreased below the target pressure, cover membrane 93 of flexible seal 67 applies a force as it is unloaded and returns to its original position, or closed state, as illustrated in
The valve 211 embodiment of
As represented schematically in
Hot water 40 is injected through entrance needle 26 and into cartridge 10, 10a where the hot water 40 fills cartridge 10, 10a and mixes with ground coffee 51. The injection of hot water under pressure can last as long as about 40 seconds. Liquid coffee or other beverage filtrate is drained through filter element 45 and from K-Cup-type cartridge 10, 10a through exit needle 28 whereupon the coffee ultimately collects in the user's cup.
The combination of vent 57, baffle 85, hole 81 and flexible seal 67 of valve 11, or vent 57, baffle 285, hole 281 and flexible seal 267 of valve 211 limit hot water 40 and/or liquid coffee flow out of cartridge 10, 10a and render cartridge 10, 10a essentially liquid-tight for a brewer application. More particularly, vent 57 and baffle 85, 285, hole 81, 281 and base layer 65, 265 and flexible seal 67, 267 defining gas flow path 87, 287 provide an inefficient and constrictive flow path for hot water 40 and/or liquid coffee. The gas flow path 87, 287 along which liquid would have to flow to exit valve 11, 211 could be characterized as “serpentine” because of the many turns which restrict liquid flow along the gas flow path 87, 287. The gas flow path 87, 287 is restrictive to liquid flow at least in part due to the fact that hot water 40 and liquid coffee are dense relative to carbon dioxide gas. Initially, vent 57 constricts movement of hot water 40 and/or liquid coffee through lid 35 because of the liquid density and small size of vent 57. Next, baffle 85, 285 acting as a buffer traps any initial flow of such hot water 40 and/or liquid coffee through vent 57. Baffle 85, 285 serves to reduce pressure of such hot water 40 and/or liquid coffee. Baffle 85, 285 provides for a momentary reduction in force of hot water 40 and/or liquid coffee while baffle 85, 285 is filled.
Without wishing to be bound by any particular theory, it is thought that baffle 85, 285 provides mitigation of a type of “water hammer” effect as pressurized hot water 40 and/or liquid coffee enters baffle 85, 285 reducing force that would otherwise open valve 11 allowing liquid to undesirably flow through valve 11 and to leak from cartridge 10, 10a. Once baffle 85, 285 fills with hot water 40 and/or liquid coffee, force will be transmitted to base layer 65, 265 where the narrow and small cross-sectional area of hole 81, 281 further restricts movement of hot water 40 and/or liquid coffee through base layer 65, 265 further limiting liquid pressure and contributing to liquid blockage.
Lastly, force applied by flexible seal 67 (i.e., closure 91, cover layer 93) and surface adhesion of closure 91 against base layer 65 first side 71 provided by wetting agent 89 or first and second layers 311, 313 of flexible seal 267 combine with the aforementioned elements to close hole 81, 281 and gas flow path 87, 287 to limit hot water 40 and/or liquid coffee from passing through valve 11, 211.
Accordingly, cartridges 10, 10a are unique in that they permit gas outflow yet limit liquid outflow. One way gas outflow can occur from valve 11 at pressure differentials which may be as little as about 0.2 psig between pressure inside and outside cartridge 10, 10a. And yet cartridges 10, 10a block passage of hot water 40 injected under pressure into cartridge 10, 10a. Cartridges 10, 10a can prevent hot water 40 and/or liquid coffee leakage even though as much as about 160 ml to about 220 mL of hot water 40 are injected into cartridge 10, 10a by brewer for as long as 40 seconds.
Improved cartridges 10, 10a of the type described herein permit the roaster to immediately load ground coffee 51 into filter element 45 and cartridge 10, 10a following roasting and grinding when coffee flavor is at its best. No degassing, with the associated degradation in coffee flavor, is required because improved cartridges 10, 10a permit carbon dioxide and other gas to be evacuated from cartridge 10, 10a. Accordingly, ground coffee 51 and other beverages can be provided to the consumer in an optimally fresh and flavorful condition to optimize the experience to the consumer.
By allowing one-way gas flow out of cartridge 10, 10a, the roaster avoids problems of cartridge 10, 10a swelling and distortion associated with conventional cartridges 1. Problems which are avoided can include: (1) possible difficulty in loading the cartridge into the brewer resulting from cartridge swelling and distortion; (2) possible negative consumer reaction to the appearance of a swollen cartridge at the point of sale or afterwards; and (3) possible damage to a carton (i.e., a secondary package) and to a case holding one or more cartons resulting from expansion of many cartridges; and (4) possible loss of cartridge integrity caused by a rupture or cartridge failure due to excessive cartridge internal pressures.
Improved cartridges 10, 10a also facilitate proper operation of the brewer in which the cartridge 10, 10a is loaded. Proper operation is ensured because cartridges 10, 10a of the type described herein function in the brewer in the same manner as a conventional undistorted K-Cup or cartridge 1 in that such cartridges 10, 10a have essentially no leakage when hot water 40 is injected into cartridge 10, 10a under pressure by the brewer. Consequently, the liquid coffee or beverage filtrate is directed toward the user's cup where it belongs and there is no mess to clean up or diluted beverage in the user's cup resulting from hot water 40, liquid coffee or other beverage filtrate leakage from cartridge 10, 10a.
While particular embodiments of the invention have been shown and described, other alternatives, variations, and modifications will occur to those skilled in the art. It is intended in the appended claims to cover all such alternatives, variations, and modifications that come within the true spirit and scope of the present invention.
