Patent Publication Number: US-10307718-B2

Title: Pneumatically operated valve for carbonation machine

Description:
FIELD OF THE INVENTION 
     The present invention relates to carbonation machines. More particularly, the present invention relates to a pneumatically operated valve for a carbonation machine. 
     BACKGROUND OF THE INVENTION 
     A carbonation machine is designed to introduce a pressurized gas, typically carbon dioxide, into a liquid, typically water. For example, a removable bottle of water may be attached to the machine such that a seal is formed between the opening of the bottle and the machine. The seal prevents gas from escaping from the bottle to the ambient atmosphere, as pressurized gas is introduced into the bottle. 
     The pressurized gas may be stored in a canister until it is released. For example, the gas may be stored in the canister as a liquid. A valve of the canister may be opened in order to release the gas from the canister. A system of conduits may then conduct the released pressurized gas from the canister to a nozzle that introduces the gas into the bottle of liquid. 
     For example, a valve may release the gas from the canister when a plunger of the valve is pressed inward. A carbonation machine may include a manually or electrically operated mechanism for operating the valve to release gas from the canister. 
     SUMMARY OF THE INVENTION 
     There is thus provided, in accordance with an embodiment of the present invention, a carbonation machine including; a pneumatic chamber with a movable wall, the movable wall configured to move outward to cause a pin of a gas release valve of a gas canister that is held in a canister holder of the machine to be depressed when air pressure in the chamber is increased; an air release valve that is closable to retain air in the chamber; an air pump that is operable to pump air from an ambient atmosphere into the chamber so as to increase air pressure in the chamber; and a controller that is configured to close the air release valve and to operate the air pump to increase the air pressure in the chamber to move the movable wall outward to open the gas release valve of the canister to cause release of gas from the canister to carbonate a liquid, and to open the air release valve to enable the gas release valve to close. 
     Furthermore, in accordance with an embodiment of the present invention, the carbonation machine includes a plunger that is configured to be pushed distally by the outward movement of the movable wall to depress the pin. 
     Furthermore, in accordance with an embodiment of the present invention, the controller is configured to stop operation of the air pump when the air release valve is opened. 
     Furthermore, in accordance with an embodiment of the present invention, the controller is configured to open the air release valve when a carbonation level of the liquid attains a selected carbonation level. 
     Furthermore, in accordance with an embodiment of the present invention, attainment of the selected carbonation level is indicated by a length of time during which the gas release valve is opened. 
     Furthermore, in accordance with an embodiment of the present invention, the controller is configured to open the air release valve after a predetermined interval after the gas release valve is opened. 
     Furthermore, in accordance with an embodiment of the present invention the controller is configured to repeat the operations of causing the gas release valve to open and of opening the air release valve in accordance with a programmed carbonation scheme. 
     Furthermore, in accordance with an embodiment of the present invention, the air release valve includes a solenoid valve that is normally open. 
     Furthermore, in accordance with an embodiment of the present invention, the carbonation machine includes a tilt sensor, wherein the controller is configured to close the air release valve or operate the air pump only when a sensed tilt angle does not exceed a threshold tilt angle. 
     Furthermore, in accordance with an embodiment of the present invention, the movable wall includes a piston. 
     There is further provided, in accordance with an embodiment of the present invention, a pneumatic valve operation mechanism for a carbonation machine, the mechanism including: a pneumatic chamber with a movable wall, the movable wall configured to move outward when air pressure in the chamber is increased; an air release valve that is closable to retain air in the chamber; and an air pump that is operable to pump air from an ambient atmosphere into the chamber so as to increase air pressure in the chamber when the air release valve is closed, wherein the movable wall is configured to cause a gas release valve of a gas canister to open when the movable wall is moved outward, the released gas being conduced to a liquid that is to be carbonated by the gas. 
     Furthermore, in accordance with an embodiment of the present invention, the mechanism includes a plunger that is configured to be pushed distally by the outward movement of the movable wall, a distal end of the plunger configured to depress a pin of the gas release valve to open the gas release valve when the plunger is pushed distally. 
     Furthermore, in accordance with an embodiment of the present invention, the air release valve includes a solenoid valve that is normally open. 
     Furthermore, in accordance with an embodiment of the present invention, the movable wall includes a piston. 
     There is further provided, in accordance with an embodiment of the present invention, a method of operation of a carbonation machine by a controller of the machine, the method including: closing an air release valve to present release of air from a pneumatic chamber of the machine; operating an air pump to pump air from an ambient atmosphere into the chamber so as to increase air pressure in the chamber so as to move a movable wall of the chamber outward to cause a gas release valve of a gas canister that is attached to the machine to open so as to release gas from the canister, the released gas being conducted to a liquid so as to carbonate the liquid; upon completion of a predetermined time interval after the gas release valve is opened, opening the air release valve to release air from the chamber to enable the gas release valve to close. 
     Furthermore, in accordance with an embodiment of the present invention, the method includes stopping operation of the air pump after the predetermined time interval. 
     Furthermore, in accordance with an embodiment of the present invention, the predetermined time interval corresponds to a selected carbonation level. 
     Furthermore, in accordance with an embodiment of the present invention, the predetermined time interval includes a length of a carbonation pulse of releasing gas from the canister. 
     Furthermore, in accordance with an embodiment of the present invention, the method includes repeatedly applying carbonation pulses. 
     Furthermore, in accordance with an embodiment of the present invention, repeatedly applying carbonation pulses is ended when a sequence of the applied carbonation pulses corresponds to a selected carbonation level. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order for the present invention, to be better understood and for its practical applications to be appreciated, the following Figures are provided and referenced hereafter. It should be noted that the Figures are given as examples only and in no way limit the scope of the invention. Like components are denoted by like reference numerals. 
         FIG. 1  schematically illustrates components of a carbonation machine with a pneumatically operated valve, in accordance with an embodiment of the present invention. 
         FIG. 2A  schematically illustrates a cross sectional view of the carbonation machine shown in  FIG. 1  with a pneumatic valve operation mechanism causing gas to be released from a canister. 
         FIG. 2B  schematically illustrates a cross sectional view of the carbonation machine shown in  FIG. 2A  with the pneumatic valve operation mechanism enabling a gas release valve of the canister to close. 
         FIG. 3  schematically illustrates operation of a pneumatic valve operation mechanism of the carbonation machine shown in  FIG. 1 . 
         FIG. 4  is a flowchart depleting a method for pneumatic operation of a carbonation machine, in accordance with an embodiment of the present invention. 
         FIG. 5  is a flowchart depicting a method for pneumatic operation of a carbonation machine with multiple carbonation pulses, in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those of ordinary skill in the art that the invention, may be practiced without these specific details. In other instances, well-known methods, procedures, components, modules, units and/or circuits have not been described in detail so as not to obscure the invention. 
     Although embodiments of the invention are not limited in this regard, discussions utilizing terms such as, for example, “processing,” “computing,” “calculating,” “determining,” “establishing”, “analyzing”, “checking”, or the like, may refer to operation(s) and/or process(s) of a computer, a computing platform, computing system, or other electronic computing device, that manipulates and/or transforms data represented as physical (e.g., electronic) quantities within the computer&#39;s registers and/or memories into other data similarly represented as physical quantities within the computer&#39;s registers and/or memories or other information non-transitory storage medium (e.g., a memory) that may store instructions to perform operations and/or processes. Although embodiments of the invention are not limited in this regard, the terms “plurality” and “a plurality” as used herein may include, for example, “multiple” or “two or more”. The terms “plurality” or “a plurality” may be used throughout the specification to describe two or more components, device, elements, units, parameters, or the like. Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed simultaneously, at the same point in time, or concurrently. Unless otherwise indicated, the conjunction “or” as used herein is to be understood as inclusive (any or all of the stated options). 
     In accordance with an embodiment of the present invention, an electrically operated carbonation machine includes a pneumatic mechanism for releasing pressurized gas from a gas canister. The gas that is released from the canister may flow to a carbonation head. At the carbonation head, the gas may be infused into liquid contents of a bottle that is held to the carbonation head so as to carbonate the liquid contents. 
     Although carbonation typically refers to infusion of water or another liquid with pressurized carbon dioxide, carbonation devices and methods as described herein should be understood to include infusion of water or another liquid with carbon dioxide or another gas. 
     The pneumatic mechanism includes a pneumatic chamber with a wall that is movable outward when air pressure within the chamber is increased. When the wall moves outward, the wall may engage cooperating structure of a gas release valve of the gas canister to release the gas from the canister. For example, the outward movement of the movable wall may cause a pin of the gas release valve to be depressed so as to open the valve. 
     As used herein, a movable wall of the pneumatic chamber may refer to rigid displaceable wall or piston, or to a wall or diaphragm that includes at least a section that is deformable outward. In the latter case, deformation of the wall such that a section of the wall bulges outward or is retracted inward is herein also referred to as movement of the wall. 
     An air pump is operable to pump air into the chamber from the ambient atmosphere. When air is pumped into the chamber, an air-release valve that enables release of air from the chamber may be closed. As air continues to be pumped into the chamber, the air in the chamber becomes compressed, increasing the air pressure within the chamber. The increased pressure in the chamber may cause the movable wall to move outward. The outward movement of the movable wall may press on the proximal end of a plunger to move the plunger distally toward a pin of a gas release valve of the gas canister. When the distal end of the plunger presses on the pin, the gas release valve may open to release gas from the canister. The gas from the canister may then be directed to a bottle or other container of a liquid to carbonate the liquid. 
     A controller of the carbonation machine may monitor a level of carbonation of the liquid. For example, the level carbonation may be indicated by one or more of a duration of time that the carbonating gas is released from the gas canister, pressure of the introduced gas in the liquid, a volume of the gas that was introduced into the liquid, or another related quantity. Thus, the controller may be configured to monitor one or more of the duration of the release of gas from the canister, a rate or volume of flow of gas through a conduit of the machine, a pressure of gas that was introduced into she liquid, or another indication of a degree of carbonation. 
     For example, a level of carbonation may be selectable by a user of the carbonation machine, e.g., by operation of a control of the carbonation machine, or may be fixed or selected automatically. 
     When a predefined level of carbonation is achieved., e.g., when a predetermined period of time corresponding to a desired level of carbonation has elapsed, the controller may stop the release of gas from the gas canister. For example, the air-release valve may be opened and operation of the air pump may be stopped, so as to enable air to escape from the chamber. The release of air from the chamber may reduce the air pressure in the chamber. As a result, a closing mechanism (e.g., a spring or other resilient element) of the gas release valve of the canister may push the pin of the gas release valve outward. The gas release valve may thus be closed. The outward movement of the pin may push the plunger in a proximal direction toward the movable wall of the pneumatic chamber. The proximal motion of the pin may cause the movable wall of the pneumatic chamber to move inward, e.g., substantially to its original position prior to the pumping of air into the chamber. 
     A pneumatically operated gas release mechanism, using electrically operated pumps and valves to release gas from a gas canister and as described herein, may be advantageous over other types of electrically operated mechanism. For example, a mechanical mechanism could include a mechanical transmission. The mechanical transmission could be configured to convert a rotational motion of an electric motor to a linear motion of a rod or plunger that presses a pin of the release valve of the gas canister. For example, such a mechanical transmission could include cams, rods, arms, levers, and similar components. Linear components, such as rods, arms, and levers, may connect to one another at hinged joints. Such a mechanical transmission could be susceptible to failure when a variation in an applied force introduces a component of force or motion that could jam or otherwise affect operation (e.g., an applied force including a lateral force component where proper operation requires a substantially longitudinal force). Potential variations or tolerances in various components or their connections could require a costly or time-consuming calibration or adjustment procedure to ensure correct operation of each manufactured carbonation machine. 
     On the other hand, the pneumatic transmission of a pneumatically operated gas release mechanism, in accordance with an embodiment of the present invention, does not require mechanical components to convert rotational motion to linear motion. Any rotational motion, e.g., of the pump, is converted to linear motion by air pressure in the chamber. Air pressure exerts a normal force on all surfaces, reducing the possibility of a lateral force that could jam the mechanism, or of variations between manufactured carbonation machines. 
     Reference is now made to the figures. 
       FIG. 1  schematically illustrates components of a carbonation machine with a pneumatically operated valve, in accordance with an embodiment of the present invention. 
     Carbonation machine  10  is shown with its outer housing removed in order to show components of carbonation machine  10  that are covered by the housing. 
     Carbonation machine  10  is configured to convey a gas, such as carbon dioxide or another gas, from gas canister  20  to carbonation head  34 . A bottle  36  that contains a liquid to be carbonated (e.g., water, a water-based beverage, or another liquid) may be attached to carbonation head  34 . The gas is conveyed to head inlet and into bottle  36 . 
     Gas canister  20  may have a cylindrical or other shape, and may be attacked to carbonation machine  10  at canister holder  21 . Gas canister  20  may be configured to hold liquefied gas, compressed gas, or a combination of the two (e.g., where some of the liquefied gas evaporates to form a layer of compressed gas above the liquefied gas). 
     A user may operate a user control  46  to cause carbonation machine  10  to initiate carbonation of a liquid in bottle  36 . For example, the operated user control  46  may select a desired level of carbonation, from a plurality of offered carbonation levels (as shown in  FIG. 3 ), such as high (H), medium (M), or low, (L). Other types of controls may be provided. Controller  42  of pneumatic valve operation mechanism  40  may operate components of pneumatic valve operation mechanism  40  in accordance with the selected user control  46 . 
     Pneumatic valve operation mechanism  40  of carbonation machine  10  may operate canister gas release valve  25  to cause the gas to be released from gas canister  20 . Air pump  48  of pneumatic valve operation mechanism  40  may be operated by controller  42  to draw air from the ambient atmosphere via air intake  50  and force the air into pneumatic chamber  12  via intake conduit  56 . For example, air pump  48  may include an air compressor, fan, blower, bellows, plunger, or other mechanism that is configured to draw in air from the atmosphere force the air into pneumatic chamber  12  while compressing the air. While air pump  48  is operating, controller  42  may close air release valve  52  to prevent release of air from pneumatic chamber  12  back to the ambient atmosphere via air outlet  54 . For example, air release valve  52  may include a normally open solenoid valve that remains open unless a voltage is applied. Another type of valve, such as a normally closed valve or a valve based on another principle of operation, may be used. 
     Operation if air pump  48  while air release valve  52  is closed may increase the air pressure in pneumatic chamber  12 . The increased air pressure may cause canister gas release valve  25  to open, releasing gas to carbonate liquid contents of bottle  36 . 
     When controller  42  determines that carbonation of the liquid contents of bottle  36  is complete (e.g., after elapse of a time period whose length is determined by operation of a user control  46 , or after otherwise determining that carbonation is complete), or that a carbonation pulse of a programmed carbonation scheme of a series of carbonation pulses is complete (e.g., after elapse of a predetermined time period since opening canister gas release valve  25 ), air may be released from pneumatic chamber  12 . For example, air release valve  52  may be opened and operation of air pump  48  may be halted. Thus, air may be vented from pneumatic chamber  12  via outflow conduit  57  and air outlet  54 , reducing the air pressure in pneumatic chamber  12 . The resulting reduction in air pressure in pneumatic chamber  12  may enable a closing mechanism of canister gas release valve  25  to close canister gas release valve  25 . 
       FIG. 2A  schematically illustrates a cross sectional view of the carbonation machine shown in  FIG. 1  with a pneumatic valve operation mechanism causing gas to be released from a canister. 
     Components of carbonation machine  10  may be enclosed in, or may be mounted to, housing  11 . Housing  11  may include one or more sections that are configured to be rotated or otherwise moved or displaced relative to another section of housing  11 . 
     When canister gas release valve  25  is open, a gas may be conveyed from gas canister  20  to a bottle  36  that is attached to carbonation head  34 . 
     Pneumatic valve operation mechanism  40  of carbonation machine  10  may operate canister gas release valve  25  to cause the gas to be released from gas canister  20 . 
     Gas canister  20  may be attached to carbonation machine  10  by canister holder  21 . For example, canister holder  21  may include threading  23   a  or other structure configured to cooperate with corresponding threading  23   b  or with other structure on canister gas release valve  25  of gas canister  20  to hold gas canister  20  to carbonation machine  10 . 
     Operation of canister gas release valve  25  by pneumatic valve operation mechanism  40  may release gas from gas canister  20 . For example, valve plunger  24  of canister gas release valve  25  may be depressed into gas canister  20 , enabling release of pressurized gas via gas fitting  28 . When an inward-pressing force is no longer applied to valve plunger  24 , canister valve closer  26  may push valve plunger  24  outward to prevent the release of the gas. For example, canister valve closer  26  may include a spring that is compressed when valve plunger  24  is pushed inward, or another type of resilient element. 
     In some cases, canister holder  21  may be provided with an overpressure device. The overpressure device may be configured to prevent outflow of gas from gas canister  20  in the event that canister gas release valve  25  fails to close. For example, canister gas release valve  25  may fail to close if canister valve closer  26  is damaged or otherwise fails, if valve plunger  24  is damaged, bent or tilted to prevent proper motion, or if a foreign object is introduced into canister gas release valve  25  that prevents proper motion of valve plunger  24 . The overpressure device may include a system of seals (e.g., constructed of plastic or of another suitable material) that closes the path of the gas flow when valve plunger  24  (or plunger  18 ) is not being depressed. The overpressure device may enable the gas to flow again when valve plunger  24  is depressed, and again stop the flow when valve plunger  24  is no longer depressed. 
     Pneumatic valve operation mechanism  40  may include a pneumatic chamber  12 . Pneumatic chamber  12  includes a movable wall. In the example shown, the movable wall includes piston  14 . 
     When controller  42  operates pneumatic valve operation mechanism  40  to open canister gas release valve  25 , air pump  48  may be operated to intake air from the ambient atmosphere via air intake  50 . The air may be forced via intake conduit  56  and air inlet opening  15  into pneumatic chamber  12 . Air release valve  52  may be closed to prevent venting of air via air outlet opening  16  and outflow conduit  57  to air outlet  54  and the ambient atmosphere. 
     When air is forced into and compressed in pneumatic chamber  12 , the air pressure may increase within pneumatic chamber  12 , and the increased pressure displaces piston  14  outward with outward movement  19 . Outward movement  19  ( FIG. 3 ) of piston  14  may be laterally constrained by lateral chamber walls  13 . For example, piston  14  may have a circular shape, and lateral chamber walls  13  may be a cylindrical wall. Piston  14 , and thus, the cross section of lateral chamber walls  13  may have another shape (e.g., oval, rectangular, polygonal, or another shape). Piston  14  may be shaped or structured so as to enable piston  14  to slide along lateral chamber walls  13  without tipping or otherwise changing its orientation relative to lateral chamber walls  13 . Piston  14  may also be configured (e.g., with low friction sealing structure, such as a low friction gasket or brushes) to reduce or eliminate escape of air from pneumatic chamber  12  between piston  14  and lateral chamber walls  13 . Alternatively or in addition to piston  14 , the movable wall may include a deformable or elastic diaphragm that may bulge outward when air pressure within pneumatic chamber  12  is increased. 
     Bottle  36  (or other container of a liquid to be carbonated) may be attached to carbonation head  34 . For example, carbonation head  34  may include bottle holder  35 . Bottle bolder  35  may include structure for holding bottle  36  to carbonation head  34 , e.g., retractable clamps as shown. Alternatively or in addition, bottle holder  35  may include threading or other structure to hold bottle  36  to carbonation head  34 . Bottle holder  35  is configured to hold bottle  36  to carbonation head  34  as pressurized gas is being introduced into bottle  36  via distal opening  33  of gas injection wand  32 . Bottle holder  35  may be configured to hold one or more specific types of bottle  36  that are each configured with structure that is designed to engage bottle holder  35 . Bottle  36  may be configured to withstand a predetermined pressure that may be formed inside bottle  36  during carbonation. When such a bottle  36  is held by bottle holder  35  and bottle  36  is filled with liquid to a predetermined level (typically marked on bottle  36 ), at least distal opening  33  of gas injection wand  32  is submerged in the liquid contents of bottle  36 . 
     When canister gas release valve  25  is opened to release gas from gas canister  20 , the released gas may flow out of gas fitting  28 , via gas conduit  30 , to gas injection wand  32 . Thus, the gas that is released from gas canister  20  may carbonate liquid contents of a bottle  36  that is held to carbonation head  34 . 
     Controller  42  may include circuitry or one or more processing units. Power for operation of controller  42  may be provided via a power connection, e.g., to a converter that converts alternating current line voltage to a direct current voltage suitable for operation of controller  42 . Alternatively or in addition, controller  42  may be powered by a direct current power supply (e.g., a storage battery, or otherwise power supply). Controller  42  may include controllable switches, contacts, or other components for controllably supplying electrical power to components of pneumatic valve operation mechanism  40  (e.g., air pump  48 , air release valve  52 , sensors  44 , or other components). 
       FIG. 2B  schematically illustrates a cross sectional view of the carbonation machine shown in  FIG. 2A  with the pneumatic valve operation mechanism enabling a gas release valve of the canister to close. 
     Piston  14  is retracted into pneumatic chamber  12 , thus enabling canister valve closer  26  to close canister gas release valve  25 . 
       FIG. 3  schematically illustrates operation of a pneumatic valve operation mechanism of the carbonation machine shown in  FIG. 1 . 
     A user may operate a user control  46  to cause the carbonation machine to initiate carbonation of a liquid in a bottle that is attached to carbonation head  34 . For example, the operated user control  46  may select a desired level of carbonation, from a plurality of offered carbonation levels, such as high (H), medium (M), or low (L). Other types of controls may be provided. Controller  42  of pneumatic valve operation mechanism  40  may operate other components of pneumatic valve operation mechanism  40  in accordance with the selected user control  46 . 
     Controller  42  may operate the components in accordance with one or more sensed conditions that are sensed by one or more sensors  44 . Operation of pneumatic valve operation mechanism  40  to release gas may be limited or prevented when one or more conditions are sensed by sensors  44 . For example, if a tilt sensor of sensors  44  indicates that a tilt of carbonation machine  10  exceeds a threshold tilt angle or deviates from a predetermined range of tilt angles, release of the gas may be prevented. Alternatively or in addition, other sensed conditions may result in prevention of gas release (e.g., a sensed condition that is indicative of a lack of a bottle or an improperly held bottle in carbonation head  34 , lack of a gas canister  20  or an improperly held gas canister in canister holder  21 , blockage of an opening or conduit such as gas conduit  30 , air intake  50 , or air outlet  54 , operational failure of a component, excess gas pressure in the bottle, or another indicated condition). 
     One or more sensors of sensors  44  may include one or more pressure sensors (e.g., for detecting release of gas from gas canister  20 , in gas conduit  30 , of carbonation of contents of a bottle held in carbonation head  34 , or elsewhere), a timer (e.g., for measuring a duration of a process, e.g., measuring different time periods of active carbonation, corresponding to obtaining different levels of carbonation), a contact or other mechanical sensor (e.g., for sensing a gas canister  20  held by canister holder  21 , a bottle held in carbonation head  34 , a position of valve pin  22 , or another mechanical sensor), a temperature sensor or other sensor of environmental conditions, or other sensors. 
     When controller  42  initiates a carbonation process, air release valve  52  may be closed and air pump  48  may be operated to increase the air pressure in pneumatic chamber  12 . As the air pressure increases within pneumatic chamber  12 , the increased pressure may displace piston  14  outward with outward movement  19 . 
     When piston  14  is displaced outward with outward movement  19  from pneumatic chamber  12 , piston  14  may push against a proximal end of plunger  18 . For example, a distal end of piston  14  may include a structure that is configured to engage the proximal end of plunger  18 . Thus, plunger  18  may be moved distally toward canister gas release valve  25  of gas canister  20 . 
     The distal motion of plunger  18  may depress valve pin  22  of valve plunger  24  (e.g., valve pin  22  referring to the end of valve plunger  24  that is accessible from outside of gas canister  20 ) of canister gas release valve  25  into gas canister  20 . Inward depressing of valve plunger  24  may cause gas to be released from gas canister  20 . The released gas may flow through gas fitting  28  as gas outflow  62 . Gas outflow  62  may flow through gas conduit  30  into gas injection wand  32  and out of distal opening  33 . Thus gas outflow  62  may carbonate a liquid that is contained by a bottle  36  that is held in carbonation head  34 , and in which distal opening  33  is immersed. Canister holder  21  may include sealing structure  17  (e.g., O-rings or other gaskets, or other sealing structure) to prevent escape of the gas through parts of canister holder  21  other than through gas fitting  28 . 
     Gas outflow  62  may continue until the carbonation level in liquid contents of bottle  36  reaches a predetermined carbonation level, or until a carbonation pulse of a programmed carbonation scheme of a series of carbonation pulses is complete. For example, the predetermined carbonation level or the end of a carbonation pulse may be determined in accordance with a user&#39;s selection of a user control  46 . The selected carbonation level may determine the duration of release of gas from gas canister  20 . Alternatively or in addition, attainment of a carbonation level may be indicated in accordance with readings by one or more sensors  44  (e.g., a gas flow meter, a sensor for measuring gas content of a liquid in bottle  36 , or another sensor). 
     Carbonation head  34  may include a pressure relief valve (not shown) that enables gas to escape to the ambient atmosphere when the gas pressure in bottle  36  exceeds a predetermined level. For example, the pressure relief valve may include a resilient element (e.g., flap, cap, spring, or other elastic or resilient element) may be opened by pressure of a carbonating gas in bottle  36 . 
     When the predetermined carbonation level is attained indicated, controller  42  may stop operation of air pump  48 . Controller  42  may, prior to, concurrently with, or subsequent to stopping of operation of air pump  48 , open air release valve  52  or stop applying a closing voltage to an air release valve  52  to enable air release valve  52  to open. Air that is held in pneumatic chamber  12  at a pressure that is above atmospheric pressure may escape from pneumatic chamber  12  via air outlet opening  17 , outflow conduit  57 , and air outlet  54  to the ambient atmosphere. 
     As the pressure in pneumatic chamber  12  is reduced, canister valve closer  26  may push valve plunger  24  outward from gas canister  20 . The outward movement of valve pin  22  of valve plunger  24  may push plunger  18  and piston  14  into pneumatic chamber  12 . The pushing of piston  14  into pneumatic chamber  12  may further force air out of pneumatic chamber  12  through air outlet  54 . Valve plunger  24  may be pushed outward until canister gas release valve  25  closes gas canister  20  to prevent any further outflow of the gas from gas canister  20 . 
     Once canister gas release valve  25  (or an overpressure device) stops gas outflow  62 , bottle  36  may be removed from carbonation head  34 . For example, a locking mechanism may be released to enable removal of the bottle from bottle holder  35 . Carbonation head  34  may be provided with a mechanism that prevents bottle holder  35  from releasing bottle  36  until the gas pressure in bottle  36  is reduced to a pressure close to atmospheric pressure. For example, bottle holder  35  may be configured to hold bottle  36  until bottle  36  is tilted forward, or a mechanical or other gas release mechanism is otherwise operated to release excess gas. Once gas pressure has been reduced, bottle  36  may be removed from bottle holder  35 . 
     Controller  42  may be configured to execute a method for pneumatic operation of carbonation machine  10 . For example, controller  42  may include circuitry that is designed to cause components of carbonation machine  10  to execute the method. Alternatively or in addition, controller  42  may include a processor that is configured to operate in accordance with programmed instructions, e.g., as stored on a data storage unit or memory of controller  42 . 
       FIG. 4  is a flowchart depicting a method for pneumatic operation of a carbonation machine, in accordance with an embodiment of the present invention. 
     It should be understood with respect to any flowchart referenced herein that the division of the illustrated method into discrete operations represented by blocks of the flowchart has been selected for convenience and clarity only. Alternative division of the illustrated method into discrete operations is possible with equivalent results. Such alternative division of the illustrated method into discrete operations should be understood as representing other embodiments of the illustrated method. 
     Similarly, it should be understood that, unless indicated otherwise, the illustrated order of execution of the operations represented by blocks of any flowchart referenced herein has been selected for convenience and clarity only. Operations of the illustrated method may be executed in an alternative order, or concurrently, with equivalent results. Such reordering of operations of the illustrated method should be understood as representing other embodiments of the illustrated method. 
     Pneumatic operation method  100  may be executed by controller  42  of carbonation machine  10  upon receiving instructions to carbonate the liquid contents of a bottle  36  that is connected to carbonation head  34  (block  110 ). For example, the instructions may be generated by, or in response to, operation of a user control  46  by a user of carbonation machine  10 . The instructions may indicate a carbonation level to which the contents of bottle  36  are to be carbonated. Alternatively or in addition, the instructions may be received when it is sensed that a bottle  36  of noncarbonated liquid is being held in carbonation head  34 . 
     Controller  42  may cause air release valve  52  to close (block  120 ). For example, controller  42  may apply electrical current to a solenoid, or otherwise cause air release valve  52  to close. 
     Prior to, concurrently with, or subsequent to closing air release valve  52 , controller  42  may operate air pump  48  to draw air from the ambient atmosphere and compress the air in pneumatic chamber  12  (block  130 ). 
     The combination of operation of air pump  48  and closing of air release valve  52  may increase the air pressure within pneumatic chamber  12  so as to push piston  14  outward. The outward movement of piston  14  may (e.g., via plunger  18  pressing valve pin  22  inward) open canister gas release valve  25  to release gas from gas canister  20  to carbonate the contents of bottle  36 . 
     Controller  42  may be configured to close air release valve  52 , to operate air pump  48 , or both to carbonate the contents of bottle  36  only when predetermined conditions are met. For example, the carbonation process may proceed only when sensors  44  do not indicate a condition that deviates from a predetermined condition or range of conditions. For example, controller  42  may be configured to not proceed with the carbonation process when a tilt that is detected by a tilt sensor of sensors  44  does not exceed a predetermined tilt. The carbonation process may be conditional on other conditions that are sensed by sensors  44 . 
     The carbonation process may continue until a predetermined time interval has elapsed (block  140 ). The duration of the period of time during which the gas is released (e.g., after canister gas release valve  25  has opened, or after a time that canister gas release valve  25  was expected to have opened, e.g., after beginning of operation of air pump  48  when air release valve  52  is closed) from gas canister  20  may be monitored until a predetermined time interval has elapsed. The predetermined time interval may correspond to a selected carbonation level. Alternatively or in addition, the time interval of a single carbonation pulse may be predetermined in accordance with a programmed carbonation scheme (in which case, a carbonation level may be determined by a series of carbonation pulses, where gas is released from gas canister  20  during each pulse). For example, a duration of the release of gas from gas canister  20  may be monitored by a timer that is incorporated into controller  42  or sensors  44 , or that is otherwise accessible to controller  42 . 
     If the predetermined time interval has not elapsed, operation of air pump  48  and closing of air release valve  52  continue (returning to block  120 ). 
     When carbonation is completed, controller  42  may cause air release valve  52  to open (block  150 ). For example, controller  42  may interrupt an electrical current in a solenoid of air release valve  52 , or may otherwise cause air release valve  52  to open. 
     Prior to, concurrently with, or subsequent to opening air release valve  52 , controller  42  may stop operation of air pump  48 . 
     Air may thus be vented from pneumatic chamber  12  to the ambient atmosphere, allowing the air pressure within pneumatic chamber  12  to be reduced. As a result, canister gas release valve  25  may be allowed to close so as to stop the flow of the gas from gas canister  20  to the liquid. For example, canister valve closer  26  may be allowed to close canister gas release valve  25 . The closing of canister gas release valve  25  may also push piston  14  (e.g., via valve pin  22  and plunger  18 ) inward into pneumatic chamber  12 . In some cases (e.g., upon failure of canister valve closer  26  to operate properly), an overpressure device may close canister gas release valve  25 . 
     When canister gas release valve  25  has closed, removal of bottle  36  from carbonation head  34  may be enabled. For example, bottle holder  35  may be configured to hold bottle  36  until bottle  36  is tilted forward, or a mechanical or other gas release mechanism is otherwise operated to release excess gas from bottle  36 . Once gas pressure in bottle  36  has been reduced, bottle  36  may be removed from bottle holder  35 . 
     In accordance with an embodiment of the present invention, attainment of a selected carbonation level may be determined by a programmed scheme of a sequence of carbonation pulses. Each carbonation pulse includes infusing gas from gas canister  20  into liquid contents of bottle  36  for the duration of a time interval. For example, the duration of each time interval may be determined in accordance with a programmed scheme that is associated with a selected carbonation level. 
       FIG. 5  is a flowchart depicting a method for pneumatic operation of a carbonation machine with multiple carbonation pulses, in accordance with an embodiment of the present invention. 
     Pneumatic operation method  200  may be executed by controller  42  of carbonation machine  10  upon receiving instructions to carbonate to a selected carbonation level the liquid contents of bottle  36  that is connected to carbonation head  34  (block  210 ). For example, the instructions may be generated by, or in response to, operation of a user control  46  by a user of carbonation machine  10 . 
     Controller  42  may cause application of a carbonation pulse to begin by causing air release valve  52  to close while operating air pump  48  to draw air from the ambient atmosphere and compress the air in pneumatic chamber  12  (block  220 ). The combination of operation of air pump  48  and closing of air release valve  52  may increase the air pressure within pneumatic chamber  12  so as to push piston  14  outward. The outward movement of piston  14  may (e.g., via plunger  18  pressing valve pin  22  inward) open canister gas release valve  25  to release gas from gas canister  20  to carbonate the contents of a bottle  36  held in carbonation head  34 . 
     Controller  42  may be configured to close air release valve  52 , to operate air pump  48 , or both to carbonate the contents of bottle  36  only when predetermined conditions are met, e.g., as sensed by one or more sensors  44 . For example, controller  42  may be configured to not proceed with the carbonation process when a tilt that is detected by a tilt sensor of sensors  44  does not exceed a predetermined tilt. 
     After a predetermined time interval that is determined by a programmed carbonation scheme, controller  42  may end a carbonation pulse by causing air release valve  52  to open (block  230 ). Prior to, concurrently with, or subsequent to opening air release valve  52 , controller  42  may stop operation of air pump  48 . 
     Air may thus be vented from pneumatic chamber  12  to the ambient atmosphere, allowing the air pressure within pneumatic chamber  12  to be reduced. As a result, canister gas release valve  25  may be allowed to close so as to stop the flow of the gas from gas canister  20  to the liquid. 
     The sequence of applying carbonation pulses (application of each carbonation pulse including the operations depicted by blocks  220  and  230 ) may be monitored to determine if the sequence of repeatedly applied pulses corresponds to completion of a scheme of carbonation pulses that corresponds to a selected carbonation level (block  240 ). 
     If the applied sequence of carbonation pulses does not complete the programmed carbonation scheme, another carbonation puke may be executed (repeating the operations of blocks  220  and  230 ). 
     If the executed carbonation pulse completes the carbonation scheme that is associated with the selected carbonation level, execution of carbonation pulses may end (block  250 ). Bottle  36  may be removed from carbonation head  34 . For example, bottle holder  35  may be configured to hold bottle  36  until bottle  36  is tilled forward, or a mechanical or other gas release mechanism is otherwise operated to release excess gas from bottle  36 . Once gas pressure in bottle  36  has been reduced, bottle  36  may be removed from bottle holder  35 . 
     Different embodiments are disclosed herein. Features of certain embodiments may be combined with features of other embodiments; thus certain embodiments may be combinations of features of multiple embodiments. The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be appreciated by persons skilled in the art that many modifications, variations, substitutions, changes, and equivalents are possible in light of the above teaching. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. 
     While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.