Patent Publication Number: US-2023157479-A1

Title: Steam wand

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Utility patent application Ser. No. 17/241,061, filed on Apr. 27, 2021, which is continuation of U.S. Utility patent application Ser. No. 16/060,858, filed on Jun. 8, 2018, which represents the United States national stage filing under 35 U.S.C. § 371 of International Application of PCT/AU2017/050195, filed on Mar. 7, 2017, which claims priority to Australian Patent Application No. 2016900843, filed on Mar. 7, 2016, the specifications of which are hereby incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to an apparatus for steaming beverages and more particularly to a steam wand that is attached to a device with a steam boiler such as an espresso making machine. 
     BACKGROUND OF THE INVENTION 
     The present invention provides a variety of alternatives and improvements to conventional steam wand technology. 
     OBJECTS AND SUMMARY 
     It is an object of the invention to provide a steam wand or steam wand assembly with improved performance benefits, or new functionality, or safety features. 
     Accordingly, there is provided a steam conveyor or steam wand assembly that is supported by a ball joint but guided to achieve a restricted range of motion in a home position. 
     In other embodiments of the invention a steam wand assembly that cooperates with a switch that provides location information to a controller. The controller may use the location information for a variety of purposes such as initiating a steam purge cycle, preventing unsafe use of the steam wand or providing display information. 
     In other embodiments of the invention, the steam wand comprises an internal hose that carries steam to a tip of the steam wand. Improvements prevent the hose from transferring heat to the main body tube, by avoiding contact with the interior side wall of the wand assembly. 
     In further embodiments of the invention, a steam wand is biased to return to a home position, the bias force that accomplishes same being resisted by a dampener that regulates the speed at which the wand returns to the home position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       In order that the invention be better understood, reference is now made to the following drawing figures in which: 
         FIG.  1    is a perspective view of a steam wand assembly and support fixture. 
         FIGS.  2 ( a )-( c )  illustrate the movement of the neck of a steam wand within its guide. 
         FIGS.  3 ( a )-( c )  illustrates the engagement and disengagement of a steam wand ball fin into a co-operating slot. 
         FIG.  4    is a perspective view, partially sectioned illustrating the engagement of a steam wand ball fin in a slot. 
         FIG.  5    is a perspective view, partially sectioned illustrating the movement of a steam wand having a ball, fin and slot arrangement. 
         FIG.  6    is a cross-sectional view of a steam wand, switch and switch actuator. 
         FIG.  7    is a cross-sectional view of a steam wand, switch and switch actuator. 
         FIG.  8    is a cross sectional view of a steam wand ball and co-operating friction cheeks. 
         FIG.  9    is a cross sectional view of a steam wand ball and co-operating friction cheeks. 
         FIG.  10    is a perspective view of another embodiment of a steam wand having a pivoting bracket and torsion spring or coil. 
         FIG.  11    is a perspective view of the device depicted in  FIG.  10    illustrating the use of a dampener in conjunction with a torsion spring. 
         FIG.  12    is a side elevation of the steam wand and dampener depicted in  FIG.  11   . 
         FIG.  13    is a cross sectional view of the steam wand depicted in  FIG.  12    illustrating an insulating spring. 
         FIG.  14    is an exploded perspective view of the lower end of a steam wand, showing its steam nozzle and tip. 
         FIG.  15    is a cross sectional view of the lower end of a steam wand, nozzle and steam wand tip. 
         FIG.  16    is a perspective view of an espresso machine having a steam wand assembly. 
         FIG.  17    is a rear perspective view of a steam wand assembly of the type depicted in  FIG.  16   . 
         FIG.  18    is a cross-sectional view of the steam wand assembly depicted in  FIG.  17   . 
         FIG.  19    is a cross-sectional view of the steam wand assembly depicted in  FIG.  17   , in an extended position. 
         FIG.  20    is a perspective view of an insulating sleeve for a steam wand. 
         FIG.  21    is a cross-sectional view of the sleeve of  FIG.  20   . 
         FIG.  22    is another embodiment of an insulating sleeve for a steam wand. 
     
    
    
     DETAILED DESCRIPTION 
     As shown in  FIG.  1   , a steam wand assembly  100  includes a steam wand  101  that is retained by a support fixture  102 . The wand may be articulated or stationary. The wand has a main body tube  120  that may be formed from one or multiple sections. Because the main body tube is generally metallic and steam passes through it, it is an advantage to insulate the tube from the steam. In this example, the steam wand  101  is articulated, having a ball  103  at one end that is received by a socket  104  that forms part of the support fixture  102 . An opposite end of the wand is formed by a removable wand tip  105 . The tip is formed, in part, from the main body tube. A ring-like handle  106  is located between the ball  103  and the tip  105 . The wand may be straight or bent. The current example is bent in two locations  121 ,  122 . 
     The ball  103  may be attached to or formed integrally with a neck  107  optionally having a smaller diameter than the remainder of the wand  101 . In this example, the neck  107  passes through a guide  108  in which is formed an opening  109  through which the neck  107  extends. 
     As further shown in  FIG.  1   , the wand  101  has a home position  111 . In the home position, the wand tip  105  is at its closest distance to the upper surface of the drip tray, grating or other support surface  110  of the device to which it is attached. The wand also has an extended position or position of normal use  112 . In the extended position  112 , the wand is free to move from side to side  113 . 
     As shown in  FIG.  2   , the guide  108  determines the limits of movement of the neck  107  and therefore the wand  101 . As shown in  FIG.  2 ( a )  the guide&#39;s opening  109  is generally triangular. Each of the three corners  201  are preferably radiused to conform to the external radius of the neck  107 . In this example, the side edges  202  of the opening are convex, the middle of each side edge extending toward the centre of the opening  109 . The front edge  203  is concave, its middle extending slightly away from the centre of the opening  109 . 
       FIG.  2 ( a )  represents the position of the neck  107  when in a home position. In the home position, the wand  101  is retracted to its maximum extent with respect to the device that supports the fixture  102 . The home position is shown by the dotted line representation  111  in  FIG.  1   . 
     In some examples, the neck may be vertical or near vertical in the home position. In the home position, steam optionally passes through the wand only for the purposes of cleaning or purging it. In the home position, the wand tip  105  is at its closest point to the device&#39;s drip tray, grating or other supporting surface  110 .  FIGS.  2 ( b ) and ( c )  represent the position of the neck with respect to the guide when the wand is in an extended position  112  (see  FIG.  1   ). In the extended position, the neck and therefore the wand can be pivoted from side to side  113 . The extension of the wand is limited by the contact of the neck against the front edge of the opening as shown in  FIG.  2 ( c ) . 
       FIG.  2    also illustrates that the wand&#39;s ball  103  is provided with a guide fin  203 , as will be explained. 
     As suggested by  FIGS.  3 ,  4  and  5   , the support fixture  102  includes a socket  301  for retaining the wand&#39;s ball  103 . As suggested by  FIG.  3 ( a ) , in the home position, the ball&#39;s fin  203  is retained by a radially extending slot  302  that extends away from the socket  301 . Because the ball&#39;s fin  203  is retained by the slot  302 , the ball and therefore the wand  101  is restrained from rotation or side to side motion  113 . As shown in  FIG.  3 ( b )  when the wand is extended toward its position of use  112 , the fin  203  exits the slot  302 . This allows the wand  101  to be rotated, also permitting side to side motion  113  as suggested by  FIG.  3 ( c ) . 
     The capture of the fin  203  by the slot  302  is also shown in  FIG.  4   . Note that the wand  101  is, in this example, essentially vertical and therefore restrained in its movement by either or both of the guide  108  and the interaction between the fin  203  and the slot  302 . The upper part  401  of the slot may be enlarged to receive the head of a switch actuator  605  as shown in  FIG.  6   . 
     As shown in  FIG.  5   , extending the wand  502  into its position of use  501  frees the fin  203  from the slot  302 . It will be appreciated that  FIGS.  4  and  5    are partially sectioned allowing the interior of the socket  301  and slot  302 ,  401  to be better illustrated. 
     As shown in  FIG.  6   , the pivoting ball  103  and its locating fin  203  cooperate with a rotating or pivoting switch actuator  601 . The switch actuator pivots about a generally horizontal axis  602  and its biased into the lower orientation depicted in  FIG.  6    by a torsion spring  603  that preferably surrounds or encircles the pivot axis  602 . In the wand&#39;s extended position as shown in  FIG.  6   , the head  604  of the actuator is extended and in contact with the proximate flat surface of the fin  203 . An opposite end of the actuator  601  forms a mechanical contact  605 . When the wand  101  is returned to the home position as shown in  FIG.  7   , the actuator  601  rotates, driving the contact  605  into a closing engagement with a switch, such as a micro switch having a flexible of leaf contact  701 . When the switch  702  is closed, a signal or switch state  703  is detected by the device&#39;s controller or microprocessor control unit  704 . The signal  703  (representative of the wand being in the home) position is utilised by the controller  704  to perform one or more of a variety of functions. For example, the controller  704  can use the signal  703  to initiate a purge or cleaning cycle of the wand  705 . The controller  704  can also use the location information signal  703  to initiate a display or audible warning from the device&#39;s graphic and audio user interface  706 . The signal  703  may also be used for other functions  707 . 
     As shown in  FIG.  7   , the ball  103 , and neck  107  have a central passageway  708  that leads into an interior  709  of the wand  101 . The hose  711  goes through the passageway into the interior  709 . The hose is preferably a non-reactive flexible polymer such as PTFE (Teflon®). The major extent of the wand&#39;s body comprises a hollow metal tube  710 . The hose  711  carries steam or a steam air mixture through the ball  103 , neck  107  and wand  101 . The ball&#39;s entry opening  712  may be circumferentially tapered or chamfered to reduce torsion stress on the hose  711  and to better accommodate the flexing of the hose  711  when the wand  101  is moved from one position to another. 
     As shown in  FIG.  8   , in some embodiments, the wand&#39;s ball  103  may be frictionally retained by a pair of opposing cheeks  801 ,  802 . Each cheek  801 ,  802  has a ball engaging concave surface  803 . As shown in  FIG.  8   , one cheek is fixed to a cup  809  and one of the cheeks  804  is carried by a stem  805 . The stem  805  is surrounded by a pair of nested or concentric compression springs  806 ,  807 . In this example, two springs  806 ,  807  are provided to increase the force against the ball  103 . The cross sectional diameter or gauge of the inner spring  806  is preferably smaller than the cross sectional diameter of the outer spring  807 . The cheek and spring assembly shown in  FIG.  8    is retained by a pair of opposing cups  808 ,  809 . The arrangement of concentric or nested coil springs  806 ,  807  provides significant force against the ball  103 , in a compact space. 
     In the example of  FIG.  9   , the wand&#39;s ball  103  is engaged by two similar cheeks  901 ,  902 . Each cheek has a stem  903  that extends toward its respective retainer or cup  908  and each stem is surrounded by a single compression spring  903 . 
     As shown in  FIG.  10   , in some embodiments, an upper end of the wand  1000  is affixed to a pivoting bracket  1001  instead of a ball. The bracket  1001  has parallel and spaced apart sides  1002 ,  1003 . The sides  1002 ,  1003  are pivotally retained by parallel walls of the retaining fixture  1004 ,  1005 . A pivot shaft  1006  extends between the side walls  1004 ,  1005  and carries the sides  1002 ,  1003 . A coil or torsion spring  1007  wraps around the shaft  1006  and is used to bias the bracket and its wand  1000  into the home position. 
     As shown in  FIG.  11   , one side  1002  of the bracket  1001  extends toward and affixes to or comprises an arcuate gear section  1100 . Accordingly, the gear section  1100  rotates in unison with the bracket about the pivot shaft  1006 . The gear teeth  1101  of the gear section engage a cooperating pinion  1102  carried by a rotary dampener  1103 . The dampener  1103  is stationery. The dampener  1103  moderates the velocity of the wand  1000 , particularly toward the home position under the influence of the torsion spring  1007 . 
     As shown in  FIG.  12   , the arcuate gear section  1100  terminates, at one end, with and actuates a switch actuator portion  1200 . The switch actuator portion of the gear section makes contact with a switch such as a micro switch  1201  when the wand  1000  is in the home position. In other positions, the actuator portion  1200  of the gear section  1100  does not contact the switch  1201 . In this way, the home position is associated with (for example) the closure of the switch  1201 , which closure can be detected by the devices&#39; controller and utilised in the manner suggested by  FIG.  7   . 
       FIGS.  13 ,  14  and  15    illustrate an exemplary embodiment of a steam wand construction. As shown in  FIG.  13   , a steam wand  1300  has a main body tube  1301 , and is bent in two locations, for ease of use. The tube is formed in sections preferably constructed from stainless steel. Here, one section is the primary tube  1350  and the tip section  1306 . The upper end of the tube  1301  is affixed to (for example) a bracket or ball as previously described. The upper end  1302  of the main body  1301  admits a steam hose  1303 , preferably a non-reactive flexible polymer such as PTFE. The polymer forms a first insulation between the steam and the tube  1301 . The lower end  1304  of the main body tube  1301  is internally threaded and thereby affixed to co-operating threads or otherwise fitted to the exterior of a polymeric (for example PTFE) steam nozzle  1305 . A lower end of the steam nozzle is also externally threaded so as to receive the co-operating internal threads of a metallic steam wand tip  1306 . In other embodiments, the main body tube  1301  is flexible. The wand tip has an exit opening  1307  through which protrudes the lower end  1308  of the steam nozzle  1305 . The steam nozzle has an optional circumferential flange  1309  that separates the lower end of the main body tube from the upper end of the tip  1306 . The steam nozzle  1305  has a central bore  1310  with an uppermost inlet that communicates with the lower end of the hose  1303 . The lower end  1311  of the hose  1303  is compressed or stabilised against the interior of the tip connector component by an internal and hollow rivet  1341  that fits into the lower end of the hose. The lower end of the hose is encircled by a tip connector  1312  that is carried within a recess in the upper part of a hose connector  1313 . The lower part of the hose connector  1313  forms a bore that receives the upper part  1314  of the steam nozzle  1305 . A seal  1315  is interposed between the hose connector  1312  and the tip connector  1312 . A second seal  1316  is interposed between the upper part of the steam nozzle  1314  and the lower bore of the tip connector. 
     Thus, the hose  1303  extends from close to the upper opening of the steam nozzle  1305  to a location  1317  external to the wand  1301 . The hose  1303  passes through an insulation spring or coil  1320  forming an elongated spacer within the wand body  1301 . In this example, the spacer or coil  1320  is continuous, having a generally constant pitch. 
     The hose has an extent outside the want and an extent internal to the want or its tube  1301 . For the purpose of preventing contact between the hose and the metallic tube, various second insulations are proposed. These insulations are elongated spacers and capable of protecting the fill (or any portion) of the internal extent of the hose. In the example of  FIG.  13   , the second insulator is in the form of a non-metallic coil, helix or spring. The effective outside diameter of the spacer  1320  alternates between each turn of the coil. Turns of a larger diameter  1321  alternate with turns of a smaller diameter  1322 . The larger diameter turns  1321  make contact, as required, with the interior of the main body tube  1301 . The smaller diameter turns  1322  make contact with the outside of the hose  1303 . In this way, the hose is prevented from making direct contact with the interior of the primary tube  1350  and thereby losing heat to it. 
     In the example of  FIG.  13   , the primary tube has two pairs of opposing through openings  1323 ,  1324 . One of the pairs  1323  is used to receive integral rivets  1325  that form a terminal end of a handle such a ring-like handle  1326  fabricated from stainless steel or other metal. The rivets  1325  are deformed by a tool that is inserted through the opposing through openings  1324 . Other methods of providing a handle may be used. 
     As shown in  FIG.  14   , a “C” clip or other retainer  1401  is accessible through an opening or slot  1402  in the hose connector  1310  prevents the inadvertent withdrawal of the tip connector  1312 . Also shown are the nozzle seals  1403 ,  1404  that are carried by the grooves  1405 ,  1406  on the upper and lower sides of the external flange  1309 . The upper seal  1403  seals the lower end of the main body tube against the steam nozzle  1305  and the lower seal  1404  seals the upper end of the wand tip  1306  against the steam nozzle  1305 . 
     As shown in  FIG.  15   , there is a small gap  1501  located between the lower extremity of the tube  1303  and the adjacent upper extremity and bore  1310  of the steam nozzle  1305 . The lower end of the steam nozzle is also shown as having one or more discharge openings  1502 ,  1503 , as required. The lower end of the steam nozzle may also have a groove for carrying a terminal seal  1504  that seals against an inside diameter or surface  1505  of the steam wand tip  1306 . 
     As shown in  FIG.  16   , an espresso making machine  1601  has a platform or drip tray  1602  that is located below the device&#39;s group head  1603  and optional coffee grinder outlet  1604 . In preferred embodiments, the steam wand is operable in the lower most or home position illustrated in  FIG.  16   . In other embodiments, the wand may be disabled when it is in the lower most or home position as shown in  FIG.  16   . 
     As shown in  FIG.  17   , a steam wand assembly  1701  has a steam wand  1702  that is carried by a wand pivot  1703 . The wand pivots  1703  is carried by and pivots about a pivot bracket  1704 . A torsion spring or other bias device  1705  is attached to the pivot bracket  1704  and urges the wand pivot  1703  and therefore the wand  1702  toward the home position depicted in  FIG.  16   . The flexible polymeric steam tube  1706  passes between the pivot bracket  1704  and the wand pivot  1703 . 
     As suggested by  FIGS.  17  and  18    the pivot bracket  1704  is rigidly affixable to the chassis or a chassis component of the device  1601 . In this example, the pivot bracket  1704  carries a leaf spring  1707  having a radius or rounded tip  1802 . The tip is received by one or more detents located on the periphery of a smooth external surface  1803  of the wand pivot  1703 . The rounded portion of the wand pivot  1803  extends from a front surface  1804  of the wand so as to occupy the gap between the front of the wand  1804  and an adjacent external part of the chassis  1805 . A similarly rounded portion of the wand pivot  1806  extends from the rear surface of the wand  1807  toward and past an adjacent rearward edge of the chassis  1808 . The rounded portions  1806 ,  1803  occupy the forward and rear gaps around the wand pivot so that a finger is not trapped or pinched between the wand and the chassis when the wand is pivoting. In the example of  FIG.  18   , the pivot point of the wand  1809  passes through a centre of the wand pivot. The lateral sides of the wand pivot are flat and generally parallel. The co-operation between the leaf spring  1707  and the detents  1803  allow the wand to assume one, two or more stable orientations. Other aspects of the wand including the construction of the insulating tip  1810  and insulating spring  1811  are similar to those previously disclosed. 
     As shown in  FIG.  19   , the pivot bracket  1901  may carry a sensor, switch or micro switch  1902  that is used to provide wand position information to the device&#39;s processor  1607 . In this example, a rearward extension of the wand pivot  1903  makes contact with the switch or its actuator  1904  when the wand is in the home position, but not when it is in the extended position depicted in  FIG.  19   . Note that in this example, the extended position is defined by the location of the leaf spring in the detent  1803 . The rearward extension  1903  of the wand pivot  1703  may also be used as a limit to the forward extension of the wand, by abutting and interfering with a part of the chassis  1905  adjacent to the wand pivot and located behind the wand. 
     As shown in  FIG.  20   , the coil depicted, for example in  FIGS.  13 ,  15 ,  18  and  19    can be formed from a flexible and heat resisted polymer as shown in  FIGS.  20  and  21   . In the examples of  FIGS.  20 - 22   , the sleeve  2000  is intended to be used within a wand for the purpose of inhibiting contact between the tube carrying steam and the inner wall of the tube  1301 . The sleeve  2000  in this example, comprises a tube  2001  having various projections, spacers or tabs  2002  along its length. In this example, the projections  2002  are provided in pairs  2002 ,  2003 . Pairs are spaced apart from one another along the length of the tube. Each projection or wing comprises a rounded or a smooth exterior. As shown in  FIG.  21   , the projections in each pair  2002 ,  2003  are separated from one another by an arch shaped notch  2100 . As suggested by  FIG.  20   , the tube may have one of more longitudinal ribs  2004  extending along all or part of the length of the tube. The tube has a central opening  2005  for receiving the steam tube. 
     As shown in  FIG.  22   , a sleeve  2200  may also comprise a skeletal tube having, for example, a pair of longitudinal ribs  2201 ,  2202 . The two ribs  2201 ,  2202  are parallel and spaced apart. The two ribs are interconnected by arches that alternate along the length of the ribs. 
     Alternating arches  2203 ,  2204  are spaced apart and located along the length of the ribs. The two ribs  2201 ,  2202  define a plane. Arches  2203  on one side of the plane extend downwardly or in one direction and arches  2204  on the other side of the plane extend upwardly or in the other direction. Each arch is associated with a pair of lateral extension tabs  2205 ,  2206 . Each arch is also associated with a pair of parallel and spaced apart fingers  2207 ,  2208 , the fingers extending away from the arch in the same direction as the arch extends away from the parallel ribs. In the example of  FIG.  22   , the arches (extending in either direction from the ribs) are evenly spaced from one another and alternating. 
     Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms. 
     As used herein, unless otherwise specified, the use of the ordinal adjectives “first”, “second”, “third”, etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner. 
     Reference throughout this specification to “one embodiment” or “an embodiment” or “example” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an example” in various places throughout this specification are not necessarily all referring to the same embodiment or example, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments. 
     Similarly it should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Any claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention. 
     Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “processing,” “computing,” “calculating,” “determining” or the like, refer to the action and/or processes of a microprocessor, controller or computing system, or similar electronic computing or signal processing device, that manipulates and/or transforms data. 
     Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination. 
     Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the scope of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. 
     While the present invention has been disclosed with reference to particular details of construction, these should be understood as having been provided by way of example and not as limitations to the scope of the invention.