Abstract:
A spray hose and spray nozzle for a commercial oven may be retracted on a spring-loaded reel. A position and recent movement of the spring-loaded reel may be used to deduce likely intent of the user with respect to use of the spray nozzle and to electronically activate or deactivate water flow to the spray hose based on the deduced intent.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a retractable spray hose for an oven or the like and in particular to a spray hose that reduces the chance of accidental discharge during extension and retraction. 
         [0002]    Commercial ovens are frequently provided with spray hoses, for example, attached to a reel that allow the interior of the oven to be readily cleaned. Such cleaning helps to reduce buildup of grease or other deposits on the walls of the oven such as may lead to the transfer of cooking flavors between foods or which may burn producing unwanted smoke or burning odors. 
         [0003]    The spray hose may provide a shower type head that may include a built-in water valve allowing the user to easily control the spray of the water. In order to prevent damage to the hose when it is not in use and conserve space within the kitchen, the hose may be stored on a spring-loaded reel, for example, attached to the bottom of the housing of the oven. In order to use the hose, the user may grasp the spray nozzle as positioned in a cradle near an opening in the reel and by pulling the spray nozzle out, pull the hose through that opening to a proper length for cleaning. A locking mechanism such as a ratchet may lock the reel against retraction during the cleaning operation and then be released to allow the hose to be fully retracted after use. 
         [0004]    It is desirable to have a positive shutoff of the water through the hose other than that provided by the shower nozzle. To this purpose an additional shutoff valve may be exposed for control by the user to allow the water to be disconnected from the hose. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention provides an automatic shutoff for a spray hose, where the shutoff is activated by movement of the retraction reel. The automatic shutoff substantially reduces the chance that the spray nozzle will be accidentally activated when it is grasped to extend the hose and can prevent water spray or leakage in certain failure conditions, important when the reel is mounted in the oven housing. By sensing reel movement to activate the shutoff, a generous shutoff state may be defined for reel positions near full retraction, eliminating the need for a full retraction and seating of the spray nozzle (for example in a cradle) such as may be necessary to activate a cradle switch or the like. Sensing of reel position eliminates the need for special sensor elements incorporated into the hose or spray nozzle that might make replacement of these parts difficult. Sensing of reel position allows for complete shutoff even if the spray head were to become dislodged or damaged. 
         [0006]    In one embodiment, the invention may be an oven with a housing providing an oven cavity accessible through a door which may be opened and closed about the cavity, the oven cavity having a heater for heating the cavity for cooking food. A spring biased hose reel is attached to the housing allowing extension of a hose from the hose reel with rotation of the hose reel to unwind the hose in a first direction against a spring biasing and allowing retraction of the hose with rotation winding of the hose about the hose reel in a second opposite direction with the spring biasing. An electronic water valve may receive water from a source of pressurized water and communicate it to the hose on the hose reel when the electronic water valve is opened with a valve open signal. A hose reel sensor senses a first state of the hose reel when the hose is fully retracted and a second state of the hose reel when the hose is fully extended to provide the valve open signal in the second state and not the first state. 
         [0007]    It is thus a feature of at least one embodiment of the invention to provide an automatic shutoff of the water to a spray nozzle that does not require special sensing or precise seating of the spray nozzle in a holder or the like. 
         [0008]    The hose reel sensor may be sensitive to movement of the hose reel position. 
         [0009]    It is thus a feature of at least one embodiment of the invention to provide a simple method of deriving the position of the hose without the need to directly sense a flexible or movable component such as the hose or spray nozzle. 
         [0010]    The hose reel sensor may detect the first state, in part, based on hose reel position. 
         [0011]    It is thus a feature of at least one embodiment of the invention to provide a system that is sensitive, at least in part, to absolute reel position such as provides an imputed intent of the user indicating whether the sprayer should be activated. 
         [0012]    The hose reel sensor may, in addition or alternatively, detect the first state in part based on a last direction of hose reel movement. 
         [0013]    It is thus a feature of at least one embodiment of the invention to allow it to look beyond simple hose position and to shut off the sprayer hose, for example, as it is being retracted even though its absolute position is momentarily in a fully extended position. 
         [0014]    The hose reel may include a ratchet system for locking the hose reel against retraction with the spring biasing and the hose reel sensor may be sensitive to a locking of the hose reel. The hose reel sensor may detect the second state, in part based, on a locking of the hose reel position with the ratchet system. The second state may occur only when the reel is in a position to lock. 
         [0015]    It is thus a feature of at least one embodiment of the invention to make use of a pre-existing ratchet mechanism to readily deduce the intent of the user, using an assumption that the hose reel will be locked for use of the sprayer. 
         [0016]    The ratchet may include a ratchet pawl and the hose reel sensor may sense the position of the ratchet pawl. 
         [0017]    It is thus a feature of at least one embodiment of the invention to make use of the existing ratchet pawl to readily distinguish among multiple states of the hose reel based on multiple states of the ratchet mechanism. 
         [0018]    The hose reel sensor may include a magnet on the ratchet pawl and a magnetic sensor. 
         [0019]    It is thus a feature of at least one embodiment of the invention to provide a simple way of deducing hose reel state that may be extracted with an environmentally robust magnetic sensing system. 
         [0020]    The hose may terminate in a spray nozzle having a user-operated valve. 
         [0021]    It is thus a feature of at least one embodiment of the invention to provide a system that reduces the possibility of accidentally activating the sprayer when extending the hose by grasping the spray nozzle. 
         [0022]    These particular objects and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is a simplified perspective view of an oven having an extendable spray hose, and a housing of the oven in partial cutaway showing an internal hose retractor; 
           [0024]      FIG. 2  is an exploded diagram of the hose retractor of  FIG. 1  showing a constant force spring biasing a hose reel, the latter having a ratchet mechanism for locking the hose reel in extension and further showing a rotational water coupling and sensor system of the present invention; 
           [0025]      FIGS. 3   a - c  are fragmentary side views of the ratchet mechanism of  FIG. 2  at different positions of the hose reel showing a sensed state for each position; and 
           [0026]      FIG. 4  is a diagram showing extension of the hose and a transition between multiple reel states associated with water being switched on and off, further showing alignment of an off state with the hose fully retracted and on state with the hose fully extended and locked. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0027]    Referring now to  FIG. 1 , an oven  10 , according to one embodiment of the present invention, may provide a housing  12  defining an internal oven cavity  14 . Sidewalls of the oven cavity  14  may provide for rack supports  16  holding conventional cooking racks for supporting pans or trays of food. A bottom wall cooking volume may provide for a drain  19  that may receive wastewater during the cleaning process. 
         [0028]    The oven cavity  14  may be accessed through a door  18  connected by a hinge at one vertical side of the oven cavity  14 . The door  18  may close over the oven cavity  14  during the cooking operation as held by a latch assembly  20  (visible on the door  18  only). In the closed position, the door  18  may substantially seal against the oven cavity  14  by compressing a gasket  21  surrounding an opening of the oven cavity  14  in the housing  12 . 
         [0029]    At one side of the oven cavity  14 , the housing  12  may support a control panel  24  accessible by a user standing at a front of the oven  10 . The control panel  24  may provide conventional electronic controls such as switches, buttons, a touchscreen or the like that may receive oven control data from the user as will be described below. 
         [0030]    Ovens of this type may include steam generators, convection fans, smokers and the like and are commercially available from the Alto-Shaam Inc. of Menomonee Falls, Wis. and are described generally in U.S. Pat. Nos. 6,188,045, 6,608,288 and 7,307,244 all assigned to the assignee of the present invention and incorporated by reference 
         [0031]    Positioned beneath the control panel may be a sprayer access panel  26  providing an operator for a sprayer water shutoff valve  28  and an opening  30  through which a sprayer hose  32  may extend. A sprayer nozzle  34  may be attached to the end of the sprayer hose  32  to direct water supplied by the sprayer hose  32  into a dispersed high-pressure spray for cleaning of the oven cavity  14 . The sprayer nozzle  34  may include a hand operated nozzle valve  36  that also provides for means of controlling the water flow through the hose  32  together with the manual shutoff valve  28 . 
         [0032]    The sprayer hose  32  extends from the sprayer nozzle  34  into the housing  12  through the opening  30  to be received by a hose retractor  40  that may serve to receive and coil the hose  32  after use. 
         [0033]    Referring now also to  FIG. 2 , the hose retractor  40  may provide for a hose reel  42 , generally providing two disc-shaped rims around a smaller radius cylindrical hub (not visible) about which the hose  32  may be fully wound in a retracted state. The hose reel  42  may rotate about an axis  44  and is biased in a retracting direction  48  (as indicated by the arrow in  FIG. 2 ) by the force of a constant force spring  46  attached to the hose reel  22 . The retracting direction  48  serves to wind the hose  32  around the hose reel  42 . 
         [0034]    The constant force spring  46  communicates with the hose reel  42  by a key  47  and with the housing  12  by means of a bracket  50  attached to the housing  12 . The constant force spring  46  may also support a support shaft (not shown) on which the hose reel  42  rotates. On an opposite side of the hose reel  42  from the constant force spring  46 , axial support of the hose reel  42  may be provided by a rotatable pipe coupling  52  extending along the axis  44  and receivable by a collar  54  to form with the collar  54  a watertight conduit through which water may flow but which nevertheless permits free rotation of the hose reel  42  about the axis  44 . The coupling  52  enters the hose reel  42  where it is attached with one end of the hose  32  so that water delivered from the collar  54  passes through the coupling  52  and into the hose  32  to supply water to the hose  32  and the spray nozzle  34 . 
         [0035]    The coupling  52  may receive water from an electric water valve  56  which in turn communicates with the valve  28 , the latter of which is attached to a source of pressurized water such as a water main or the like. 
         [0036]    Generally as a hose  32  is withdrawn from the reel  42 , the reel  42  rotates counter to the retracting direction  48  urged by the constant force spring  46  (clockwise as shown in  FIG. 2 ) allowing the hose  32  to be extracted. When use of the hose  32  is complete, the constant force spring  46  urges the hose reel  42  in the counterclockwise direction (as viewed in FIG. S) to wind the hose  32  about the hose reel  42  until the spray nozzle  34  is pulled against the opening  30  for retention there. 
         [0037]    Referring now to  FIGS. 2 and 3 , rotation of the hose reel  42  may be constrained by a ratchet assembly  57  comprising an arcuate rack  60  following a radius of an outer periphery of one rim of the hose reel  42  approximately halfway around the circumference of the reel  42 . The rack  60  may have inwardly extending rack teeth  62  canted back along an axis spiraling counterclockwise (as shown) as one moves toward a center of the hose reel  42 . 
         [0038]    A pawl  64  may engage the teeth  62  to prevent counterclockwise rotation of the hose reel  42  when the pawl  64  is engaged with the teeth  62  and to allow clockwise rotation despite any such engagement. The pawl  64  may be mounted to pivot about a pivot point  66  fixed with respect to a portion of a support bracket  50  as is attached to the housing  12 . 
         [0039]    Referring now to  FIGS. 2 and 3   a , the pawl  64  when unengaged with the teeth  62  of the rack  60  assumes a neutral position  73  under a biasing of the spring  68  attached between the pawl  64  and the bracket  50 . In this unengaged position, a pawl finger  70  of the pawl  64  such as may engage the teeth  62  is directed generally radially outward toward the rim of the hose reel  42 . 
         [0040]    A portion of the pawl  64  between the pivot point  66  and an attachment of the springs  68  may include a magnet  72 . In this neutral position  73 , the magnet  72  is displaced away from a sensing location  74  where the magnet  72  may be sensed by a magnetic sensor  76  generally fixed with respect to the housing  12 . 
         [0041]    The magnetic sensor  76  may, for example, be a reed relay (as shown) or Hall effect device and is wired in series with electrical power provided to the valve  56  so that the valve  56  opens or operates only when the magnet  72  is in the sensing location  74  as sensed by the magnetic sensor  76 . The magnetic sensor  76  may be shielded from the reel  42  by the support bracket  50  which may, for example, be a non-ferromagnetic material such as stainless steel. In this neutral position  73 , a state of the hose reel  42  is identified to an “off” state  78  where water flow to the hose  32  is prevented by the valve  56 . 
         [0042]    Referring now to  FIG. 3   b , after the spray hose  32  has been extended from the housing  12  with clockwise rotation  80  of the reel  42 , the pawl  64  may engage the teeth  62  of the rack  60  and move to an active position  81  where the magnet  72  overlies the sensing location  74 . In this active position  81 , the state of the hose reel  42  is identified to an “on” state  84  where water flow to the hose  32  is allowed by valve  56 . In this active position  81 , if the hose  32  were to be released, the pawl  64  would prevent rewinding of the spray hose  32  on the hose reel  42  by engagement of the pawl finger  70  with the teeth  62  of the rack  60 . In this state, the hose reel  42  is termed “locked” meaning that retraction of the hose  32  is prevented such as suggests the user is ready to use the spray nozzle  34  (shown in  FIG. 1 ). 
         [0043]    Referring now to  FIG. 3   c , the hose reel  42  may be unlocked by continuing to draw the hose  32  from the hose reel  42  with a clockwise rotation  80  until the rack  60  passes completely by the pawl  64  and the pawl  64  returns to a neutral position  73  shown in  FIG. 3   a . Upon release of the spray hose  32  and counterclockwise movement  90  of the hose reel  42 , the pawl  64  is pushed backward against the biasing of spring  68  to a third inactive position  92  with the magnet  72  removed from the sensing location  74  producing an off state  78  as described above. In this position, a release of the spray hose  32  will cause its further retraction into the housing  12  wrapped around the hose reel  42  because the pawl  64  is out of position to engage in the retracting teeth  62 . This unlocked state suggests that the hose  32  is being returned after use and spraying of the nozzle  34  is not desired thus justifying the off state  78 . 
         [0044]    Referring now to  FIG. 4 , typically multiple rotations of the reel  42  may be required to move the spray nozzle  34  from a fully retracted position  96  to a fully extended position  98 . During that retraction process the detected state of the hose reel  42  will move between “off” state  78  and “on” state  84  several times. Nevertheless, the size of the hose reel  42  and the full extension position of the spray nozzle  34  determined by the length of the hose  32  may be set such that when the spray hose  32  is in the fully retracted position  96 , the state of the reel  42  is comfortably within the off state  78  whereas when the hose  32  is substantially fully extended (except for a minor extension required to initiate the retraction process) the detected state of the hose reel  42  is comfortably in “on” state  84 . 
         [0045]    It will be understood generally that the system described above can be said to detect the position of the hose reel  42  (by virtue of the partial coverage of the reel  42  with rack  60 ) as well as to detect recent reel movement (based on the state of the pawl being in either active position  81  or inactive position  92  and thus that considerable information may be derived from this sensing related to probable intentions of the user. 
         [0046]    By shutting off the spray hose  32  when it is fully retracted, occurrences of accidentally grabbing the spray nozzle  34  and activating the nozzle valve  36  are greatly reduced. Further, water spray during an accident such as detachment of the spray nozzle  34  from the spray hose  32  may be limited by a resulting rapid recoiling of the hose  32  to an over-retracted position associated with the off state  78 . This over-retracted position may correspond with the full unwinding of the constant force spring  46  set to align with an off state  78  (perhaps with an additional full rotation after the normal full retraction of the hose  32 ). 
         [0047]    Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. 
         [0048]    When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0049]    It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications, are hereby incorporated herein by reference in their entireties.