Abstract:
A thermostat assembly for controlling a flow of a fluid through an aperture, the thermostat assembly comprising: a displaceable valve for controlling the opening and closing of the aperture; a flange and a lower bridge, both configured for securing said displaceable valve in place; a flexible member positioned between said lower bridge and said displaceable valve; wherein said lower bridge comprises a locking mechanism integrally formed therein and configured to lock said displaceable valve in a position where said aperture is open.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 61/412,408, filed Nov. 11, 2010 and entitled “Thermostat Assembly”, which is incorporated herein by reference in its entirety. 
     
    
     FIELD 
       [0002]    Embodiments of the disclosure relate to a thermostat assembly for controlling a flow of a fluid through an aperture. 
       BACKGROUND 
       [0003]    A thermostat is often defined as a device for regulating the temperature of a system and maintaining it within a desired range. Commonly, the thermostat achieves this by switching heating or cooling devices on or off, or regulating the flow of a coolant fluid. 
         [0004]    Thermostats commonly serve as control units for heating or cooling systems, components of air conditioner and the like. Thermostats may be constructed in many ways and may use a variety of sensors or temperature-sensitive materials to measure the temperature or act upon it. 
         [0005]    Mechanical thermostats are widely used in the internal combustion engine cooling mechanisms. These thermostats often use a temperature sensitive valve to control the opening of the thermostat&#39;s aperture and maintain the core temperature of the engine at its optimum by regulating the flow of a coolant fluid to an external heat sink, usually a radiator. 
         [0006]    While the thermostat is closed, there is no flow of coolant in the loop allowing the combustion chambers to warm up rapidly. The thermostat stays closed until the coolant temperature reaches the nominal thermostat opening temperature. The thermostat then progressively opens as the coolant temperature increases to the optimum operating temperature, increasing the coolant flow to the radiator. Once the optimum operating temperature is reached, the thermostat progressively increases or decreases its opening in response to temperature changes, dynamically balancing the coolant recirculation flow and coolant flow to the radiator to maintain the engine temperature in the optimum range as engine heat output, vehicle speed, and outside ambient temperature change. 
       SUMMARY 
       [0007]    The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. 
         [0008]    An aspect of some embodiments relates to a thermostat assembly comprising an advantageous locking element. 
         [0009]    Generally, the thermostat assembly includes a displaceable valve for controlling the opening and closing of an aperture of the thermostat assembly, respective to the surrounding temperature. The displaceable valve may be secured in place using an upper bridge and a lower bridge. A flexible member, such as a spring, may be located between the lower bridge and the displaceable valve to keep the aperture of the thermostat assembly normally closed. 
         [0010]    Advantageously, the lower bridge includes an integrally formed locking element, shaped as one or more teeth bent inwards. 
         [0011]    The valve is displaceable along a certain range, which may be divided into a normal working range and a high-risk range. In the high-risk range, there is an increased risk of damage to one or more of the valve&#39;s inner components, which may cause inappropriate opening and/or closure of the aperture. The ultimate risk is that, as a result of damage to the valve, it will fail to open the aperture sufficiently, and therefore prevent sufficient flow of cooling liquid. This may then lead to damage to the system being cooled. Therefore, the locking element is configured such that it locks the valve in an open position when it exceeds the working range and enters the high-risk range, so that the situation where the valve fails and does not allow sufficient flow is prevented. 
         [0012]    The advantageous locking element, which is integrally formed with the lower bridge, adds an important feature to the thermostat assembly without adding more parts which may move, become damaged or the like during assembly or operation. 
         [0013]    An additional issue is the need for one-direction flexibility of the locking element; the locking element has to be flexible when it lets the displaceable valve pass it and enter the high-risk range, but inflexible when it blocks the displaceable valve from retracting back to its working range. 
         [0014]    There is provided, in accordance with an embodiment, a thermostat assembly for controlling a flow of a fluid through an aperture, the thermostat assembly comprising: a displaceable valve for controlling the opening and closing of the aperture; a flange and a lower bridge, both configured for securing said displaceable valve in place; a flexible member positioned between said lower bridge and said displaceable valve; wherein said lower bridge comprises a locking mechanism integrally formed therein and configured to lock said displaceable valve in a position where said aperture is open. 
         [0015]    In some embodiments, said locking element comprises at least one leaf bent inwards. 
         [0016]    In some embodiments, said displaceable valve comprises a disc configured for physically closing said aperture. 
         [0017]    In some embodiments, said displaceable valve comprising a thermal sensitive material. 
         [0018]    In some embodiments, said displaceable valve comprising a displaceable pin. 
         [0019]    In some embodiments, said displaceable valve is configured to extend according to the surrounding temperature. 
         [0020]    In some embodiments, said flange further comprises a jog pin configured for providing pressure relief of said thermostat assembly. 
         [0021]    In some embodiments, said lower bridge further comprising one or more connectors and said upper bridge further comprising one or more sockets matching said one or more connectors. 
         [0022]    There is further provided, in accordance with an embodiment, an integrated lock-support mechanism for a thermostat, the mechanism comprising a body having a base and at least two lateral arms, said base comprising an aperture configured to accommodate a displaceable valve of the thermostat, and said lateral arms each comprising a locking leaf configured to lock the thermostat in a locked position upon exceeding a predetermined displacement range. 
         [0023]    In some embodiments, each of said lateral arms further comprises an additional locking leaf for enhancing the locking. 
         [0024]    In some embodiments, each of said locking leaves is bent inwards. 
         [0025]    In some embodiments, each of said locking leaves is configured to bend outwards responsive to displacement of the displaceable valve. 
         [0026]    In some embodiments, each of said lateral arms further comprises one or more connectors configured to match one or more sockets of a flange of the thermostat. 
         [0027]    In some embodiments, said integrated lock-support mechanism, further comprising: a displaceable valve for controlling the opening and closing of a fluid aperture of the thermostat; a flange configured, together with the integrated lock-support mechanism, for supporting said displaceable valve in place; and a flexible member positioned between said base and the displaceable valve. 
         [0028]    In some embodiments, each of said locking leaves is bent inwards. 
         [0029]    In some embodiments, said displaceable valve comprises a disc configured for physically closing said fluid aperture. 
         [0030]    In some embodiments, said displaceable valve comprises a thermal sensitive material for causing said displaceable valve to extend according to the surrounding temperature. 
         [0031]    In some embodiments, said displaceable valve further comprises a displaceable pin. 
         [0032]    In some embodiments, each of said lateral arms further comprises one or more connectors, and said flange comprises one or more sockets matching said one or more connectors. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0033]    Exemplary embodiments are illustrated in referenced figures. Dimensions of components and features shown in the figures are generally chosen for convenience and clarity of presentation and are not necessarily shown to scale. The figures are listed below. 
           [0034]      FIG. 1A  shows an upper perspective view of a thermostat assembly; 
           [0035]      FIG. 1B  shows a lower perspective view of the thermostat assembly; 
           [0036]      FIG. 2  shows a perspective view of a lower bridge of the thermostat assembly; 
           [0037]      FIG. 3A  shows a cross sectional view of the thermostat assembly with a displaceable valve situated in a closed position; 
           [0038]      FIG. 3B  shows a cross sectional view of the thermostat assembly with the displaceable valve situated in an open position; 
           [0039]      FIG. 3C  shows a cross sectional view of the thermostat assembly with the displaceable valve situated in a locked position; and 
           [0040]      FIG. 4  shows a diagram of valve disk displacement relative to temperature. 
       
    
    
     DETAILED DESCRIPTION 
       [0041]    An aspect of some embodiments relates to a thermostat assembly comprising an advantageous locking mechanism, which is integrally formed with a lower bridge of the assembly. 
         [0042]    Reference is now made to  FIGS. 1A and 1B , which show a thermostat assembly  100  in upper and lower perspective views, respectively, according to an embodiment. Thermostat assembly  100  advantageously includes an integrally-formed locking mechanism, shaped as one or more locking leaves  124  integrated into a lower bridge  120 . 
         [0043]    Thermostat assembly  100  may be adapted to operate in a fluid environment; the thermostat is configured to respond to temperature variations and to control the fluid flow by closing and opening an aperture  112  accordingly. 
         [0044]    As schematically shown, thermostat assembly  100  may include a displaceable valve  144  as well as a flange  102  and a lower bridge  120 , the latter two being configured to provide the valve with structural support; while the flange delimits the valve from the top, the lower bridge defines the valve&#39;s motion track from the bottom, optionally with the assistance of a flexible member such as a spring  154 . 
         [0045]    Flange  102  may include a flange disk  104  having at least two flange sockets  114 . Flange disk  104  surrounds an optionaly flange ring  106  which is generally disposed perpendicular to it, forming a substantially circular aperture  112 . 
         [0046]    Flange  102  may further include an upper bridge  108 , formed as an arc optionally having a pin niche  110  suitable for accommodating a valve pin, which is further discussed below. Upper bridge  108  may be connected to, attached to or integrally formed with flange ring  106  at its edges and may optionally have a convex cross-section. 
         [0047]    Reference is now made to  FIG. 2 , which shows lower bridge  120  in more detail. For ease of comprehension, reference numerals in  FIG. 2  match those appearing in  FIGS. 1A-B , and some of the features of lower bridge  120  may be seen both in  FIGS. 1A-B  and in  FIG. 2 . As schematically shown, lower bridge  120  includes a base  122  formed as a circumferential plate having, for example, two opposing lower bridge round edges  128 . Base  122  borders with an elevated lower bridge ring  130  forming an optionally circular aperture located in the center of the base, and having a diameter large enough to accommodate a valve body, which is further discussed below. 
         [0048]    Two arm bases  138 , shaped, for example, as bent panels, may be perpendicularly adjacent, with their longer edge, to lower bridge rounded edges  128 . 
         [0049]    Two arms  132  may be shaped as elongated plates extending from arm bases  138 , and optionally having a narrow arm lower end  134  and a wide arm upper end  136 . Arms  132  may be bent outwards and form obtuse angles with base  122 . 
         [0050]    Lower bridge  120  may further include, at each of wide arm upper ends  136 , one or more connectors  140  which are formed as localized extensions of the upper ends, and being matching to one or more flange sockets  114  of  FIGS. 1A-B . Connectors  140  may be used to secure lower bridge  120  to flange  102  of  FIGS. 1A-B . 
         [0051]    Reference is now made to  FIGS. 3A ,  3 B and  3 C, which show cross-sectional views of thermostat assembly  100  of  FIGS. 1A-B , with its displaceable valve  144  situated in different positions. 
         [0052]    Displaceable valve  144  may be located between flange  102  and lower bridge  120 , and being displaceable along a main axis  118 . Displaceable valve  144  may have a cylindrical valve body  146  accommodating a valve pin  148  and containing a thermal sensitive material. 
         [0053]    The displaceable valve  144  further includes a valve disk  150  connected to, attached to or integrally formed with valve body  146 , and used for physically closing aperture  112  of  FIGS. 1A-B , by pressing against flange disk  104  of  FIGS. 1A-B . Optionally, thermostat assembly  100  includes one or more gaskets (not shown) disposed on valve disk  150  and/or on flange disk  104  of  FIGS. 1A-B , in order to improve the sealing of aperture  112 . 
         [0054]    Valve pin  148  is at least partially located within valve body  146 , having one of its ends laid within the thermal sensitive material and the other end protruding, at least in operation, from valve body  146  and pushing against upper bridge  108  and/or pin niche  110  of the upper bridge. Valve pin  148  may or may not be secured to pin niche  110 . 
         [0055]    The thermal sensitive material in valve body  146  may be adapted to respond to temperature variations and displace valve pin  148  along main axis  118 , so that it presses against upper bridge  108  and/or pin niche  110  of the upper bridge. The higher the temperature, the harder valve pin  148  presses. 
         [0056]    Spring  154 , which is shown as an example of a flexible member, may be located between valve disk  150  and lower bridge  120 , and be configured to normally contract displaceable valve  144  and drive valve disk  150  along main axis  118  towards closing the aperture  112 . These opposite forces applied on the valve pin  148  constantly aspire to reach equilibrium and consequently place the displaceable valve  144  in the right position and open or close the aperture  112  accordingly. 
         [0057]    Reference is now made back to  FIG. 1A . In some scenarios, such as when a liquid coolant gets heated very quickly, pressure differences may build up under displaceable valve  144 . The pressure differences between the area below displaceable valve  144  and above it can make it difficult (or even impossible) for valve pin  148  to push displaceable valve  144  and open the aperture  112 . Consequently, this may interfere with the thermostat&#39;s normal operation. Therefore, an optional pressure discharge valve, such as a jog pin  116 , is embedded into flange disk  104  and set to relief pressure differences beyond a certain threshold. 
         [0058]    Reference is now made back to  FIGS. 1A-B . The displaceable valve  144  is configured to be displaced within a certain vertical range, which may be divided, for the purpose of the discussion, into a normal working range and a high-risk range. Overheating and/or malfunction may cause displaceable valve  144  to extend beyond the working range and reach into the high-risk range. The high-risk range involves a high risk of permanent damage to one or more of displaceable valve&#39;s  144  inner components, which may, in turn, cause inappropriate opening and/or closure of the aperture  112 . 
         [0059]    Once displaceable valve  144  is damaged, one or more malfunctions may occur. One possible malfunction may cause the thermal sensitive material not to apply the appropriate force to extract the desired portion of valve pin  148  out of valve body  146 . The extraction force applied by the thermal sensitive material may not be sufficient to overcome the opposite force applied by spring  154 . The valve pin will not be able push the valve disk away from aperture  112  and, consequently, the aperture will remain closed or at least not sufficiently open. 
         [0060]    Therefore, using a conventional thermostat involves a risk of running into a “fail-closed” scenario in which the thermostat assembly  100  becomes damaged and the displaceable valve  144  is unable to open the aperture  112  and therefore does not enable the thermostat assembly  100  to dispose the hosting system&#39;s excessive heat, and consequently cause heavy damages to the hosting system. 
         [0061]    Having a locking mechanism integrated into thermostat assembly  100  has the advantage of preventing thermostat assembly  100  from getting into such a “fail-close” scenario. Once displaceable valve  144  displaces beyond the working range and reaches the locking range, locking leaves  124  lock the displaceable valve in position and prevent it from retracting back into the working range. This, essentially, locks thermostat assembly  100  in an open position before thermostat assembly  100  becomes damaged. 
         [0062]    As schematically shown in  FIG. 2 , lower bridge  120  advantageously includes at least two locking leaves  124 , each integrally formed as a flexible tab partially cut of the lower bridge and bent inwards, into the path of valve disk  150 . Those of skill in the art will recognize that a locking leaf may have any suitable structural that is adapted to lock the valve and prevent it from returning to its normally closed position once it reaches beyond certain displacement; locking leaves  124  are shown as flexible tabs merely as one example. 
         [0063]    Reference is now made back to  FIGS. 3A ,  3 B and  3 C. As mentioned, locking leafs  124  may be bent inwardly such that an open edge of each of the leaves crosses the path of displaceable valve  144 . The position of the open edges of locking leafs  124  determines the beginning of valve disk&#39;s  150  locking range. As the edge of valve disk  150  reaches the edge of locking leaf  124 , the locking leaf is pushed outwardly and allows the displaceable valve  144  to pass and enter the locking range. Once the edge of valve disk  150  passes locking leaf  124 , the locking leaf returns to its original position and prevents displaceable valve  144  from returning back into its normal working range and, consequently, locks the displaceable valve in an open position. 
         [0064]    As schematically shown in  FIG. 3A , thermostat assembly  100  has its displaceable valve  144  is in an open position. The thermal sensitive material applies a force greater than the force applied by spring  154  in the closed position; this causes the extraction of a greater portion of valve pin  148  out of valve body  146 , towards upper bridge  108 . The extraction force applied by the thermal sensitive material is sufficient to overcome the opposite force of the flexible member  154  and push the valve disk  150  away from the aperture and, consequently, aperture  112  opens. 
         [0065]      FIG. 3B  shows thermostat assembly  100  with displaceable valve  144  in a closed position. The thermal sensitive material applies a force that extracts a portion of valve pin  148  out of valve body  146  towards the upper bridge  108 , but this extraction force is not sufficient to overcome the opposite force of spring  154 . Consequently, aperture  112  closes. 
         [0066]      FIG. 3C  shows thermostat assembly  100  with the displaceable valve  144  in a locked position. The thermal sensitive material applies a force greater than the force applied in the open position, which force extracts a greater portion of valve pin  148  out of valve body  146 , towards upper bridge  108 . The extraction force applied by the thermal sensitive material is sufficient to overcome the opposite force of spring  154  and push valve disk  150  away from aperture  112 . Valve disk  150  reaches beyond the edge of locking leaf  124  and, consequently, displaceable valve  144  becomes locked in the locked position and aperture  112  remains permanently open. 
         [0067]      FIG. 4  shows a diagram of the displacement length of valve disk  150  (and, essentially, that of displaceable valve  144 ) of the previous figures, relative to changes in temperature. As shown, the displaceable valve is displaced under normal working conditions from its initial position D i  at initial temperature T i , up to a distance D w  at a maximum normal working temperature T w . The range between temperatures T i  and T w  is the normal working zone of the thermostat and will vary according to the design characteristics of the thermostat. 
         [0068]    As the temperature exceeds T w , the valve disk is further displaced, and then reaches the pre-determined locking distance D L  at the pre-determined extreme temperature T L . The range between temperatures T w  and T L  is an overheating buffer zone for the thermostat. While the temperatures in this zone exceed the normal working temperatures of the thermostat, they are not considered to be high enough that permanent damage is likely to occur to either the hosting system, or the thermostat assembly itself. At the pre-determined extreme temperature T L  the thermostat is being subjected to extreme overheating and at this point there may be a risk of damage to the thermostat and to the hosting system. Further increases in temperature above the pre-determined temperature T L  cause a further displacement of the valve disk up to a failure distance D f  where a failure temperature T f  is reached. At this point, the internal components of the displaceable valve will probably fail. For conventional thermostats, failure typically occurs at temperature T f . When the thermostat has failed, the valve pin may no longer act to force the valve disk axially away from the upper bridge and, consequently, the flexible member drives the valve disk towards closing the aperture. However, since the valve disk has been displaced beyond the pre-determined distance D L , the locking leaf prevents it from returning to the closed position. The pre-determined locking distance D L  is thus set between the maximum normal working distance D w  and the failure distance D f . The overheating buffer zone is provided to account for minor, non-detrimental, temperature increases above the working zone. However, once D L  has been reached, the locking leaf will engage the displaceable valve to prevent the valve disk from returning to the closed position. 
         [0069]    While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced be interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope. 
         [0070]    In the claims description of the application, each of the words “comprise” “include” and “have”, and forms thereof, are not necessarily limited to members in a list with which the words may be associated.