Abstract:
A temperature sensing device is mounted to a structure of a building and senses temperature within a building space of the building. The temperature sensing device includes a housing. The housing includes a front surface that faces the building space when the temperature sensing device is mounted to the structure. The housing further includes a protrusion that protrudes from the front surface into the building space. The temperature sensing device further includes a mounting device within the housing and a temperature sensor mounted to the mounting device, the mounting device holding the temperature sensor within the protrusion.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
       [0001]    This application is a continuation of application Ser. No. 11/241,846, filed Sep. 30, 2005, which is a continuation-in-part of application Ser. No. 10/801,313, filed Mar. 16, 2004. The entire contents of U.S. patent application Ser. No. 11/241,846 and U.S. patent application Ser. No. 10/801,313 are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present description relates generally to temperature sensing devices such as thermostats, etc. More specifically, the present description relates to mounting devices for sensors in temperature sensing devices. 
         [0003]    Climate control systems, such as heating, ventilating, and air conditioning (HVAC) systems, typically include one or more thermostats to monitor, for example, an ambient air temperature within a particular room or space within a building to provide feedback as to whether the air temperature of the room needs to be adjusted to satisfy a predetermined set point. The thermostat is typically configured such that a temperature sensor is housed within an enclosure to sense the temperature of the air passing over, through, or in contact with the enclosure. The climate control system may then compare this air temperature to the predetermined set point to determine if the air temperature of the room needs to be adjusted to satisfy the predetermined setpoint. Typically, the temperature sensor is interconnected with a processor circuit to accomplish this function. The temperature sensor can be either indirectly coupled or directly secured to the processor circuit which includes a plurality of interconnecting members (or conductive wires). The processor circuit is coupled to the housing and is enclosed therein. 
         [0004]    For convenience, the thermostat may be mounted to a wall or other structure within a space or room. However, when the thermostat is mounted to the surface of an outside wall or another location where the wall surface is significantly warmer or colder than the air temperature of the space or room, there may be substantial differences between the air temperature measured by the thermostat and the actual ambient air temperature of the space or room. Further, air flow through the thermostat may be minimal due to a low profile enclosure designed such that the thermostat is minimally noticeable and does not project undesirably from the wall or other mounting location. Under these conditions, the climate control system may perform inefficiently because the temperature measured by the thermostat may not be the ambient air temperature of the room, but rather a temperature somewhere between the air temperature of the room and the wall surface temperature. Previous attempts to solve this problem include affixing the sensor against a surface of the temperature sensing device housing opposite the mounting structure with an adhesive. This surface is generally planar or flat. In this arrangement extension of the sensor into the room or space is, however, limited by the dimensions of the housing which—in order to provide a low profile appearance—typically affords minimal area. Thus there is need for a device for mounting a sensor within a temperature sensing device so that the temperature sensing device may compensate for mounting surface temperature effects. 
       SUMMARY OF THE INVENTION 
       [0005]    According to a first exemplary embodiment, a temperature sensing device is provided having a housing and a first temperature sensor mounted to the housing at a first location proximate a first surface of the housing. The first temperature sensor is configured to sense a first temperature. A second temperature sensor is also provided which is configured to sense a second temperature. Further included with the present temperature sensing device is a processor circuit coupled to the first and second temperature sensors and a mounting device coupled to at least one of the housing or the processor circuit which is configured to mount the second temperature sensor at a second location proximate a second surface of the housing and spaced apart from the first surface. The processor circuit is configured to estimate a third temperature based on the first and second temperatures and a distance between the first and second locations. The third temperature is an estimate of a temperature at a third location and the distance between the first and third location is greater than the distance between the first and second locations. 
         [0006]    According to another exemplary embodiment, a temperature sensing device with housing defining a protrusion is provided. Also included are a temperature sensor mounted with respect to the housing and configured to sense a temperature and a processor circuit which is coupled to the first temperature sensor. Further provided is a mounting device coupled to at least one of the housing and the processor circuit which is configured to mount the temperature sensor at a second location proximate the protrusion of the housing. The mounting device has a semi-annular configuration. 
         [0007]    According to another exemplary embodiment, a processor circuit for a temperature sensing device having a plurality of sensors is provided. The processor circuit is configured in a manner to selectively interconnect the plurality of sensors. A mounting device which protrudes outward a first distance from the processor circuit is also included. At least one of the sensors in the plurality of sensors is coupled to the mounting device and spring biased with respect to the processor circuit by the mounting device. The mounting device is configured to interconnect at least two of the sensors in the plurality of sensors with the processor circuit. 
         [0008]    According to another exemplary embodiment a temperature sensing device with housing defining a protrusion is provided. The sensor mounting device coupled to the processor circuit is configured to project one or more sensors into the protrusion in an effort to get an improved estimate of room temperature. The sensor mounting device is simply and securely connected to the processor board while still providing a sufficient thermal connection between the protrusion and the thermal sensor. The flexible circuit permits the processor board to be assembled and disassembled from the enclosure without the inconvenience or danger of damaging or severing the sensor leads. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0009]      FIG. 1  is a perspective view of a temperature sensing device according to an exemplary embodiment. 
           [0010]      FIG. 2A  is a perspective view of a temperature sensing device with housing partially cut away along line  2 - 2  of  FIG. 1  according to an exemplary embodiment. 
           [0011]      FIG. 2B  is a perspective view of a temperature sensing device with housing partially cut away along line  2 - 2  of  FIG. 1  and fastener according to an exemplary embodiment. 
           [0012]      FIG. 3  is a perspective view of a temperature sensing device with housing partially cut away according to an exemplary embodiment. 
           [0013]      FIG. 4  is a perspective view of the flexible circuit for a temperature sensing device according to an exemplary embodiment. 
           [0014]      FIG. 5  is a perspective view of a processor circuit isolated from the housing of a temperature sensing device according to an exemplary embodiment. 
           [0015]      FIG. 6  is a perspective view of a processor circuit with module isolated from the housing of a temperature sensing device according to an exemplary embodiment. 
           [0016]      FIG. 7  is a top view of a module isolated from temperature sensing device according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]      FIG. 1  illustrates a temperature sensing device  100  according to an exemplary embodiment. Temperature sensing device  100  may be a thermostat, such as a wall-mounted electronic thermostat configured for use with a climate control system to measure the air temperature of a room or space. In other embodiments, temperature sensing device  100  may be adapted for use with other systems or locations. Temperature sensing device  100  includes a housing  102 , temperature sensors  104  and  106 , mounting device  136 , and a processor circuit  108  (as shown in  FIGS. 1-7 ). Temperature sensing device  100  may be generally used to sense a first temperature and a second temperature and to estimate a third temperature using the first temperature and the second temperature. More specifically, temperature sensing device  100  may be used to compensate for external temperature effects resulting from the location of temperature sensing device  100  by measuring a first temperature and a second temperature, and estimating the third temperature based on the first temperature and the second temperature. 
         [0018]    Housing  102 , as illustrated in  FIG. 1 , is configured to provide a structure within which temperature sensors  104  and  106 , and optionally processor circuit  108 , may be mounted and enclosed, as shown in  FIGS. 2A-B . In the illustrated exemplary embodiment, processor circuit  108  is shown as being enclosed within housing  102 . In another embodiment, processor circuit  108  is located within another device or controller remotely located and/or external to housing  102 . Housing  102  is made of a rigid material such as a hard plastic, metal or other material suitable to protect the internal components of housing  102 . In one embodiment, portions of housing  102  may be made of a thermally conductive material such that at least one of the temperatures sensed by temperature sensors  104  and  106  may be sensed by conduction through housing  102 . In another embodiment, the housing  102  is made of a material having low density so that in a similar manner to the highly conductive material at least one of the temperatures sensed by temperature sensors  104  and  106  may be rapidly sensed by conduction through housing  102 . In yet another embodiment, housing  102  may include one or more openings or vents to facilitate the flow of air through the housing once the temperature sensing device has been mounted such that at least one of the temperatures sensed by temperature sensors  104  and  106  may be sensed by convection through housing  102 . 
         [0019]    Housing  102  is further configured to be mounted to a structure  110 , as shown in  FIG. 1 . In the illustrated exemplary embodiment, housing  102  is configured to be mounted to the surface of structure  110 , such as a building wall, ceiling, column, floor or other structure utilizing any suitable mounting hardware or other means of attachment. Housing  102  includes orifices in surface  114  to accommodate a variety of suitable mounting hardware. Structure  110  to which temperature sensing device  100  is mounted may be, for example, an exterior wall or other structure for which the temperature of the surface is different from, for example, the air temperature in the middle of the room or other area which includes or is exposed to the structure and in which temperature sensing device  100  is mounted. 
         [0020]    Housing  102  may be any suitable size or shape depending on the particular application. However, in the illustrated exemplary embodiment surface  112  and surface  114  of housing  102  are spaced proximate to each other so as to provide a “low profile” appearance of housing  102 . For example, in the illustrated embodiment, housing  102  is an essentially rectangular hollow protrusion with a low profile such that housing  102  does not significantly extend beyond the surface of structure  110  (e.g., a wall) to which it is mounted. In this embodiment, housing  102  is shaped such that it has surface  112  and surface  114  spaced apart from structure  110 . In the illustrated embodiment shown in  FIG. 2B , housing  102  is formed from a mounting base  118  and a mating cover  120  such that mounting base  118  includes structure  110  and mating cover  120  includes surface  112 . In other embodiments, housing  102  may be formed from additional pieces, or may be a single piece. 
         [0021]    Surface  114  is configured to be adjacent to a surface of a structure  110 , such as a wall, to which housing  102  is mounted. Surface  114  is configured to be spaced slightly apart from the surface of structure  110  and exposed to a temperature at a distance from the surface of structure  110 , such as the temperature of the air at a distance from the surface of a wall to which temperature sensing device  100  is mounted. Alternatively, surface  114  may abut the structure of surface  110 . Preferably, surface  112  is spaced apart from surface  114  such that the distance between surface  114  and surface  112  is maximized while maintaining an overall low profile for temperature sensing device  100 . For example, the embodiment shown in  FIG. 1  includes a protrusion  122  (shown as a contoured dome) extending from mating cover  120  which is configured to maximize the spacing between surface  114  and surface  112  while maintaining an overall low profile of temperature sensing device  100 . Protrusion  122  includes a annular shoulder  126  as shown in  FIGS. 2A and 2B . Additional support may be added to protrusion  122  by a series of struts (not shown) extending between surface  112  of housing  102  and the contoured dome of protrusion  122 . Protrusion  122  is composed of a thin polymer so to decrease the response time of any temperature sensor abutting protrusion. In one embodiment protrusion  122  is stationary with respect to housing  102  and an adjustable ring  124  (or dial as shown in  FIGS. 1-2B ) is coupled to protrusion  122 . Ring  124  is annular and configured to rotate with respect to housing  102  when slidably coupled to annular shoulder  126  of protrusion  122 . In other embodiments, protrusion  122  may be eliminated, such that mating cover  120  is substantially planar. 
         [0022]    The inner diameter of ring  124  includes a series of gear teeth  128 , as shown in  FIG. 2A  which are compatible with an adjustment gear  130 . Adjustment gear  130  is coupled to a position sensor  132  such as potentiometer which is interconnected to the processor circuit. Rotation of position sensor  132  adjusts the temperature set point of temperature sensing device  100 . In another embodiment, rotation of position sensor  132 , via adjustable ring  124 , adjusts the image displayed on a display screen  134 . In the illustrated exemplary embodiment display screen  134  is an LCD display, however, it may be any other suitable display screen. Preferably, ring  124  and adjustment gear  130  are composed of a hard plastic or metal; however, the conductivity and/or density of the material in which the two are composed does not significantly impact the performance of temperature sensor  104 . Therefore, ring  124  and adjustment gear  130  may be composed of a variety of materials without influencing the performance of temperature sensor  104 . Additionally, position sensor  132  need not be a rotational position sensor; in another exemplary embodiment, position sensor  132  is responsive to longitudinal or transverse adjustments. 
         [0023]    Temperature sensors  104  and  106  may be mounted within housing  102 , as shown in  FIGS. 2A-B , and may be any suitable temperature sensor. For example, in one embodiment, temperature sensors  104  and  106  may be resistance thermal detectors (RTDs). In another embodiment, temperature sensors  104  and  106  may be thermistors. In one embodiment temperature sensors  104  and  106  may be electrical or electronic devices that provide an analog output signal. In another embodiment, temperature sensors  104  and  106  may be electrical or electronic devices that provide a digital output signal. In the illustrated exemplary embodiment, temperature sensors  104  and  106  are configured to sense temperatures at different locations with respect to the surfaces  112 ,  114 ,  118  and  120  of housing  102 . For example, in the illustrated embodiment as shown in  FIG. 2A-B , temperature sensor  104  is mounted proximate to surface  112  and temperature sensor  106  is spaced apart from temperature sensor  104  and mounted proximate to surface  114 . Each sensor ( 104  and  106 ) is mounted relative to housing  102  or mounting structure  110 . Temperature sensor  104  is mounted to housing  102  at a first distance relative to housing  102  and the temperature sensor  106  is mounted to housing  102  at a second distance relative to the housing  102 . Preferably, the spacing between temperature sensors  104  and  106  is the maximum possible spacing that housing  102  will permit. 
         [0024]    Temperature sensor  104  may be configured to sense the temperature at or near the surface of structure  110  to which housing  102  is mounted, as surface  114  of housing  102  is typically adjacent structure  110 . Temperature sensor  106  may be configured to sense the temperature of the air in which mating cover  120  and surface  112  are exposed. In another embodiment, temperature sensor  106  may be coupled directly to the mating cover  120  in order to position temperature sensor  106  as close as possible to the air in which mating cover  120  and surface  112  are exposed (i.e., as far as possible from structure  110  to which housing  102  is mounted. In another exemplary embodiment, temperature sensor  106  is configured to abut protrusion  122  in surface  112  of housing  102  and the temperature of protrusion  122  is sensed by temperature sensor  106  through conduction. In this embodiment, sensor  106  may be placed on the inner surface or outer surface of protrusion  122 . In another embodiment, the temperatures sensed by temperature sensors  104  and  106  are sensed primarily by convection. In this embodiment, housing  102  may also include openings or vents to permit the flow of air through housing  102  and temperature sensor  106  may be mounted within protrusion  122  without abutting protrusion  122  of housing  102  such that it is spaced apart from temperature sensor  104  while being exposed to the flow of air, therefore the temperature of the air flowing through housing  102  is sensed by sensor  104 . 
         [0025]    While the illustrated embodiment shows both sensors  104  and  106  mounted within housing  102 , other mounting locations are possible. For example, in one embodiment, temperature sensor  106  may be mounted outside housing  102 . In another embodiment, temperature sensing device  106  may be mounted on an extension to housing  102  to increase the distance between temperature sensor  104  and  106 . In yet another embodiment, temperature sensors  104  and  106  may be mounted in separate housings, so long as they are both in communication with processor circuit  108 . 
         [0026]    Processor circuit  108 , as shown in  FIGS. 2A-3  and  5 - 6 , is coupled to temperature sensors  104  and  106  and may be any suitable processor circuit. Processor circuit  108  is configured to receive a temperature measurement from temperature sensor  104  and a temperature measurement from temperature sensor  106 . In the illustrated embodiment, processor circuit  108  is shown as being coupled to (or interconnected with) temperature sensors  104  and  106  and mounted within housing  102 . In another embodiment, processor circuit  108  is coupled to temperature sensors  104  and  106 , but is located external to housing  102 . Processor circuit  108  is also configured to use the temperature measurements from temperature sensors  104  and  106  to estimate a third temperature. For example, in one embodiment processor circuit  108  may be configured to estimate the temperature of an air mass in a room or other area in which temperature sensing device  100  is mounted using temperature measurements from temperature sensors  104  and  106 . Because temperature sensing device  100  may be located on the boundary surface of the room air mass, neither temperature sensor  104  nor temperature sensor  106  may be sufficiently exposed to the actual temperature of the air mass. Additionally, temperature sensing device  100  may further be mounted to the surface of a structure  110 , such as an exterior wall, such that it is exposed to various external or other temperature effects. Accordingly, in this embodiment processor circuit  108  may be configured to estimate the third temperature from the temperature measurements from temperature sensors  104  and  106  by compensating for the various external temperature effects due to the mounting location of temperature sensing device  100 . The third temperature may be estimated from the temperature measurements from temperature sensors  104  and  106  in a number of ways. For example, in one embodiment, the third temperature is estimated using a predetermined extrapolation function which defines an approximate mathematical relationship between the temperature measurements from temperature sensors  104  and  106  and the third temperature to be estimated. In other embodiments, methods other than mathematical extrapolation may be used. The details of the processor circuit  108  configured to estimate the third temperature based on the first and second temperatures is described in detail in commonly assigned U.S. patent application Ser. No. 10/801,313. 
         [0027]    In one exemplary embodiment (as shown in  FIG. 3 ) mounting device  136  is secured to housing  102 . In this embodiment fastener  138  is configured to couple any one of temperature sensors  104 ,  106  to protrusion  122  of housing  102 . Interconnecting members  142  are attached to surface  112  of housing  102  and extend to processor circuit  108 . In another exemplary embodiment, processor circuit  108  includes a position sensor  132  which is attached to an adjustment gear  130  and mounting device  136  is configured to avoid interference with adjustment gear  130  and the components of position sensor  132 . In another exemplary embodiment as shown in  FIG. 4 , mounting device  136  is a flexible circuit  140  which may be coupled directly or indirectly onto processor circuit  108 . Flexible circuit  140  includes interconnecting members  142  extending between temperature sensor  104  and an end of flexible circuit. When flexible circuit  140  is detached from processor circuit  108  (or in “free state”) it extends flat. When coupled to processor circuit  108 , flexible circuit  140  acts as a leaf spring thereby biasing temperature sensor  104  with respect to processor circuit  108 . Flexible circuit  140  is configured to protrude outward from processor circuit  108  as much as possible without exceeding the space provided by protrusion  122  or surface  112  of housing  102 . In such case, when enclosed by housing  102 , temperature sensor  104  may abut protrusion  122  or surface  112  of housing. In this embodiment sensor  104  is configured to measure the temperature of protrusion  122  or surface  112  of housing  102  through conduction. Since flexible circuit  140  is slightly deformable with respect to processor circuit  108  the assembly tolerances for temperature sensing device  100  may be more lenient than an arrangement having a non-deformable mounting device  136 , thereby potentially reducing the manufacturing costs for the assembled temperature sensing device  100 . Flexible circuit  140  may be composed of thin, flexible, nonconductive plastic substrate such as polyimide, epoxy laminate etc. While the illustrated embodiments show temperature sensor  104  attached to mounting device  136  any sensor disclosed herein may be alternatively coupled to mounting device. 
         [0028]    In another embodiment, flexible circuit  140  has an semi-annular shape or configuration when coupled to processor circuit  108 , as shown in  FIGS. 3-5 . The semi-annular shape enables interconnecting members  142  to avoid interference with adjustment gear  130  of position sensor  132 . Flexible circuit  140  is sufficiently long so as to avoid interference with adjustment gear  130  when temperature sensor  104  abuts either protrusion  122  or surface  112  of housing  102 . 
         [0029]    Flexible circuit  140  includes end  144  and end  146 . End  144  of flexible circuit  140  is notched (as shown in  FIG. 4 ) so that end  144  may couple to a complementary slot in processor circuit  108 . Notch pattern  148  is configured to create barbed members  150  extendable through slot  152  in primary circuit board  108  for mechanical support and retention. End  146  of flexible circuit  140  includes two shoulder portions  153 , 154  (or tab inserts). Shoulder portion  153  fits into processor circuit  108  and shoulder portion  154  fits into niche  162  in module  160 , as shown in  FIG. 5  Niche  162  includes a series of small orifices having variable sizes; the intersection of the inner surfaces of the orifices creates a jagged profile for the interior surface of niche  162  which is configured in a manner to fit end  146  of flexible circuit  140  within the series of orifices. Moreover, since niche  162  is formed from a series of orifices, as opposed to cutting operations typically used to produce a narrow straight-edged interior surface, the manufacturing costs can be significantly reduced. Shoulder portion  154  includes interconnecting members  142  configured to extend to through end  144  and terminate in primary circuit board  108  when mounting device  136  is connected thereto. 
         [0030]    Interconnecting members  142  may be composed of any conductive material suitable for use in conventional processors. Interconnecting members  142  are configured for soldering of sensors and termination to processor circuit  108 . According to an exemplary embodiment, interconnecting members  142  are copper traces. The response time of temperature sensor  104  is inversely related to the mass of flexible circuit  140 . To decrease the response time, one embodiment includes interconnecting members  142  of a suitably reduced diameter. 
         [0031]    In addition to sensor  104  mounting device  136  may include a plurality of sensors ( 104 ,  156 ,  157  and/or  158 ) as shown in  FIG. 4 . In one embodiment, mounting device  136  includes a third sensor  156  and/or  157 . Third sensor  156  and/or  157  is configured to assess an additional temperature reading and enables temperature sensing device  100  to be simultaneously compatible with an additional processor circuit. For example, if temperature sensor  104  is configured to be compatible with processor circuit  108  third sensor  156  and/or  157  may be configured to be compatible with an external processor circuit (not shown). Any sensor which provides the desired level of resistance may be utilized with temperature sensing device  100 , including a PT1000 resistive output or a thermistor resistive output. A fourth sensor  158  may also be coupled to mounting device  136 . In one embodiment, fourth sensor  158  is a humidity sensor configured to assess the humidity of the air circulating through housing  102  of temperature sensing device  100 . Fourth sensor  158  may alternatively be mounted directly to processor circuit  108  or to a module coupled thereto. 
         [0032]    In another embodiment, processor circuit  108  includes a module  160 , as shown in  FIG. 6 . Module  160  may include sensor  158  for sensing the humidity, temperature, etc. In the illustrated embodiment module  160  includes a RH module with interconnecting members  166  and  168  extending from module  160  to processor circuit  108 . Mounting device  136  may be indirectly coupled to processor circuit  108  through module  160  or directly coupled to processor circuit  108 . In one embodiment, mounting device  136  is a flexible circuit  140  configured to couple to module  160 . Flexible circuit  140  may include interconnecting members  142  extending between a plurality of sensors ( 158  and any others) mounted thereto and module  160  or processor circuit  108 . Module  160  attaches to processor circuit  108  through soldering connectors  166  and strut  168 . Flexible circuit  140  may connect to module  160  at end  146  by insertion into niche  162  so that shoulder  154  abuts module  160 ; additionally, end  144  is connectable by insertion of barbed members  150  into slots  164 . 
         [0033]    It should be understood that the construction and arrangement of the elements of the temperature sensing device in the exemplary embodiments are illustrative only. Although only a few embodiments of the present invention have been described in detail in this disclosure, many modifications are possible without materially departing from the novel teachings and advantages of the subject matter recited in the claims. For example, the temperature sensing device may be adapted for use in other systems or locations, may incorporate additional temperature sensors or other inputs, or may include other variables or factors in the extrapolation function. Accordingly, all such modifications are intended to be included within the scope of the present invention as defined in the appended claims. Unless specifically otherwise noted, the claims reciting a single particular element also encompass a plurality of such particular elements. Moreover, claims reciting that one element is coupled to another should be interpreted to mean that the elements are selectively coupled to each other and may be uncoupled or disconnected at any point. The order or sequence of any process or method steps may be varied or resequenced according to alternative embodiments. In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and/or omissions may be made in the design, operating conditions and arrangement of the preferred and other exemplary embodiments without departing from the spirit of the present invention as expressed in the appended claims.