Abstract:
This invention relates to a device for testing a heat detector. The device has a housing that is shaped to surround a heat detector and includes a heating element. A fan is located near the heating element and is adapted to activate the heat detector by increasing the temperature around the heat detector. The housing also includes a temperature device that measures the temperature near the heat detector. Furthermore, a display is attached to the housing to show the temperature around the heat detector during testing.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Not applicable 
     REFERENCE REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable 
     SEQUENTIAL LISTING 
     Not applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a device for testing a heat detector. More specifically, the present invention relates to a device for testing heat detectors that are located at various locations including those within a user&#39;s reach and those high above the floor, such that they cannot be easily reached. 
     2. Description of the Background of the Invention 
     Various types of heat detectors exist on the market including those that measure a fixed temperature and those that measure the rate of temperature rise. Fixed temperature heat detectors are designed to activate a visual and/or audible alarm after a fixed temperature is reached during a slow heat rise. Rate of rise heat detectors, on the other hand, sense rapid changes in the temperature in the surrounding air and when a certain change threshold is met will activate an alarm. Although fixed temperature and rate of temperature rise heat detectors can be installed as separate devices, they are also available in a single device. In addition, heat detectors come in myriad sizes and shapes. Some heat detectors exhibit a more traditional semi-circular shape and, when mounted, hang close to the ceiling or wall, while other heat detectors are more rectangular in shape and hang down from the ceiling when mounted. 
     Each type and style of heat detector has a range of effectiveness associated with it; therefore, large buildings such as warehouses and factories require multiple heat detectors. To ensure the safety of workers, goods, and equipment, heat detectors need to be tested regularly, efficiently, and accurately. A device for testing a heat detector should therefore be lightweight, durable, adaptable, reliable, easy to use, and provide necessary information to its operator or user. 
     The present invention seeks to improve upon the prior art through the use of an improved design for a device for testing heat detectors that enables efficient testing by providing a portable, lightweight device that can be used to test heat detectors of varying shapes, sizes, and locations and by providing a read out that can be recorded to check that the heat detector that is being tested has functioned properly. 
     SUMMARY OF THE INVENTION 
     In one aspect of the invention, a device for testing a heat detector is disclosed. The device comprises a housing shaped to receive a heat detector. A heating element is carried by the housing, and a fan is located proximate to the heater and adapted to activate the heat detector by increasing a temperature around the heat detector. The device also comprises a temperature device that is carried by the housing that measures the temperature near the heat detector. Furthermore, a display is attached to the housing that shows a value that relates to the temperature. 
     In another aspect of the invention, a device for testing a heat detector is disclosed. The device comprises a housing shaped to receive a heat detector. A heating element is carried by the housing and adapted to activate the heat detector by increasing a temperature around the heat detector. A temperature device is also carried by the housing that measures the temperature near the heat detector. Additionally, a memory is carried by the housing for storing a value related to the temperature. The device further comprises a test switch carried by the housing, wherein a change of state of the test switch causes the value to be stored in the memory. 
     In a further aspect of the invention, a method of testing a heat detector using a device is disclosed. The device comprises a housing shaped to receive a heat detector, a heating element carried by the housing and adapted to activate the heat detector by increasing a temperature around the heat detector, a temperature device carried by the housing that measures the temperature near the heat detector, a display attached to the housing that shows a value that relates to the temperature, a start switch carried by the housing, and a test switch carried by the housing, wherein a change of state of the test switch freezes the value shown on the display. The method comprises the step of moving the device toward the heat detector to be tested until a testing position is reached, wherein the housing of the device substantially surrounds the heat detector in the testing position and wherein the heating element is activated by the start switch upon contact of the start switch with an object. The method also comprises the step of maintaining the device in the testing position until the heat detector is activated. The method further comprises the step of moving the housing away from the heat detector once the heat detector is activated to change the state of the test switch, whereby changing the state of the test switch freezes the value shown on the display. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of a device for testing a heat detector; 
         FIG. 2  is a top view of the device of  FIG. 1 ; 
         FIG. 3  is a front view of the device of  FIG. 1 , with the device in an extended position; 
         FIG. 4  is a bottom and back slanted view of the device of  FIG. 1 ; 
         FIG. 5  is a left side elevational view of the device of  FIG. 1 ; the right side being essentially a mirror image thereof; and 
         FIG. 6  is a cross-sectional view of the device along the lines  6 - 6  of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Turning now to the drawings, a device  10  for testing a heat detector is shown in  FIG. 1 . The device  10  includes a housing  12 , which is comprised of a testing chamber  14 , a body  16 , battery compartments  18   a  and  18   b , and a base  20 . Also shown in  FIG. 1  is a handle  22 , which is connected to the body  16 . 
     As shown in  FIG. 1  and  FIG. 3 , the testing chamber  14  comprises a cup  24 , which is frusto-conical in shape, and a cylindrical neck  26 . The testing chamber  14  is attached to the body  16  via the neck  26 . The cup  24  and the neck  26  guide the device  10  over the heat detector being tested to an optimal testing position, in which the testing chamber  14  surrounds the heat detector creating a close-fit between the heat detector being tested and the testing chamber  14 . In a preferred embodiment, the cup  24  and the neck  26  can be made of a durable, transparent material to enable a user to observe the heat detector during testing and see any visual alarms associated with the heat detector. Optionally, the cup  24  and the neck  26  can be made from a durable, non-transparent material. The testing chamber  14  also includes a removable lid  28 , which is attached to the upper edge of the cup  24 , distal to the neck  26 . The lid  28  is placed on the device  10  when heat detectors of a smaller diameter are to be tested. When heat detectors having a larger diameter are to be tested, the lid  28  can be removed. It is preferred that the lid  28  is made of a flexible, heat resistant, non-conductive material such as silicone rubber or Santoprene® so that a firm seal can be created around the heat detector without the user having to exert a lot of pressure to the device  10 . A firm seal is important to prevent the loss of heat generated by the device  10  during testing. 
     The body  16  of the device  10  comprises an upper section  30  and a lower section  32 . The upper section  30  is generally cylindrical in shape and the lower section  32  is generally rectangular in shape although any shape can be used so long as the body  16  and the neck  26  have similar shapes. The body  16  is hollow and suitably sized to carry the neck  26  of the testing chamber  14 , as well as a heating element  34  and a fan  36  (shown in  FIG. 6 ), both of which will be discussed in more detail below. The body  16  is preferably constructed from a durable, light-weight, heat resistant, and non-conductive material such as nylon, polypropylene, or acrylonitrile butadiene styrene. 
     The upper section  30  has an inner surface (not shown). Protrusions  38  provided on the neck  26  create a friction fit with the inner surface of the upper section  30 . The friction fit of the protrusions  38  and the inner surface of the upper section  30  is such that the testing chamber  14  is able to slide from a compact position as shown in  FIG. 1  to an extended position as shown in  FIG. 3  and vice versa. In addition, between each of the protrusions  38  are channels  40 . The channels  40  enable room-temperature air and excess heat to escape the device  10  during use. Furthermore, a stopping mechanism (not shown) may be provided such as a ledge on the inner side of the upper section  30  and an annular protrusion (not shown) on the bottom of the neck  26  to prevent the neck  26  from being removed from the body  16 . An adjustable height of the testing chamber  14  is desirable in order to allow for the testing of both traditional and pencil style heat detectors. The upper section  30  also includes a front side  42 , which contains an elongated aperture  44 . An adjuster slide  46 , which is carried by the neck  26 , fits within the elongated aperture  44 . The adjustor slide  46  enables a user to select between the compact or extended positions, by moving the adjustor slide  46  along the elongated aperture  44 . It is preferable that the adjustor slide  46  contain a mechanical clicking mechanism that enables the neck  26  to be held in place at various points along the elongated aperture  44  to accommodated heat detectors of varying heights. Although a manual adjustor slide is discussed an electronic switch is also contemplated. 
     In one embodiment as best shown in  FIG. 3 , the elongated aperture  44  has an upside-down L-shape. In this embodiment, the adjuster slide  46  is moved vertically up the elongated aperture  44  and then pushed to the side to lock the neck  26  in the extended position. Optionally, a second elongated aperture  44   a  and a second adjuster slide  46   a  also may be included on a back side  48  of the neck  26  as shown in  FIG. 4 , to provide added stability and support to the testing chamber  14  when in the extended position. 
     The upper section  30  further includes ears  50   a  and  50   b . The ears  50   a ,  50   b  are located on corresponding left and right sides  52   a  and  52   b , respectively, of the upper section  30 . The handle  22  is attached to the ears  50   a ,  50   b  with pins  54   a  and  54   b  (shown in  FIG. 6 ) and extends behind the back side  48  of the upper section  30 . The pins  54   a ,  54   b  can be held in place by any suitable mechanical connection mechanism known to those skilled in the art. The housing  12  is movable about a horizontal axis that extends through the midpoints of the ears  50   a  and  50   b , thus enabling the housing  12  to be positioned in numerous locations relative to the handle  22 . 
     As best seen in  FIG. 2  and  FIG. 5 , the handle  22  comprises a U-shaped portion  56  and a connection tail  58 . The connection tail  58  is attached to the U-shaped portion  56  at a midpoint  60 . In one embodiment, the lower part of the U-shaped portion  56  and the connection tail  58  may be positioned at a downward angle of approximately 135 degrees from the upper part of the U-shaped portion  56 . The angle and shape of the handle, however, may vary or contain a hinge. In addition, it is preferred that the U-shaped portion  56  be large enough to allow the housing  12  to pass through it as the housing  12  is rotated relative to the handle  22  to enable the testing of heat detectors positioned horizontally, vertically, or at an angle. Furthermore, it is also preferable that the housing  12  be able to lock at a specific position relative to the handle  22 . This can be accomplished by including a locking mechanism, ratchet mechanism, or rotary damper. An extension device  62  may be attached to the handle  22  through the connection tail  58  to enable a user to test heat detectors that are in a remote location, e.g., out of reach of the user. The extension device  62  is ideally made out of a lightweight, non-conductive material such as fiberglass and adjustable to enable a user to test heat detectors at varying heights from the floor. 
     Turning to  FIG. 3  and  FIG. 4 , the lower section  32  comprises left and right portions  64   a  and  64   b , respectively. Attached to the left and right portions  64   a ,  64   b  are the battery compartments  18   a  and  18   b , which house standard sized batteries. The battery compartment  18   a  is attached to the left portion  64   a  and the battery compartment  18   b  is attached to the right portion  64   b . The battery compartments  18   a ,  18   b  also comprise battery base portions  66   a  and  66   b , respectfully. By including the power source (i.e., batteries) for the device  10  within the housing  12  provides for more efficient testing of heat detectors. First, it eliminates the need for a power outlet and the use of electrical wires or cables that are heavy and burdensome. Second, it enables the device  10  to be quickly mounted on different extension devices for the testing of heat detectors at varying heights and locations. Furthermore, although two battery compartments are provided, the device  10  only requires one battery to operate. The use of a single battery reduces the weight of the device  10 , thereby further improving the efficiency of testing high mounted detectors. 
     Attached to the battery base portions  66   a ,  66   b , and an underside portion  68  of the body  16  is the base  20 . In one embodiment, the base  20  has a generally recta-cylindrical shape and is constructed from material similar to or the same as that used for the body  16 . On a bottom  70  of the base  20  are a display  72 , power switch  74 , mode switches  76   a ,  76   b ,  76   c , and a test start button  78 . The display  72  includes one or more light emitting diodes or LEDs, which are connected by any suitable electronics known by those skilled in the art. LEDs that correspond with the mode switches  76   a ,  76   b ,  76   c  may also be included to provide the user with a visual indication as to which mode they have selected. The display  72  provides the user with the measurement of the temperature taken by a temperature device  80  (shown in  FIG. 2 ), which is preferably housed within the body  16 . The temperature device  80  can be an infrared thermometer, thermocouple, or other suitable temperature measuring device. The ability to display the temperature measurement while testing is critical in determining whether the heat detector is operating properly. In addition, the location of the display  72  on the bottom  70  of the base  20  enables the user to observe the temperature measurements displayed during testing. The display  72  may also provide the user with additional information including battery life, type of test being performed, e.g., rate to rise/fixed temperature or high/low temperature test, the date, and time. 
     The power switch  74  turns the device  10  on and off. When the power switch  74  is activated, power is provided to the display  72 , the mode switches  76   a ,  76   b ,  76   c , the test start button  78 , the temperature device  80 , and the various LEDs and electronics contained within the device. The test start button  78  is pressed by a user before a test is conducted to clear the information from a previous test shown on the display and/or stored in a memory  82 , which is discussed in more detail below. In addition, the test start button  78  is connected to the heating element  34  and the fan  36  via a control board  83  (shown in  FIG. 6 ) and, upon actuation of the test start button  78 , power is provided to the heating element  34 , the fan  36 , and a start switch  86  (shown in  FIGS. 1 and 6 ). 
     The mode switches  76   a ,  76   b ,  76   c  enables the user to select a testing mode of the device  10 . Mode switch  76   a  allows a user to choose between a fixed temperature test mode and a rate of temperature rise test mode. Mode switch  76   b  enables a user to select whether the test is to be performed at a high or low temperature, and mode switch  76   c  enables a user to choose the desired temperature unit, i.e., Fahrenheit (F) or Celsius (C), at which the test is to be performed and displayed. The ability to selectively choose between a fixed temperature and rate of temperature rise test is advantageous because it eliminates the need for multiple heat detector testing devices. Rather than having to switch between two different devices, a user can use one device, device  10 , to test two different types of heat detectors or to test two different functions within one heat detector, thereby saving time and money. In addition, the ability to select a high or low temperature test is desirable because it enables two different categories of heat detector to be tested—one category grouped around 135 degrees F. and one category grouped around 200 degrees F. Although multiple mode switches are discussed, a single multi-mode switch can be used. Furthermore, in lieu of separate mode and power switches, the device  10  may contain a single, combined power/mode switch. 
     When a fixed temperature test is selected by the user, the control board  83  is programmed to monitor the temperature of the air around the heat detector and adjust power to the heating element  34  and the fan  36  to maintain a desired or maximum temperature for a period of time. For example, if a low temperature test is selected, the control board  83  will regulate the heating element  34  and the fan  36  such that when a maximum temperature of 150 degrees F. is reached, that temperature is maintained for approximately 20 seconds. Similarly, if a high temperature test is selected, the control board  83  will adjust the power to the heating element  34  and the fan  36  so that once a maximum temperature of 200 degrees F. is reached, it is maintained for several seconds. The ability to reach and maintain a maximum temperature is beneficial and an important improvement because some heat detectors do not actuate immediately, i.e., as soon as the air around the detector is heated to a specific temperature. Rather, some heat detectors require the heating of the entire heat detector itself before actuation will occur, which requires more time and exposure to the heated air. If the temperature is not monitored and the heating element  34  and the fan  36  are not regulated, the temperature of the heated air produced by the heating element and directed by the fan will continue to rise, which may cause internal and/or external portions of the heat detector to melt or become damaged in some way. Therefore, by programming the control board  83  to regulate the heating element  34  and the fan  36  such that a specific temperature is reached and maintained, damage to the internal and external portions of the heat detector can be prevented. 
       FIG. 6  is a cross-sectional view of the device  10  taken along the line  6 - 6 . Housed within the upper and lower sections  30 ,  32  of the body  16  are the heating element  34 , the fan  36 , and a nozzle  85 . The heating element  34  may be a positive thermal coefficient (PCT) ceramic heating element, an open coil heater, or similar heating device. In one embodiment, a PCT heating element is used such as a Cirrus 40/2 Fan Heater manufactured by DBK David+Baader GmbH. 
     The fan  36  is disposed on one side of the heating element  34  and the nozzle  85  is located on a different side. For example, as shown in  FIG. 6 , the fan  36  may be located below the heating element  34  and the nozzle  85  may be located above the heating element  34 . When activated, the fan  36  blows air through the heating element  34 , which heats the air, and the nozzle  85  further directs the heated air at the heat detector being tested. The use of the fan  36  is important because it provides for efficient testing of the heat detector by blowing the heated air directly at the heat detector. 
     The start switch  86  may be disposed on an inner rim  87  of cup  24  as shown in  FIGS. 1 and 6 , or attached to the exterior of the housing  12 . The start switch  86  may be a mechanical switch that is activated manually by the user by placing the device against a heat detector or surface such that the heat detector or surface changes the state of the start switch  86  by contact. The start switch  86  may also be a photoelectric eye or force sensing resistor. A photoelectric eye is activated upon a change in ambient light. A force sensing resistor is a device that exhibits a decrease in resistance with an increase in the force applied to an active surface, and acts as a switch when a threshold or “break force” is applied to the active surface. 
     In the preferred embodiment, the start switch  86  is a mechanical switch that requires physical contact to be activated. It is preferable that more than one start switch  86  be provided to ensure that activation occurs without the need for great accuracy when placing the device  10  up to the heat detector. In addition, springs  88  and an annular plate  90  (as best shown in  FIG. 1 ) are also provided to assist in the activation of the start switch  86 . The springs  88  bias the annular plate such that the annular plate  90  remains in contact with the start switches  86  but does not trigger them. When pressure is applied to the annular plate  90 , the springs  88  depress and at least one start switch  86  is activated. Therefore, when the device  10  is held up to the heat detector, the start switch  86  is activated when it comes into physical contact via the annular plate  90  with the heat detector or a surface such as a ceiling or wall. Activation of start switch  86 , turns on the heating element  34  and fan  36  thereby commencing a test cycle. The heating element  34  generates heated air, which is directed by the fan  36  and nozzle  85  to the heat detector. 
     In order to protect against an inadvertent continuation of the test cycle, a test switch  84  is provided to determine if the test cycle should be continued. The test switch  84  may be located within the body  16  as shown in  FIG. 6  and is connected to the heating element  34 , the fan  36 , and the power switch  74  via the control board  83 . In a preferred embodiment, the test switch  84  is an optical proximity switch, which senses the presence of the heat detector using a light transmitter and a receiver. Alternatively, the test switch  84  may be a sonar proximity switch, which sends and receives sound waves to detect the presence of the heat detector. In a further embodiment, the test switch  84  may be a solid state charge-coupled device (CCD) light sensing device with appropriate electronics to detect or identify an object at the opening of the test chamber  14 . 
     The test switch  84  determines if a heat detector is located within the testing chamber  14  of the device  10  approximately five seconds after the start switch  86  is actuated. If the test switch  84  confirms the presence of a heat detector, then the test switch  84  remains in a first state and the test cycle is continued. If a heat detector is not present, then the test switch  84  enters a second state. In the second state, the test switch  84  does not detect the physical presence of the heat detector and turns off the heating element  34  and the fan  36  thereby ending the test cycle. In one embodiment, a sound or light indicator (not shown) is included in the device  10  to inform the user that the test cycle has ended. 
     If the test switch  84  confirms the presence of a heat detector, the heating element  34  and fan  36  remain activated. The user maintains the device  10  in a testing position until the heat detector is activated. Once the heat detector is activated (i.e., an alarm is observed), the user moves the device  10  away from the heat detector. Moving the device  10  away from the heat detector causes the test switch  84  to enter the second state. When this occurs, the testing cycle is concluded, i.e., the heating element  34  and fan  36  are deactivated, and the temperature shown on the display  72  is frozen. Freezing the display  72  then enables the user to observe and record the temperature at which the heat detector was activated. 
     Alternatively, when the second state occurs, the temperature at which the heat detector is activated is recorded and stored in the memory  82  contained within the device  10  as shown in  FIG. 6 . This may occur with or without a simultaneous freezing of the display  72 . The memory  82  may be a computer chip or other similar device for recording and storing the temperature reading at which the heat detector was activated and other pertinent information. As shown in  FIG. 5 , the recorded and stored data can then be transmitted to a remote display  92  for further analysis through the use of a data transmitter  94 . The data transmitter  94  can be a wireless device such as Bluetooth, a removable drive, a wireless network, an optical data transmission device, or a standard computer connection such as a USB. The remote display  92  may be a LED display board, computer monitor, television monitor, or similar device. The remote display  92  may be attached to a computer, to the end of the extension device  62 , or to a handheld device carried by the user. 
     To test a heat detector that is located in a remote location with the device  10 , a user attaches the device  10  to the extension device  62  via the handle  22 . The user turns on the device  10  with the power switch  74  and uses the mode switches  76   a ,  76   b ,  76   c  to select the appropriate testing modes. With the mode switches, the user selects the type of heat detector to be tested, i.e., rate of rise or fixed temperature, the temperature unit to be used and displayed, and whether a high temperature or low temperature test is to be conducted. The user may also adjust the height of the testing chamber  14  using the adjuster slide  46  depending on the size of the heat detector to be tested. After the appropriate height of the testing chamber and testing modes are selected, the user presses the start test button  78 , raises the device  10  to the heat detector being tested. The start switch  86  is activated when it comes into physical contact via the annular plate  90  with the heat detector or a surface upon which the heat detector is mounted. The heat detector is then moved closer to the heat detector until a testing position is reached. In the testing position, the testing chamber  14  surrounds and lies in close proximity to the heat detector and the lid  28  is pressed against the surface on which the heat detector is located. 
     When the start switch  86  is activated, it turns on the heating element  34  and the fan  36 . After five seconds the test switch  84  determines if a heat detector is present. If a heat detector is present, then the test switch  84  continues the test. The user maintains the device  10  in the testing position until the heat detector is activated. Once the heat detector is activated, the user moves the device  10  away from the heat detector; moving the device  10  away from the heat detector causes the test switch  84  to turn off the heating element  34  and the fan  36  and at the same time freeze the temperature shown on the display  72  and/or stores the temperature in the memory  82 . The user then lowers the device  10  and may record the temperature measurement shown on the display  72 . 
     INDUSTRIAL APPLICABILITY 
     Numerous modifications to the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and use the invention and to teach the best mode of carrying out same. The exclusive rights to all modifications which come within the scope of the appended claims are reserved.