Patent Publication Number: US-2007098038-A1

Title: Radiator cap with a thermometer

Description:
BACKGROUND OF THE INVENTION  
      This invention relates to the field of automotive parts, and is a radiator cap. More particularly, it is a cap that provides the instantaneous display of the temperature at the filler neck of the vehicle&#39;s cooling system.  
      Various radiator caps have been devised so as to relieve the pressure within the cooling system to allow for the safe removal of the radiator cap. A coolant temperature gauge provided on the dashboard of the vehicle for driver viewing is also known. These devices do not allow the vehicle operator to quickly, accurately and efficiently check the temperature of the coolant, at the filler neck of the vehicles cooling system, i.e. radiator.  
      From a safety standpoint, it is important to know the temperature of the coolant prior to cap removal, to help prevent escaping hot steam from spraying upon the vehicle&#39;s user. A dash mounted temperature gauge does not efficiently address this desire because it is usually situated within the vehicle, and is only operating when the engine is running. The user, prior to removing the cap, might not take the time to start the engine and wait for the temperature gauge to properly register the coolant temperature. Additionally, a typical dash mounted gauge is not always calibrated with numbers. Therefore, it may not be possible to ascertain the actual temperature of the coolant. It is therefore desirable to have a radiator cap that indicates the temperature of the coolant with calibrated numbers, at the filler neck of the cooling system, without the need for vehicle start-up.  
      In response thereto, I have invented a radiator cap equipped with a descending temperature probe for extension into the cooling system upon cap installation onto the radiator. The cap has a numbered readout on the exterior surface in mechanical communication with the probe.  
      It is an object of this cap invention to: 1) indicate the temperature of the cooling system, 2) allow for removal of the cap for adding coolant to the vehicles cooling system, 3) provide a predetermined superatmospheric pressure to the coolant to increase the efficiency of the cooling system, 4) provide a cap which needs no modification of the cooling system prior to use. Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.  
     BRIEF SUMMARY OF THE INVENTION  
      The radiator cap invention described herein is called “ThermoCap”. This cap is equipped with a numbered and calibrated temperature display background with a visible rotating needle which points to the correct temperature number. The rotating needle is directly connected to the temperature probe, which descends into the cooling system at the radiators filler neck. Like current existing radiator caps, ThermoCap is equipped with a spring pre-loaded valve that provides for extra positive pressure within the cooling system, when installed. Also like current existing radiator caps, ThermoCap is equipped with a return-valve that allows for coolant reclamation from an external coolant bottle, during cases of negative pressure within the cooling system.  
      It is important to know the temperature of the coolant in the cooling system, prior to cap removal, to prevent the possibility of hot coolant spraying upon the vehicles user. ThermoCap addresses this need by indicating the temperature of the coolant in the fahrenheit scale and celsius scale. The method of communication between the rotating needle indicator, and the temperature probe is mechanical, thus eliminating the need for electricity or other complicated means.  
      As with other typical radiator caps, ThermoCap is easily removable from the cooling systems radiator, so as to allow for coolant filling.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of the radiator cap with the temperature probe showing at the bottom.  
       FIG. 2  is a top view of the radiator cap showing the numbered meter face and indicator needle.  
       FIG. 3  is a side view of the radiator cap.  
       FIG. 4  is a cross sectional view of the radiator cap  
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring now to  FIG. 4 , the radiator cap  5  is shown installed on a conventional radiator filler neck  15 . The cap  10  includes a manually manipulable crown or shell  10  covering the filler neck  15 . The crown  10  has a pair of oppositely opposed cam fingers  33  which pass through corresponding openings (not shown) in the filler neck  15  and engage the lip  34  of the filler neck  15  when the crown  10  is rotated onto the filler neck  15  to thereby securing the cap  5  to the filler neck  15 .  
      The crown  10  has a center aperture with which a rivet  36  is employed to secure the seal support disk  11 , seal retainer disk  14  and bell housing  17 , by way of a flared lip at the bottom of the rivet  36 . The upper rubber ring seal  12  is retained in position by the seal retainer disk  14 . When the cap  5  is secured to the filler neck  15 , the rubber ring seal is pressed upon the upper surface  35  of the filler neck  15 , thereby preventing coolant from escaping from the cooling system, unless the cap  5  is removed from the filler neck  15 .  
      Moving downward in  FIG. 4 , the bellhousing  17  centers and retains a valve spring  16 . Valve spring  16  applies pressure to the lower seal support flange retainer  30 . The lower seal support flange  18  is retained onto the lower seal support flange retainer  30  by way of four equally spaced small indentations  29 . The force from the valve spring  16  is transferred through the lower seal support flange retainer  30  to the lower seal support flange  18 . The lower seal support flange  18  then transfers the said pressure to the lower rubber ring seal  19 . The lower rubber seal is pressed upon the top surface of the lower annular valve seat  28  of the filler neck  15 , and thus provides a seal or separation between the pressure inside the cooling system (not shown) and the atmospheric pressure. The lower seal support flange  18 , lower rubber ring seal  19  are retained by way of a rivet  25  with a center aperture. The water reclamation valve  20  is tightly attached to the temperature probe cover  21 . The temperature probe cover  21  is situated through the aperture of the rivet  25  and is able to move slightly up or down along the axis of the temperature probe  22 . The water reclamation valve spring  26  applies force between the top surface of the lower seal support flange  18 , and a small washer  17 , which in turn has been secured onto the top of the temperature probe cover  21  by flaring the top portion of the temperature probe cover  21 . The normal position of the temperature probe cover  21  and the water reclamation valve  20  is such that the water reclamation valve is pressed against the lower rubber ring seal  19 , under the force provided by the small water reclamation valve spring  26  and any existing superatmospheric pressure from the inside of the cooling system.  
      From it&#39;s seated and sealed position, the water reclamation valve can move in a downward fashion is cases where atmospheric pressure exceeds the pressure inside the cooling system. In a typical cooling system, an plastic water reclamation bottle is usually present outside the radiator, and water pass from the water reclamation bottle, through an opening  32  in the water filler neck  15 . This water or coolant can then further pass through the opening  31  in the bell housing  17 . The water or coolant can then pass through the small space between the center aperture of the lower rivet  25 , and the temperature probe cover  21 , finding it&#39;s way back into the radiator. Once the pressure between the inside of the cooling system, and atmospheric pressure is equalized, the water reclamation valve  20  will close under the pressure of the water reclamation valve spring  26 .  
      A typical bi-metal thermometer is used to read the temperature of the cooling system. Referring to  FIG. 4  again, we have a basic bi-metal thermometer consisting of a temperature probe  21 , being secured to a gauge housing  41 . Inside the temperature probe is a long coiled bi-metal strip  23 . This bi-metal strip  23  employs two different strips of metal, bound to each other and wound in a circular fashion many times. The bi-metal strip  23  employs two different types of metal, and each type of metal has a slightly different rate of expansion or contraction when heated or cooled. As the temperature of the temperature probe  22  changes, the bi-metal strip  23  will coil tighter or uncoil in response to the change in temperature. This coiling or uncoiling of the bi-metal strip  23  is indicated by the position of the needle indicator  39 . The lower end of this bi-metal strip  23  is adhered to the bottom of the temperature probe  21  using a suitable adhesive  24  compatible with metal. The top end of the bi-metal strip  23  passes through a small aperture in the meter face  40 , and is directly connected to the needle indicator  39 . The needle indicator  39  is able to rotate according to the motion of the bi-metal strip  23 , and indicate the temperature of the coolant, by pointing to the corresponding calibrated numbers painted on the meter face  40 . The meter face is protected from environmental debris by means of a glass cover  38   
      Lastly, in  FIG. 4 , there is a non-essential colored trim piece  37  attached to the top of the cap crown  10  by means of two opposite rivets (not shown). The reason for the addition of the trim piece is purely aesthetic.  
      Referring now to  FIG. 2 , I have included a color coded section on the meter face  40  to indicate the temperature severity of the cooling system. There is a thin semi-circular strip of paint corresponding to the color green  42 , which would indicate a relatively safe condition to remove the radiator cap. Then there is another semi-circular strip of paint corresponding to the color yellow  43 , which would indicate an unsafe condition for removing the radiator cap. Lastly, there is another semi-circular strip of paint corresponding to the color red  44 , which would indicate a very hazardous condition for removing the radiator cap.  
      While I have described herein a preferred embodiment of the present invention, it is to be under stood that changes and modifications can be made without departing from the true scope and spirit of the present invention. This true scope and spirit are defined by the my claims and their equivalents, to be interpreted in light of the foregoing specification.