Abstract:
An apparatus mounted on a valve of each of a plurality of tires of motor vehicle for indicating a pressure thereof. The apparatus comprises a first portion projected from the tire, a second portion inserted into the tire and in communication with air therein, and a scale on the first portion for facilitating a display of tire pressure.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to tires of motor vehicle and more particularly to a pressure indicating device for tire of motor vehicle with improved characteristics  
         BACKGROUND OF THE INVENTION  
         [0002]    As understood that good tires are important to a safe driving. However, most drivers do not take much attention to tires before driving. Thus, it is common for the occurring of tire(s) broken while driving. In a worst case, it may cause a traffic accident. Thus, it is desirable to provide a pressure indicating device for tire so that driver can be aware of the pressure of each tire before driving.  
         SUMMARY OF THE INVENTION  
         [0003]    It is therefore an object of the present invention to provide an apparatus mounted on a valve of each of a plurality of tires of motor vehicle for indicating a pressure thereof. The apparatus comprises a first portion projected from the tire, a second portion inserted into the tire and in communication with air therein and a scale on the first portion.  
           [0004]    The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]    [0005]FIG. 1 is a side view showing a wheel with fixed tire incorporating a pressure indicating device according to a first preferred embodiment of the invention,  
         [0006]    [0006]FIG. 2 is a cross-sectional view of the scale member with bellow member of FIG. 1 pressure indicating device being expanded by inflated air;  
         [0007]    [0007]FIG. 3 is a cross-sectional view of assembled pressure indicating device according to a second preferred embodiment of the invention and valve illustrating an air flow for indicating pressure of tire,  
         [0008]    [0008]FIG. 4 is a cross-sectional view of assembled pressure indicating device according to a third preferred embodiment of the invention and valve;  
         [0009]    [0009]FIG. 5 is a cross-sectional view of assembled pressure indicating device according to a fourth preferred embodiment of the invention and valve with a greatly enlarged fragmentary view on top showing the area in circle A, and  
         [0010]    [0010]FIG. 6 is a cross-sectional view of pressure indicating device according to a fifth preferred embodiment of the invention, where pressure indicating device is mounted on valve 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0011]    Referring to FIG. 1, there is shown a wheel having a tire  2  fixed about rim  1 , a valve  3  through rim  1  for pumping air into tire  2 , a pressure indicating device  4  of a first preferred embodiment within tire  2  being in communication with air therein, and a scale member  44  through and projected from rim  1 , scale member  44  being coupled to one end of pressure indicating device  4  in which both pressure indicating device  4  and scale member  44  are constructed in accordance with the invention  
         [0012]    Referring to FIG. 2 in conjunction with FIG. 1, scale member  44  is a hollow cylinder with top (i.e., outer end) enclosed. Scale member  44  is formed of hard, transparent plastic material. Scale member  44  has a scale  41  Within scale member  44 , there is provided a bellow member  42 . Bellow member  42  is formed of strong elastic material having its wavy peripheral section  43  urged against the inner periphery of scale member  44  by the pressure of air  5  of tire  2  Also, top of bellow member  42  may lift or lower due to the nature of elastic material as the pressure of air  5  of tire  2  changes. In use, prior to driving driver can know the pressure of tire  2  by observing the top of bellow member  42  which is aligned with a certain scale  41   
         [0013]    Referring to FIG. 3, a pressure indicating device  6  of a second preferred embodiment mounted on a valve is shown. Pressure indicating device  6  comprises a base  61  consisting of an inner hollow cylinder  611  having an inner threaded section being secured to outer threaded section of valve and an outer hollow cylinder  612  with bottoms of cylinders  611  and  612  coupled together as a closed section and tops thereof open, thus forming a space  614  between cylinders  611  and  612 , a helical spring  62  put on inner hollow cylinder  611  having a lower end rested on bottom of base  61 , a hollow disk-shaped seal  63  put on inner hollow cylinder  611  being urged by top of the biased spring  62 , an outer ring  65  sleeved between seal  63  and inner wall of outer hollow cylinder  612 ; an inner ring  64  sleeved between seal  63  and outer wall of inner hollow cylinder  611  so as to eliminate a potential air flow through inner or outer periphery of seal  63 , and a cap  66  having a downward peg  661  engaged with air inlet of valve, cap  66  being threadedly secured to top of base  61  If driver wants to know the pressure of tire the driver can mount pressure indicating device  6  on valve. At this position, air is flowed from tire to push down seal  63  through valve and pressure indicating device  6  as indicated by arrow  5  in FIG. 3. Thus, driver can know the pressure of tire by observing the seal  63  which is aligned with one of marks of the scale.  
         [0014]    Referring to FIG. 4, there is shown a third preferred embodiment of pressure indicating device  6  constructed in accordance with the invention. The difference between second and third preferred embodiments is detailed below A well known second valve  67  is formed on top of and in communication with pressure indicating device  6  This has the benefit of no need to disengage pressure indicating device  6  from valve for inflating tire.  
         [0015]    Referring to FIG. 5, there is shown a fourth preferred embodiment of pressure indicating device  7  constructed in accordance with the invention mountable on a valve  3  which is projected from rim  1  of tire of an automobile The pressure indicating device  7  is threadedly secured onto top of valve  3  The pressure indicating device  7  comprises a hollow cylinder  73  projected from bottom, a mainspring  71  having one end coupled to the cylinder  73 , the mainspring  71  being capable of pivoting as air through cylinder  73 , and a pointer  72  coupled to the other end of mainspring  71  In a mounted state of pressure indicating device  7  and valve  3 , cylinder  73  is urged against elongate slender bar  31  of valve  3  to press down the elongate slender bar  31  a predetermined distance. Hence, air is flowed from tire to mainspring  71  through valve  3 , and cylinder  73 . As a result, pointer  72  is pivoted an angle proportioned to the pressure of air applied on mainspring  71  In brief, it is possible of knowing a pressure of tire by mounting pressure indicating device  7  on valve  3   
         [0016]    Referring to FIG. 6, there is shown a fifth preferred embodiment of pressure indicating device  7  constructed in accordance with the invention The differences between fourth and fifth preferred embodiments are detailed below The pressure indicating device  7  of fifth preferred embodiment further comprises a spring  75  put on cylinder  73  and a cap  74  having an inner thread so as to threadedly secure to outer threaded section of valve  3 . In a case that for example, driver wants to know the pressure of tire the driver can press pressure indicating device  7  to compress spring  75  so as to urge top of elongate slender bar  31  by the cylinder  73 . Hence, elongate slender bar  31  is pressed down a predetermined distance. Accordingly, air is flowed from tire to mainspring  71  through valve  3  and cylinder  73 . Pointer  64  is thus pivoted an angle proportioned to the pressure of air applied on mainspring  71  In brief, it is possible of knowing a pressure of tire by pressing pressure indicating device  7  on valve  3 .  
         [0017]    While the invention has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.