Abstract:
A triggering plate of a chemical thermos bag has at least a groove with a slit, having two opposite tip parts hiding each other and the tip parts being different in thickness.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a triggering plate (trigger) of a heating pack and particularly to a triggering plate with grooves being stamped to have oblique wall thickness thereof getting smaller due to special stamping tool (die).  
       BACKGROUND OF THE INVENTION  
       [0002]     A typical chemical heating pack is the cold/hot applying bag familiar to us and due to heat accumulation and releasing theory, a preset duration of cold or hot temperature can be maintained with the heating pack while it is applied to skin of human body for healing, health caring or physical curing. That is why the chemical heating pack can be seen in a family, a hospital and a clinic  
         [0003]     In order to release heat, a triggering plate has to be placed in the heating pack for generating a fluctuation force to actuate the heat accumulating/releasing material such as ethylic acid sodium solution being crystallized and releasing heat.  
         [0004]     Hence, the triggering plate design is an subject emphasized by the manufacturers and there are patents related the prior art such as Taiwanese Utility Model No. 80848, which was granted to the present inventor, entitled ELASTIC METAL SHEET IN A CHEMICAL heating pack and continuation applications for disclosing technique of the metal sheet.  
         [0005]     Other prior art such as U.S. Pat. Nos. 4,077,390, 4,572,158, 4,872,442 and 5,205,278 has disclosed configuration and arrangement of the triggering plate.  
         [0006]      FIG. 1  shows a top view of a conventional triggering plate and  FIG. 2  shows a sectional view of the conventional triggering plate. The conventional triggering plate is made of metal mostly with a circular shape. One side of the conventional triggering plate is stamped with a plurality of grooves A and the grooves are disposed in a radial way symmetrically with respect to the center of the triggering plate. The grooves A are provided with identical wall thickness respectively, that is, the wall surrounding the respective groove A is the same thickness in spite of having local deformation.  
         [0007]     Some of the preceding cited references of U.S. Patents have disclosed the metal sheet being stamped through vertically and this is one of the types frequently seen.  
       SUMMARY OF THE INVENTION  
       [0008]     A main object of the present invention is to provide a triggering plate of a chemical heating pack, which has at least a groove with a slit, having two opposite tip parts hiding each other and the tip parts being different in thickness. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The present invention can be more fully understood by reference to the following description and accompanying drawings, in which:  
         [0010]      FIG. 1  is a top view of conventional triggering plate;  
         [0011]      FIG. 2  is sectional view of the conventional triggering plate;  
         [0012]      FIG. 3  is a sectional view of the triggering plate according to the present invention;  
         [0013]      FIG. 4  is a perspective view of the triggering plate according to the present invention; and  
         [0014]      FIG. 5  is a sectional view illustrating the triggering plate of the present invention being stirred as another moving direction.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]     Referring to  FIGS. 3, 4  and  5 , basically, the improvement of the triggering plate according to the present invention resides in at least a groove formed with stamping so that the triggering plate  1  is provided with the groove  2 . In case of two or more grooves being provided, the groves can be arranged in pairs and two grooves in each pair are disposed symmetrical to each other with respect to center of the triggering plate or the grooves can be arranged to be disposed continuously. Due to arrangement of the grooves being not the key point of the present invention, no detail will be described further. The triggering plate of the present invention is made of metallic material and the groove is obliquely formed by way of being stamped along cross-section of the triggering plate instead of being formed by way of being stamped vertically as the conventional triggering plate does. Further, the groove is provided with a little bit circular shape, that is, a side of the groove is concave downward and the other side thereof is concave upward.  
         [0016]     Referring to  FIG. 3  again, the groove  2  at the first side thereof has a thinnest tip  21   a  and at the second side thereof has a thickest base  21   b  with at least lateral circular recess  22 . The tip  21   a  overlaps another tip  21   a  neighboring tip  21   a  during the circular moving direction being toward one side of the triggering plate and another tip  21   a  becomes overlapping the first tip  21   a  during the circular moving direction being toward another side of the trigging plate. In other words, the groove  2  is formed with stamping mold being provided with circular shapes and oblique moving direction such that the groove  2  is deformed with different thickness.  
         [0017]     In practice, both sides of the groove  2  at the bottom thereof are different in thickness and opposite to each other and both tips  21   a  constitute interference each other with fluctuating force caused by the interference. Hence, it is helpful for starting heat accumulating/releasing material and it can supply fluctuating force to the conventional triggering plate with identical thickness.  
         [0018]     It is appreciated that the present invention offers a problem-solving alternative for the triggering plate to break though puzzle thought of the groove being the same in thickness.  
         [0019]     While the invention has been described with reference to the a preferred embodiment thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims.