Patent Publication Number: US-6981604-B2

Title: Synthetic resin container having a body with concaved portion for gripping and absorbing distortion of the body

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a cylindrical container of a large volume (e.g., a content of approximately 2 liters) having a long cylindrical body and formed by blow-molding of various thermoplastic synthetic resins, and improvement of a structure of the body of the container made of synthetic resin adapted to be held with hands and fingers. 
     In general, in a conventional large containers of this type, distortion absorbent regions and reinforcing ribs are formed in a circumferential wall of the body in order to prevent the circumferential wall of the body from causing deformation due to increase/decrease of an internal pressure of the container, and a handle for holding the container is also provided to said circumferential wall of the body in order to facilitate the handling of the container. 
     However, said container-holding handle provided to the body has a problem, because a structure of the container comes to complex, an amount of a resin required to be used for each container increases, and because the handle affects deformation absorbent portion and facility of the circumferential wall of the body due to the increase/decrease of the internal pressure of the container, irrespective of the structure of the container manufactured either in a type of which the handle is integrally molded with the body or a type in which a separate handle is mounted to the container. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a container having a body which has a left side and a right side, wherein each of the right and left sides has a region of a center of the body, which region is formed with a concaved portion for absorbing distortion of a circumferential wall of the body due to changes of an internal pressure of the container. The concaved portions in right and left sides are analogous or conformable in shape each other. Each of the concaved portions for absorbing distortion has a bottom wall in a form of a substantially shallowly concaved arc in at least one direction of a longitudinal direction and a lateral direction of the circumferential wall. Each of the concaved portions has an upper edge and a lower edge, and is formed with reinforcing portions adjacent to the upper and lower edges. Each of the reinforcing portions is protruded outwardly, and has a substantially triangular shape. Each of the reinforcing portions has a height and a lateral width. The height is gradually reduced from the circumferential surface of the body toward the bottom wall of the concaved portion. The lateral width is gradually reduced from the upper and lower edges toward the bottom wall. 
     The present invention also relates to a bottle-shaped container made of synthetic resin including a body having left and right sides which are symmetric to a central axis line of the container, wherein each of the right and left sides is formed with the concaved portion in a region including the center of the body, which concaved portion absorbs distortion due to changes in the internal pressure of the container. The concaved portions in right and left sides are analogous or conformable in shape each other, and have same dimensions. Each of said concaved portions includes an upper edge, a lower edge and a bottom wall. Said bottom wall is in a form of shallowly concaved arc in at least one direction of a longitudinal direction and a lateral direction of a circumferential wall of the body. Each of the concaved portion is formed with protruded reinforcing portions at an upper and lower portion thereof Each of the reinforcing portions has a height gradually reduced from the upper or lower edge to the bottom wall. Each of the reinforcing portions has a lateral width gradually reduced from the upper or lower edge to the bottom wall, so that the reinforcing portion has a substantially triangular shape. 
     The bottom wall of each of the concaved portions is formed with a protruded longitudinal rib which serves as a stopper for slipping of finger heads. 
     The bottom wall may be formed with a protruded lateral rib at a center thereof. 
     Since the container according to the present invention has the structure as described above, the container can be held surely with safeness by holding the approximately central portion of the body of the container with fingers and a palm of a single hand from either the front side or the rear side even if it has a large content and a heavy weight. 
     Further, since said concaved portion for absorbing distortion is configured in the above-described arc plane, it can perform the function similar to an end plate of a high-pressure resistant container. Thus, it can prevent deformation of the body of the container due to changes, of the internal pressure of the container, and large deformation of the container at the time of holding it from occurring. Furthermore, since the container according to the present invention does not require a handle, it is achievable to reduce a quantity of a resin to be used for manufacturing the container. 
     Still further, since it is no need to form a handle, a material resin to be used for the handle can be used for the container itself. Also, since there is no need to provide a protruded handle to the container, a space for storing the container can be reduced. 
    
    
     
       BRIEF EXPLANATION OF THE DRAWINGS 
         FIG. 1  is a right side view of a bottle-shaped container according to the present invention; 
         FIG. 2  is a front view of the bottle-shaped container shown in  FIG. 1 ; 
         FIG. 3  is a cross sectional view cut along a line  3 — 3  shown in  FIG. 1 ; and 
         FIG. 4  is a longitudinal-sectional view cut along a line  4 — 4  shown in  FIG. 1 . 
     
    
    
     EMBODIMENTS 
       FIGS. 1 to 4  illustrate a bottle-shaped container made of PET resin with a content of 2 liters and formed by biaxially-oriented blow-molding according to one example of the present invention. 
     A container  1  shown in the drawings comprises a long cylindrical body  2 , a shoulder  3  provided on the body, a neck  4  provided on the shoulder, and a bottom  5  provided under the body. The character or the feature of the present invention does not relate to the body, the shoulder, the neck and the bottom themselves, these structures may be similarly understood based on a known body, a known shoulder and a known neck of a container made of a synthetic resin, except the below described matters. 
     The body  2  has a left side  6 A and a right side  6 B which are symmetric to a central axis O—O of the container. The left side  6 A is formed with a concaved portion  9  for absorbing distortion in a region  7  thereof including a center of the body. The right side  6 B is formed with a concaved portion  10  for absorbing distortion in a region  8  thereof including the center of the body. An internal pressure in the container is decreased, if liquid or content having a high temperature is filled in the container, the neck is sealed, and then the temperature of the liquid is fallen. When the internal pressure is reduced, each of the concaved portions  9  and  10  can be bent inwardly, to thereby absorb and ease the deformation of the body wall. 
     The neck  4  may be thermally crystallized in order to fill the content having high temperature. The concaved portions  9  and  10  in the body are analogous each other, and the same in their dimensions. Each of the concaved portions  9  and  10  includes an upper edge  14 , a lower edge  15 , a left edge  20  and a right edge  21 . In the illustrated example, each of the concaved portions  9  and  10  surrounded by the upper edge  14 , the lower edge  15 , the left edge  20  and the right edge  21  is formed in an elongated rectangular shape. However, there is no limitation for the shape of the concaved portion, and it may be formed in the other forms, for example, elliptic or the like. 
     Each of the concaved portions  9  and  10  for absorbing distortion has a bottom wall  13 . As shown in  FIG. 3 , the cross section of the bottom wall  13  is in a form of shallowly concaved arc  11 . As shown in  FIG. 4 , the longitudinal section of the bottom wall  13  is in a form of a substantially flat  12 . 
     Each of the concaved portions  9  and  10  is formed with reinforcing portions  18  and  19  adjacent to the upper edge  14  and the lower edge  15 . Each of the reinforcing portions  18  and  19  has an approximately triangular shape, is protruded outwardly, and has a height H and lateral width W. The height H of each of the reinforcing portions  18  and  19  is gradually reduced from circumferential surfaces  16  and  17  of the body toward the bottom  13  of the concaved portion  9  or  10 . The lateral width W of each of the reinforcing portions  18  and  19  is gradually reduced from the upper edge  14  or the lower edge  15  toward the bottom  13  of the concaved portion  9  or  10 . 
     Each of the left edge  20  and the right edge  21  in the concaved portions  9  and  10  is a rib having a convex arc shape of the cross section. Each of the left edge  20  and the right edge  21  is arranged such that when an adult holds the body  2  of the container in the concaved portions  9  and  10  with a palm of a single hand, the palm between a carpal bone and a phalange bone is positioned in the concaved portion  9  or  10 . 
     Each of the bottom walls  13  of the concaved portions  9  and  10  is formed with a plurality of longitudinal protruded ribs  22  and  23  with a low height, in order to prevent finger heads from slipping at holding. 
     Further, each of the bottom walls  13  is formed with a lateral protruded rib  24  in the center thereof. 
     A number of said longitudinal ribs  22  and  23  and a number of the lateral ribs  24  are not limited to the illustrated examples, and the shapes thereof is not limited to the illustrated shapes. Any shapes and the heights of the protrusion may be employed for the longitudinal ribs  22  and  23  as far as they can prevent the finger heads from slipping at holding. Any shapes and heights of the protrusion may be employed for the lateral rib  24  as far as it can reinforce the bottom wall  13  of the concaved portions  9 ,  10 . 
     In the present invention, the bottom wall of the concaved portions  9 ,  10  is in the form of substantially shallowly concaved arc in at least one direction of the longitudinal direction and the lateral direction of the circumferential wall of the container. Further, outwardly protruded portions  18  and  19  are formed from each of the upper and lower edges  14  and  15  to the bottom wall  13  of each of the concaved portions  9 ,  10 . Hence, each of the concaved portions  9  and  10  has a pressure-resistant strength same as that of an end plate of a high-pressure-resistant container. Accordingly, the concaved portions  9  and  10  retain strength enough to endure to changes in the internal pressure of the container and external pressure due to holding by a hand. 
     Although the container of the above-described example is made of PET resin, the material for the container is not limited to PET resin, and other polyester resins, polyolefin resins, polycarbonate resins and other known resins can be used to manufacture the container of the present invention. The container according to the present invention may have a structure of either monolayer or multilayer of the above-recited resins. For example, the container of this invention may be manufactured in a multilayer structure consisting of PET resin and an oxygen barrier material such as MDX-6 nylon resin and ethylene vinyl alcohol copolymer resin. Note that it is also possible to blend a known resin with said oxygen barrier material. Further, recycled PET resins and the like may be used for the same purpose. 
     Note that, in the  FIGS. 3 and 4 , the thickness of the container is illustrated in the size magnified several times larger than the actual thickness of the wall, in order to show the structure distinctly, and the thickness of the wall does not directly affect the said strength. Further, the shape of the longitudinal cross section shown with a broken line in  FIG. 2  is a sectional view when the bottle is cut along the line  4 — 4  shown in  FIG. 1 .