Abstract:
A composite pillow for preventing difference from occurring in level and a depression from being formed on a contact surface between divided core material parts, thereby preventing discomfort from being brought about to a user, capable of locating core material parts different in material or core material parts different in hardness at proper positions. The composite pillow is divided into a central part and a holding part for holding the central part by a face pair; each of the parts are arranged parallel so as to be in contact on a contact surface; the central part and the holding part differ in hardness or material; and right and left contact surfaces of the holding part contacting the central part and a contact surface of the central part corresponding the relevant contact surface are diagonally formed.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a composite pillow configured by combining a plurality of (more properly, three or more) divided parts, and mainly to a composite pillow for improving the fit and functions of a pillow by changing the hardness or material of each part.  
         [0003]     2. Description of the Related Art  
         [0004]     In order to improve the fit or other functions of a pillow, different materials or hardnesses are required in accordance with the sections therein. Examples of an integrally formed pillow include one made of a urethane-based resin, one made of a natural material such as a rubber-based material, one made of a liquid material, gel material or gaseous material filled into a pillow case having a structure which can maintain the shape thereof. In such a pillow, it is extremely difficult to locate parts of different materials or hardnesses at proper positions.  
         [0005]     In order to locate parts of different materials or hardnesses at proper positions, as shown in Patent Documents 1 and 2, there has been provided a composite pillow in which a pillow core material is divided into a plurality of parts so as to be arranged in desired sections in parallel. A pillow has also been provided, as shown in Japanese Unexamined Patent Publication No. 2003-180499, in which a plurality of rooms are formed within a pillow case, a core material being filled thereinto.  
         [0006]     In the case where the pillow in which divided parts of a core material are stacked in a vertical direction as shown in Japanese Unexamined Patent Publication No. Hei 11-056562, the areas of distribution for different materials or hardnesses cannot be set accurately and minutely, thereby being not much different from an integrally formed pillow. Also, although the pillow in which divided parts of a core material are arranged in a horizontal direction as shown in Japanese Unexamined Patent Publication No. 2003-144286 and the pillow in which a plurality of rooms are arranged in parallel, and a core material is filled thereinto as shown in Japanese Unexamined Patent Publication No. 2003-180499 can be set up accurately and minutely, since the contact surface between adjacent divided parts of a core material is almost perpendicular, there are drawbacks in that it brings about discomfort such that difference occurs in level when the levels of hardness are different between the parts, and such that a depression is formed by the divided parts of a core material being separated from each other when used.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention has been made to eliminate the above-mentioned drawbacks and to achieve the following objects.  
         [0008]     It is a first object of the present invention to configure a pillow for preventing difference from occurring in level and a depression from being formed on a part where divided core material parts are in contact, thereby preventing discomfort from being brought to a user.  
         [0009]     It is a second object of the present invention to configure a pillow for locating core material parts of different materials or core material parts of different hardnesses at proper positions.  
         [0010]     In order to achieve the above-mentioned objects, a first aspect of the present invention is a composite pillow in which each of the parts which are divided into a central part and a holding part for holding the central part by a face pair are arranged parallel in contact on the contact surface, are characterized in that the central part and the holding part differ in hardness or material, and in that the right and left contact surfaces of the holding parts contacting the central part and the contact surfaces of the central part corresponding to the relevant contact surfaces are diagonally formed. The first aspect includes not only a composite pillow in which the holding parts are arranged parallel on the right and left sides of the central part, but also a composite pillow in which the holding parts are arranged parallel on the upper and lower sides of the central part.  
         [0011]     A second aspect of the present invention is a composite pillow in which each of the parts which are divided into a central part and right and left holding parts for holding the central part by a face pair are arranged parallel in contact on the contact surface, and are characterized in that the central part and the holding part differ in hardness or material, and in that the contact surfaces of the right and left holding parts contacting the central part are inclined so as to intrude into a lower portion of the central part, and in that the corresponding contact surface of the central part is inclined so as to cover the contact surface of the holding part. Specifically, the second aspect is a composite pillow in which the holding parts are arranged parallel on the right and left sides of the central part, limiting the inclination direction of the contact surface of both parts.  
         [0012]     A third aspect of the present invention is an improvement of the composite pillow according to the second aspect, adding the following solutions to the solutions of the composite pillow according to the second aspect.  
         [0013]     The central part is divided into a neck side part and a head top side part contacting the neck side part by a face pair; both parts differ in hardness or material; and the contact surface of the neck side part and the head top side part arranged parallel on the contact surface are diagonally formed.  
         [0014]     In accordance with the first aspect of the invention, in the composite pillow in which each of the parts divided into the central part and the holding part for holding the central part by a face pair are arranged parallel in contact on the contact surface, the right and left contact surfaces of the holding parts contacting the central part and the contact surface of the central part corresponding to the relevant contact surface are diagonally formed. Accordingly, since the adjacent portion of either of the adjacent parts and the adjacent portion of the other part overlap each other, difference does not occur in level even when the parts differ in hardness or material, thereby configuring a composite pillow whose joint is imperceptible to a user.  
         [0015]     Also, since the central part and the holding part differ in hardness or material, the overlap between the central part and the holding part can bring a sense of use of the composite pillow which a single core material cannot achieve, and can make functions to be obtained by employing parts different in hardness or material available.  
         [0016]     In accordance with the second aspect of the invention, the holding parts are located on the right and left sides of the central part; the contact surfaces of the right and left holding parts contacting the central part are inclined so as to intrude into the lower portion of the central part; and the corresponding contact surface of the central part is inclined so as to cover the contact surface of the holding part. Accordingly, the upper portion of the contact surface of the central part diagonally overlaps with the lower portion of the holding part, thereby configuring a composite pillow in which difference does not occur in level and its joint is imperceptible to a user.  
         [0017]     Furthermore, the central part presses from the upper portion against the contact portion of the holding part located in the lower portion, due to the load of a head applied onto the center of the composite pillow, the central part and the holding part are tightly fixed to each other, thereby eliminating the possibility of sliding off from other part even by a simple fixation method.  
         [0018]     In accordance with the third aspect of the invention, the central part is divided into the neck side part and the head top side part contacting the neck side part by a face pair; both parts differ in hardness or material; and the contact surface of the neck side part and the head top side part arranged parallel in contact on the contact surface is diagonally formed. This enables the composite pillow to be easily manufactured for protecting a neck and a cervical vertebra, difference between the neck side part and the head top side part in level being imperceptible. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]      FIG. 1  is a perspective view showing a composite pillow according to a first embodiment;  
         [0020]      FIG. 2  is an exploded perspective view showing the composite pillow according to the first embodiment;  
         [0021]      FIG. 3  is a plan view showing the composite pillow according to the first embodiment;  
         [0022]      FIG. 4  is a front view showing the composite pillow according to the first embodiment;  
         [0023]      FIG. 5  is a perspective view showing a right and left holding parts integral type composite pillow;  
         [0024]      FIG. 6  is an exploded perspective view showing the right and left holding parts integral type composite pillow;  
         [0025]      FIG. 7  is a plan view showing the right and left holding parts integral type composite pillow;  
         [0026]      FIG. 8  is a front view showing the right and left holding parts integral type composite pillow;  
         [0027]      FIG. 9  includes explanatory diagrams showing a contact surface, in which  FIGS. 9A and 9B  show the contact surface of a curved waveform, and  FIGS. 9D and 9F  show the contact surface of a zigzag waveform;  
         [0028]      FIG. 10  is a perspective view showing a composite pillow according to a second embodiment;  
         [0029]      FIG. 11  is a plan view showing the composite pillow according to the second embodiment;  
         [0030]      FIG. 12  is a perspective view showing a composite pillow according to a third embodiment;  
         [0031]      FIG. 13  is an exploded perspective view showing the composite pillow according to the third embodiment;  
         [0032]      FIG. 14  is a transverse sectional view showing a section of right and left holding parts and a neck side central part;  
         [0033]      FIG. 15  is a longitudinal sectional view showing a section of a neck side central part and a head top side central part;  
         [0034]      FIG. 16  is a perspective view showing a composite pillow according to a fourth embodiment;  
         [0035]      FIG. 17  is an exploded perspective view showing the composite pillow according to the fourth embodiment;  
         [0036]      FIG. 18  includes explanatory diagrams showing a using state of the composite pillow, in which  FIG. 18A  shows a using state of the composite pillow when lying on the back;  
         [0037]      FIG. 18B  shows a using state of the composite pillow when turning sideways; and  FIG. 18C  shows a using state of the composite pillow when lying on the side; and  
         [0038]      FIG. 19  includes explanatory diagrams showing a relation between the using state of the composite pillow and a cervical vertebrae condition, in which  FIG. 19A  shows a state when lying on the back; and  FIG. 19B  shows a state when lying on the side, 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0039]     In the following, embodiments and best modes for carrying out the present invention will be described with reference to the drawings.  FIG. 1  is a perspective view showing a composite pillow according to a first embodiment;  FIG. 2  is an exploded perspective view showing the composite pillow according to the first embodiment;  FIG. 3  is a plan view showing the composite pillow according to the first embodiment; and  FIG. 4  is a front view showing the composite pillow according to the first embodiment.  
         [0040]     The composite pillow according to the first embodiment, which corresponds to claims  1  and  2 , is divided into a central part  1 , and a left holding part  2  and a right holding part  3  for holding the central part  1  by a face pair.  
         [0041]     The central part  1  and the right and left holding parts  2 ,  3  are differently formed in hardness or material. In this embodiment, low-repulsion urethanes of different hardnesses are employed. Describing the hardnesses by expressing by the sinking ratio by the weight of a human head when using the composite pillow, a soft low-repulsion urethane whose sinking ratio is 60% is employed for the central part  1  and a hard low-repulsion urethane whose sinking ratio is 20% is employed for the right and left holding parts  2 ,  3 , thereby achieving different hardnesses. This is just an example of the hardness combination, and another setting is possible as a matter of course.  
         [0042]     It is to be noted that a urethane or polyethylene resin material, or a rubber-based natural material is suitable when the same materials of different hardnesses are employed as in this embodiment.  
         [0043]     While an integrally formed part is employed for the central part  1  and the right and left holding parts  2 ,  3  in this embodiment, a part formed by filling with a material suitable for filling into a case having the shape of each part  1 ,  2 ,  3 , such as feather, floss, resin chips, wood chips such as Japanese cypress, cushioning material, buckwheat chaff, and tea leaves, can also be employed.  
         [0044]     The contact surfaces  4 ,  5 ,  6 ,  7  of the central part  1  and the right and left holding parts  2 ,  3  are diagonally formed. Specifically, the contact surfaces  6 ,  7  of the right and left holding parts contacting the central part  1  are inclined so as to intrude into the lower portion of the central part  1 , and the corresponding contact surfaces  4 ,  5  of the central part  1  are inclined so as to cover the contact surfaces  6 ,  7  of the right and left holding parts  2 ,  3 . If the central part  1  is made of a material capable of changing the shape thereof according to the surrounding shape when the contact surfaces  6 ,  7  of the right and left holding parts  2 ,  3  is inclined so as to intrude into the lower portion of the central part  1 , since the contact surfaces  4 ,  5  of the central part  1  is regulated by the contact surfaces  6 ,  7  of the right and left holding parts  2 ,  3  and diagonally formed of themselves so as to cover the relevant contact surfaces  6 ,  7 , the contact surfaces  4 ,  5  need not be fixedly inclined so as to be into a definite shape beforehand.  
         [0045]     While the contact surfaces  4 ,  5 ,  6 ,  7  are formed as a smooth plane in this embodiment, the contact surfaces  4 ,  5 ,  6 ,  7  may be formed as a curved waveform at which the contact surfaces meet from the right and left as shown in  FIGS. 9A and 9B  or may be formed as a zigzag waveform at which the contact surfaces meet from the right and left as shown in  FIGS. 9C and 9D .  
         [0046]     The central part  1  and the right and left holding part  2 ,  3  are arranged parallel so that the contact surface  6  of the left holding part  2  is in contact with the contact surface  4  of the central part  1 , and that the contact surface  7  of the right holding part  3  is in contact with the contact surface  5  of the central part  1 . The central part  1  and the right and left holding parts  2 ,  3  are normally adhered to each other by an adhesive or the like. As a matter of course, when each part is put into a pillow case inside which is partitioned or the like, or when the contact surfaces  4 ,  6  and the contact surfaces  5 ,  7  are in contact so as to be fitted with each other, a non-adhesive state is sometimes acceptable. While the first embodiment shows a case in which the holding parts  2 ,  3  are separated from each other for convenience of explanation, a right and left integral type holding part  31  may be used in place of the holding parts  2 ,  3 ; a recess portion  34  for housing the central part  1  may be provided at the center of the right and left integral type holding part  31 ; and right and left holding parts  32 ,  33  may be coupled, as shown in FIGS.  5  to  8 .  
         [0047]      FIG. 10  is a perspective view showing a composite pillow according to the second embodiment, and  FIG. 11  is a plan view showing the composite pillow according to the second embodiment. The composite pillow according to the second embodiment, which corresponds only to claim  1 , is divided into an oblong central part  8 , a neck side holding part  9  for holding the oblong central part  8  by a face pair and a head top side holding part  10 . While the holding parts  2 ,  3  of the first embodiment are arranged parallel so as to hold the central part  1  from the right and left sides, the second embodiment arranges parallel the oblong central part  8  held from the neck side and the head top side when used (from the upper and lower sides in  FIG. 10  and  FIG. 11 ).  
         [0048]     For the material of the oblong central part  8  and the neck side and head top side holding parts  9 ,  10  in the second embodiment, similarly to the first embodiment, low-repulsion urethanes of different hardnesses are also employed. Describing the hardnesses by expressing by the sinking ratio with the weight of a human head when using the composite pillow, a soft low-repulsion urethane whose sinking ratio is 60% is employed for the central part  1  and a rather hard low-repulsion urethane whose sinking ratio is 40% employed for the neck side and head top side holding parts  9 ,  10 , thereby achieving different hardnesses. This is just an example of the hardness combination, and another setting is possible as a matter of course.  
         [0049]     The contact surfaces of the oblong central part  8  and the neck side and head top side holding parts  9 ,  10  are also diagonally formed. Specifically, the contact surfaces of the neck side and head top side holding parts  9 ,  10  contacting the oblong central part  8  are inclined so as to intrude into the lower portion of the oblong central part  8 , the corresponding contact surfaces of the oblong central part  8  are inclined so as to cover the contact surface of the neck side and head top side holding parts  9 ,  10 . In addition, the shape and contact condition of the contact surface and the like of the second embodiment are similar to those of the first embodiment.  
         [0050]      FIG. 12  is a perspective view showing a composite pillow according to a third embodiment;  FIG. 13  is an exploded perspective view showing the composite pillow according to the third embodiment;  FIG. 14  is a transverse sectional view showing a section of right and left holding parts and a neck side central part; and  FIG. 15  is a longitudinal sectional view showing a section of the neck side central part and a head top side central part. In the composite pillow according to the third embodiment, which corresponds to claim  3 , each edge of the pillow is rounded; the central part  1  of the first embodiment is broken down into a neck side central part  11  and a head top side central part  12 ; the neck side and head top side central parts  11 ,  12  are formed into a plane curved so as to orient downward at the center in a right and left direction; and the planes are arranged parallel by being held by a left holding part  22  and a right holding part  23 .  
         [0051]     For the material of the neck side and head top side central parts  11 ,  12  and the right and left holding parts  22 ,  23 , similarly to the first embodiment and the second embodiment, low-repulsion urethanes of different hardnesses are employed. Describing the hardnesses by expressing by the sinking ratio with the weight of a human head when using the composite pillow, a soft low-repulsion urethane whose sinking ratio is 60% is employed for the head top side central part  12 ; a rather hard low-repulsion urethane whose sinking ratio is 40% employed for the neck side central part  11 ; and furthermore a hard low-repulsion urethane whose sinking ratio is 20% for the right and left holding parts  22 ,  23 , thereby achieving different hardnesses This is just an example of the hardness combination, and another setting is possible as a matter of course.  
         [0052]     The contact surfaces  13 ,  14  of the neck side central part  11  and the head top side central part  12  are diagonally formed. Specifically, the contact surface  13  of the neck side central part  11  contacting the head top side central part  12  is inclined so as to intrude into the lower portion of the head top side central part  12 , and the corresponding contact surface  14  of the head top side central part  12  is inclined so as to cover the contact surface  13  of the neck side central part  11 .  
         [0053]     Furthermore, the contact surfaces  15 ,  16 ,  17 ,  18  of the neck side and head top side central parts  11 ,  12  with the right and left holding parts  22 ,  23  are also diagonally formed. As a matter of course, the contact surfaces  19 ,  20  of the right and left holding parts  22 ,  23  are also diagonally formed corresponding to the contact surfaces  15 ,  16 ,  17 ,  18 . Specifically, the contact surfaces  19 ,  20  of the right and left holding parts  22 ,  23  contacting the neck side and head top side central parts  11 ,  12  are inclined so as to intrude into the lower portion of the neck side, and the corresponding contact surfaces  15 ,  16 ,  17 ,  18  of the neck side and head top side central parts  11 ,  12  are inclined so as to cover the contact surfaces  19 ,  20  of the right and left holding parts  22 ,  23 . In addition, the shape and contact condition of the contact surface and the like of the third embodiment are similar to those of the first embodiment.  
         [0054]      FIG. 16  is a perspective view showing a composite pillow according to a fourth embodiment, and  FIG. 17  is an exploded perspective view showing the composite pillow according to the fourth embodiment. The composite pillow according to the fourth embodiment corresponds to claim  3 , similarly to the composite pillow according to the third embodiment. Although the configuration of the fourth embodiment is almost the same as the configuration of the third embodiment, the neck side central part  11  differs from the head top side central part  12  in height and width in right and left directions. Specifically, as shown in  FIG. 16  and  FIG. 17 , the neck side central part  11  is formed to be slightly higher and wider in right and left directions than the head top side central part  12  in the light of cervical vertebrae protection. Due to the difference in shape between the neck side central part  11  and the head top side central part  12 , the contact surface is a slope having an uneven slope shape, not an even slope as in the third embodiment.  
         [0055]      FIG. 18  includes explanatory diagrams showing a using state in a third and the fourth embodiments, in which  FIG. 18A  shows a using state of the composite pillow when lying on the back;  FIG. 18B  shows a using state of the composite pillow when turning sideways; and  FIG. 18C  shows a using state of the composite pillow when lying on the side.  FIG. 19  includes explanatory diagrams showing a relation between the using state of the composite pillow and a cervical vertebrae condition in the third and the fourth embodiments, in which  FIG. 19A  shows a state when lying on the back; and  FIG. 19B  shows a state when lying on the side.  
         [0056]      FIG. 18A  and  FIG. 19A  show a using state when lying on the back. If a head is put at the center of the pillow at this time, the head is located on the head top side central part  12  and the neck is located on the neck side central part  11 . In this configuration, since the neck side central part  11  is made of a rather hard low-repulsion urethane whose sinking ratio is 40% and the head top side central part  12  is made of a soft low-repulsion urethane whose sinking ratio is 60%, the neck side central part  11  supports the neck without sinking deeply, thereby preventing the cervical vertebrae from being damaged by the use of the pillow.  
         [0057]     Also, when using the pillow with lying on the side, the position of a head is preferably maintained higher than the case when lying on the back in the light of cervical vertebrae protection. The composite pillow according to the third and the fourth embodiments, in which the right and left holding parts  22 ,  23  employ a hard low-repulsion urethane whose sinking ratio is 20%, sinks only slightly due to the weight of the head as shown in  FIG. 18C  and  FIG. 19B , thereby maintaining the head higher than the case when lying on the back. This enables the cervical vertebrae to be maintained straight when using the pillow as shown in  FIG. 19B .  
         [0058]     When turning sideways from upward (as a matter of course, vice versa), a head moves from the soft head top side central part  12  to the hard right and left holding parts  22 ,  23  as shown in  FIG. 18B . Since the contact surface of both parts is diagonally formed and the right and left holding parts  22 ,  23  intrude into the lower portion of the head top side central part  12 , the joint between both parts is imperceptible to a user. This is because the hard part gradually increases from the center toward the right and left.