Pillow

Abstract

A pillow (1) according to present invention comprises a body (3) including a concave portion (7) in a central part and a cold insulator (5) incorporated in the concave portion (7). The cold insulator (5) has a gel material enclosed in a bag member which is formed by an enclosing film. It is preferable that the body (3) should be formed of a rubber or a synthetic resin material and should have a flexibility and a restoring property for a deformation. It is more preferable that the gel material should be a hydrogel or a lipogel. Furthermore, a plurality of dents (9) is provided on the surfaces of the body (3) and the cold insulator (5). The pillow can hold and cool a head in such a shape as to conform to the shapes of a neck and a head, thereby casting no burden on a human body. A cooling function lasts long by the cold insulator (5) incorporated in the body (3). Plural kinds of cold insulators (5) to be incorporated can be retained and replaced, and can be regulated depending on a user and a situation.

Description

This application claims priority on Patent Application No. 2003-312629 filed in Japan on Sep. 4, 2003

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a pillow. More particularly, the present invention relates to a pillow to be used for cooling a head.

2. Description of the Related Art

Conventionally, a water pillow has been used for cooling a head of a person. The water pillow is troublesome to replace ice or water. For the replacement, a place, a vessel or the like for treating the water is required. In order to eliminate the troubles, various devises have been made. For example, Japanese Laid-Open Patent Publication No. 2002-330986 has described a pillow in which a capsule requiring no water is put. In place of the ice, the capsule is cooled and filled in the pillow for use.

Japanese Laid-Open Patent Publication No. 2001-297 has described a pillow in which a cold insulator is accommodated in a pocket provided on a pillow cover. The cold insulator is put on the market. Since the cold insulator takes the shape of a simple sheet, it is thin. The cold insulator has a larger contact area with the air and a small cold insulating capability.

Japanese Laid-Open Patent Publication No. 2001-198151 has described a cooled type cooling package utilizing an endothermic reaction in the dissolution of salt in water. When a pillow is to be used, an isolated cooling agent is mixed with the water and they are dissolved to start the endothermic reaction. The endothermic reaction process is caused to progress continuously for a long period of time by the gelation of salt water to be a reactive product. The gel thus generated is used in the same manner as the cold insulator.

SUMMARY OF THE INVENTION

The shape of a pillow which conforms to a cervical vertebrae in the same manner as a stand-up posture is better because it does not cause a body to carry a burden. For this purpose, it is necessary to hold a stability and a comfort to sleep when a head is put on the pillow while maintaining the shape of the pillow formed to be constant. In order to maintain the shape of the pillow, it is necessary to cause the pillow to have a restoring property. Both the pillow and a package are deformed according to the motion of the head and have no shape holding function in the same manner as a conventional water pillow. On the other hand, if a shape holding capability is too large, a shape following property is poorer so that the stability of the head and the comfort to sleep are deteriorated. More specifically, a flexibility is required for the pillow in order to enhance the stability and the comfort to sleep. In consideration of the actual circumstances described above, it is an object of the present invention to provide a pillow in which a head can be held and cooled in such a shape as to conform to the shapes of a neck and a head so as not to cast a burden on a human body, the cooling can last long and a comfort to sleep can be enhanced.

The present invention provides a pillow comprising a body including a concave portion in a central part, and a cold insulator incorporated in the concave portion, the cold insulator having a gel material enclosed in a bag member.

It is preferable that the body should be formed of a rubber or a synthetic resin material and should have a flexibility and a restoring property for a deformation.

It is more preferable that the gel material should be a hydrogel or a lipogel.

It is further preferable that a plurality of dents should be provided on surfaces of the body and the cold insulator.

This pillow can hold and cool the head portion in such a shape as to conform to the shapes of a neck and a head. Therefore, a burden is not cast on a human body. The cooling function of a cold insulator which is incorporated can last long. Moreover, plural kinds of cold insulators to be incorporated can be retained and replaced. An adjustment can be carried out depending on a difference in the physical constitution and uses of a user.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a pillow according to an embodiment of the present invention,

FIG. 2(a) is a plan view of FIG. 1, FIG. 2(b) is a front view of FIG. 1, and FIG. 2(c) is a side view of FIG. 1,

FIG. 3 is a sectional view taken along a III-III line in FIG. 2,

FIG. 4 is a sectional view taken along a IV-IV line in FIG. 2,

FIG. 5 is a perspective view showing a pillow according to another embodiment of the present invention, and

FIG. 6 is a graph showing a change in a temperature which is obtained when pillows according to an example and a comparative example are used.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described below in detail based on a preferred embodiment with reference to the accompanying drawings.

FIGS. 1 to 4 show a pillow 1 according to an embodiment of the present invention. The pillow 1 is formed by a body 3 and a cold insulator 5. The body 3 has a concave portion 7 for incorporating the cold insulator 5 therein. The cold insulator has such a contour as to almost conform to the shape of the concave portion 7 so as to be fitted in the concave portion 7. More specifically, the cold insulator 5 is incorporated into a central part in the longitudinal direction of the body 3. Thus, the body 3 and the cold insulator 5 are combined to obtain the configuration of the pillow to be used.

The size of the body 3 is not particularly restricted but always has a width L of 400 mm to 1000 mm, a depth W of 300 mm to 500 mm and a height H of 10 mm to 190 mm. As will be described below, the shape of the concave portion 7 is determined corresponding to the cold insulator 5 to be formed in consideration of the figure of a person. The shape (mainly a height and a curved shape) of the cold insulator 5 to be incorporated in the concave portion 7 is set in such a manner that the shape of the whole pillow is smoothened in combination with the cold insulator 5.

It is preferable that the body 3 should have such a hardness as to support the head of a person and should have a flexibility and a restoring property. For this reason, it is preferable that a rubber or a synthetic resin material should be used for the body 3. The rubber to be used includes a natural rubber, an isoprene rubber, a butadiene rubber, a styrene-butadiene rubber, an acrylonitrile-butadiene rubber and the like. The synthetic resin material to be used includes a thermoplastic elastomer belonging to a type such as polyurethane, polyester, polyamide, polyolefin, polystyrene, polyvinyl chloride, silicone, polybutadiene and the like, or a combination of plural kinds.

It is more preferable that the material of the body 3 should be a polyurethane foam because a flexibility and various hardnesses can be regulated. In particular, a polyurethane foam having a low repulsion is further preferable. The body 3 is obtained by molding these materials through a molding method such as injection molding, blow molding or extrusion molding.

In the case in which a flexibility (which is also referred to as a softness) of the cold insulator 5 is large and a shape holding capability is small, particularly, the body 3 is formed in such a manner that the cold insulator 5 is maintained within the range of a predetermined shape by the concave portion 7. For example, a material having a comparatively small flexibility and a high shape holding property is selected for the material of the body 3. Alternatively, a material such as a side wall forming the concave portion 7 may be partially thickened and the shape of the concave portion 7 may be changed with difficulty. Moreover, a material having a higher elastic modulus than that of the material of the body 3 may be partially provided around the concave portion 7.

The cold insulator 5 can be replaced and incorporated into the concave portion 7 of the body 3 as will be described below. For this reason, the concave portion 7 is formed in conformity to the shape of the cold insulator 5. When plural kinds of cold insulators 5 formed separately have a difference in a dimension, however, a slight clearance may be formed between the concave portion 7 of the body 3 and the cold insulator 5 in order to absorb the error. Also in the case in which the clearance is not formed, the cold insulator 5 can be incorporated within the range of the flexibility because the body 3 and the cold insulator 5 have flexibilities. In some cases in which the clearance is too large, the range of a predetermined shape cannot be maintained, for example, the sink of a head is too deep, which is not preferable.

The concave portion 7 of the body 3 is provided based on a position on which a rear head is mounted and a size in use. A curved surface conforming to a shape from a neck to a rear head when a person stands up is formed in the central part of the pillow 1. The shape of the curved surface is taken by both the body 3 and the cold insulator 5.

As is apparent from FIGS. 3 and 4, a portion of the body 3 in which the rear head is positioned when a person puts a head has a height reduced. The portion on which a neck provided just above a shoulder is put has a height increased. In the case in which the cold insulator 5 is large, this shape is mainly taken and held by the cold insulator 5. In the case in which the cold insulator 5 is small, a predetermined shape is mainly defined by the shape of the body 3.

The body 3 has a flexibility capable of following a deformation in a state in which the cold insulator 5 is incorporated. A person having a head put on the pillow 1 changes the direction of the head or shifts the position of the head. In order to enhance the deformation following property of the pillow 1, a material having a low repulsive elastic modulus is preferable. In order to obtain a good feeling of use, the body 3 including the concave portion 7 requires the deformation following property to some extent. For this reason, it is necessary to have a proper flexibility and restoring property and to distribute and support the weight of the head over the whole surface of the head.

It is preferable that the body 3 should have a plurality of dents 9 on a surface. The dent 9 prevents the adhesion of the head or the like to the body 3 when the head of a person or the like is put on the pillow 1. More specifically, a clearance is formed between the head or the like and the body 3. Since the clearance has a gas permeability, neither a sticky feeling nor stuffiness is generated. The dent 9 is formed by providing a groove, a hole, a projection or the like on a surface. The pillow 1 illustrated in FIGS. 1 to 4 has a parallel groove in a longitudinal direction on a surface. The shape of the groove, that is, a depth, an interval or the like is taken in conformity to the properties of the body 3 and the cold insulator 5 in order to enhance the feeling of use.

The surface of the cold insulator 5 is formed in conformity to a curved surface from a nape to the rear head in a stand-up posture. The cold insulator 5 is independently fabricated separately from the body 3. Plural kinds of cold insulators 5 can be prepared for one of the bodies 3. More specifically, only the cold insulator 5 can be removed from the body 3 and can be cooled or frozen. As long as the cold insulator 5 can be incorporated in the concave portion 7 of the body 3, particularly, it can be replaced with a cold insulator having a different shape, for example, a different height (thickness), a different curved shape of a surface or the like. Moreover, it is also possible to prepare various cold insulators 5 having different hardnesses and cold insulating performances of a cold insulating material. These can be selected according to circumstances.

The size of the cold insulator 5 usually has a width N of 100 mm to 500 mm, a depth M of 150 mm to 500 mm and a height P of 10 mm to 190 mm. In order to combine the cold insulator 5 with the body 3 to adjust the shape of the pillow 1, the shape of the pillow 1 is mainly adjusted depending on the height of the cold insulator 5. The height of the cold insulator 5 can be varied according to a distance among the depth of the neck portion of a user, a shoulder of the user lying down and a side head, and furthermore, the preference of the user.

The cold insulator 5 is fitted in the central part of the pillow 1 with a constant thickness, thereby forming a part of the pillow 1. The side surface of the cold insulator 5 is maintained to be protected from an outside through the body 3 formed of a foam or the like. Since the foam of the side surface has a heat insulating function, a thermal conduction from the side surface of the cold insulator 5 is lessened. Accordingly, an area on the surface side of the pillow 1 to which a heat is transferred from the outside is relatively reduced with respect to the volume of the cold insulator 5. By the combination structure of the cold insulator 5 and the body 3, an excessive heat is transferred from the outside to the cold insulator 5 with difficulty. Referring to the pillow 1, therefore, a cooling time is prolonged.

The cold insulator 5 also has some shape holding capabilities while supporting the weights of the head and the neck. By this function, the burden of the neck can be decreased when a person puts a head on the pillow 1. If the shape holding property is too great, however, the cold insulator 5 tends to be too hard. If the cold insulator 5 is too hard, the deformation following property becomes insufficient when the positions of the head and the neck are shifted. In order to enhance the feeling of use, the deformation following property is required to some extent. The cold insulator 5 has a flexibility capable of following a deformation. The cold insulator 5 has a proper flexibility and restoring property and can distribute and support the weight of the head over the whole surface of the head. For a material, a gel material is preferable.

The cold insulator 5 is usually used at a surface temperature of 5° C. to 30° C. The surface temperature of the cold insulator 5 is preferably 1° C. to 25° C., and more preferably, 12° C. to 20° C. There is selected a gel material which is advantageous to uses for a long time at this temperature.

Examples of the gel material include a hydrogel having water as a solvent and a lipogel having oil as the solvent depending on the solvent. Examples of the hydrogel include polyacrylic acid, polyacrylate (sodium polyacrylate or the like), polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide, sodium carboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, methyl cellulose, sodium alginate, xanthan gum, gum arabic, traganth gum, karayagum and a maleic anhydride copolymer. For example, polyacrylic acid having a weight-average molecular weight of approximately 1000000 to 5000000 is suitably used.

Examples of the lipogel include gels comprising polyurethane, polyolefin, polystyrene, silicone, polyethylene, polyester, a vinyl acetate copolymer, polyvinyl chloride, neoprene and a polybutadiene rubber. These polymers are used singly or in combination. Moreover, it is possible to give or regulate an elasticity by adding a softening agent, a plasticizer, a filler or the like depending on the properties of these polymers.

The lipogel is prepared by crosslinking these polymers together with oil. For example, there are used 100 parts by weight of oil in which a polymer is dissolved at an ordinary temperature, 10 to 20 parts by weight of a polymer, and organic peroxide. For the oil, there is used a plasticizer, for example, vegetable oil such as olive oil or castor oil, mineral oil such as liquid paraffin or process oil, ester oil such as diethyl sebacate, dioctyl phthalate, dioctyl adipate, ethyl cinnamate, ethyl phenylacetic acid, ethyl oleate or benzyl benzoate, or animal oil such as squalene.

Examples of the organic peroxide include lauroyl peroxide, acetyl peroxide, benzoyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, t-butyl peroxybenzoate and dicumyl peroxide.

Referring to the hydrogel and the lipogel, the lipogel is preferable because it has a viscosity at a low temperature. In particular, a polyurethane gel is preferable because a pressure dispersibility, a workability, a price and the like are balanced. A thermosetting polyurethane gel is more preferable. The polyurethane gel is obtained by heating and curing a mixture of polyol and isocyanate. Examples of the polyol include polyether polyol, polyester polyol, polycarbonate polyol and polybutadiene polyol. In particular, polyether type polyol is more preferably used in respect of a softness and a restoring property. Examples of the isocyanate include MDI, TDI, IPDI, HDI, HMDI, PPDI and XDI.

These gel compacts are obtained by carrying out filling in a bag having a predetermined shape formed by an enclosing film and crosslinking, for example. The gel compact may be obtained by pouring into a metal mold, and carrying out extrusion molding by means of an extruder and then performing crosslinking. If the enclosing film is resistant to some external force, a gel material is not soaked therein and properties are not changed by the gel material, there is no particular restriction. For example, the enclosing film is formed of polyurethane, polyethylene, polypropylene, polyester, polyethylene-terephthalate (PET), polybuthylene-terephthalate (PBTO), polyamide, polyvinyl chloride and polyvinylidene chloride or the like. Moreover, their composite film or an aluminized film can also be used.

In the case in which the thermosetting polyurethane gel is used, a polyurethane film is suitable for the enclosing film. The polyurethane gel and the polyurethane film have excellent adhesive properties. Therefore, the film is rarely peeled from the gel. For this reason, the surface condition of the cold insulator 5 is maintained uniformly and excellent shape holding properties can also be obtained.

It is preferable that the enclosing film should have a thickness of 0.02 mm to 1 mm. If the thickness is smaller than 0.02 mm, there is a possibility that the film might be easily broken, resulting in a deterioration in a durability. If the thickness is greater than 1 mm, a flexibility is poor and a person feels a hardness when his (her) head comes in contact so that a comfort to sleep cannot be obtained.

It is preferable that the enclosing film should have a tensile strength of 10N or more, an elongation at break of 200% or more and a tear strength of 5N or more. In the case in which the tensile strength and the tear strength are smaller than the values described above, there is a possibility that the durability might be deteriorated. If the elongation at break is smaller than 200%, a flexibility is low. Consequently, there is a possibility that the degree of freedom of a deformation might be too low. For this reason, the cold insulator 5 conforms to the shapes of human necks and heads with difficulty and the comfort to sleep tends to be deteriorated. If the elongation at break is too small, moreover, the film restrains the deformation of the gel material from being caused by a turn-over in bed or the like. Consequently, only the film bears a deforming force. In this case, a stress concentration is easily generated on the film so that the durability of the film is deteriorated.

It is preferable that the surface of the cold insulator 5 should have a plurality of dents 9. A groove, a hole, a projection and the like are provided on the surface of the pillow 1 including the cold insulator 5. As shown in FIGS. 1 to 4, the cold insulator 5 has the same groove-shaped dent 9 as that of the body 3. The shape of the dent 9 of the cold insulator 5 does not need to be identical to that of the dent 9 of the body 3. By the dent 9, the cold insulator 5 has an air permeability. In the cold insulator 5, when the head or neck of a person directly comes in contact with the cold insulator 5, a stuffiness can be prevented from being caused by the perspiration of the person.

The same armor cover as the body 3 can be attached as an armor for the enclosing film to the cold insulator 5. The material of the armor cover may be the same as that of a well-known cover. For the armor cover, there is used a natural fiber such as silk, cotton or wool or a synthetic fiber such as polypropylene, polyester, polyamide, polyvinyl alcohol or polyvinylidene chloride. A nonwoven fabric, a woven fabric, a knitted fabric or the like constituted by these fibers is used. In respect of an enhancement in a touch, their layered product and a fabric having a high porosity are preferable. It is also possible to use a natural leather or an artificial leather for the armor cover. The thickness of the armor cover or the like is taken into consideration so as not to lose the function of the concavo-convex shape of the surface.

In the case in which the head and the neck portion of the person are to be cooled, it is preferable that a body temperature should be dropped by 1° C. in two hours when the person is induced to sleep. When the pillow 1 is used, the cold insulator 5 cooled previously in a refrigerator or the like is embedded in the body 3. The cold insulator 5 effectively cools the rear head and the neck which are put on the pillow 1. The cold insulator 5 has an excellent cold insulating property because an excessive heat is transferred with difficulty as described above. Accordingly, the cold insulator 5 lasts a cooling effect for a long period of time.

FIG. 5 is a perspective view showing a pillow 15 according to another embodiment of the present invention. The pillow 15 also comprises a body 17 and a cold insulator 19. The body 17 has such a shape that the height of a central part on which the head of a person is put is the smallest. The cold insulator 19 is embedded in the body 17 in such a shape as to correspond to a concave portion provided in the central part of the body 17. The shape of a surface formed by combining the cold insulator 19 and the body 17 conforms to the shapes of a neck and a rear head in the stand-up posture of a person.

The surface of the cold insulator 19 is provided with a plurality of elliptical dents 21. The body 17 also has a concavo-convex dent, which is not shown. In the same manner as in FIG. 1, a shape holding property and a flexibility are taken into consideration and the materials of the cold insulator and the body and the like are used. The pillow 15 can also cool the head without casting a burden on a human body. Moreover, the cold insulator 17 can have an excellent cold insulating property and a cooling capability can last long, and furthermore, a comfort to sleep can be obtained.

EXAMPLES

While the advantages of the present invention will be apparent from examples, the present invention should not be construed to be restricted based on the description of the examples.

Example

A rubber composition containing a natural rubber as a base material (100 parts by weight of a natural rubber, 115 parts by weight of a filler, 4 parts by weight of a softening agent, 5.5 parts by weight of zinc white, 1.1 parts by weight of stearic acid, 5 parts by weight of a foaming agent, 2 parts by weight of sulfur, 0.9 part by weight of a vulcanization accelerator and 0.6 part by weight of an antioxidant) was put in a metal mold and was vulcanized and foamed at 150° C. for 10 minutes, and was thus molded to manufacture a body comprising a concave portion. On the other hand, a polyurethane film (a thickness of 0.1 mm, a tensile strength of 20N, a tear strength of 8N and an elongation at break of 220%) was laid over a metal mold having such a shape as to correspond to the shape of the concave portion of the body, and the temperature of a polyurethane gel was raised to 50° C. and was poured in an amount of approximately 50 mm into the metal mold, and was filled with a curing type polyurethane gel and was crosslinked for 30 minutes at 120° C., and the metal mold was cooled to take out a molded product so that a cold insulator was obtained. The cold insulator was combined with the body and was covered with an armor cover (for the body; 100% cotton). Thus, a pillow according to the example was obtained.

Comparative Example

As a comparative example, there was used a general flat pillow put on the market which includes a cold insulator put on the market (manufactured by Dunlop Home Products Co., Ltd., trade name of “Soft Snow Pillow”, a thickness of 30 mm, a length of 190 mm and a width of 340 mm) (which is fabricated by a polyurethane foam, a width of 550 mm, a depth of 380 mm and a height of 10 mm, having an armor cover made of 100% cotton).

[Evaluation]

Testing method: A head was put and the surface temperatures of a neck and a cold insulator were measured by using MT-8 manufactured by Gram Co., Ltd. A result is shown in FIG. 6. Furthermore, ten testers were caused to use the cold insulator at 15° C. to carry out a functional evaluation for a comfort, a feeling of a fitness and a feeling of a stuffiness. An average value was calculated based on an evaluation in five stages (very good: 5, good: 4, normal: 3, bad: 2, very bad: 1) so that a result in Table 1 was obtained.

	TABLE 1
	Example	Comparative Example
	Comfort	4.5	3.4
	Feeling of fitness	4.1	2.2
	Feeling of stuffiness	3.5	1.8

As shown in FIG. 6, in the pillow according to the example, a rise in a temperature after the start of use is smaller, and apparently, a cooling function lasts longer and is more excellent than the pillow according to the comparative example. As shown in the Table 1, moreover, a manufacturing method according to the example has a higher evaluation than a manufacturing method according to the comparative example. From the result of the evaluation, the advantages of the present invention are apparent.

The above description is only illustrative and various changes can be made without departing from the scope of the present invention.

Claims

1. A pillow comprising:

a body including a concave portion in a central part; and

a cold insulator incorporated in the concave portion, the cold insulator having a gel material enclosed in a bag member.

2. The pillow according to claim 1, wherein the body is formed of a rubber or a synthetic resin material and has a flexibility and a restoring property for a deformation.

3. The pillow according to claim 1, wherein the gel material is a hydrogel or a lipogel.

4. The pillow according to claim 1, wherein a plurality of dents is provided on surfaces of the body and the cold insulator.