1. Field of the Invention
The present invention relates to a seat structure including a seat portion and a backrest portion adjustable in inclination angle, and more particularly to a seat structure suitable for nursing equipment.
2. Description of the Background Art
In nursing equipment such as a baby carriage, a baby rack and a child seat, an inclination angle of a backrest portion of a seat is usually adjustable. In the nursing equipment receiving a baby shortly after birth, the backrest portion is inclined backward to an approximately horizontal state in order to realize a bed state. Nursing equipment that can be switched between the form of a bed and the form of a chair in accordance with the developmental stages of infants is commercially available.
A back end portion of seat portion 1 has a protruding portion 1a and a notch portion 1b that are positioned alternately. Similarly, a front end portion (or a lower end portion) of backrest portion 2 has a protruding portion 2a and a notch portion 2b that are positioned alternately. A shaft 3 passing through protruding portion 1a of seat portion 1 and protruding portion 2a of backrest portion 2 is provided to allow seat portion 1 and backrest portion 2 to be coupled in a flexible manner.
Usually, a seat plate and a backrest plate made of a resin to form seat portion 1 and backrest portion 2 are provided with concave, groove portions 1c, 2c in places as shown.
As shown in
A structure for coupling seat portion 1 and backrest portion 2 to each other in a flexible manner is not limited to that shown in
In the form of a chair shown in
In particular, in baby carriages or child seats, the stimulation of the sensory nerves by the local loads is considered great because vibrations involved with movements always act on the seat. Furthermore, in a case of a premature baby, even a small step at a body-supporting portion may have an adverse affect on a baby's growth. Therefore any local loads on the buttocks have to be avoided by any means.
The uncomfortable feeling because of the local loads acting on the buttocks may apply to adult's seats.
An object of the present invention is to provide a seat structure capable of dispersing a body pressure acting on the buttocks.
Another object of the present invention is to provide a seat structure capable of preventing local loads acting on the buttocks both in the form of a bed and in the form of a chair.
A further object of the present invention is to provide a seat structure with comfortableness and relieved fatigue for a baby with unstable loins and back.
A seat structure in accordance with the present invention includes a seat portion, a backrest portion adjustable in inclination angle, and a bridging member covering up a flexion portion between the seat portion and the backrest portion for bridging the seat portion and the backrest portion smoothly.
Although a concave and convex portion or a corner gap is formed at the coupling portion between the seat portion and the backrest portion, the buttocks rest on the bridging member positioned at this coupling portion whereby a body pressure is uniformly dispersed on the bridging member. In particular, in a seat structure having a backrest portion that can be inclined backward to take the form of a bed, when it is in the form of a bed, the buttocks are not in direct contact with the concave and convex portion, thereby avoiding local loads. Furthermore, when the seat takes the form of a chair, the bridging member covers the corner gap to extend smoothly and supports the buttocks tightly with its entire upper surface.
Preferably, the bridging member is a member shaped like a flat plate exerting an elastic force against a bending force. Since the bridging member is a flat-like member having a flexural elasticity, the bridging member extends flatly when the seat takes the form of a bed, while the bridging member is pressed with the buttocks to assume a curved shape to conform to the shaped of the buttocks when the seat takes the form of a chair.
Preferably, the bridging member has its one end coupled to one of the seat portion and the backrest portion and has its other end arranged to be displaceable on the other one of the seat portion and the backrest portion in accordance with an inclination operation of the backrest portion. In a preferable embodiment, the bridging member has its one end coupled to the seat portion and has its other end arranged to slide on the backrest portion. Because of such a configuration of the bridging member, the existence of the bridging member does not inhibit the inclination operation of the backrest portion. The bridging member always covers up the flexion portion between the seat portion and the backrest portion at any inclination angle of the backrest portion.
The seat structure may include a seat assembly including a seat plate and a backrest plate, and a seat mat placed over and extending on the seat plate and the backrest plate continuously. In one embodiment, the bridging member is provided on the seat assembly. In another embodiment, the bridging member is provided on the seat mat.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
As shown, a bridging member 13 is arranged on a flexion portion (coupling portion) between seat plate 10 and backrest plate 11. Bridging member 13 is preferably a member shaped like a thin flat plate exerting an elastic force against a bending force and has its one end 13a coupled to seat plate 10 by an adhesive or the like. The other end 13b of bridging member 13 is a free end and may slide on backrest plate 11 in accordance with the inclination operation of backrest plate 11. Polypropylene can be listed as an exemplary material forming bridging member 13.
As described above, the formation of concave and convex is inevitable at the coupling portion between seat plate 10 and backrest plate 11, as a matter of design. When the baby's buttocks directly rest on such concave and convex in the seat assembly in the form of a bed, local loads act at the concave and convex portions to give an uncomfortable feel to the baby. Bridging member 13 functions to prevent such local loads. More specifically, as bridging member 13 covers the concave and convex at the coupling portion and extends flatly, the entire upper surface of bridging member 13 supports the baby's buttocks from underneath. Therefore the body pressure is dispersed, thereby giving the baby a comfortable environment.
When backrest plate 11 is lifted upward in order to switch from the form of a bed shown in
While in the embodiment shown in
A bridging member 16 is attached to the back surface of seat mat 15. One end 16a of bridging member 16 is coupled to the back surface of seat mat 15 using an adhesive or the like, and the other end 16b may slide on the back surface of seat mat 15. Bridging member 16 is arranged at a position to cover up the flexion portion (coupling portion) between seat plate 10 and backrest plate 11. The operational effect of bridging member 16 is the same as bridging member 13 in the embodiment described above and therefore the description thereof will not be repeated.
As shown, on the upper surfaces of core members 21 and 22, a bridging member 25 is attached. One end 25a of bridging member 25 is coupled to the upper surface of seat core member 21 using an adhesive or the like, and the other end 25b may slide on the upper surface of backrest core member 22. The operational effect of bridging member 25 is the same as that in the embodiment described above and therefore the description thereof will not be repeated.
Bridging member 33 is positioned to cover up the coupling portion between seat plate 30 and backrest plate 31. As shown, the length of bridging member 33 in the forward and backward direction (the length in the lateral direction in
As the other embodiment, the opposite ends of the bridging member may be coupled to the seat portion and the backrest portion. In this case, the bridging member should be formed of a stretchable material. The length of the bridging member in the case of the seat structure in the form of a bed is longer than in the form of a chair.
Although the present invention advantageously applies to nursing equipment, in particular, it may apply to a seat for adults in the sense that the local loads on the buttocks can be avoided.
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.
Number | Date | Country | Kind |
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2002-061972 | Mar 2002 | JP | national |
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0911008 | Apr 1999 | EP |
Number | Date | Country | |
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20030168898 A1 | Sep 2003 | US |