A base structure for a bed

Abstract: A base structure (2) for an adjustable bed (1) having a mechanism (3, 4, 5) for raising portions thereof to inclined positions incorporates transverse flexible corrugated hollow members (8) at positions where the base structure is to be bent, which members can adopt gently curved configurations.

Description: The present invention relates to a base structure for an adjustable bed having at least one base portion which can be raised to a position in which it is inclined to the horizontal and can support a user in a position other than the normal supine position on bed. Many recent beds are adjustable and equipped with a base-raising mechanism; various mechanisms are available. A simple form of adjustable bed has a head-end portion for supporting the user's back and head connected by a hinge to a central portion for supporting the user's buttocks and thighs which is in turn connected to a foot portion. When the head portion is raised the hinge between the head and central portions acts as a pivot while, when the leg portion is raised the hinge between the waist and leg portions also acts as a pivot. It will be appreciated that, as the head portion is raised, the angular space between the head and central portions is narrowed and unless the angle fits the body of the user, the user's waist and abdomen may be compressed uncomfortably by the mattress, with similar problems occurring when the foot portion is raised. The object of the present invention is to achieve a solution to the above problem by providing a base structure for a bed, which can be bent in appropriately gentle curves so as to minimise any displeasing pressure points for the user. To solve this problem, the present invention provides, a bed base structure (2) for an adjustable bed (1) including at least two distinct supporting parts defining support surfaces extending transverse and longitudinally of the bed, characterised in that the supporting parts are spaced from each other longitudinally of the bed and joined by a flexible supporting part (8) spanning the space between them and also defining a support surface extending transverse and longitudinally of the base structure, the flexible part being capable of adopting a configuration in which the three support surfaces are substantially coplanar and continuous and of adopting a configuration in which the support surface defined thereby is curved in longitudinal section and the two supporting parts are inclined to each other. The flexible part preferably comprises or includes a corrugated laminar element, the corrugations extending transverse the base structure with the crests of the corrugations essentially defining the support surface of the flexible part. The corrugations are preferably of zig-zag form, that is, straight-sided. Even more preferably, the flexible part comprises two spaced-apart such laminar elements. The corrugations of the two elements are preferably 180° out of phase, the two elements being mirror imaged across the major plane of the member. In the above structures, the flexible parts, which may be hollow may be formed by blow moulding from a thermoplastics resin. They can thus be made as single parts, at a low manufacturing cost and can reduce the number of assembly steps. One embodiment of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view showing parts of a bed having a base structure in accordance with the present invention; Figure 2 is an enlarged sectional view showing an embodiment of a flexible hollow bed base member forming part of the bed base structure shown in Figure 1; and Figure 3 is a perspective view of the flexible hollow member of Figure 2. With reference to the drawings, Figure 1 shows part of a bed, incorporating an adjustable base structure generally indicated 2 supporting a mattress (not referenced). The base structure 2 includes a central portion for supporting the user's buttocks and thighs connected by respective flexible portions 8 to a foot portion for supporting the user's lower legs and feet and a head-end, or, back portion for supporting the user's back and head. An electric actuator, generally indicated 3, beneath the base structure 2 is connected to operate back-raising arms 4 pivotally connected at one end to the housing 3 and carrying rollers 6 at their opposite ends which contact the underside of the base back portion. The electric actuator 3 also operates knee-raising arms 5 also carrying rollers 7 at their free ends which contact the underside of the base 2 in correspondence with the flexible portion 8 between the central and foot portions of the base 2, in the lowered position of the arm 5. The flexible base members 8 are in fact hollow and constituted by upper and lower sheets which are corrugated in longitudinal section and formed from a blow-moulded thermoplastics resin (see Figures 2 and 3). In use of the bed 1, when the actuator 3 is operated to raise the back and knee portions, the flexible hollow base members 8 bend so as to take up gentle curves (see Figure 2). The waist, abdomen, and underside of the user's legs at the bent portions are therefore not uncomfortably compressed by the mattress. The flexible hollow members 8 are single parts made using blow moulded thermoplastic resin which is an advantage from the point of view of manufacturing costs. The base 2 can be assembled simply by connecting the flexible hollow bottom members 8 between known base portions constituting the back, central, and foot portions mentioned above. Therefore, the number of assembling steps and hence assembly costs can be small. Furthermore, since the hollow parts are made of a thermoplastic resin, they are bendable, extensible, and light in weight. Moreover, the base 2 can be formed as a continuous whole, facilitating cleaning.

Claims: A bed base structure (2) for an adjustable bed (1) including at least two separate supporting parts defining support surfaces extending transverse and longitudinally of the bed, characterised in that the supporting parts are spaced from each other longitudinally of the bed and joined by a flexible supporting part (8) spanning the space between them and also defining a support surface extending transverse and longitudinally of the base structure, the flexible part being capable of adopting a configuration in which the three support surfaces are substantially coplanar and continuous and of adopting a configuration in which the support surface defined thereby is curved in longitudinal section and the two supporting parts are inclined to each other. A bed base structure according to Claim 1, characterised in that the flexible part (8) comprises or includes a corrugated laminar element, the corrugations whereof extend transverse the bed and the crests of the corrugations whereof define the support surface of the flexible part. A bed base structure according to Claim 2, characterised in that the flexible part (8) comprises two spaced-apart corrugated laminar elements. A bed base structure according to Claim 1, Claim 2 or Claim 3, characterised in that the flexible part (8) comprises a hollow structure. A bed base structure according to any one of the preceding claims, characterised in that the flexible part (8) comprises a blow-moulded thermoplastics resin structure. An adjustable bed incorporating a bed base structure according to any one of the preceding Claims, characterised in that the base structure (2) includes a central part for supporting a user's buttocks and thighs connected by a said flexible part (8) to a head-end part for supporting the user's back, the bed including means (3, 4, 6) for raising the head-end part at an angle to the central part with the flexible part (8) forming a curved connecting support between the two parts to support the user in a seated position without discomfort due to compression of the abdominal region. An adjustable bed incorporating a bed base structure according to any one of Claims 1 - 5, characterised in that the base structure (2) includes a central part for supporting a user's buttocks and thighs and a foot-end part connected by a knee-supporting flexible part to the central part, and the bed includes means (3, 5, 7) for raising the knee-supporting flexible part (8) to a position in which it adopts a downwardly concave shape to support the user's legs with the knees bent.

Inventors: SHIRAI KUNITO, SHIRAI, KUNITO
Applicants: PARAMOUNT BED KK, PARAMOUNT BED COMPANY LIMITED
Application year: 1993
Main classification: A47C23
IPC codes: A47C20, A61G7