A bed base structure

Abstract: A bed base structure (1) for an adjustable bed has a plurality of transverse support strips (8) joined together by two longitudinally extending flexible connector strips (9) to form composite support surfaces which can adopt a smooth curvature when the bed base is adjusted to raise a back or leg support portion thereof in use.

Description: The present invention relates to a bed base structure which can be bent to a smooth curve while allowing a user to continue feeling relaxed even though the bed base is partially raised. Many recent beds are equipped with an adjustable bed base having a mechanism for raising a part of the bed in relation to the other parts. An ordinary bed has a back portion simply connected to a central portion. The central portion is simply connected to a leg portion. When the back portion is raised, the joint between the back and central portions acts as a pivot, (i.e. forming an actual fulcrum), and when the leg portion is raised, the joint between the central and leg portions also acts as a pivot. Therefore, as the back portion is raised forming an angle, the angular space between the back and central portions near the joint becomes narrowed, and unless the angle fits the body of the user in the bed, the waist, abdomen, and underside of the user's legs are subjected to uncomfortable pressure by the mattress. The present invention seeks to provide a solution to the above problem and to provide a bed base structure which can be adjusted to adopt a curved configuration to provide gently curved portions of the bed so as to minimise any displeasing pressure points for the user. Other bed base structures are known. For example EP-A-0274371 described a bed base comprising a plurality of rigid transverse support strips linked by flexible strips able to be rolled up for easy storage and transport, and which is easily dismantled and reassembled. There is, however, no provision for varying the spacing of the transverse support strips, and the flexibility of the bed base is accordingly limited. DE-U-9107820 described a padded base comprising a plurality of support strips connected by at least one connector strip, which can be rolled up for storage and transport. The base offers no support to the body, merely providing a comfortable padded surface on which to sit or lie. According to the present invention there is provided a bed base structure for an adjustable bed having a plurality of transverse support strips connected together in a spaced relationship by at least one flexible connector strip extending longitudinally of the bed base structure to form a flexible curve portion of the bed base, characterised in that the said flexible connector strip has curved portions between adjacent transverse support strips whereby to allow a variation in the spacing of the transverse support strips. The curved portions serve to increase the range of flexibility so that, for a given spacing between adjacent transverse support strips, a sharper maximum curvature can be obtained when the bed base is adjusted to raise a portion thereof which results in curvature of the bed base with the transverse support strips radially inwardly of the longitudinally extending connector strips. Of course, curvature in the opposite direction is not limited by contact between the adjacent transverse support strips. In a preferred embodiment of the invention each said transverse support strip has four faces and the or each said flexible connector strip is connected to one face of each transverse support strip by attachment means. Such attachment means may be any suitable fastener for the material used, and may, for example, comprise screws. Although the minimum requirement is for a single longitudinal flexible connector strip, it is preferred that two longitudinal connector strips be provided, each attached adjacent a respective end of each transverse support strip. The longitudinal flexible connector strip may be attached to the upper or to the lower faces of the transverse support strips. A flexible covering over at least one surface defined by corresponding faces of the said transverse support strips may be provided, and this has the advantage, among other things, of preventing dust from collecting between adjacent transverse support strips. Embodiments 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 a bed having the bed base structure of the present invention; Figure 2 is an enlarged sectional view showing a further embodiment of the present invention; Figure 3 is a schematic perspective view showing a curved portion of the bed base structure of Figure 2; Figure 4 is an illustration showing the upper and lower faces of the bed base structure of Figure 2 covered with a flexible sheet, as an additional feature suitable for incorporation into a bed base embodying the invention; Figure 5 is a sectional view showing a flexible sheet attached to the upper surface of the bed base structure, as an additional feature suitable for incorporation into a bed base embodying the invention; and Figure 6 is an enlarged sectional view showing an embodiment where a mattress is caught in the gaps of the bed base structure. Referring now to the drawings, Figure 1 shows a bed 1, having a bed base structure formed as an embodiment of the present invention. The bed 1 can be raised at the back and knee portions by an electric actuator 3 provided below a central portion of the bed base structure 2. The actuator 3 is provided with back-raising arms 4 for raising the back portion and knee-raising arms 5 for raising the knee portion. The back-raising arms 4 contact the underside of the bed base structure at the back portion, through rollers 6; and the knee-raising arms 5 contact the portion of the bed base structure corresponding to the user's knees. In this bed 1, a plurality of transverse strips 8 are sequentially attached by screws or any other appropriate means, to elastic or resilient connector strips 9 at predetermined intervals. This allows the bed base structure 2 to be bent at the bendable portion between the back portion and the central portion of the bed base 2 and at the portion corresponding to the user's knees. The transverse support strips 8 and the longitudinal flexible strips 9 can be formed as shown in Figure 2, in which it can be seen that the longitudinal flexible strips 9 are curved into transverse corrugations at the portions not in contact with the transverse strips 8. The bed base can not only be partially curved but may also be adjusted in overall length along the longitudinal direction of the bed by applying a tension to straighten some of the corrugations. The paralleled transverse support strips 8 may be secured, for example by screws at predetermined intervals to the flexible or elastic longitudinal connector strips 9. This allows the bed base 2 to be bent at the bendable portion between the back portion and the central portion as can be seen in Figure 3, in which the bed base 2 is subjected to tension which has the effect of pulling the curves in the connector strips 9 straight. The transverse support strips 8 may be made using mouldable material or a rigid material such as wood. They may also be hollow if they are sufficiently rigid. The transverse support strips 8 are attached to the longitudinal connector strips 9, either above the longitudinal strips 9 of the bed base as shown in Figure 2, or on the underside of the longitudinal strips (not shown) and are thus either interior or exterior respectively, to the curve formed by the longitudinal strips when the bed base structure is curved in a given direction. The longitudinal strips 9 are preferably positioned near respective ends of a transverse support strip 8 and connected to the transverse strip by screws 14 or any other appropriate fixing means. In a bed 1 having the above bed base structure, if the actuator 3 is operated to elevate a portion of the bed base 2, the parallel transverse strips 8 are raised, forming a gentle curve, since the longitudinal strips 9 connecting the transverse strips 8 are also curved. In this case, if the spacing interval between adjacent transverse strips 8 is changed, the angle of maximum curvature will also be adjusted. When the bed base 2 is raised at the back and centre portions, with the longitudinal strips 9 and the attached transverse strips 8 being raised to form a gentle curve, the waist, abdomen and the underside of the user's legs will not experience any uncomfortable pressure exerted by the curved raised portions of the mattress. Since the transverse strips 8 and the longitudinal flexible strips 9 can be of standardised size and shape and are simple in structure, they can be readily mass produced and are advantageous in view of the cost of manufacturing. A predetermined number of the transverse strips 8 can be screwed to the longitudinal strips 9. The longitudinal strips are attached near respective ends of the transverse strips, with predetermined intervals separating the transverse strips, to form the flexible portions of a bed base structure. In this case, the number of transverse strips 8 connected to the longitudinal strips can be varied between a rather short section to the entire length of the bed base 2. Further, if one of the transverse support strips 8 or one of the longitudinal flexible strips 9 is broken during use, only the broken part need be changed, allowing easy maintenance. In the present invention, when the bed base structure is bent, a mattress 10 placed on the bed base structure might be caught in the gaps 13 formed between the transverse support strips (see Figure 6). To prevent this, the entire bed base structure may be covered with flexible sheet 11 (see Figure 4) or a flexible sheet 11 may be attached to the upper surface of the bed base structure (see Figure 5). The symbol 12 in Figure 5 represents means for fixing or attaching the flexible sheet 11 to at least one transverse support strip of the bed base structure. When the bed base structure in Figure 2 is bent, the gaps 13 formed on the upper side are pinched together and the curves in the longitudinal flexible strips 9 are pulled straight, as shown in Figure 3. It may also happen that dust and dirt may have collected in the gaps 13. However, if a flexible sheet 11 is provided, the accumulation of dust can be reduced or prevented. A flexible sheet 11 is preferably provided to permit easier cleaning and is shown in Figures 4 and 5 which do not illustrate embodiments of the invention, but illustrate additional features suitable for incorporation into the invention. Further, it also prevents anything from being caught in the gaps formed during bending which might impair the function of the bed base structure. As described above, the present invention provides the following advantageous features Since paralleled transverse support strips of the same form are connected at bendable portions, the bed base can be raised at the back and knee portions without giving any feeling of displeasing pressure or discomfort. Since the transverse support strips and longitudinal connector strips can be standardized to be the same shape and form, they can be easily mass-produced and are advantageous in view of manufacturing costs. If the intervals between respective adjacent transverse support strips are changed, the maximum bend angle can be adjusted. If the number of connected transverse support strips is changed, the length of the bottom can be changed. If the longitudinal connector strips are curved at portions between the attached transverse support strips, the bed base structure can be partially bent and the overall length in the longitudinal direction of the bed can be adjusted. Even if one of the transverse support strips or one of the longitudinal connector strips is broken during use, only the broken strip need be changed, allowing for easy maintenance. When a flexible sheet is used to cover the bed base structure, the structure is easier to clean, and dust and like such materials are prevented from impeding the function of the bed base structure during bending.

Claims: A bed base structure (2) for an adjustable bed (1), having a plurality of transverse support strips (8) connected together in a spaced relationship by at least one flexible connector strip (9) extending longitudinally of the bed base structure (2) to form a flexible curve portion of the bed base, characterised in that the said flexible connector strip (9) has curved portions between adjacent transverse support strips (8) whereby to allow a variation in the spacing of the transverse support strips (8). A bed base structure according to Claim 1, characterised in that each said transverse support strip (8) has four faces and the or each said flexible connector strip (9) is connected to one face of each transverse support strip (8) by attachment means (14). A bed base structure according to Claim 2, characterised in that the said attachment means (14) by which the flexible connector strip (9) is connected the said one faces of the transverse support strips (8) comprise screws. A bed base structure according to any preceding Claim, characterised in that it includes two longitudinal flexible connector strips (9) each attached adjacent a respective end of each transverse support strip (8). A bed base structure according to any preceding Claim, characterised in that the or each said longitudinal flexible connector strip (9) is attached to that face of each said transverse support strip which is an upper face when the bed base structure (2) is in a normal orientation of use. A bed base structure according to any of Claims 1 to 4, characterised in that the or each said longitudinal flexible connector strip (9) is attached to that face of each said transverse support strip (8) which is a lower face when the bed base structure is in a normal orientation of use. A bed base structure according to any preceding Claim, characterised in that there is a flexible covering (11) over at least one surface defined by corresponding faces of the said transverse support strips (8).

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