A bottom structure of a bed

Abstract: A bottom structure (2) of a bed (1) having a bottom formed so as to be bendable by a series of paralleled strips (5) mutually sequentially connected such that the strips (5) are shorter in width on the side away from the sequentially connected side. In this way the bottom structure (2) of the bed (2) allows a portion of a bed bottom (2) to be bent in a large curvature, thus is provided a bed (1) which is comfortable and highly adaptable for patients of various body sizes.

Description: The present invention relates to a bottom structure of a bed which allows the bottom to be bent upward, forming a large curvature such that it does not cause a patient to feel any discomforting pressure. The present invention also relates to a bottom structure of a bed which allows a patient to experience minimum physical discomfort irrespective of his body size when the bottom structure of a bed is bent, forming a large curvature in the leg portion corresponding to the leg or knee position of the patient or forming a large curvature in the waist portion of the patient. In many recent beds, e.g. as shown in DE-A-3912442, the bottom structure is divided into a back portion, waist portion, leg portion etc. to allow the back portion and/or the leg portion to be raised by a drive. In these beds the bottom structure can be bent upward to alter the position of the back portion or knee portion, using various mechanisms. Thereby in DE 3912442 the bottom structure comprises a number of longitudinal members extending in the longitudinal direction of the bottom structure. Said longitudinal members which are interconnected by traverses can be bent for forming a desired curvature in the bottom structure. FR-A-2624711 discloses a bottom structure comprising hollow strips having a rectangular cross section and being interconnected by two parallel belts. The present invention provides a bottom structure of a bed as defined in claim 1. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side illustration showing an essential region of a bed having a bottom structure with a leg portion according to the present invention. Figure 2 is an enlarged side view showing a cross section of the leg portion shown in the figure 1. Figure 3 is an enlarged side view showing a cross section of the bottom of another embodiment. Figure 4 is a side illustration showing an essential region of a bed having a bottom structure with a back portion of the present invention. Figure 5 is an enlarged side view showing a cross section of the back portion shown in Figure 4. Figure 6 is an enlarged side view showing a cross section of the back portion of another embodiment. Figure 7 is an illustration showing a bottom structure of a bed where the bottom is covered with a flexible sheet. Figure 8 is an illustration showing a bottom structure of a bed where a flexible sheet is laid on the upper side of the bottom structure. Figure 9 is an illustration showing a bottom structure of a bed where a mattress (or other material) is caught in the bottom structure. The bottom structure of a bed according to one embodiment of the present invention, is designed to allow the leg portion of a bed bottom, corresponding to the leg position of a patient, to be bent at a large curvature. The leg portion of a bed bottom corresponding to the leg position of the patient is formed by parallel strips, which allow bending. The parallel strips are preferably formed by thermoplastic molding as hollow strips. The parallel strips are preferably almost trapezoidal in cross section and are sequentially connected on the upper side, with gaps formed between the respectively adjacent paralleled strips on the under side. The leg portion may be provided with a leg portion raising mechanism, which raises the leg portion using a support arm. Thus is provided a bed which is highly adaptable for patients of various body sizes. The bottom structure of a bed according to another embodiment of the present invention, is designed to allow a bed bottom to be bent upward in a large curvature, thus providing a bed which allows back formation without causing a patient to feel any displeasing pressure. A bottom is formed by using parallel strips at the portion corresponding to the waist of the patient, to allow being upward. The number of parallel strips is preferably five, and they are preferably formed by thermoplastic molding as hollow strips. The parallel strips are preferably almost trapezoidal in cross section, to form gaps with an angle of about 16 degrees between the respectively adjacent faces of the parallel strips on the upper side. The bottom is provided with a back raising mechanism for bending the bottom upward through a support arm. Thus is provided a comfortable bed designed to ease the feeling of pressure caused to a patient by back raising action. The bottom structure of a bed according to yet another embodiment of the present invention, includes a flexible sheet. If a bottom structure has gaps on the upper side, when it is bent, mattress material or other covering material can be caught between the parallel strips. One way to minimize material being caught in the gaps and reduce interference with the bottom structure, is to insert a flexible bottom sheet. This sheet prevents material from interfering with the operation of the bottom structure and reduces the collection of dust and dirt in the gaps of the bottom structure as well. The bottom structure of a bed of the present invention is described below in reference to the figures shown in the attached drawings. As shown in Figure 1, in a bed 1, a bottom 2 is divided into a back portion 3 and a leg portion 4 corresponding approximately to the leg position of the patient. The leg portion (4) is formed by paralleled strips 5 to allow bending, and the parallel strips are sequentially mutually connected on the upper side. Each of the parallel strips is shorter in width on the under side than on the upper side. The parallel strips 5 of the leg portion 4 are preferably formed by thermoplastic molding as hollow strips almost trapezoidal in cross section as shown in Figure 2, and sequentially connected on the upper side, with gaps 7 formed between the respectively adjacent parallel strips 5 on the under side. Under the leg portion 4 , a leg portion raising mechanism is provided to bend the leg portion upward through a support arm 6. In this embodiment of the bottom structure, if the leg portion is raised by the leg portion raising mechanism, the support arm 6 is pivotally rotated to rise, causing the respective parallel strips 5 to be brought into mutual contact on the under side, thus causing the leg portion 4 to bend and protrude upward. As a result, the leg portion 4 is generally bent at a large radius of curvature 8 . Therefore, even if the protruding top does not suit the knee position of the patient, the knees are still kept from experiencing pressure, and the patient does not feel any discomfort. In another embodiment of the present invention, the parallel strips 5 are formed in a trapezoidal shape only at the lower halves of the strips in cross section as shown in Figure 3. In this embodiment, the gaps 9 formed between the respectively adjacent parallel strips 5 allow the leg portion to be bent generally at a large curvature by leg portion raising; and thus the bed is especially suitable for tall patients. Since the leg portion 4 is preferably formed by thermoplastic molding as hollow strips, it can be easily prepared, is simply in structure, and economically advantageous in view of the reduced cost to manufacture. As described above, the present invention can provide a bed highly adaptable for patients of various body sizes. As shown in Figure 4, another embodiment of the bed 11 has parallel strips 13 as parts of the bottom 12 at the portion corresponding approximately to the waist of the patient, to allow bending of the bottom. The strips are connected with each other on the under side. Each of the strips 13 is shorter in width on the upper side than on the under side. The bottom 12 has preferably five parallel strips 13 formed preferably of thermoplastic molding as hollow strips. The parallel strips 13 , as shown in Figure 5, are almost trapezoidal in cross section and are sequentially connected on the under side, with gaps 17 formed at an angle of preferably about 16 degrees between the respectively adjacent opposite faces of the parallel strips 13 . Under the bottom 12 , a back raising mechanism 14 for bending the bottom 12 through a support arm 15 may be provided. In this bottom structure, if the back raising mechanism 14 is driven for raising the back portion, the support arm 15 is pivotally rotated to a raising position, causing the respective parallel strips 13 to be brought into mutual contact on their upper side, to bend the bottom upward at a large curvature (radius of curvature 18). As a result, the bottom 12 can be bent upward to an angle of about 80 degrees, to secure a proper space around the waist of the patient, which eases the feeling of pressure caused by raising the back portion. The present invention can also be provided with parallel strips 13 formed to be trapezoidal in cross section only at approximately the upper half of the strips as shown in Figure 6. Also in this modification, since gaps 19 are formed between the respective parallel strips 13 on the upper side on the bottom, the back raising action makes the bottom bent upward, generally in a large curvature, to secure a moderate space around the waist of the patient. This bed bottom can be especially suitable for tall patients. Since the bottom 12 is preferably formed of thermoplastic molding as hollow strips, it can be easily prepared, is simple in structure, and thus economically advantageous in view of the cost to manufacture. As described above, the present invention provides a comfortable bed designed to ease the feeling of pressure caused by raising the back portion. In the bottom structures, as shown in Figures 4 to 6, the gaps formed by the bottom structure are on the top and next to the bedding material. When the bottom structure is bent, the mattress 20 placed on the bottom, may become caught between the parallel strip. Figure 9 shows how mattress or bedding material 20 can be caught in the gaps of the bottom structure when bent. Figure 9 includes an enlarged view of material caught in a gap. To prevent this, it is preferable to cover the bottom structure with a flexible sheet 21 . The flexible sheet 21 may cover the entire structure as shown in Figure 7, or be laid on top of the structure as shown in Figure 8. Figure 8 includes an enlarged view of one means 22 for connecting the flexible sheet to the bottom structure. In this method of attachment, the flexible sheet is attached directly 22 to the bottom structure at the end of the structure. Also, in the embodiments shown in Figures 4 to 6, the gaps formed on the upper side can collect dust and dirt. However, when the structures are covered with a flexible sheet, dust and dirt can not collect in the gaps. Furthermore, the flexible sheet is easily cleaned, improving the health and safety of the patient. The sheet also prevents any other objects from being caught in the gaps and impairing the function of the bottom structure. The above particular embodiments have been described for the purpose of illustration of the invention. It is to be understood that these embodiments and other variations and modifications are within the spirit of the invention and the invention is not to be taken as limited except by the scope of the appended claims.

Claims: A bottom structure of a bed (1, 11) comprising a base (2, 12) formed so as to be bendable and comprising a series of parallel hollow strips (5, 13) mutually sequentially connected and extending perpendicular to the longitudinal length of the bottom structure and over the width of said bottom structure the connections of the strips being located on the upper or lower side of the base and extending over the whole length of said strips, said strips (5, 13) being formed by thermoplastic molding and being shorter in width, measured longitudinally of the bottom structure, on the side away from the connected side than on the connected side. A bottom structure of a bed according to claim 1 wherein a series of strips (5) are connected on the under side and form a part of the bottom structure which is bent forming a large curvature below the plane extending through the ends of the bottom structure and a series of strips (13) are connected on the upper side and form a part of the bottom structure which is to be bent forming a large curvature above the plane of the bottom structure. A bottom structure of a bed according claim 1 or 2, wherein said parallel strips (5, 13) are substantially trapezoidal in shape in cross section. A bottom structure of a bed according to any preceding claim wherein a gap (7, 17) is formed between the parallel strips (5, 13) at the interconnected shorter side forming an angle of about 16 degrees. A bottom structure of a bed according to any preceding claim wherein said parallel strips (5) are formed in trapezoidal shapes only at about the lower halves of the strips. A bottom structure of a bed according to any preceding claim further comprising a leg portion raising mechanism (16). A bottom structure of a bed according to any preceding claim further comprising a back portion raising mechanism (15). A bottom structure of a bed according to any preceding claim wherein said bottom (12) can be bent upward to an angle of about 80 degrees. A bottom structure of a bed according to any preceding claim further comprising a flexible sheet (21) covering the entire bottom structure (12) at the side away from the connected side.

Inventors: IKEDA YASUHIRO, IKEDA, YASUHIRO
Applicants: PARAMOUNT BED KK, PARAMOUNT BED COMPANY LIMITED
Application year: 1993
Main classification: A47C31
IPC codes: A47C31, A47C23, A47C20