Adjustable bed

[57] ABSTRACT

The invention relates to an adjustable bed having a bottom resting upon a tripartite, hinged frame, and being provided with means for adjusting the bottom from a neutral, horizontal position to an oblique position with the foot end elevated, and to a folded position, wherein the back-supporting part is oblique or vertical, the two other parts forming a reversed V, the adjustment means being designed so as to be operated by a single mechanism maneuvered by the person occupying the bed.

UNITED STATES PATENTS

3,398,411 8/1968 Douglass..................................5/69 X

Claims, 4 Drawing Figures

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<img file="US3665528A_D0002.tif" />

PATENTED km 30 io??

3.665,528

SHEET 1 OF 3

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INVENTORS

FINN ANDRE KJELLBERG SVEND EDVARD NIELSEN LEMVIG BENT IVAN KJELLBERG

ATTORNEYS

PATENTEDMAY 30 1972

3,665,528

SHEET 2 OF 3

<img file="US3665528A_D0004.tif" />

INVENTORS

FINN ANDRE KJELLBERG

SVEND EDVARD NIELSEN LEMVIG

BENT IVAN KJELLBERG

ATTORNEYS

PATENTED MAY 3 Ο 1972

3,665,528

SHEET 3 OF 3

<img file="US3665528A_D0005.tif" />

INVENTORS

FINN ANDRE KJELLBERG

SVEND EDVARD NIELSEN LEMVIG BENT IVAN KJELLBERG

<img file="US3665528A_D0006.tif" />

ATTORNEYS

3,665,528

ADJUSTABLE BED

This invention relates to an adjustable bed of the kind having a bottom which, preferably infinitely variable, may be adjusted to a substantially flat horizontal position, called the neutral position, to a substantially flat extreme position with the foot elevated, the so-called Trendelenburg position, and to an extreme position, wherein the back-supporting part, in the following referred to as the back part, is raised to an oblique or vertical position, the remainder ofthe bottom being folded to support the legs and the tendons of the knees, by the buttocks-supporting part, in the following referred to as the seat part, being in an inclining position, and the leg-supporting part being in a declining position, intermediates between the said positions also being possible. The bottom, which may be in one flexible piece or in three pieces, which may be hinged together, rests upon a longitudinally tripartite frame with hinged connections between the parts to make it foldable on transverse axes, and has manually or motor-driven members effecting the adjustment into the various positions.

In known types of beds of the said kind, which are used e.g. in hospitals, rest homes, sanatoria, and nursing homes, several different adjustment members have to be operated to bring the bed into one of the desired positions, and as a rule this cannot be done by the person in the bed, since in practise the members to be operated have to be placed on the outer bedside at a level with or below the bed bottom, or on a special panel at the bedside.

The object of the invention is to provide a bed of the said kind, in which the adjustments are made by a single mechanism controlled by only one maneuvering member.

With this object in view, the bed of the invention is characterized in that the back part of the tripartite frame is pivotally, but immovably connected, by means of a joint, with a rigid supporting frame or a supporting member connected to the frame at or near its joint with the seat part, the frame also being movably supported by one or two supporting members on an adjustment member pivotally connected with the frame, and that the seat part is pivotally connected with the back part through a short lever, and loosely supported by a member being secured to the supporting frame, whereas the leg-supporting part is supported by a supporting member on an adjustment member also pivotally secured to the supporting frame, members being provided, which are adapted for exerting a pull to turn one of the adjustment members at a time.

In the neutral position, the tripartite frame is thus supported at five places on each side, viz. at two places of the back part by the adjustment member adjacent the head of the bed, by a supporting member secured to the rigid supporting frame near the joint between the back part and the seat part, by a supporting member at the middle of the seat part, and by a supporting member on the adjustment member acting upon the leg-supporting part. Since the adjustment to the various positions of the bed bottom is effected by pivoting the adjustment members only at one end at a time, all movements can be performed by a single mechanism, the operation of which brings the bed smoothly and continuously moving from one position to another.

In an embodiment of the bed of the invention, the supporting member for the seat part is adjustably secured to the rigid frame. This makes it possible to adjust the angle formed by the seat part and the leg-supporting part in the folded position, when the back part is raised to a vertical or oblique position.

In a further embodiment, the seat part and the leg-supporting part of the tripartite bottom adjacent to their joint have furnishings converging downwards towards one another and having near the bottom ends a pin on one furnishing engaging an arched slot in the other. This limits the pivoting at the joint so that the two parts remain flush when the foot is elevated from neutral to the Trendelenburg position, and generally strengthens the construction.

The adjustment members are preferably of triangular shape, one side of the triangle being substantially shorter than the two others, and being pivotally secured to the rigid supporting frame at one vertex at the short side, whereas the pulling members are secured neat the other vertex at the short side. This allows for a very simple fastening of the draw bar or chains acting upon the adjustment members, while still utilizing the pulling force to almost its full extent, when the adjustment members are mounted to pivot so that the short side of the triangle oscillates about a vertical position.

In a preferred embodiment, the adjustment member acting upon the back part of the bed bottom, and possibly also the adjustment member acting upon the leg-supporting part, has a furnishing of approximately shape as a sector of a circle, the arched side of which furnishing makes an unwinding curve for the pulling member. This allows for maximum utilization of the pulling force at all positions of the adjustment member acted upon.

The adjustment movements are preferably made by means of a reversible electromotor, the transmission of force taking place e.g. by means of spindles, racks or chain drives. In an appropriate embodiment of the bed of the invention, the pull activating the adjustment members is established by means of a cross-bar through openings in the ends of which the pulling members are loosely carried, and secured by nut, split pin or the like member, the cross-bar being movable by means of a nut connection cooperating with a reversibly rotatable spindle. This gives a simple manipulation of the adjustment members, since a movement of the cross-bar to one side from a central position brings the bed in Trendelenburg position and to the other side in the folded position. Reversing of the motor, and thus of the spindle acting upon the cross-bar, may be accomplished by means of switches, which are acted upon by the cross-bar in its extreme positions, or in other known manner, so that the only action needed for bringing the bed into the desired position is working a switch to start the motor, and to turn it off when the desired position is established.

Similar conditions, as when a motor is used, are in evidence, if the adjustment of the bed into the various positions is performed manually. Then, a turning movement of a hand-wheel is transmitted e.g. by a worm gear to the spindle as stated.

In the following, an embodiment of the bed of the invention will be more specifically described with reference to the accompanying drawings, wherein

FIG. I is a side elevation of the bed in the said neutral position, however, with all members removed, which are not of direct importance for understanding the invention,

FIG. 2 is a similar view of the bed in the so-called Trendelenburg position, i.e. with the foot of the bed elevated relatively to the head,

FIG. 3 is a similar view of the bed in the opposite extreme position with the back part in a steeply sloped position, and the remaining parts in a folded position for supporting the tendons of the knees, the legs, and the buttocks, and

FIG. 4 is a bottom side view of the bed.

To carry the (not shown) bottom of the bed, the bed of the invention has a frame consisting of three parts, a back part 10, a seat part 12, and a leg-supporting part 14. The said three parts of the frame may be made from L-girders of iron or other metal, or from other girders, and they may be designed as three rectangular frames, possibly each of these may be fitted with, or be in one piece with a rigid bottom, so that these three bottoms constitute the total bed bottom. Surrounding the frame 10,12,14, side boards and gables (not shown) for the bed may be arranged, and legs or other carrying members, possibly with wheels, may be provided.

The girders bordering the back part 10 each has an extension 16, which, as will be explained later, forms a small lever being rigidly mounted upon, or in one piece with the said girders to make the latter rigid throughout from the head part 18 of the frame to the extreme end of the extensions 16. By means of joints 20, preferably consisting of a pivot at each side of the frame, but possibly a through-going axle, the extensions 16 are pivotally connected with the girders bordering the seat part 12. Thus, the back part and seat part are mutually pivotal at this location around an axis transverse to the longitudinal direction of the bed.

3,665,528

The girders bordering the seat part 12 of the frame are pivotally connected by means of joints 22, which are preferably pivots at either side of the frame, but may be a through-going axle, with the girders bordering the leg-supporting part of the frame. Thus, the latter and the seat part are mutually pivotal at this location around an axis transverse to the longitudinal direction of the bed. In the connection formed by the joints 22, a limiting member for the pivoting is provided. This limiting member may be designed in several different ways and placed on one or both sides, or between the sides of the frame. Preferably, the limiting member is secured to the respective side girders at both sides of the frame. In the shown embodiment, the limiting member consists of furnishings 24 and 26 which are secured to the side girders of the seat part 12 and the leg-supporting part 14, respectively. The furnishings 24,26 extend below the frame and overlap one another here. One furnishing has an arched slot 28, and the other a pin 30, engaging and being movable in the slot 28. When the frame is in the neutral position shown in FIG. 1, or in the extreme position shown in FIG. 2 (extreme Trendelenburg position), the pin 30 is in one extreme position (in the shown orientation the extreme left position) in the slot 28. The member 24,26,28,30 thus prevents a turning upwards of the leg-supporting part 14 relatively to the seat part 12, thus ensuring that the said two parts are in aligned extension of one another, and preventing them from forming an angle with down-pointing vertex. In the extreme position shown in FIG. 3, corresponding to the seated position of a person in the bed, the pin 30 is at the opposite (in the shown orientation the extreme right) end of the slot 28, and the member 24,26,28,30 thus prevents, in the shown embodiment, the angle between the seat part and the leg-supporting part from becoming greater than corresponding to the length of the slot, in the shown length thus greater than shown in FIG. 3. By the angle between the two parts should always be understood the angle between one of the two and an extension of the other, as distinguished in FIG. 3 by the angle a; the angle a thus is 0° when the bed is in the positions shown in FIGS. 1 and 2, and in intermediate positions. It takes a value between 0° and the maximum value, for instance 30°, in an intermediate position between the neutral position shown in FIG. 1 and the extreme position shown in FIG. 3. It is not, however, necessary to limit this extreme position by means of the slot 28, since the limitation can also be made by means of cams cooperating with fixed stops.

By means of various members to be described later, the frame 10,12,14 is supported by a supporting frame 40. This can, for instance, be in the form of a lengthy, comparatively wide plate at each side of the bed, said plates being interconnected by angle bars, rods or in other manner. The supporting frame 40 is shorter than the frame 10,12,14, extending beyond the ends of the supporting frame, and the latter may repose upon the floor or be provided with facings, legs, or wheels reposing on the floor.

In the shown embodiment, the supporting frame 40 carries an upwards projecting furnishing 42 being provided at the top with a pin 44 cooperating with a pivot bearing in a rigid furnishing 46 secured to a side girder of the back part 10. The pin may also be on the furnishing 46, and the pivot bearing in the furnishing 42, and the resulting hinged connection may, if desired, take the form of an axle extending from one side of the back part 10 to the other. Deciding is that a joint is provided at this place between the frame 10,12,14 as a whole on one hand, and the rigid supporting frame on the other hand. The axis of rotation for the total frame 10,12,14, when turning from the position in FIG. 1 to that in FIG. 2, is that determined by the pins 44. As determined in horizontal projection, the distance between the axis determined by the pins 44 and the axis for the joint 20 should be small, for example 1-2 percent of the length of the bed, the piece between these two axes being the said short lever 16.

Pivotal on a pin or axle connection 48 a furnishing SO is attached to the head end of the supporting frame on either side. The two furnishings SO are mutually rigidly interconnected e.g. by girders. Each of the furnishings 50 carries at its top two supporting members 52 and 54, which both in the neutral position shown in FIG. 1 bear against a horizontal part (e.g. the horizontal part of an L- or U-shaped girder) of the side girders of the back part 10 of the frame 10,12,14. The supporting members 52,54 may be for instance small rolls or sliding blocks, e.g. made from nylon, and they may be rolls which are through-going from one side of the bed to the other. When the bed is in Trendelenburg position (FIG. 2) or in an intermediate position between the latter and the neutral position (FIG. 1), the supporting members 54 rest against the side girders of the back part 10, and when in the position shown in FIG. 3 or an intermediate position between this and the neutral position, the supporting members 52 only rest against the said side girders.

Pivotal on a pin or axle connection 56, a furnishing 60 is mounted on either side at the foot end of the supporting frame 40. The two furnishings 60 are mutually rigidly interconnected, e.g. by means of girders. At the top, each of the furnishings 60 carries a supporting member 62, which may be designed exactly like the supporting members 52,54, and which rests from below against a horizontal part of the girders forming the sides of the leg-supporting part 14 of the frame 10,12,14. There will always be contact between the supporting members 62 and the leg-supporting part 14 of the frame.

As stated, the supporting frame 40 is shorter than the frame 10,12,14, and is placed centrally or about centrally to the latter in the shown embodiment. On either side in the middle of the supporting frame 40, a furnishing 66 is provided, extending a little above the frame 40 and carrying a supporting member 68, e.g. a roll or a cylindrical slide block, at the top; the supporting members 68 may extend from one side of the bed to the other. The supporting members 68 bear from below against the bottom side of the side girders of the seat part 12 of the frame 10,12,14, when the bed is in neutral position, as shown in FIG. 1, or in the extreme position as shown in FIG. 3 as well as in intermediates between these two positions. The supporting members 68 serve as rocking point for the seat part 12 when the bed is adjusted from neutral position to folded position (FIG. 3) or vice versa. The steepness of the seat part 12 in folded position thus depends upon the ratio between on one hand the length of the lever between joints 44 and 20, and on the other hand the distance in horizontal projection between the joint 20 and the supporting member 68. The steepness is naturally also dependant on the angular position of the back part 10, but by a suitable choice of the ratio between the two distances 44-20 and 20-68, a comfortable, to the position of the back part adjusted oblique position of the seat part 12 can be obtained. The position of the seat part and that of the furnishing 60 determines the angle formed by the leg-supporting part 14 with the seat part 12, however, limited by the member 24,26,28,30.

In the shown embodiment, the furnishing 66 is rigidly connected to the supporting frame 40 and, accordingly, the supporting member 68 is not in contact with the seat part 12 when the bed is in Trendelenburg position (FIG. 2). However, the furnishing 66 or the supporting member 68 may be vertically adjustable, e.g. by means of a spring, so as to support the seat part also when the bed is in Trendelenburg position. The same effect can be attained if the furnishing 66 is adjustable in the longitudinal direction from the shown position in the middle towards the head 18 of the bed frame. By similar displacements, the angle between the seat part and the leg-supporting part at a given oblique position of the back part may also be changed.

At points above the centers of rotation (the joints 48 and 56) the furnishings 50 and 60 are connected, as very schematically shown in the drawings, with pulling members. These may be attached to the furnishings themselves, e.g. by a pivotal connection, but the connection is here shown as draw chains 70 and 72 (FIG. 4) which are carried over the arched rim of plates 74 and 76 shaped as sectors of a circle and mounted upon the furnishings 50 and 60. The draw chains 70 and 72 are continued by drawbars 78 and 80 passing loosely each

3,665,528 from its side through openings at the ends of a cross-bar 82, and being terminated by a nut screwed on.

The cross-bar 82 is movable in the longitudinal direction of the bed and is driven by means of a spindle 84 passing through a nut 86 in the cross-bar. The spindle 84 is driven from a reversible electromotor 88, e.g. as shown through a reduction gear 90 and a gear assembly 92.

The motor is operated by means of a push button control which may be mounted upon the side of the bed, on a stringer above the level of the bed bottom, on the head of the bed or at other suitable place within easy reach of a person in the bed, or it may be on a flexible cable to the motor so as to rest in the bed beside the person.

The pulling system operates as follows: In the neutral position of the bed, the cross-bar 82 is near the middle of the spindle 86. By operating the push button control, the motor is started, and it happens, for instance, that the cross-bar 82 is drawn towards the motor. Thus, a pull is exerted upon the drawbars 80, which act through the chains 72 carried over the plates 76 to turn the furnishings 60, whereby the leg-supporting part 14 is elevated when the supporting member 62 is forced against and rolls or slides on the bottom side of the part 14. Owing to the coupled furnishings 24 and 26, the seat part 12 will follow in the movement, which is a turning movement around the joint 14.

The movement of the cross-bar towards the motor further brings about that the bars 78 will be able to follow in the same direction, and the furnishings 50 will thus turn counterclockwise (in FIGS. 1 and 2) owing to the pressure from the back part 10, which thus pivots on the joint 44, so that the back part remains aligned with the two other parts, the bed thus being brought into Trendelenburg position.

The movement of the cross-bar to the left may be stopped by a switch (not shown) which may be designed to reverse the current supply to the motor 88, causing the latter to change its direction of rotation. The bed will then, as the cross-bar 82 is moving towards the middle of the spindle 84 (to the right in FIG. 4), return to the neutral position. If the motor is not stopped when this position is reached, the cross-bar will proceed to exert a pull on the bars 78, which via the chains 70 over the plates 74 forces the furnishings 50 to move clockwise, whereby the supporting members 52 will move upwards and slide or roll against a downward facing surface of the side girders of the back part 10 of the frame, while the supporting members 54 loose contact with the latter. Thus, the back part 10 is forced upwards in an oblique position, the turning point being the joint 44. Since the turning of the back part is clockwise (the orientation shown in FIGS. 1-3), the small lever between the joints 44 and 20 will move downwards and force the joint slightly downwards. The seat part as a whole, however, cannot partake in the downward movement as this is prevented by the supporting member 68. The seat part 12 is thus forced into a seesaw motion counter-clockwise (the orientation in FIGS. 1—3) with the supporting member 68 as the turning point. The end of the seat part 12 being closer to the foot of the bed will therefore be elevated together with the end of the leg-supporting part being closer to the head of the bed, a folding taking place in the joint 22, so that the parts 12 and 14 taken together and seen in elevation forms a reversed V. The opposite end of the leg-supporting part 14 is supported by the supporting member 62, and the angle formed by the folding is limited by the furnishings 24 and 26.

By readjustment from the sitting position shown in FIG. 3 to the neutral position, the motor has again to be activated, e.g. by means of a switch activated by the cross-bar, to rotate reversely, i.e. in the same direction of rotation as that bringing the bed from neutral position to Trendelenburg position.

Obviously by stopping the motor before the bed has gained one or the other of the extreme positions, the bed can be brought into any intermediate position between the two extreme positions. Also the push button control of the motor can be fitted with several contact positions in order to reverse the 5 current supply.

The motor may be replaced or supplemented by manually driven adjustment means.