Beds

[57] ABSTRACT

A hospital type bed in which the legs at each end of the bed are connected together by a cross member so that legs at each end pivot together to adjust the height of the bed from the floor. Threaded centrally controlled adjusting rod connected to each cross member and to a central control position under the bed frame.

Claims, 8 Drawing Figures

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PATENTED APR 91974

3^802,002

SHEET 1 OF 2

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PATENTED APR 91974

3,802,002

SHEET 2 OF 2

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3,802,002

BEDS

This invention relates to beds. In particular the invention relates to beds in which the height of the bed, or of either end of the bed, above a floor on which the bed is standing may be varied.

In hospitals and other places caring for patients who are bed ridden it is often desirable to vary the height of a bed to assist in the nursing or examination of the patient.

It is also necessary in many cases to have one end of a bed higher than the other to assist in treating a patient’s ailment.

It is an object of this invention to provide a bed in which height of the bed, or height of either end of the bed, above a floor may be readily and easily varied.

According to this invention there is provided a bed comprising a frame having supporting legs therefor; the legs being pivotally mounted to be disposable at varying angles to a floor on which the bed is situated; two threadably engaged male and respective female threaded members operatively associated with the frame and legs so that one of each of the male and respective female threaded members is rotatable to cause generally linear movement of the one or the respective other of the threaded members whereby to vary the angular relationship of the legs with respect to the floor.

Preferably the bed has four supporting legs one at each corner of the bed and the two legs at each end of the frame are constructed to pivot together such as by having a cross-member jointing them together.

It is also preferred that the male threaded members are adapted to rotate and that each of the female threaded members are held in a non-rotatable manner. In a particularly preferred embodiment of the invention the male threaded members are threaded shafts engaging female threaded members secured to such a crossmember joining the two legs at each end of the frame.

In a further preferred embodiment of the invention the threaded members which are to be rotated may be rotated independently of one another.

The invention also envisages the use of a drive means for the members which are to rotate. In one embodiment of the invention the drive means includes a mechanical drive mechanism. In a particularly preferred construction the mechanical drive mechanism is a gearbox having two bevel gears therein.

An input drive member is attached to one bevel gear and is adapted to be rotated as by a detachable handle. Two output drives are provided which are connected to the rotatable members via release couplings.

In another embodiment of the invention the drive means includes an electric motor. The electric motor is arranged with one of its output shafts driving a dual output gearbox. From each output of the gearbox the rotatable members are driven via an electromagnetic clutch. All functions of the motor and clutch being controlled by a detachable plug-in control panel.

In addition to the use of an electric motor to provide drive to the shafts a further preferred construction of bed has an adjustable mattress supporting surface. This mattress supporting surface is in three parts and also has its adjustment means driven by the electric motor through further electromagnetic clutches.

In this case the adjustment panel has controls to operate both functions of the bed.

The invention will now be more fully described with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of a bed in accordance with the invention,

FIG. 2 is a side elevational view of the bed of FIG. 1 and shows the legs substantially perpendicular to a floor,

FIG. 3 is the same view of the bed as in FIG. 2 but the legs are shown at an angle whereby to reduce the height of the bed frame above the floor,

FIG. 4 is a sectional view taken on the line 4—4 in

FIG. 2,

FIG. 5 is a sectional view on line 5—5 of FIG. 4 and shows a part in a certain condition,

FIG. 6 is a sectional view on line 5—5 of FIG. 4 but shows said part in another condition.

FIG. 7 is a side elevational view of one embodiment of the invention.

FIG. 8 is a view of the drive means of the bed of FIG. 7.

FIG. 1 shows a bed having a bed frame 1, an adjustable and detachable headrest 3 and a detachable foot panel 5. Adjacent each corner of the bed are four supporting legs 7. The two legs at each end of the bed being joined together approximately mid-way along their length by cross-members 9 and 11.

Each of the four legs is fitted with a wheel to enable movement of the bed and for ease of adjustment of the height of the frame.

Near one side of the frame 1 and on the underside thereof is attached a gearbox 13.

Threaded shafts 15 and 17 are connected to drive shafts 31 and 33 of the gearbox 13 and engage correspondingly threaded female members 19 and 21.

Referring now to FIGS. 2 and 3. Each of the threaded shafts 15 and 17 is driven by the gearbox 13 through a universal joint 23 and a release coupling 25. As best seen in FIG. 4 the release couplings each have an operating lever 27 which is pivoted at 29 to a flange on the gearbox 13.

Each of the output drive shafts 31 and 33 from the gearbox is slotted at the end remote from the gearbox.

FIG. 5 shows one of the release couplings in the disengaged condition. The output drive shaft 31 is received in the end of a drive transfer shaft 35 to which one part of the universal joint 23 is mounted. A sleeve 37 surrounds the shaft 35 and is slidable thereon. A pin 39 extends through the sleeve 37 and through the shaft 35 which is slotted longitudinally at 41. The lever 27 has two forks 43 each with a projection 45 which engages a corresponding groove in the outer surface of sleeve 37. In the condition shown in FIG. 5 rotation of the shaft 31 does not cause rotation of shaft 35 or sleeve 37.

When it is desired to drive shaft 35 and consequently the threaded shaft 17, the lever 27 is moved to cause the pin 39 to move into the slot 47 in the output drive shaft 31 (See FIG. 6). Now rotation of shaft 31 causes shaft 35 and sleeve 37 to rotate — the projections 43 sliding in the groove in the sleeve 37.

Referring to FIGS. 2 to 4, when a handle 51, such as the one shown in FIG. 2, is attached to an input shaft 53 of the gearbox 13, rotation of the handle will turn a bevel gear 55 mounted on a bearing 57 which in turn

3,802,002 will rotate a bevel gear 59 and a shaft 61 mounted on bearings 63 and 65. Shafts 31 and 33 are extensions of shaft 61.

When the release couplings 25 are engaged, turning the handle 51 rotates shafts 15 and 17 in the same direction. The shafts 15 and 17 are threaded on the ends remote from the gearbox 13 but the thread on shaft 15 is of the reverse hand to that on shaft 17 so that turning the handle either causes the legs 7 to move apart or to move toward each other.

From the position of the legs 7, as shown in FIG. 2, turning the handle in either direction will lower the height of the bed frame 1. For reasons of stability spreading of the legs 7 to a position shown in FIG. 3, or any position in between what is shown in FIGS. 2 and 3, is preferred. At the position shown in FIG. 3 the shafts 15 and 17 are parallel to the floor and the bed frame is at its lowest position. To raise the height of the bed frame the handle is turned in the opposite direction.

If only one end of the bed is to be raised or lowered the threaded shaft attached to the legs 7 at the other end of the bed is disengaged from the gearbox by movement of the appropriate lever 27 which disengages the appropriate release coupling 25 as described above.

When the release coupling is disengaged the shaft 15, or 17 as the case may be, does not rotate as a result of the weight of the bed, even when the legs 7 are in the position shown in FIG. 3. This stability is achieved by the pitch of the thread on the threaded shaft being such as to withstand the forces on the legs 7 without rotating.

The handle 51 is provided with a bracket 52 secured to the frame 1 for holding the handle 51 when it is not in use.

In another embodiment of the invention the gearbox 13 and the release couplings 25 are replaced by an electric motor 67 and electromagnetic clutches 69 and 71, as seen from FIG. 8.

A control panel is also provided which actuates the electric motor and which separately actuates the required electromagnetic clutches when a particular movement of the bed is desired. For example, if one end of the bed is to be lowered then only the threaded shaft operating the legs at that end of the bed receives drive from the electric motor 67 by actuation of the particular electromagnetic clutch which is associated with that threaded shaft.

In a further embodiment of the invention there is provided a bed having a lowering, raising and tilting mechanism as herein described in combination with an adjustable mattress supporting surface. As shown in FIG. 7 the mattress supporting surface of the bed is in three parts. A first member 77 pivoted at one end thereof to the bed frame 1 and a second member 79 pivotally mounted at one end to member 77, the other end of the member 79 being slidably engaged with the bed frame. A third member 81 is pivoted at one end to the bed frame adjacent the pivoted end of member 77. The lever arms 83 pivot about points 85 and 87 which in turn raise or lower the mattress supporting surface.

Shafts 89 are threaded at their ends remote from the electric motor and have female threaded members 91 engaged therewith. The female threaded members 91 are pivotally secured to lever arm 83. Rotation of shafts 89 which cause the members 91 to be drawn towards the electric motor will cause the lever arms 83 to pivot the first member 77 and the third member 81 about their pivot points on the bed frame.

A spring may be necessary to retain the member 91 at its position on the threaded shaft 89 once the electromagnetic clutch is disengaged. This will depend on the pitch of the threads on the threaded shaft and may also depend on the way the patient is to be positioned on the bed.