Hospital bed

Abstract

A hospital bed having an adjustable head section which is preferably combined with an adjustable seat section. A head gatch mechanism couples the head section to the bed frame and can be operated to move the head and seat sections from a horizontal position into a position in which the seat section is inclined downwardly towards the head section which is inclined upwardly. The mechanism is adjustable for patient weight so that the head section can be made to follow patient movement between supine and sitting positions.

Description

This invention relates to hospital beds, and more particularly to a hospital bed having a head section which can be moved between lowered and raised positions by a patient moving himself between respective supine and sitting positions.

Hospital beds are commonly provided with various adjustments which are considered necessary both from a medical standpoint and also from the standpoint of patient comfort. One of these adjustments commonly permits a head section to be moved between a horizontal or lowered position and an inclined or raised position. An improvement on this adjustment is to also provide a seat section which is coupled to the head section and which becomes inclined downwardly towards the head section as the head section is inclined upwardly. Consequently, in a sitting position, the seat section tends to better locate the patient against sliding movement down the bed and is therefore more comfortable for the patient.

The head section is commonly elevated by a manual actuator located at the foot of the bed and operated by a nurse when the patient wishes to change his position. Consequently, the patient must first call a nurse before such a bed can be adjusted. An alternative arrangement is to provide an electrical control which the patient can operate himself. Although such controls are used with success, they nevertheless suffer from the disadvantages both that they are relatively expensive and that they must include safety controls which are designed to make it difficult for a patient to injure himself by accidental misuse of the electrical control.

It is an object of the present invention to provide a head section which will move between a lowered or horizontal position and a raised or inclined position as a patient moves himself between the supine and sitting positions.

It is a further object of the invention to provide a combination head section and seat section which move to support a patient as the patient moves between a supine position and a sitting position.

Accordingly, in one of its aspects, the present invention provides a hospital bed having an adjustable head section on a bed frame. A head gatch mechanism couples the head section to the bed frame and can be operated to raise and lower the head section. The mechanism is adjustable for patient weight so that the head section can be made to follow patient movement between supine and sitting positions.

In another of its aspects the present invention provides a hospital bed having adjustable head and seat sections pivotally connected to one another and coupled to a bed frame. A head gatch mechanism couples the head section to the bed frame and can be operated to move the head and seat sections from a horizontal position into a position in which the seat section is inclined downwardly towards the head section which is inclined upwardly. The mechanism is adjustable for patient weight so that the head section can be made to follow patient movement between supine and sitting positions.

These and other aspects of the invention will be better understood with reference to the drawings, in which:

FIG. 1 is a perspective view of a bed incorporating the invention;

FIG. 2 is a side view of the bed with parts in section to illustrate hidden detail and including a double-acting locking mechanism in a locked position;

FIG. 3 is a sectional view on line 3--3 of FIG. 2;

FIG. 4 is a sectional view on line 4--4 of FIG. 2;

FIG. 5 is a sectional side view of the double-acting locking mechanism in a released position; and

FIG. 6 is a view similar to FIG. 2 showing the bed in another position.

Reference is first made to FIG. 1 which shows an exemplary bed frame 10 to which is attached a head gatch mechanism 12 for use in adjusting the head section 14 and seat section 16 of a mattress support 18. This support is adapted to carry a conventional mattress such as that indicated at 19 in FIG. 2.

The bed frame 10 is typical of any suitable frame and includes longitudinal members 20, 22 connected at their ends to respective transverse members 24, 26. The longitudinal and transverse members define a rectangular frame and four legs 28 extended downwardly from corners of this frame. As is conventional, the legs are supported at their lower ends on respective castors 30.

Three support members 32, 34, and 36 extend transversely between the longitudinal members 20, 22. Each of the support members is in the form of a shallow inverted U and these members are positioned so that the members 32, 34 support a leg section 38 of the mattress support 18 and the member 36 supports an outer end of the head section 14.

The leg section 38 is attached to the members 32, 34 and is connected by a pair of pivots 40 (one of which is shown) to the seat section 16. Pivots 42 at the other end of the seat section 16 connect this section to the head section 14. The respective pivots 40, 42 lie on parallel transverse axes. Head section 14 is also supported by a pair of links 44, 46 which are connected at their respective lower inner sides of the longitudinal members 20, 22 by pivots 48, 50 and to the head section 14 by pivots 52, 54. The links 44, 46 combine with the head gatch mechanism 12 to control the movement of the seat section 16 and head section 14 as these sections move between the positions shown in FIGS. 1 and 6. These movements will be described after completing description of the structural components of the head gatch mechanism 12.

Reference is now made to FIGS. 1 and 2 with particular reference to FIG. 2 to described the head gatch mechanism 12. This mechanism is operated manually by a crank 56 on an outer end of a shaft 58 which is carried in a swivel bearing 60 on the transverse member 24 of the frame 10. The shaft 58 is threaded at its inner end for engagement in threaded end piece 62 of a first element 64. This element is telescoped at its forward end in a second element 66 for relative axial movement of one element relative to the other element. The element 66 is connected by a pivot 68 to a distal end of a heavy bracket 70 attached to the underside of the head section 14 adjacent the pivots 42.

The element 64 includes a cover 72 having a generally U-shaped section and attached at its end to the end piece 62. A fillet 74 is also attached to the cover 72 and is adapted to slidably receive an elongated hardened shaft 76 forming part of the second element 66. As seen in FIG. 3, this shaft is also located between a pair of transverse pins 78, 80 which are engaged in the cover 72. A washer 82 is held against these pins by a compression spring 84 contained in the second element 66.

The cover 72 also has a pair of pins 86, 88 attached to it above the shaft 76 between the fillet 74 and the pins 78, 80. The pins 86, 88 form parts of a double-acting locking mechanism 90 which is adapted to limit relative movement between the elements 64, 66 as will be described. The mechanism 90 includes a pair of similar locking elements 92, 94 which are biased away from one another by respective tension springs 96, 98 anchored in opposition in the cover 72. These elements are of a material which complements the shaft 76 to permit the elements to lock the shaft frictionally without substantial damage either to the elements or to the shaft. Locking element 94 is typical of both locking elements and is better seen in FIG. 4. The element 94 fits relatively snugly inside the cover 72 to locate the element 94 transversely and the shaft 76 passes through the element 94 loosely. The spring 98 biases the element into frictional engagement with the shaft 76 and this frictional engagement will become sufficient to lock the element to the shaft under certain conditions which will be described.

Returning to FIG. 2, the frictional engagement of the locking elements 92, 94 on the shaft 76 can be relieved by actuating a hand control 100 which is connected by a sheathed cable 102 to the locking mechanism 90. On operating the hand control the sheath bears against the locking element 92 and the cable pulls the locking element 94 so that the elements are moved toward one another into a position such as that shown in FIG. 5. In this position there is a minimal frictional engagement between the locking elements 92, 94 and the shaft 76 so that the elements 64, 66 are no longer locked to one another.

The element 66 includes a cover 104 to which an anchor 106 is attached for connecting an end of the shaft 76 to the cover 104. The compression spring 84 is retained in compression between the washer 82 (FIG. 3) and the anchor 106 to bias the elements 64, 66 apart when the locking mechanism 90 is in the position shown in FIG. 5. The significance of this arrangement will become apparent upon describing the operation of the bed as follows.

In use, the head gatch mechanism 12 can be used conventionally with the handle control 100 in the normal or locked position corresponding to the position of the locking mechanism 90 shown in FIG. 2. In effect the elements 64 and 66 are then locked to one another and form the equivalent of a single link connecting the heavy bracket 70 on the underside of the head section 14 to the threaded shaft 58 which is attached to the crank 56. Consequently, upon rotating the crank in a direction corresponding to raising the head section, the bracket 70 is made to rotate in a generally anti-clockwise direction as drawn in FIG. 2. Consequently, the head section 14 also rotates guided by its connection with the seat section 16 and the respective links 44, 46 (FIG. 1). Further rotation of the crank 56 will ultimately result in the sections 14 and 16 taking the positions shown in FIG. 6 in which the head section 14 is at an angle of about 60 degrees to the horizontal. The seat section 16 is then inclined downwardly from the leg section 38 to better locate the patient in a sitting position.

Returning to FIG. 2, it will be evident that use of the head gatch mechanism as just described requires that a nurse is available. However, the combination of the first and second elements 64, 66 is also intended to permit the patient to raise and lower himself as will now be described.

Imagine the situation in which the compression spring 84 is compressed sufficiently that it tends to force the second element 66 away from the first element 64 to raise the head section 14. Such a substantial force from the spring 84 causes the friction in the locking element 94 of the locking mechanism 90 to tend to move towards the associated spring 98 about the pin 88. This attempted movement will result in increased reaction forces between the locking element 94 and the shaft 76 to lock the shaft 76 in position relative to the element 74. Consequently, no movement can take place in this condition. Also, if a patient or nurse were to attempt to unlock the mechanism 90 by operating the hand control 100, the result would simply be that the locked element 94 would be unmoved and the other element 92 would be free to move under the influence of the sheathed cable 102. The mechanism would however, remain locked. It will therefore be evident that the mechanism 90 can be unlocked by pressing downwardly on the head rest to balance the force exerted by the spring 84 on the mechanism 90. The crank 56 can then be rotated to relax the spring until the upward force at the head rest is removed.

Consider now the situation shown in FIG. 2 in which the spring 84 is relaxed and a patient is lying on the bed. The mechanism 12 is adjusted by operating the hand control 100 and turning the crank 56 until the head section is about to move upwardly. The patient then balances the spring force and if the patient moves towards a sitting position the seat section 16 and head section 14 will follow him as seen in FIG. 6. If he gets out of bed, then the locking element 94 will come into play automatically to prevent sudden movement of the head and seat sections under the influence of the compressed spring 84. When a patient is to give up his bed to another patient it is preferable to relax the spring 84 by turning the crank 56. The mechanism is then adjusted to the weight of the next patient by turning crank 56 to compress the spring as previously described with reference to the first patient. However, if the first patient simply leaves the bed set for him and a lighter or heavier second patient then takes the bed, it will be necessary to readjust the bed.

In the case of a lighter second patient his weight will not be sufficient to unlock the locking element 94. Consequently, he can do one of two things. Firstly he can apply more weight to the head section by moving himself or by having a nurse help him by pushing down on this section. This permits the hand control to release the locking element 94 and the crank 56 is then used to relax the spring to a condition in which the second patient is balanced. Secondly he can have a nurse turn the crank 56 to raise the head section until the limit of the travel is reached to balance the spring force. Consequently the locking elements 92, 94 can then be released using the control 100 and the crank is then used to allow the spring to relax to the desired condition to balance the patient.

In the case of a heavier second patient his weight will tend to cause the locking element 92 to lock to the shaft 76. Here again there are two possibilities. Firstly, the patient can reduce the weight on the head section either by raising himself slightly or by having a nurse apply an upward force to the head section to permit the control 100 to be relaxed. The crank 56 is then turned to re-set the spring compression to match the second patient's weight. Secondly, he can have a nurse turn the crank 56 to lower the head section to the limit of its travel which will cause a reaction between the head section and the support member 36 sufficient to permit the control 100 to release the locking element 92, 94 so that the spring 84 can be adjusted.

It will now be evident that when the mechanism 12 is adjusted, the head section 14 and seat section 16 move towards a sitting position under the influence of the spring 84 and return to the lowered or flat position under the influence of the patient's weight. Also, it is necessary to re-set the mechanism 12 whenever a new patient uses the bed unless this patient happens to have substantially the same weight characteristics as the previous patient.

Although the preferred embodiment shown in the drawings includes a pivotal seat section, the principle of a balanced head section can also be applied to a mattress frame in which the seat section 16 is permanently aligned with the leg section 38. In such a structure the links 44, 46 could be eliminated and the head section would be supported at pivots 42 during movement above the support member 36. While a structure of this type is within the scope of the invention the embodiment described with reference to the drawings provides greater advantages and is therefore considered to be preferable.

In some instances electric actuation could be preferable. The crank 56 would then be removed in favour of an electric motor and gear box to drive the shaft 58. Generally the crank 56 and shaft 58 are typical of any suitable actuator means adapted to cause the head and seat sections to move as described.

Claims

I claim:

1. A hospital bed comprising:

a bed frame;

a mattress support coupled to the bed frame and including a head section rotatable about a horizontal axis between a horizontal position and a raised position in which the head section is inclined upwardly from said axis;

a head gatch mechanism comprising: first and second elements coupled together for axial telescopic movement relative to one another; a bracket attached to the head section and pivotally connected at a distal end thereof to an end of the second element remote from the first element; spring means coupled at its ends to said first and second element and adapted to bias the first element axially away from the second element; a double-acting locking mechanism coupled to the first and second elements and adapted to prevent relative movement between the first and second elements when a substantial force is applied to move one of said elements axially with respect to the other of the elements; control means coupled to the locking mechanism and operable to unlock the mechanism when said substantial force is removed; and actuactor means coupling the first element to the bed frame and adapted to move the first element axially relative to the bed frame, whereby when the bed is in use, the head gatch mechanism can be adjusted to the weight of a patient on the bed by first operating the control means to release the locking mechanism to permit relative movement between the first and second elements, and then moving the said first element axially using the actuactor means, so as to vary the biassing effect to the spring means until the said effect is balanced by the weight of the patient.

2. A hospital bed as claimed in claim 1 in which the second element includes a shaft and the first element includes means locating the shaft for longitudinal movement as the elements telescope relative to one another, and in which the locking mechanism comprises a pair of locking elements engaged about the shaft and movable between a released position in which the locking elements are generally perpendicular to the shaft and a locked position in which the locking elements are inclined with respect to the shaft for frictionally engaging the shaft; location means coupled to the first element and adapted to locate the locking elements relative to the first element such that the locking elements can pivot about said location means between said released and locked positions; and means biassing the locking elements towards said locked positions; the said control means being adapted to permit the locking elements to be moved from the locking positions into the released positions upon removal of said substantial force.

3. A hospital bed comprising:

a bed frame;

a mattress support coupled to the bed frame and including a head section, a seat section, and a leg section, the seat section being pivotally coupled to the leg section for movement about an axis between a horizontal position and an inclined position in which the seat section slopes downwardly from the leg section, and the head section being pivotally connected to the seat section for movement about another axis parallel to said first mentioned axis between a lowered position in planar alignment with the seat section when the seat section is in the horizontal position and a raised position in which the head section is inclined upwardly from said another axis with the seat section being in the inclined position;

link means coupling the head section to the bed frame to at least partly support the head section as this section moves between the lowered and raised positions;

a head gatch mechanism comprising: first and second elements coupled together for axial telescopic movement relative to one another; a bracket attached to the head section and pivotally connected at a distal end thereof to an end of the second element remote from the first elements; spring means coupled at its ends to said first and second elements and adapted to biass the first element axially away from the second element; a double-acting locking mechanism coupled to the first and second elements and adapted to prevent relative movement between the first and second elements when a substantial force is applied to move one of said elements axially with respect to the other of the elements; control means coupled to the locking mechanism and operable to unlock the mechanism when said substantial force is removed; and actuactor means coupling the first element to the bed frame and adapted to move the first element axially relative to the bed frame, whereby when the bed is in use, the head gatch mechanism can be adjusted to the weight of a patient on the bed by first operating the control means to release the locking mechanism to permit relative movement between the first and second elements, and then moving the said first element axially using the actuactor means, so as to vary the biassing effect of the spring means until the said effect is balanced by the weight of the patient.

4. In a hospital bed of the type having a bed frame, a mattress supported above the frame and coupled to the bed frame, and a head gatch mechanism coupled to the bed frame and to a head section of the mattress support for moving the head section between a horizontal position and an inclined position, the improvement in which the head gatch mechanism comprises: first and second elements telescopically interconnected for axial movement relative to one another; spring means coupled at its ends to said first and second elements, said spring means. biasing the elements away from one another; means coupling the second element to the head section; a double acting locking mechanism coupled to the first and second elements and adapted to prevent movement between the first and second elements when a substantial force is applied to move one of said elements; and actuactor means coupled to the first element and to the bed frame and adapted to move the first element axially relative to the bed frame, whereby when the bed is in use, the head gatch mechanism can be adjusted to the weight of a patient on the bed by first releasing the locking mechanism to permit relative movement between the first and second elements, and then by moving the said first element axially using the actuactor means so as to vary the biassing effect of the spring means until the said effect is balanced by the weight of the patient.

5. Apparatus as claimed in claim 4 in which the second element includes a shaft and the first element includes means locating the shaft for longitudinal movement as the elements telescope relative to one another, and in which the locking mechanism comprises a pair of locking elements engaged about the shaft and movable between a released position in which the locking elements are generally perpendicular to the shaft and a locked position in which the locking elements are inclined with respect to the shaft for frictionally engaging the shaft; location means coupled to the first element and adapted to locate the locking elements relative to the first element such that the locking elements can pivot about said location means between said released and locked positions; means biassing the locking elements towards said locked positions; and control means adapted permit the locking elements to be moved from the locking positions into the released positions upon removal of said substantial forces.