Patient lifting apparatus

A patient lifting apparatus is provided that attaches to a bed frame having a plurality of legs and a headboard. The apparatus includes an upright member, a boom mechanically associated with the upright member, an upper support bar that extends across the bed frame and secures the upright member to each side of the headboard, and a lower support bar that extends across the bed frame and secures the upright member to the legs. The upright member is supported for rotation about a vertical axis by upper and lower bearings on the upper and lower support bars, respectively. A telescoping foot member extends from the lower support bar and is movable between a stored position and an extended position for stabilizing the lifting apparatus. A support arm extends from a lower end of the upright member and rotates along with the upright member to transfer vertical forces into the floor.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to patient lifting equipment. In particular, the present invention relates to a patient lifting apparatus for lifting and transferring incapacitated persons to and from a bed.

2. Description of the Related Art

Persons confined to a bed due to illness, age, obesity and so forth often have such limited mobility that movement or transfer from their bed is extremely difficult. It is well known to provide such persons with a patient lift to hoist the person from the bed and move him or her into a wheel chair or other desired location. Most such prior art patient lifts permit the patient to be raised or lowered and also permit the patient to be swiveled away from the bed about a vertical support member.

For example, in U.S. Pat. Nos. 4,554,691 and 5,459,891, patient lifting devices are disclosed in which a vertical support member is attached to support brackets which are secured to a floor and to a ceiling. A boom extends from the vertical support member and can be raised and lowered to lift the patient. However, the support brackets make these devices difficult to install in many locations where a permanent installation is undesirable (e.g., a temporary home care situation).

In U.S. Pat. Nos. 4,144,713, 5,560,054, 5,845,348, 5,987,664, 6,026,523 and 6,289,534, patient lift devices are disclosed which include wheeled support structures that allow the devices to be wheeled from place-to-place in a health care facility and used as stand alone equipment (i.e., they are not attached to the floor, ceiling or other fixture in the room). However, these devices typically require relatively heavy materials to provide the structural strength necessary to handle the bending moments and vertical forces encountered during use. As a result, these devices are expensive to manufacture and quite heavy, making them unsuitable for many health care facilities and home care situations.

Thus, there is a need for an improved patient lifting apparatus that is lightweight and capable of being temporarily attached to a fixture within the patient's room to lift and transport the patient to and from the patient's bed.

SUMMARY OF THE INVENTION

An object of the present invention to provide an improved patient lifting apparatus that overcomes the problems and disadvantages of the conventional patient lifts described above.

More specifically, it is an object of the present invention to provide a patient lifting apparatus that attaches to a patient's bed frame and uses the bed frame as a structural component for lifting and moving the patient, thereby reducing the weight and cost of the apparatus without sacrificing strength and durability.

It is a further object of the present invention to provide a patient lifting apparatus having an attachment system that is adjustable to accommodate different sizes and styles of bed frames.

It is a further object of the present invention to provide a patient lifting apparatus that is relatively simple mechanically while at the same time being reliable and safe in operation.

It is a further object of the present invention to provide a patient lifting apparatus that may be conveniently operated by a patient through the use of mechanical actuators and a hand held control to selectively raise, lower and/or translate the patient from one location to another.

In order to accomplish these and other objects of the invention, a patient lifting apparatus is provided that attaches to a bed frame having a plurality of legs and a headboard. The apparatus includes an upright member formed of a central inner column and an outer pipe that fits over the inner column. A boom is mechanically associated with the upright member and has a structure supported at its free end for attaching to or being gripped by the patient. The upright member is attached to the bed frame by upper and lower support bars. The upper support bar extends across the bed frame and secures the upright member to each side of the headboard of the bed frame. The lower support bar extends across the bed frame and secures the upright member to the legs of the bed frame. The upright member is supported for rotation about a vertical axis by upper and lower bearings on the upper and lower support bars, respectively. A telescoping foot member extends from the lower support bar and is movable between a stored position and an extended position for stabilizing the lifting apparatus. A support arm extends from a lower end of the upright member and rotates along with the upright member to transfer vertical forces from the lifted weight into the floor.

According to a broad aspect of the present invention, a patient lifting apparatus is provided, comprising: an upright member; a boom mechanically associated with the upright member for conveying a patient from one location to another; and a support structure for attaching the upright member to a bed frame. The support structure is arranged to transfer torque from the lifting apparatus to the bed frame during operation.

According to another broad aspect of the present invention, a patient lifting apparatus is provided, comprising: an upright member having upper and lower ends, the upright member being pivotal about a vertical axis; a boom means mechanically associated with the upright member for lifting and conveying a patient from one location to another; and a support means for attaching the upright member to a bed frame, the support means being arranged to transfer torque from the upright member into the bed frame during operation.

Numerous other objects of the present invention will be apparent to those skilled in this art from the following description wherein there is shown and described preferred embodiments of the present invention, simply by way of illustration of some of the modes best suited to carry out the invention. As will be realized, the invention is capable of other different embodiments, and its several details are capable of modification in various obvious aspects without departing from the invention. Accordingly, the drawings and description should be regarded as illustrative in nature and not restrictive.

DETAILED DESCRIPTION OF THE INVENTION

A patient lifting apparatus according to preferred embodiments of the present invention will now be described in detail with reference toFIGS. 1 to 8bof the drawings.

The patient lifting apparatus10according to a first embodiment is shown inFIG. 1in combination with a bed frame11, and is shown inFIG. 2as an exploded view of the various individual components. The bed frame11is a conventional design including left and right side rails12, a headboard13, and a footboard14. A first pair of legs15,16are formed at the bottom of the headboard13, and a second pair of legs17,18are formed at the bottom of the footboard14. A plurality of cross members (not shown) normally extend between the side rails12to support a box spring and mattress assembly (not shown) in the case of most beds found in private homes, or a platform and folding mechanism (not shown) in the case of adjustable hospital beds.

Although little standardization exists in bed frames, standard mattress sizes tend to drive the typical designs of the bed frames. The most common mattress sizes are Twin (39″ W×75″ L), Full (54″ W×75″ L), Queen (60″ W×80″ L), and King (78″ W×80″ L). The patient lifting apparatus10of the present invention is adjustable to accommodate these common sizes and also a large range of other sizes and constructions of bed frames11.

The patient lifting apparatus10includes an upright member19and a boom20mechanically associated with the upright member19. The boom20is pivotally attached to the upper end of the upright member19for pivoting movement about a generally horizontal axis21. A grapple, sling or other suitable structure22is secured to the free end23of the boom20for engaging a patient to be lifted.

A mechanical means is provided to selectively raise and lower the structure22at the end23of the boom20for lifting and conveying a patient from one location to another. The mechanical means can be a linear actuator24driven by an electric motor25, as shown inFIGS. 1 to 7a. However, other types of linear actuators, such as an actuator driven by hydraulic pressure, can also be used. Alternatively, the mechanical means can be a winch assembly (as described below) or a rack and pinion or other suitable mechanical assembly that accomplishes the objective of raising and lowering the structure22at the end23of the boom20. In the illustrated embodiment, the linear actuator24is operable to move the boom20between a lowered position, as shown inFIG. 3a, and a raised position, as shown inFIG. 3b.

The linear actuator24inFIG. 1has a first end26pivotally connected to the upright member19, and a second end27pivotally connected to the boom20. The linear actuator24is thus arranged to selectively raise and lower the free end23of the boom20upon extension and retraction of the actuator24. The electric motor25of the actuator24is connected to an electrical power source (not shown). A hand held control28is connected to the electric motor25, which can be operated easily by the patient or an assistant to energize the motor25and raise or lower the boom20as desired.

In the preferred embodiment, the upright member19comprises a central inner column29made of pipe and an outer pipe30that slips over an upper portion of the central column29. The use of pipe for the upright member19will allow the assembly to swivel freely, and will maximize the strength-to-weight ratio of the main components29,30supporting the patient's weight. For example, Schedule 80 steel pipe can be used, with the outer pipe30being provided in a 2-inch diameter nominal size and the inner pipe29being provided in a 1 2-inch diameter nominal size to nest within the outer pipe30.

The linear actuator24and the boom20are both attached to the outer pipe30. As such, the linear actuator24and boom20can be easily removed to facilitate mobility from one bed to another. For example, several inexpensive base assemblies (i.e., the central column29and other parts attached to the bed frame11) could be attached to the appropriate beds in a health care facility, and the comparatively more expensive actuator24and boom20assembly moved from bed-to-bed as needed.

A support structure31is provided for attaching the patient lifting apparatus10to the bed frame11. The support structure31includes an upper attachment system32that secures the upright member19to an upper portion33of the headboard13, and a lower attachment system34that secures the upright member19to at least one, and preferably two, of the legs15,16of the bed frame11. The support structure31is arranged to transfer torque from the lifting apparatus10to the bed frame11during operation.

The lower attachment system34of the support structure31comprises a lower support bar35that extends across the bed frame11and has each of its ends fastened to a respective leg15,16of the bed frame11. The particular fastening means in the preferred embodiment comprises a predrilled clamping plate36and a pair of U-bolts37at spaced locations along the lower support bar35. The U-bolts37allow the lower support bar35to be attached to bed legs15,16with both square and round cross sections, as well as other less common shapes. Various other types of threaded fasteners, such as hex head bolts, can also be used in conjunction with the clamping plates36, instead of the U-bolts37, to clamp the lower support bar35to the legs15,16of the bed frame11.

The U-bolts37and predrilled clamping plates36can be slid along the length of the lower support bar35to accommodate different sizes of bed frames11. Alternatively, the lower support bar35can be made as a telescoping assembly of two members that allow an adjustment in length to accommodate different widths of bed frames11.

The upper attachment system32of the support structure31comprises an upper support bar38that extends across the bed frame11and has each of its ends fastened to a respective side of the headboard13of the bed frame11. Since the headboard13is often the most expensive part of the bed, it is important to avoid marring the headboard13with the upper support bar38. Thus, it is desired that the upper portion33of the headboard13carry as little load as possible. A pair of L-shaped clamps39,40are positioned at each side of the headboard13. The clamps39,40each have a threaded portion41for receiving a nut (not shown) that can be tightened to apply and maintain a clamping force on the headboard13. A soft molded plastic jaw member42is used with each of the clamps39,40to avoid marring the headboard13.

A plurality of mounting holes43are spaced along the upper support bar38for accommodating different sizes of bed frames11. Alternatively, the upper support bar38can be made as a telescoping assembly of two members that allow an adjustment to accommodate different widths of bed frames11. The lower and upper support bars35,38can be made identical to each other, with the exception of the respective clamping structures, to reduce manufacturing costs.

The lower and upper support bars35,38each have a bearing structure44,45secured to one end thereof for supporting the upright member19. The bearing structures44,45are mounted to the support bars35,38by respective bent plate weldments46,47with vertical bores48,49extending therethrough. A lower bearing50is received in the vertical bores48of the weldment46on the lower support bar35, and an upper bearing51is received in the vertical bores49of the weldment47on the upper support bar38. The lower and upper bearings50,51allow smooth rotation of the upright member19relative to the support bars35,38, while transferring radial forces and the torque generated by such radial forces through the bearings50,51and into the bed frame11during use.

In the preferred embodiment, plastic coated bushings (e.g., Teflon7 or similar) are used as the upper and lower bearings50,51. The bushings50,51each have a collar52at one end that rests on the respective upper surface of the weldment46,47of the lower or upper support bars35,38to maintain the bushings50,51in place. The bushings50,51are arranged to absorb radial forces from the upright member19when a vertical force is applied at the end23of the boom20. Instead of bushings, the lower and upper bearings50,51could also be radial ball bearings or other suitable bearing structures. A collar (not shown) can be fixed to the upright member19just above the lower bearing50to transmit axial (i.e., thrust) forces from the vertical force of a patient's weight through the lower support bar35into the legs15,16of the bed frame11.

Typical bed frames11are designed to handle significant weights. However, a moment or twisting force imparted to a bed frame11is something the frame is likely to encounter only incidentally as it is moved, or momentarily as a person moves on top of the bed. Thus, the joint that joins the side rails12to the headboard13cannot be relied upon to resist the more than 1,500 ft-lbs of torque created by suspending a large weight from the end23of the boom20.

One solution to this problem is to reinforce the bed frame11. This can be accomplished by installing a pair of braces54between the headboard13and the side rails12, as shown inFIG. 1, to help stabilize the bed frame11when used with the patient lifting apparatus10of the present invention. While simple and effective, this solution is difficult to generalize to all bed frames because some side rails are angle iron, some rails are wooden, and some rails form a “box” to contain a spring and mattress set. The large variety of construction techniques for bed frames makes offering kits to encompass all of them difficult.

Rather than, or in addition to, reinforcing the bed frame11to handle the additional torque, the preferred embodiment incorporates a support arm55mechanically associated with the upright member19that minimizes the torque and stress on the bed frame11. The support arm55extends from the lower end56of the central column29of the upright member19and has a free end57placed as directly under the weight of the patient as is possible. The support arm55pivots with the upright member19and the boom20about a vertical axis between a first position with the end23of the boom20over the bed, as shown inFIG. 4a, and a second position with the end23of the boom20away from the bed, as shown inFIG. 4b. The free end57of the support arm55remains under the end23of the boom20(hence, the weight of the patient) at all times, and the twist transmitted to the bed frame11is thereby minimized.

A small wheel or caster58is provided at the end57of the support arm55to provide smooth travel over the floor. The support arm55can be used to transmit all of the vertical load from the weight of the lifted patient to the floor without passing through the bed frame11, thus making a thrust bearing between the lower support bar35and the upright member19unnecessary (e.g., a radial ball bearing or bushing similar to the upper bearing51will suffice).

As the patient's weight is swung out away from the bed, the bed may be susceptible to tipping. This tendency is reduced by use of the support arm55described above, but may still be present to a lesser degree. A telescoping foot member59that extends from the lower support bar35solves this problem. The telescoping foot member59is movable between its stored position, as shown inFIG. 6a, and its extended position, as shown inFIG. 6b. An adjustable support pad60for contacting the floor is provided at the free end61of the telescoping foot member59. The adjustable support pad60is coated with a soft, high friction material, such as molded rubber, to ensure a stable footing and to minimize scratching of the floor.

A second telescoping member62can be provided at the other end of the lower support bar35for further stabilizing the apparatus10. The second telescoping member62can be provided with a plate weldment63, as shown in detail inFIGS. 5aand5b. The plate weldment63has a plurality of mounting holes formed therein for attaching directly to the floor, to an extra-wide bed frame, or to a wall or other available structure for supporting and stabilizing the apparatus10.

Although operation of the patient lifting apparatus10requires very little force to rotate the patient once he or she is raised, it is desirable to have the ability to automatically rotate the upright member19and the boom20using the push of a button. To accomplish this, a gear motor64can be mounted to the lower support bar35, as shown inFIGS. 7aand7b. The gear motor64has a driving gear65engaged with a driven gear66near the lower end56of the central column29. The gear motor64is connected to a power source (not shown), such as an electrical outlet, and can be conveniently controlled using a switch button on the hand held control28.

The ability to automatically rotate the upright member19and the boom20provides a more complete level of independence to the final users of the apparatus10. Also, having complete control over the lift and rotation of the apparatus10might help to calm the fears of some patients, and give more independence to others.

An alternative embodiment of the patient lifting apparatus100will now be described with reference toFIGS. 8aand8b. In this embodiment, a winch101and cable102are used instead of a linear actuator to lift a patient. The boom103is integral with the upright member104in this embodiment and does not pivot relative thereto as in the embodiment described above. Instead, the tip105of the boom103remains at a constant height, and the cable102of the winch101raises and lowers as necessary to raise and lower the patient.

The winch101is mounted to the upright member104, and the cable102extends from the winch101into a bent pipe or the like that serves as the upright member104and the boom103. The end106of the cable102hangs from the tip105of the boom103and has a grapple, sling or other suitable structure (not shown) secured thereto for engaging a patient to be lifted. One or more pulleys (not shown) may be incorporated into this embodiment to minimize friction forces as the cable102is moved within the upright member104and the boom103. Operation of this embodiment100is much the same as the embodiment10described above, with a hand held control (not shown) being used to selectively energize the motor of the winch101to raise and lower the patient.

The present invention provides a patient lifting apparatus10,100that uses a common household fixture, i.e., a bed frame11, for support. As a result, a cheaper, lighter, yet still robust patient lift is provided, making the lift apparatus suitable for both in-home care situations and small managed health care scenarios. The apparatus10,100is flexible and adjustable to accommodate a wide variety of sizes and constructions of bed frames11.

While the invention has been specifically described in connection with specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.