WO2007014331A2

WO2007014331A2 - Bed lifting system

Info

Publication number: WO2007014331A2
Application number: PCT/US2006/029428
Authority: WO
Inventors: Josef M. Anderson
Original assignee: Anderson Josef M
Priority date: 2005-07-27
Filing date: 2006-07-27
Publication date: 2007-02-01
Also published as: CN2900461Y; CN1903697A; WO2007014331A3

Abstract

A power bed-lifting system raises a bed on its frame to a desired height so the bed can be made by a worker standing upright. The system uses an electric motor or other drive system to create the motion necessary to drive threaded-rod and scissors assemblies to raise or lower the bed. The scissors assembly includes X shaped legs, joined at a center pivot point and attached to a frame of the system, and track rollers locked in a channel frame. The threaded actuating rod or ballscrew acting on the scissor assemblies causes the system to raise or lower the bed. The motor is made operable to raise and lower the bed through switches, pushbuttons, or other types of controllers so the height may be custom adjusted to the worker. Adjustable extension rails make the lifting unit adaptable to any size bed frame from a twin at 38' x 75' to an Eastern Icing, measuring 76' x 80'. Other types of lifting assemblies are described.

Description

BED LIFTING SYSTEM

BACKGROUND OF THE INVENTION

The present invention relates to a lifting system for raising a bed to a desired height so the bed can be made by a standing person. In addition, a U-shaped rack attached to the foot of the frame and hidden beneath the bed, can be pulled out, and used as a holding support for a bedspread and pillows while malting the bed, keeping them off the floor and within arms reach.

Housekeepers are subject to one of the highest rates of repetitive-motion injury. The making of a bed involves kneeling and bending over two dozen times. Leaning over to pull a heavy comforter off the bed places strain on the lower back. It takes extra steps to carry the comforter and pillows to a nearby chair or table, then bring them back once the sheets are changed. By raising the bed to a workable height, housekeepers can avoid the repetitious bending and stooping that strains back muscles, as well as additional steps. These small motions add up the end of the day when cleaning, for example, sixteen rooms in a hotel, motel, or hospital.

There are over 7 million hotel beds in North America. There are 8 million in Europe. Untold numbers of workers could be spared lower-back strain and unnecessary fatigue by simply raising the bed to a workable height. There is good reason to do this. There were 17,980 reported injuries among housekeepers and maids across the country in 2004 that led to days missed from work, according to the Bureau of Labor Statistics. The numbers are probably higher because workers are reluctant to report their injuries for fear of being reprimanded or fired.

The University of California at San Francisco published a study in July of 2005 that found three out of four hotel housekeepers experience severe pain while at work and afterwards. The reported number of injuries has increased, the study reported, because workers are trying to clean the same number of rooms per shift even as the beds grow bigger and more elaborate.

Housekeepers must clean about sixteen rooms per day, and make up or change twenty-six beds per shift. Each bed can have up to seven pillows, a down quilt, and accessories like bedscarves, bolsters and skirts.

The study also found that 62% of hotel workers had seen a doctor for their pain, and 84% were talcing medication for pain they incurred at work. A just-released study of 40,000 hotel workers' injuries at 87 U.S. lodgings from 1999 to 2005, found that room attendants had the highest injury rate.

The "Creating Luxury, Enduring Pain" study, compiled from hotel mandatory injury records, and released by the UNITE HERE union, said hotel housekeepers had a 10.4% injury rate. That was more than 85% higher than the 5.6% injury rate of non-housekeepers. The study said housekeeper injury rates increased from 2002-2005. A major culprit is the industry's switch to heavy mattresses, triple-sheeting, and more pillows. In a different UNITE HERE survey of 622 housekeepers in 2005, 91% reported experiencing workplace pain. Of those 66% said they take pain medication. The cost of lower back injuries and insuring workers has risen dramatically. Costs per room for insurance has risen from $248.00 per room in 2000, to well over $600 in 2005. A lot of money is at stake. Lower-back injuries accounted for 15 percent to 20 percent of workers' compensation injuries, and about 35 percent of workers' compensation costs in the last year. Low-back disorders account for almost 30% of injury requiring time away from work. Its estimated economic impact in lost productivity, health-care-related expenses, and disability are staggering.

The average cost of low-back-associated workers-compensation claim is nearly $8,500. This is double the cost of an average injury claim. The total estimate of injury costs paid out each year in the United States ranges between $50 and $100 billion dollars. A large portion of this cost is directly related to workers compensation.

Injuries to the back are one of the most prevalent and costly work-related musculoskeletal disorders in the United States. Low-back pain adversely affects about one- million workers in the United States every year, and is responsible for more lost work days than any other musculoskeletal disorder. On average, people with back injuries miss a total of six working days. However, nearly 20 percent of persons with back injuries missed more than 31 days of work. One quarter of all compensation indemnity claims involve back injuries, with an economic cost of billions of dollars to industry, without consideration of the pain, suffering, and impact upon quality of life. It has been long recognized that it is desirable, for both comfort and utility, to be able to adjust the height of the work at which one is standing. Hydraulic lifting tables are standard in industry. Pallet jacks have long been used to position heavy items at a level where back strain is avoided. Extended periods of bending can lead to unnecessary fatigue and discomfort that, in the interest of safety and occupational satisfaction should be minimized. Any field where the work is, by necessity or custom, performed in a standing position confronts this hazard. Bending over, even slightly, for protracted periods of time without relief, can lead to chronic back problems, or exacerbate an already existing condition.

SUMMARY OF THE INVENTION This invention is directed to a bed lifting system for raising a bed off the floor to a more comfortable height for bedmaldng. The system comprises a generally rectangular frame engageable with an undersurface of the bed. A plurality of vertically extendible means are secured at corners of the frame to move the bed between raised and lowered positions. A drive means such as a bidirectional electric motor is mounted on the frame, and operable to extend and retract the extendible means. In the extended position, the entire bed is raised above the floor. In the retracted position, the bed rests on the floor, and the lifting system is retracted beneath the bed and above the floor. Alternative embodiments are described, including the addition of a rack which is slidably mounted on the frame, and extendible therefrom to receive pillows and bedspreads during bed making.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a double bed supported on a first embodiment of a bed-lifting system of this invention, the system being in a lowered, retracted position.

FIG. 2 is a view similar to FIG. 1, but with the bed in phantom to show the system;

FIG. 3 is a perspective view of an underside of the bed, with the system in a retracted position;

FIG. 4 is a perspective view, similar to FIG. 1, but with the system in a raised or elevated system;

FIG. 5 is an end view of the bed as supported on an elevated system;

FIG. 6 is a side view of the bed as supported on an elevated system;

FIG. 7 is a perspective view of the bed underside, with the system in an elevated position; FIG. 8 is a simplified perspective view of the bed-lifting system alone, and in an elevated position;

FIG. 9 is a simplified perspective view of a second embodiment of a bed-lifting system in an elevated position;

FIG. 10 is similar to FIG. 9, but with the system in a retracted, lowered position; FIG. 11 is an end view of a third embodiment of the frame and legs of a bed-lifting system using telescoping legs, and in an elevated position;

FIG. 12 is a partial and broken-away side view of the third embodiment; and

FIG. 13 is a bottom plan view of the third embodiment.

DETAILED DESCRIPTION OF THE INVENTION Description Of The Preferred Embodiments

FIGS. 1-8 show a first embodiment of a bed lifting system 10 according to the invention. Fig. 1 shows system 10 in a retracted position, and secured beneath a conventional double bed 11, having a mattress 12 supported on a frame and box spring 13, and a headboard 14. In the retracted position, system 10 and bed 11 are supported on casters 15 at each corner of the bed.

Fig 8 shows system 10 alone, and in an elevated position. The system has a rectangular metal frame 17 with adjustable flanged clamps 18 at each corner to secure the system to bed 11 as shown in Fig. 3. An adjustable rack 19 is slideably extendable from the foot end of the frame to provide a support for pillows and bedspreads while the bed is being made.

Four sissor assemblies 20 are pivotably secured at their upper ends to frame 17, and each assembly has a pair of legs 21 which are centrally pivoted to be moveable between an X-shaped elevated position (Figs. 4-8), and a retracted position in which the legs are nearly parallel (Figs. 1-3). Wheels 22 are mounted at the lower end of each leg. A reversible a-c motor 24 is secured to a mounting base 25 which is rotatably mounted on a round shaft 26 secured between the lower ends of two of the sissor assemblies as shown in Fig. 8. Extending from the motor shaft is an elongated ballscrew 27 which extends through a mating threaded block 28 pivotable mounted on a round shaft secured to and extending between the opposite pair of sissor assemblies. The motor circuitry (in a box 29) is conventional, and can be actuated by pushbuttons, a keyswitch, or an infrared controller to select clockwise or a counterclockwise rotation of the shaft. FIG. 1 shows a pushbutton control box 30 mounted on the bed headboard, but other convenient locations can be selected.

In one rotational direction, ballscrew 27 drives threaded block 28 away from the motor to push the sissor assemblies into a fully extended X-shape to raise the bed to a convenient heightened position (FIGS. 4-8). Opposite rotation of the motor and ballscrew will draw together and nearly flatten the sissor assemblies to a retracted position (FIGS. 1-3) with the bed casters 15 resting on the floor, and the lifting system fully retracted upwardly beneath the bed, and with sissor-assembly .wheels 22 above the floor. An elongated hand crank (not shown) may be engaged with the ballscrew to operate the system in the event of power failure.

A second embodiment of a bed lifting system 32 is shown in FIGS. 9 and 10, and is generally similar to system 10, but uses a different style of sissor assemblies 33 at the corners of a frame 34. Each assembly 33 has an elongated leg 35 pivotably secured to the frame, and having a wheel 36 at its lower end. A shorter leg 37 is pivotably secured at its upper end to the frame, and at its lower end to a midsection of leg 34.

System 32 has a motor 38, which rotates a ballscrew 39 threadably engaged with crossmembers 40 pivotably secured to the upper ends of opposing pairs of legs 34, and slideably mounted on frame 34. One direction of rotation of the ballscrew drives crossmembers 40 apart to move the sissor assemblies to an extended position (FIG. 9), and the opposite rotational direction draws the crossmembers together to nearly flatten the sissor assemblies in a retracted position (FIG. 10). System 32 is otherwise generally similar to system 10, and accordingly need not be described in further detail. The system again includes a slidable rack 41 (shown extended in FIG. 9, and retracted in FIG. 10) for holding pillows and bedspreads during bed making. The invention is not limited to sissor assemblies for raising and lowering a bed, and a third embodiment of a lifting system 45 is shown in FIGS. 11-13, and which uses four telescoping threaded legs 46 secured at their upper ends to the corners of a bed-supporting frame 47 as already described. A bi-directional drive motor 48 has a sprocket 49 engaged with a chain 50 which extends around, and is engaged with sprockets 51 at the upper end of each leg.

The legs of course extend and retract in synchronism, but for illustrative purposes, one leg is shown fully extended, and another fully retracted in FIG. 12. The chain is protected by channels (not shown) as it extends from sprocket 49 to sprockets 51, and is elsewhere channeled through the frame.

The invention is not limited to an electric-motor drive, and may also be pneumatically or hydraulically actuated. Similarly, other types of extendable legs or jacks can be used to raise or lower the system. Whatever type of leg or linkage is used, it should preferably allow the elevation of the mattress top to about 48 inches for comfortable bed making by a tall worker.

Lifting of the entire bed off the floor enables easy vacuum cleaning beneath the bed. When the lifting system is lowered, it retracts fully beneath the bed frame, and does not interfere with an attractive appearance of the bed.

Claims

WHAT IS CLAIMED IS :

1. A bed lifting system for raising a bed to a more comfortable level for bed making, comprising: a frame with attachment means for securing the frame to an underside of the bed; a plurality of vertically extendible means secured at corners of the frame, and moveable between extended and retracted positions, the bed being lifted off an underlying floor in the extended position, and the bed resting on the floor with the lifting system raised beneath the bed and off the floor in the retracted position; and a drive means actuable by a user and coupled to each extendible means to raise and lower the bed.

2. The system of claim 1 in which each vertically extendable means is a sissor assembly having a pair of pivotedly connected legs.

3. The system of claim 1 in which the drive means is a bidirectional electric motor having a ballscrew extending therefrom to threaded blocks coupled to the sissor assemblies for extending and retracting the sissor assemblies.

4. The system of claim 1, and further comprising a rack which is slidably mounted on the frame and extendible therefrom to receive pillows and bedspreads during bedmaking.

5. The system of claim 1 in which the vertically extendible means are telescoping legs secured to the frame.

6. The system of claim 5 in which the drive means in a bidirectional electric motor engaged with a chain which extends around mating sprockets at the upper ends of the telescoping legs.