AU9723698A - Lifting device - Google Patents

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Lifting device The following statement is a full description of this invention, including the best method of performing it known to me: FHPMELC698351023.2 LIFTING DEVICE Field of the invention This invention relates to a lifting device and refers particularly, though not exclusively, to a lifting device for use with beds or other similar products.

Throughout the specification reference to bed or beds is to not be taken as being limited to beds. It may be for a mattress, a work platform or other device requiring lifting and retraction.

Background of the invention In the hospitality industry, and in particular in hotels, motels, guest houses, serviced apartments and the like, as well as in the domestic environment, there is a significant problem quite often in the making of beds. By making of beds this is meant the replacing of sheets and other bed linen, and representing the bed in good form. With most beds in the hospitality sector being somewhat lower than waist height, workers are quite often performing these tasks, including the lifting of the mattress, below waist height. This requires bending. This quite often causes injury to the worker. Injury to workers has resulted in significant loss of productivity and increased medical expenses insurance to the employers.

In the domestic environment, those suffering from lower back problems, or the elderly, quite often have difficulty in properly making beds as they again have to bend to make the bed.

It is therefore the principal object of the present invention to provide a lifting device for use with beds and which enables the beds to be selectively raised and lowered.

Brief description of the invention With the above and other objects in mind the present invention provides a i/98334018.2 2 lifting device having a lower frame, an upper frame, at least one hinged device connecting the lower frame to the upper frame to retain the upper frame and the lower frame in alignment during the raising and lowering of the upper frame relative to the lower frame, at least one lifting means attached to the upper frame and the lower frame to enable upper frame to be raised relative to the lower frame without external assistance, and retention means on one of the upper frame and lower frame adapted to hold the upper frame and lower frame in close relationship prior to the raising of the upper frame, the retention means being able to be released to allow the lifting means to raise the upper frame relative to the lower frame, and the retention means being able to engage on the other of the upper frame and lower frame when the upper frame is lowered relative to the lower frame.

Preferably, the means for raising the upper frame is a hydraulic or pneumatic ram. More preferably, the lifting means further includes a second hydraulic or pneumatic ram. Advantageously, the second ram is connected at its upper end to the upper frame and is free at its lower end. More advantageously, the second ram is disposed substantially vertically.

Advantageously, there are two hinged devices, one at each end of both the upper frame and lower frame.

More preferably, the retention means is at least one ratchet mounted for arcuate movement on the lower frame, there being a retaining plate for engaging in the ratchet, the retaining plate being attached to the upper frame.

More preferably, there are two retention means one on either side of the bed.

Advantageously, there is a release device attached to the retention means to enable the retention means to be disengaged to allow the upper frame to be raised relative to the lower frame. More advantageously, the release device is biased to the engage position so that upon the upper frame being lowered relative to the lower frame the retention means will engage automatically. Most X/98334018.2 3 advantageously, the biasing is by means of a spring or springs.

The upper frame may have a peripheral frame having longitudinally extending members on either side thereof, and laterally extending members joining the longitudinally extending members. Preferably, the longitudinally extending members have arms extending laterally outwardly therefrom.

Preferably, the arms extending laterally outwardly are releasably engaged with the longitudinally extending members. In this way the width of the upper frame can be varied by adding/removing the lateral arms, or by using lateral arms of different lengths, so that beds of differing widths can be placed on the one upper frame.

Advantageously, there are transverse members at each end of the upper frame, the transverse members at the end each having releasable arms attached thereto extending outwardly therefrom. In this way beds of different lengths may be placed on the upper frame in the same way as for the lateral arms.

Brief description of the drawings In order that the invention may be fully understood it will be described by way of non-limitative example only a preferred construction of a lifting device incorporating the principal features of the present invention, the description being by way of non-limitative example only and with reference to the accompanying illustrative drawings in which: Figure 1 is a perspective view of the lifting device in the lowered position; Figure 2 is a perspective view of the lifting device of Figure 1 in the raised position; and Figure 3 is an enlarged perspective view of the retaining means of the lifting device of Figures 1 and 2.

.;D/98334018.2 4 Description of preferred embodiment The lifting device shown has a lower frame generally designated as 10, and an upper frame generally designated as 12. The lower frame 10 has two spacedapart and generally parallel longitudinally extending members 14 interconnected by transverse members 16. In this way, the lower frame 10 is created. The lower frame 10 may be mounted on suitable feet or castors 18 as shown. At a first end of each of the longitudinally extending members 14, there is provided a depending mounting block 22, the purpose of which will be understood from the following description. Further mounting blocks 24 are provided intermediate the length of the longitudinal members 14, and again the purpose of the mounting blocks 24 will be understood from the following description.

The upper frame 12 also has two longitudinally extending members 26 which are spaced apart and generally parallel. It is preferred that the length and orientation of the upper frame longitudinal members 26 and the lower frame longitudinal members 14 are generally the same. Again, extending between the upper frame longitudinal members 26 are upper frame transverse members 28.

Extending between the upper frame 12 and lower frame 10 are two hinge members generally designated as 30. These hinge members 30 have side arms 32 on each side thereof which are pivotally attached to the mounting blocks 22, 24 at their lower end and to the longitudinally extending members 26 at the upper ends. Extending between the side arms 32 are transverse rails 34. Extending between the transverse rails 34 is a support rail 36. In this way upon the upper frame 12 being raised relative to the lower frame 10 the hinge members 30 keep the upper frame 12 in correct orientation and relationship with the lower frame Extending transversely from the upper longitudinal members 26 are lateral arms 38. These may be provided on each of the longitudinal arms 26. The lateral arms 38 may be integral or securely attached to the longitudinal members 26, or may be releasable therefrom. If releasable, this enables beds of different widths to be used in relation to the one lifting apparatus. Either way, the length of, the lateral arms 38 may be varied to allow for the one lifting apparatus to be used for beds of 30/98334018.2 different widths.

Although not shown, transverse members may be placed at each end of the upper frame 12 with longitudinally extending arms similar to the lateral arms 38 so that beds of different lengths may be used with the one lifting mechanism.

A hydraulic or pneumatic ram 40 is provided and which connects a lower transverse member 16 to an upper transverse member 28. The ram 40 biases the upper frame 12 to the raised position and must have sufficient strength to be able to raise the upper frame 12 and any bed placed thereupon. However, it should not be overly strong so that one person can lower the upper frame 12 by weight of the upper body pressing on the bed using the arms and hands. A spring may be used instead of ram A second hydraulic or pneumatic ram 41 may also be provided as illustrated in Figure 2. The ram 41 is connected at its upper end to upper transverse member 28. The lower end 43 of ram 41 remains free and contacts lower plate 45 when the upper frame 12 is in its lowered position. As illustrated, the ram 41 is disposed substantially vertically. Ram 41 serves to assist the ram in raising the upper frame 12 by providing a relatively large vertical component of lift in the early stage of raising the upper frame 12. In this early stage, the vertical component of lift provided by ram 40 is relatively small.

On one of the lower frame transverse members 16 is provided a retention means generally designated as 42. This is more accurately illustrated in Figure 3.

Extending through a hole 44 in a lower longitudinally extending arm 14 is an operating shaft 46 which, at its outer end, has an operating handle 48. A plurality of bearings 50 secured to the transverse member 16 maintain operating shaft 46 in correct location.

Extending radially outwardly and upwardly from shaft 46 and on either side of the lower frame 10 are two ratchet members 52. The ratchet members 52 have a plurality of barbed teeth 54 which co-operate with a plate 56 attached to a ,98334018.2 6 transverse member 28 of upper frame 12. In this way, when the upper frame 12 is lowered, the plate 56 will pass along the sloping upper edge 58 of each of the teeth 54 and engage under the teeth 54. The appropriate height may then be selected. By providing a biasing means (not shown) such as a spring to bias the ratchet member 52 to the engaging position, the lowering of the upper frame 12 will automatically cause engagement and therefore holding.

A lower plate 60 may be provided on the lower transverse members 16 to provide a limit for the ratchet member 52.

In operation, a user merely has to provide small pressure to the handle 48 to rotate shaft 46 to cause teeth 54 to no longer engage plate 56. The upper frame 12 will then move upwardly under the action of ram 40 and ram 41 until ram reaches its upper limit, or is stopped by the length of the hinge members S whichever is the earlier. When in this position, the bed can be made. By controlling the nature of the ram 40, its operating length, and the hinge members 30, it can be assured that the upper frame 12 will lift the bed to an appropriate height for ease of making of the bed.

If desired, the upper frame 12 can be integral with the base or mattress of the bed so that it may be sold as an integral unit. If desired, the lower longitudinal members 14 may be provided with limit blocks 62 (see Figure 2) so that the upper frame 12 will always be spaced slightly from the lower frame 10. It also provides a lower limit of movement.

Also, if desired, the hinge members 30 may have at least one diagonal brace to assist in the rigidity of the structure.

Whilst there has been described in the foregoing description a preferred construction of a lifting device in accordance with the present invention, it will be understood by those schooled in the technology concerned that many variations or modifications in details of design of construction may be made without departing from the essential features of the present invention.

(,;98334018 2 7 It will be understood that the term "comprises" or its grammatical variants as used herein is equivalent to the term "includes" and is not to be taken as excluding the presence of other elements or features.

It will be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.