NZ229526A - Elevating bed with tilt facility and safety features - Google Patents

Description

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P.O. Journal, ^o: ....f .3r5.L 2 3 DEC 1991 NEW ZEALAND PATENTS ACT, 1953 No.: Date: COMPLETE SPECIFICATION "ELEVATION BED" SANWA SHUTTER CORPORATION, a Japanese corporation of 1-1, 2-Chome Nishi Shinjuku, Shinjuku-ku, Tokyo,, 163, Japan hereby declare the invention for which I / we pray that a patent may be granted to me /us, and the method by which it is to be performed, to be particularly described in and by the following statement: - (followed by page la) 22p26 - la- The present invention relates to a bed for installation in a room having relatively little floor #pj*ce. In particular, the present invention relates to an elevation bed which can be moved up and down between positions in which it is used and stored.

The increasing cost of apartment space has created th<3 need for a bed which utilises floor space more effectively than a conventional bed. In consequence/ elsvation beds have been proposed in which one end of the be J is hinged to a wall or furniture and the other end of ths bed is raised or lowered as needed. In this kind of bei, it is necessary to make sure that the mattress and beS clothes are securely bound to the sleeping platform before the bed is raised.

It is also well known to use elevation beds in which the sleeping platform moves vertically while maintaining a horizontal posture. Such beds must be provided with means for limiting the movement of the sleeping platform. Typically, each corner of the sleeping platform engages a guide rail and motion is limited by the ends of the guide rail. Rubber stoppers majy be provided in the guide rail to cushion the impact the sleeping platform at the limits of motion. pically also, the sleeping platform is raised or wered by means of cord members from an electrical or nual driving device. Where movement of the sleeping of Ty lo ma pl ca atform is limited by the ends of the guide rails^frhe bles may become slack creating problems in the wtfading^a * r 13 NOV 1991 \ 22*526 mechanism.

It is an object of the present invention to overcome, or at least ameliorate, this disadvantage of the prior art.

Accordingly, there is provided an elevation bed of the type having a sleeping platform suspended by cord members from a driving device supported by a structural frtme, said structural frame including guide rails in sliding engagement with said sleeping platform, said 10 driving device operable to selectively extend and retract said cord members and to move thereby the sleeping pl<itform between upper and lower positions, said driving device including a level regulating device for limiting extension and retraction of said cord members to define 15 thoreby said upper and lower positions.

Preferably, the driving device includes a shaft mounted for rotation, a winding drum for receiving the cord members and a spring for resiliently biasing rotation of the shaft such that the sleeping platform is 20 ur<ied toward an upper position.

Preferably also, the cord members take the form of belts and the driving device includes a further winding drikm connected to the shaft by a clutch such that cord members from the head and foot of the sleeping platform 25 may be independently extended and retracted so that the sleeping platform assumes an inclined posture. In a preferred embodiment, the elevatioi includes a first safety device for detecting|4oss7j>JL r 13 HOV19911 e \ 22^526 terision in any of the cord members and for preventing further rotation of the shaft upon loss of tension.

Also in a preferred embodiment/ the elevation bed includes a second safety device for preventing disengagement of the sleeping platform from the guide rails and a third safety device disposed on at least one of the sides of the bed for preventing an occupant of the betfl from falling therefrom.

Preferably also, the elevation bed is electrically 10 driven.

Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure l is a perspective view illustrating the 15 ovarall construction of a conventional elevation bed inside a room; Figure 2 is a perspective view illustrating the overall construction of an elevation bed in accordance with a first embodiment of the present invention; 20 Figure 3 shows in detail the driving device of Figure 2; Figure 4 is a perspective view of an elevation bed in accordance with a second embodiment of the present in/ention; Figure 5 is a perspective view of an elevation bed accordance with a third embodiment of the present in in mention; /V Figure 6 is a side elevational view bf the ' 13 NOV 1991 . 22 f 526 at 7 le elevation bed of Figure 5: Figure 7 shows detail of the driving device of Figures 5 and 6; Figure 8 shows in greater detail part of the driving device of Figure 7; Figure 9 illustrates in sectional form the tachment of wire belts to the driving device of Figures and 8; Figure 10 shows in part sectional form detail of a /el regulating device in accordance with the present indention; Figure 11 shows in schematic form top and side ews of an elevation bed employing the level regulating /ice of Figure 10; Figure 12 shows an end elevational view of a first safety device in accordance with a preferred aspect of thp present invention; Figure 13 shows a side elevational view of the rst safety device of Figure 12; Figure 14 shows a top view of a fourth embodiment the present invention; Figure 15 shows a side view of the the fourth embodiment of Figure 14; Figure 16 shows a schematic circuit diagram of the fojurth embodiment of Figures 15 and 14; Figure 17 shows an end elevation of a second-safety vi de fi of deivice in accordance with a preferred aspect of th®"^\ present invention; V-I? J 229526 Figure 18 shows a side elevation o£ the second safety device of Figure 17; Figure 19 shows a top view of the second safety device in retracted position; Figure 20 shows a top view of the second safety deyice in extended position; Figure 21 shows a part sectional side elevation of a further embodiment of the second safety device; Figure 22 shows a prior art guide rail with disengagement device; Figure 23 shows a perspective view of a third safety device in accordance with a preferred aspect of th£ present invention; Figure 24 in detail an end elevation of the third safety device of Figure 23; Figure 25 shows in perspective an exploded view of thja third safety device of Figure 23; Figure 26 shows a fourth safety device in accordance with a preferred aspect of the present indention; Figure 27 shows in detail the fourth safety device Of Figure 26; Figure 28 shows in graphical form the motor torque cujrve achieved by the fourth safety device of Figure 26; Figure 29 shows a part sectional side elevation of Eurther embodiment of the fourth safety device; * / Figure 30 shows in side elevation a still further embodiment of the fourth safety device; ^ 229526 Figure 31 shows in section details of a construction method in accordance with a preferred aspect of the present invention; Figure 32 shows in section details of a conventional construction method.

Referring now to Figure 1, there is shown a conventional elevation bed 1 located within a room. Reference numerals 2/ 3 and 4 represent the floor/ celling and wall respectively of the room. The structural frame 5 of the elevation bed consists of four columns which serve as guide rails 6. Beams 7, shown in shadow, connect the top of the guide rails to provide structural rigidity.

Shown generally as reference numeral 10, a sleeping be3 consists of lower frame member 11/ side board 12 and am members 13. Each arm member consists of a square tube with a section smaller than the frame member and extends longitudinally beyond the sleeping platform to enjgage a groove 6a in a corresponding guide rail.

A hand rail 14 is provided on the side boards 12 and a base member IS extends between the side boards to prjovide a support for a mattress and bed clothes.

Beneath the sleeping platform, a driving device 20 located. The driving device comprises an electric tor 21, supporting shaft 22, a plurality of winding is mo dr 24 ea urns 23 fixed on the shaft, an6 an endless belting means to deliver the power of the motor to the shaft.,^^n ch of the drums, one end of a wire rope 30, forming a - '«• \ tv 229526 CO I d member is fixed. Each wire rope runs from the drum thzjough a plurality of pulleys 31/ including a pulley 32 in each arm member 13, then up through the hollow guide raljl 6 to the top of the structural frame where it is fi^ed once more. Accordingly, the wire ropes may be selectively wound about the drums by the action of the motor 21 to move the sleeping platform up and down along tho guide rails.

In contrast to the conventional arrangement 10 dencribed above, a first embodiment of an elevation bed in accordance with the present invention is shown generally in Figure 2. Referring now to Figure 2, whiirein components common to those of Figure 1 are shown wi :h like numerals, a driving device 20 is-enclosed by 15 casing 25. The compact construction of the driving de/ice allows it to be located on the structural frame of thia elevation bed, but it may equally be placed beneath th'3 sleeping platform. Figure 3 shows the driving device of Figure 2 in more detail. An electric motor 21 drives 20 through belt 24 a shaft 22 supported by brackets 26.

Wilding drum 23 receives wire ropes from each corner of tha sleeping platform. In this embodiment, of course, tha wire ropes are fixed to the sleeping platform and not tha frame of the bed.

A coil spring 40 is fixed to the shaft by.means of dikk 41 and one end, and the other end is restrained from ro sp tating with the shaft by disk 42. Accordingly^fc$e^' ring is twisted when the winding drum deli ,v'<* wire » \ V f- 229526 rope as the sleeping platform descends, storing rotational energy. Then, when the winding drum rotates to raise the sleeping platform, the biased spring reduces th£ load on motor 21. in this embodiment of the present invention, the casing 25 containing the driving device 20 can be mounted upon the wall 4 (in Figure 1) allowing a lighter stjructural frame.

Moreover, the volume of casing 25 can be reduced to gii/e a more effective use of the space above the bed.

Figure 4 shows an alternative embodiment of the present invention in which the driving device 20 is located beneath the sleeping platform 10. Again, coil spring 40 reduces the load on the driving device. This embodiment has the advantage that it may be freestanding within the room.

Figures 5 to 9 illustrate an elevation bed 1 according to the present invention, in which the casing 125, enclosing the driving device 120, is reduced in size by a more efficient arrangement of eternal components. An advantage offered by this embodiment is that the wire ropes are replaced by belts which travel through the structural frame in two dimensions only. This reduces we|ar on the belts and the load on the motor.

Referring to Figure 7, in the casing 125 a shaft bo(dy 122 of hollow cylindrical form is supported rajtatably on brackets 126 which are fixed to ,thev top if < gt^ide rail 6. Within the shaft body 122 is fixed o| 13 NOV 1991 j 229526 electric motor 121 supported by one of the brackets 126. Th« shaft body rotates to wind and unwind the belts 130 on winding drums 123. Figure 8 shows in greater detail tho construction of the winding drums 123. Flanges 127 re:aln two belts per drum. It will be appreciated that each drum receives belts for the head and foot of the sleeping platform. Figure 9 shows in section the at:achment of these belts 130 to the drum 123. An advantage of this embodiment is that the motor 121 is located within the hollow part of the shaft body 122 and requires no endless belting means 24 to deliver its power.

Figure 7 also shows a coil spring 40 mounted to the shaft body in similar manner to the coil spring of Figure 3. ac ge Figure 10 illustrates a level regulating device in cordance with the present invention. In Figure 11/ the neral plan (a) and elevation (b) views of a manually opgerated elevation bed incorporating the device are illustrated Conventionally/ stoppers provided on the guide rails support the sleeping platform in its lower pojsition. Adjustment of the stoppers at each of the four gujide rails is not only cumbersome/ but may produce unlstable settling of the sleeping platform. Furthermore/ with stoppers defining the lower position/ the inertia of the driving system may cause the cord members to become slack. This creates problems with the system ,of^pulleys\ * • •*- > M and presents an uneven load to the driving device., . • " . -y' 229526 Accordingly, the level regulating device provides a means of defining the lower position of the sleeping pliitforra without the use of stoppers on the guide rails. Instead, the level regulating device limits rotation of supporting shaft 22. Referring to Figure 10, the supporting shaft extends beyond bracket 26 to a tubular body 201 which is threaded on its outer surface. A movable plate 202 of square shape is threaded to engage tha tubular body. Therefore, as the supporting shaft rotates, the moveable plate, prevented from rotation by bracket 205 moves longitudinally along the tubular body between positions defined by first adjustable set-screw 203 mounted to the plate and second adjustable set-screw 207 mounted to the support bracket 205.

In Figure 11 a manually operated elevation bed 1 is provided with the level regulating device 200. A driving shaft 210 is rotated by operation wheel 211 by the manual operation of ball chain 212 engaged with the operation wheel, worm gear 209a and worm wheel 209 convert rotation of the driving shaft to rotation of a support shaft (not shown). Thereafter, the level regulating device 200 limits the upper and lower positions of the sleeping platform in a manner substantially as described atjove. It will be appreciated that the level regulating delvice may be applied to an electrically driven, evaluation bed with for example microswitches detecting the limits of rotation of supporting shaft 22.

In Figures 12 and 13 there is illustrated a first v i. Jia'ViV,! 229526 satiety device in accordance with a preferred aspect of th<» present invention as applied to the embodiment of Figures 5 to 9. In particular. Figure 12 shows an end elevation and Figure 13 shows a side elevation of the wilding drum 123 of Figure 7 with the first safety device applied. For each of the two belts 130 wound by each drum, a cylindrical actuating roller 51 mounted to the end of tension spring 54 biases the belt away from a straight path. One end 53 of the tension spring is fixed while the other moves according to the tension in the belt. It will be understood that the spring must be chosen such that the weight of at least the sleeping platform is sufficient to extend the spring and actuate microswitch S5, closing a circuit which permits the driving device to operate. However, should any cord member break the corresponding tension spring would no longer be extended and the microswitch would act to prevent further operation of the driving device.

Figure 14 and 15 show in simplified form a further enjbodiment of the present invention. For clarity certain features of the invention have been omitted and Figure 14 illustrates two driving shafts 22 with winding drums 23 at dr ir each extremity. The shafts are connected to the iving device through belt means 24 and electromagnetic clutches 21A, 21B. in this manner, the shafts respectively of the sleeping platform. dependently control the height of the head and foot Figure 15 shows a side view of the'^elevation **c^d of «.y OOQ^O/C c. L. y J L. O Figure 14. in this embodiment and inclined posture of th<i sleeping platform 10 (shown in shadow) is achieved by selectively operating the electromagnetic clutches through a control system illustrated in Figure 16.

Figure 16 is a simplified circuit diagram of a trol system for the elevation bed of Figures 14 and co 15 to .11 It will be appreciated that the circuit is connected a source of electrical energy and controls the application of the energy to electromagnetic clutches 21A and 2IB. The electric motor 21 is activated when either electromagnetic clutch is active. In Figure 16 normally open push button switches PBU and PBD and normally closed push button switch PBS allow the operation to select up/ dcwn and stop respectively. As will be seen from the diagram, PBU and PBO energise relays RyU and RyD respectively to apply power to the electromagnetic clutches, however the relay contacts are connected such that operation of both push buttons has no effect.

Normally open push button switch SW energises a stepping relay RyS which selects the posture of the sleeping platform. The three postures, head up, hcrizontal and feet up are indicated by lamps LI, L2 and L3 respectively. In addition, the two inclined postures er electromagnetic clutches 21B and 21A respectively. he ergise relays RyA and RyB for activating Accordingly, when the changeover switch SW selects fc a T nzontal posture the elevation bed is capabl^#"of if % orjdinary vertical motion according to push b;u|tons iPBU, \ >v 229526 PBD and PBS. However when an inclined posture is selected limit switches LtA and LtB come into effect to prevent extreme inclinations of the sleeping platform through operation of the up push button PBU. These linits switches may be of conventional type.

Further limit switches Ltl and Lt2 are located in th<s level regulating device and prevent operation of the dr:.ving device at the upper and lower limits of the slneping platform.

An elevation bed advantageously provides a safety derice which protects against horizontal movement of the sloeping platform. To secure safe vertical movement of th<» sleeping platform along the guide rails* each of the arm members 13 must be in good engagement with the guide LI. Figure 22 shows a guide rail 6 typically found in Lor art elevation beds. This guide rail takes the form a C-shaped channel 6a and a pair of rollers mounted to tha extremity of arm member 13. Flanges 6b prevent disengagement of the arm member and guide rail.

According to a preferred aspect of the present indention, a second safety device is provided in each arm menber 13. The second safety device 60 is explained with ference to Figures 17 to 20. A projecting body 62 is ring loaded within arm member 13 such that the npression spring 63 biases the projecting body toward e guide rail groove 6C. The arm member is divided into o compartments by a dividing plate 64 in order%o,\ commodate a pulley 32 for the cord member 30, and a ra pr of re bp CO th tw ac 7 13 N0VS9 91 t'i , ■ x.-, 1 o 9 0 c: o £ c L J J iL O low er space 13b. Within the lower space, an end plate 65 retains the spring. The limits of extension and retjraction of the projecting body are defined by a groove 66 in the lower surface of arm member 13 which engages a piA 67 mounted to the projecting body. Figure 20 illustrates the fully extended position of the projecting body.

In Figure 21 is shown a further embodiment of the second safety device. In Figure 21, the projecting body 10 (2A is a plate hinged to the bottom of arm member 13 by a shift 68. The projecting body is spring loaded by coil spring 69 around the shaft.

The various embodiments of the present invention ara advantageously provided with a third safety device to 15 pravent the occupant of the sleeping platform from falling out. Figures 23 to 25 illustrate the third safety device in perspective detail and exploded view respectively. The third safety device 70 comprises a roll of guard net 71 between at least one side of the 20 sleeping platform 10 and the ceiling 3. A winding device 72 for the guard net is installed along the corresponding si3e of the sleeping platform so as to allow sufficient acbess at either the head or foot of the bed. As shown in Figures 24 and 25, the winding device 72 comprises a palir of brackets 73 fixed to the side board 12 of the si 74 th eeping platform with an intermediate supporting shaft between the brackets. A coil spring 7lHis-f £xie$ to e support shaft 74 at one end and fixed at the o;ther /V.

; • * T -'li: \ <V V t £ - & // 1^4 o 9 o c; r> /c c: L / J u O en<j! to an end plate 76 of a tubular body 75 supported for rotation around the shaft. An end 78 of the guard net is fi:ced to the ceiling by bracket 79 and the other end is ficed to the tubular body 75- It will be apparent that 5 as the sleeping platform rises, the tubular body is rotated by the spring and the guard net rolls up within tha enclosure 73a.

A fourth safety device is advantageously provided in various embodiments o£ the present Invention. The 10 fourth safety device provides cushioning means to reduce tha shock which may be associated with starting and stopping of the vertical movement. Figure 26 is a sectional elevation showing the location of the cushioning devices 80 in accordance with a- preferred 15 as,pect of the present invention. Figure 27 shows in more detail one embodiment of the cushioning device attached to the arm member 13 within the guide rail 6. In this embodiment of the present invention, the driving device is not located within the sleeping platform and the cord 20 numbers terminate at the arm members. A cylindrical body 8] terminated by end plates 82 is mounted to arm member 13. Within the cylindrical body a piston 83 moves against a spring 84. Cord member 30 is terminated at the ston and passes down the centre of the spring to exit 25 fijom the cylindrical body at the upper end plate before travelling around various pulleys 33a to the driving dc d< vice. It will be apparent that the foU;rth, safety vice takes the form of a shock abs:orb<5r' reducing the ?'■ ' i <f : I l, 1 ' ' ■ ' «. '• > * 229526 sh<j>ck felt by both the occupant of the bed and the driving device when vertical movement of the sleeping platform is started and stopped. Figure 28 illustrates a typical motor torque curve for an elevation bed embodying 5 th<s fourth safety device.

Figure 29 shows a further embodiment of the fourth safety device mounted upon a stopper attached to the guide rail 6. Compression springs 85 absorb the shock, but only at the extremity of movement of the sleeping 10 platform defined by the stopper. This embodiment provides a backup in the event of failure of the level regulating device.

A still further embodiment of the fourth safety device is illustrated in Figure 30. In this instance the 15 cushioning device is located within the arm member 13 of the sleeping platform. Once more, a compression spring 84 is provided and in addition a gas shock absorber 87 increases its cushioning action and reduces the load on the motor 21.

With reference to Figure 31, an advantageous construction method is proposed in which components of the sleeping platform, for example the side boards 12, typically wooden panels, are replaced by plastic sections having longitudinal cavities 12b. Within the cavities 25 are inserted wooden cores 91 for receiving conventional wclod screws 90. This construction method offers ,d, advantages of strength and rigidity and i^^m^psE^asy to assemble than the conventional method 'sh&&n in Furore 32 a* 229526 in which core members 92 having threaded holes 93 must be carefully aligned with screw holes 94 to receive machine screws.

Although reference has been made to specific examples, it will be appreciated by those skilled in the at: that the invention may be embodied in many other forms.

Claims (10)

229526 - 18 - WHAT# WE CLAIM1SI -. -—- — — —4 tenj i-r/^/r CLAIM IS 1
1. An elevation bed of the type having a sleeping plitforra suspended by cord members from a driving device supported by a structural frame, said structural frame including guide rails in sliding engagement with said 5 sleeping platform, said driving device operable to selectively extend and retract said cord members and to move thereby the sleeping platform between upper and lower positions, said driving device including a level regulating device for limiting extension and retraction 10 of said cord members to define thereby said upper and lower positions.
2. 2. An elevation bed as claimed in Claim 1, wherein said driving device includes a shaft mounted for rotation a winding drum for receiving said cord members; and spring means resiliently biasing said shaft and 5 winding drum toward an upper position of said sleeping platform.
3. 3. An elevation bed as claimed in Claim 2, wherein said driving device further includes a second winding dzjum connected to said shaft by clutch means whereby cord members supporting opposite ends of said sleeping platform may be independently extended and retracted providing thereby an inclined posture of said sleeping platform. ;•» s o'v i; i W-1 s It 229526 - 19 -
4. 4. An elevation bed as claimed in any one of the preceding claims, wherein the cord members take the form of belts.
5. 5. An elevation bed as claimed in any one of the preceding claims, further including a first safety device for detecting loss of tension in any of said cord members, said first safety device including means for sensing tension in said cord members and means to prevent rotation of said shaft upon loss of tension.
6. 6. An elevation bed as claimed in any one of the preceding claims, further including a second safety device for preventing disengagement of said sleeping platform from said guide rails, said second safety device including a resiliently biased extensible projecting body located at each point of engagement of said sleeping platform and a corresponding guide rail.
7. 7. An elevation bed as claimed in any one of the preceding claims, further including a third safety device disposed on at least one of the sides of said elevation bed for preventing an occupant of said bed from Calling therefrom, said third safety device including a guard net and winding device therefore, said winding device keeping s« id guard net always in tension notwithstanding the location of said sleeping platform between upper and lower positions. UrsWftm-jl v. ' 4 -» * ^ v 229526 - 20 -
8. 8. An elevation bed as claimed in any one of the preceding claims, wherein said driving device is manually operated.
9. 9. An elevation bed as claimed in any one of Claim 1 tcj Claim 7, wherein said driving device is electrically operated.
10. 10. An elevation bed substantially as herein described with reference to any embodiment shown in Figures 2 to 31 of the accompanying drawings. DATED THIS 1 DAY OF ^ I A. J. PARK & SON PEP AGENTS FOR THE APPLICANTS