US 3003159 A
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Description (OCR text may contain errors)
Oct. .10, 1961 J. HEBERT ETAL 3,
HOSPITAL BED Filed July 11, 1958 4 Sheets-Sheet 1 SEE? Jul/en HE Irving SHUL/(l/V ATWRNEYS Oct. 10, 1961 J. HEBERT ET AL HOSPITAL BED Filed July 11, 1958 4 Sheets-Sheet 2 "VI Wm Julian HE BERT Ir vin q SI/Ul. KIN
D 1961 J. HEBERTQ ETAL 3,003,159
HOSPITAL BED Filed July 11, 1958 4 Sheets-Sheet 3 a 3 4/ Eg IN VIN "R8 J l'en HEBERT [rang swumv Canada, assignors to Hyman Singer, Montreal, Quebec, Canada Filed July 11, 1958, Ser. No. 747,859 1 Claim. (Cl. 63)
The present invention relates to hospital beds and, more particularly, to a hospital bed of the type provided with a lift mechanism for raising or lowering the bed with respect to the floor and of the type which is also provided with hinged sections adapted to take a seat forming position.
The extra height of conventional hospital beds is such as to facilitate attendance of the patient by doctors and other hospital staff. However, such a height is an inconvenience for a patient when getting out of bed. Consequently, some types of conventional hospital beds are provided with a lift mechanism for raising or lowering the height of the mattress. However, in conventional hospital beds of this type, the headboard and foot board remain at the same level because they form the supporting legs of the bed. These boards are designed to have a suitable height when the mattress is at the high level position and, therefore, are much higher than necessary when the mattress is at the low level position. In the low level position, the high headboard and footboard'detract from the appearance of the bed and also cause inconveniences when attending the patient as, for instance, when serving a meal which is normally deposited on a tray mounted on wheeled legs and adapted to pass over the footboard of the bed.
Accordingly, the general object of the present invention is the provision of a hospital bed which has a main frame onto which the headboard and footboard are permanently secured to form a unit which is bodily raised or lowered with respect to the floor by means of a novel lifting arrangement. 1
Yet another important object of the present invention is the provision of a lifting mechanism of the character above mentioned which is free from vibrations when in operation, which is of very sturdy construction, and which maintains the bed in stable position at any desirable level.
Yet another important object of the present invention is the provision of a lift mechanism for hospital beds which is preferably driven by an electric motor for eifortless operation.
Yet another important object of the present invention is the provision of a hospital bed having a plurality of hinged sections adapted to take a seat forming position and in which the footrest section is adapted, when-elevated, to take a nearly horizontal position which has been found to be very useful for certain types of treatment.
Another important object of the present invention is the provision of a hospital bed of the character described in which the lifting mechanism for the hinged sections is operated by a hydraulic power unit for smooth, noiseless and effortless operation.
Yet another important object of the present invention is the provision of a hospital bed of the character described which requires a minimum of maintenance and lubrication of only very few parts.
The foregoing and other important objects of the present invention will become more apparent during the following disclosure and by referring to the drawings in which:
FIGURE 1 is a perspective view of one embodiment of the hospital bed;
FIGURE 2 is a side elevation of the same in raised atent position and also showing the lowered position in dot and dash lines;
FIGURE 3 is a plan view of the bed;
FIGURE 4 is a partial side sectional view along line 44 of FIG. 3, showing in a schematic way the movements of the bed lifting mechanism;
FIGURE 5 is a side sectional view along line 5-5 of FIG. 3, of the bed showing in a schematic manner the movement of the hinged sections;
FIGURE 6 is a longitudinal section along line 6-6 of FIGURE 3, shown on an enlarged scale;
FIGURE 7 is a cross-section along line 7-7 of FIG- URES 3 and 6;
FIGURE 8 is a partial perspective View of the underframe;
FIGURE 9 is a cross-section along line 9-9 of FIG- URE 8.
Referring now more particularly to the drawings in which like reference characters indicate like elements throughout, the bed, in accordance with the first embodiment of the present inyention, comprises a main frame 1 having a generally rectangular shape and provided at its ends with upright headboard 2 and footboard 3 which are reinforced by angle irons 4. Two pairs of brackets 5 are rigidly secured to the sides of the main frame 1 in transversely opposed relationship and at an equal distance from the headboard 2 and footboard 3 respectively. A tubular cross bar 6 is secured to and extends between each pair of brackets 5. Crank-shaped levers 7 are pivotally mounted at their upper ends on the cross tube 6 by means of sleeves 8 and are pivotally attached at their lower ends by means of sleeves 9 to a tubular transverse member 10 of the underframe of the bed, generally indicated at 11. The two transverse members 10 of the undercarriage 11 have secured at their outer ends the bearings 12' of swinging shafts 12" (FIG. 8) of swivelled wheels 12 and are interconnected by means of a telescopic tube 13, the sectube 13 joins the middle of the transverse tubular members 10.
An actuating arm 16 is associated with each crankshaped lever 7; the lower end of each actuating arm 16 is pivotally connected at 17 to the crank-shaped lever 7 adjacent the bend thereof, while the upper end of said actuating arm 16 is rigidly secured to the outer end of a transversely extending motion transmitting member 18 in the form of a tube. There is a motion transmitting member 18 for each actuating arm 16 and these members 18 are arranged in axially aligned pairs transversely of the main frame 1.
The adjacent ends of the members 18 of each pair are provided with a stud shaft 19 pivotally engaging recesses made in a block 20 which forms a nut threadedly engaging a screw 21 which forms an axial extension of a main shaft 22 disposed in the central longitudinal axis of the main frame 1 and adapted to be rotated by means of electric motor 23 and speed reducer 24.
The shaft 22 is journalled at suitable intervals along the main frame 1 in ball bearings 25 mounted in cross members 26 which are rigid with the main frame 1.
The electric motor 23 is supported on brackets 27 which extend between and are secured to two adjacent cross members 26.
The adjacent ends of the motion transmitting members 18 are rigidly interconnected by a yoke plate 28 which maintains said members 18 in axial alignment, while allowing the same to rotate with respect to theb lock I of the shaft 22. bymeans of the speed-reducer: 24 and electric motor 23 causes axial movement of the nuts 20 at both ends of the bed and, therefore, displacement of the motion transmitting members 13 longitudinally of the bed and. away or toward each otherthus allowing upward or downward movement of the crank-shaped levers 7, resulting in lowering or raising of the main frame 1 with respect to the underframe 11 and the floor.
It will be noted that there are no torsional stresses exerted on the motion transmitting members 18 but' only bending stresses imparted thereto by the actuating arms 16; Said bendingstresses are completely resisted by the yoke plate 23 which preferably extends in the plane containing the pair of actuating arms 16 on each side of the bed. The upward thrusts exerted by the actuating arms 16- on the'motion'transmitting members 18 are further resisted by the fact that the outer ends of said members 18' engage underneaththe horizontal flange of the sides of the main frame 1 which consists of angle irons.
As clearly shown in FIGURE 2, upon lowering of the bed, the swivelledwheels at each end of the underframe move away from each other thereby tensioning the spring 14; the energy thus stored in the spring is used during raising of the bed. The spring 14 is preferably calibrated so as to exert a force corresponding to more than the weight of the bed so as to take care of at least part of the weight of the occupant. Thus the force needed to operate the lifting mechanism is substantially balanced for the lowering and raising operations.
It will also be noted that the movements of the swivelled wheels longitudinally of the bed is limited in extent during raising or lowering movement of the bed whereby, even when the latteris in'raised position, the swivelled wheels are a short distance from the ends of the bed and stability of the latter is maintained.
The bed, in accordance with the present invention, is also provided with a bed spring made in a plurality of sectlons. which is disposed at approximately the centre of the main frame 1 and is secured to the latter by means of four upstanding bracket plates'30 which are in turn secured to the sides of the main frame. A head section 31 is pivotally mounted at 32 to one pair of bracket plates '30, while a leg section 33 is pivotally mounted at 34 to the other pair of bracket plates 30. A foot section 35 is pivotally connected at 36 to the outer ends of the leg section 33.
Supporting bars 37, shown in FIGURE 1, arepivotally connected at their outer ends to the outer end of the foot section 35 and are secured at their inner ends to the cross tube 6 supporting the crank-shaped levers 7 and pivoted thereon by means of sleeves 8. .The support bars 37 are arranged to maintain the foot section 35 in substantially horizontal position despite the various inclinations taken by the leg section 33, as clearly shown in' FIGURE 5.
The head section 31 and leg section 33 are pivoted by' transmitting mechanism: the'piston of the cylinder and piston unit 39 is pivotally connected to the lower end of an arm 42 which is rigidly secured at its outer endto a transverse sleeve shaft 43 -journalled on the shaft 6 (FIG. 3). Arms 44 are rigidly secured to the shaft 43at both ends thereof and are each connected to a link 45 whichin The bed spring comprises a seat section 29' 1 turn is pivotally connected to one side of the head section 31.
A similar motion transmitting mechanism is used between the hydraulic cylinder and piston unit 40 and the leg section 33. More particularly, the piston of the unit 40 is pivotally connected to arm 46 which is rigid with a transverse shaft 47 journalled at its ends in the sides of the main frame 1 and on which arms 48 are rigidly mounted. The arms 48 are pivotally connected to links 49 connected at their outer ends to the sides of the leg section 33.
A suitable hydraulic distributor valve (not shown) is used to control the operation of the cylinder and piston units 39 and 40 independently of each other or in unison so as to raise or lower the head section 31 and leg section 33 independently of each other or in unison.
Obviously, the power means represented by the electric motor 23 for the bed lifting mechanism and the hydraulic unit 38'andcylinder and piston units 39 and 40 for th lifting mechanism of the bed sections 31, 33 and 35 could be replaced by manually operated means.
From the foregoing it is apparent that the lifting mechanism for the main frame 1 comprises essentially two pairs of articulated deformable triangles disposed near each end portion of the main frame 1 and extending underneath the same; the sides of each triangle are constituted by elements 7, 16 and by the distance between the pivotal connections of elements 7 and 16 to the main frame 1, said latter side being adjustable in length and blocked to any adjusted value so that the inclination of the bed supporting levers 7 may be varied and locked to any adjusted value with respect to the main frame 1. Thus the level of the main frame 1 may be adjusted while the articulated deformable triangles provide a very stable support for the main frame.
In the embodiment just described, the crank-shaped levers 7 are directly pivotally connected to the main frame 1 and to the undercarriage 11 While the actuating arms 16 have their upper ends arranged to move longitudinally of the main frame 1 by means of the motion transmittingmembers 18, blocks 20 and screws 21, the two last named elements serving also to lock the longitudinal position of the arms 16 with respect to the main frame; Because the levers 7 are directly pivotally connected to the main frame their outer ends, when said levers pivot in space, necessarily describe an arc portion generally extending longitudinally of the main frame 1 whereby the underframe 11 is made extensible.
While a preferred embodiment in accordance with the present invention has been illustrated and described, it is understood that various modifications may be resorted to without departing from the spirit and scope of the appended claim.
We claim: v
A bed comprising a main frame, levers pivotally connected to said main frame and adapted to support said main frame above the floor, bracing arms pivotally connectedat one end to said levers intermediate the ends of the latter and joined at the other end to a block through pivotal connections and means to displace said block longitudinally of said' main frame and to lock said pivotal connections in adjusted position to thereby vary the inclination of said levers with respect to said main frame and vary the level of said main frame with respect to the floor while maintaining said inclination of said levers at an adjusted angular position; swinging wheels having swinging shafts, bearings for'said swinging shafts, and a longitudinally extensible underframe rigidly interconnecting said hearings to keep said swinging shafts in a vertical position, said extensible underframe consistingof two T-shaped members having their main legs in axial alignment andin telescopic engagement, said bearings being rigidly mounted at the outer ends of the References Cited in the file of this patent UNITED STATES PATENTS Hadley Nov. 18, 1884 Yarbrough Feb. 19, 1918 6 Krakauer July 28, 1942 Goeller Sept. 19, 1950 Sweetland Sept. 19, 1950 Kelly Aug. 14, 1951 Murray Mar. 17, 1953 Terry et a1. Apr. 13, 1954 Tallman June 22, 1954