US 3220020 A
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Nov. 30, 1965 T. NELSON ADJUSTABLE HEIGHT BED 5 Sheets-Sheet 1 Filed April 30, 1953 INVENTOR. TED NELSON A 7' TOR/VE l/ Nov. 30, 1965 T. NELSON ADJUSTABLE HEIGHT BED 5 Sheets-Sheet 2 Filed April so, 1963 @www PN @N INVENTOR. TED NELSON #M1 @Mw N IGP* TTO/P/VEV Nov. 30, 1965 Filed April 30, 1965 T. NELSON 3,220,020
ADJUSTABLE HEIGHT BED 3 Sheets-Sheet S FIG.. 3
INVENTOR, TED NELSON A T TOR/VEY United States Patent O 3,220,020 ADJUSTABLE HEIGHT BED Ted Nelson, S638 Patterson Pass Road, Livermore, Calif.
Filed Apr. 30, 1963, Ser. No. 276,772 Claims. (Cl. 5-63) This invention relates to improvements` in adjustable beds and more particularly to the method of raising and lowering the height of the bed which nds particular usefulness in hospitals where the bed may be adjusted at the will of either the patient or the hospital attendant.
It is well-known that hospital requirements provide that the bed shall be a certain number of inches from the floor, primarily to avoid the bending and stooping of nurses, orderlies and other persons required for proper attention and administration to the patient. On the other hand, when the hospital beds are at the required height, it is impossible for a patient to either get out of bed or into the bed without a footstool or some other exertion which in many instances is both detrimental to the patient and contrary to the treatment prescribed. Likewise, during the period just prior to convalescence it may be necessary for the patient to get in and out of bed with as little exertion as possible in order to provide the required mild exercise and bodily functions.
Under these latter circumstances particularly, it is well to have the bed so that the patient can have his feet reach the tloor when he is sitting on the bed itself at the side thereof, or in some instances at the end thereof. To meet this requirement, it is necessary to lower the bed height so that this can be accomplished.
Since all people do not have the same length of legs, then as a practical requirement, it is necessary to have the bed adjustable as to height to accommodate the various and varying heights of patients involved.
No matter the purpose for the requirement, it is an object of the present invention to provide an adjustable means for raising or lowering the hospital bed from the required height for hospital regulations down to the range where the height will lit the wide variations of the human beings so that the patients feet will touch the oor when sitting at the side or on the end of the bed itself.
The raising and lowering of hospital beds to accommodate the height adjustment to various purposes is not new per se, but heretofore there has been no single practical, troublefree means for accomplishing this result. Accordingly, it is an object of this invention to provide a novel, troublefree means for raising and lowering the height of the bed with controlled speed and with very minor physical effort or exertion.
In the prior devices the raising and lowering of the bed has been accomplished by means of cables under tension and wound on drums. In the continued movement of cables over shives, the cables are subject to wear and even to breakage, which not only results in a failure of the structure, but cable systems are exceedingly diflicult to fix and service. In the elort to provide a minimum amount of weight due to such a system, so little room is left for the cables and the mechanism to operate them that in modern-day hospital structures there is really no room for this type of equipment. Accordingly, the present invention provides a structure which eliminates the use of cables with their resulting disadvantages.
Other structures in the prior art require gears and pinions to raise or lower the bed height. Here again. appropriate gears are not only costly but requireV an excessive amount of room or space, and are a constant source of trobule resulting in maintenance. It is therefor an object of the present invention to accomplish this adjustment of height by the provision of a structure which does not require gears and pini-ons with their attendant disadvantages.
3,22%,020 ?atented Nov. 30, 1965 It is apparent that the system must operate all four legs at once, in unison and equally, in order to prevent cocking and binding in the operation. This invention has for another object, the accomplishment of such a system.
Further objects are to provide a construction of maximum simplicity, economy and ease of assembly and disassembly, also such rfurther objects, advantages and capabilities as will fully appear and as are inherently possessed by the device and invention described herein.
The invention further resides in the combination, construction and arrangement of parts illustrated in the accompanying drawings, and while there is shown therein a preferred embodiment thereof, it is to be understood that the same is illustrative of the invention and that the invention is capable of modification and change and comprehends other details of construction without departing from the spirit thereof of the scope of the appended claims.
In the drawings:
FIGURE l is a simplified plan view of the bed main frame assembly showing the positioning of the several parts and mechanism `for raising and lowering the height of the bed;
FIG. 2 is an elevational view taken on the line Il-Il of FIGURE 1, and looking in the direction of the arrows, with the legs in the retracted or lowermost position; and
FIGURE 3 is an elevational view similar to FIGURE 2, but with the legs extended to the maximum height.
Referring now to the drawings `in which like reference numerals indicate like parts in the several views, there is shown the frame structure of a bed embodying the principles of the present invention. The bed frame comprises a pair of hollow leg posts 10 at the foot end of the bed and a pair of hollow leg posts 11 at the head of the bed. At each side, the posts 10 and 11 are joined by a side panel 12 which is secured to the posts 10 and 11 in any suitable manner. Suitable cross braces are used, except that the transverse brace 19 is spaced inwardly from the foot of the bed, rin order to provide a firm and rigid frame structure. The reason for omitting cross braces at the foot end is to permit pivoting of the mattress support on pivots 24 between the leg members 10. The side panels 12 have inturned iianges 14 and 15 at their marginal edges. At either end the flange 14 is cut away to provide for the equilateral triangular llets 16 at the foot end, and 17 at the head end. Along the hypotenuse of the iillets 16 and 17 having anges 18 and Z0 respectively, which are inturned a distance comparabile to the ange 14 so that when the llets are secured in place there is the appearance of a continuous inturned ilange angled upwardly to the legs at both ends. Y
Since beds of this type are intended principally for hospital or invalid use, a reinforcing plate 21 is secured in a vertical plane to the foot leg 1t)l behind the fillet 16 and in contact with its inturned flange 18 as well as the inturned flange 14 of the side panel 12. Abutting the hypotenuse or inturned flange 18 is a triangular member 22 with its altitude substantially at right angles to the tlange 18.
The member 22. is so shaped that it slopes inwardly in both directions from the line 23 of its altitude, to contact the plate 21 in such a manner that its perimeter other than its base, is in continuous contact with the plate 21 while its base is in continuous contact with flange 18 of the triangular member 16. It is secured both to the ilange 18 and to the plate 21 in any suitable manner, as by welding. At the apex of the triangular member 2.2 a xed pivot 24 is positioned, whichis the pivot point around' which the mattress support for the hospital bed rotates in a vertical plane. opposite relationship on the other side of the frame.
The hollow foot leg members 1l) and the hollow head This structure is repeated inv leg member 11 are provided with leg members Z5 and 26 respectively, which are slidably or telescopically received therein. At the lower ends of each of these leg members 25 and 26, a caster 27 is secured, each of which is in turn equipped with the conventional locking means 2S. The casters provide the mobility for the bed and the vconventional locking means supply the lixed safety of the bed in its established position. The tops of the hollow foot leg members may be suitably closed with removable friction it caps 29 and the hollow head legs are left open at the top to receive a transverse headboard 29a.
It is apparent that both the caps 29 and the headboard tenons may be retained in place by set screws if desired. At the top of each telescoping leg member and 26 is a hollow box 30 which is secured to the top thereof by any suitable means, which boxes are open at the side facing in the plane of the side panel member 12, and have a slot in the top thereof with enough clearance to allow the end 46 to pass therethrough as it is rotated downward. The corresponding face of the hollow leg members 10 and 11 are slo-tted vertically from a point well up within the triangular fillets 16 and 17 down to a point approximately representing the intermediate point of the side member 12, to provide access to the interior of the boxes 30. l
The hollow leg members 10 and 11 with their internally telescoping leg members 25` and 26 respectively, are 0bviously for the purpose of raising and lowering the bed from a height for example, representing the normal height of the hospital bed down to a distance where even a short patient may sit on the side of the bed or the end of the bed, and touch his feet to the oor.
In order to accomplish the retraction and extension of the legs 25 and 26 within the hollow leg members 10 and 11 in uniform, but with relatively swift and sure action, a hydraulic cylinder 31 is pivotally connected at one end by pivot pin 31a to a bracket 32 which is in turn secured to the side frame 12. The piston rod 33 of the hydraulic cylinder 31. is pivotally connected by pivot pin 34 to an arm 35. The arm 35 is firmly axed in position on a torque bar 37, which bar rotates on stub shafts 38 journalled in self-lubricating bearings 39 secured on the opposite sides internally of the side frame 12. The securing of the arm 35 to the torque bar 37 is offset radially and spaced from the pin 34. Secured on the face of the arm 35 are two pivot pins 40 and 41. These two pins are 180 out of phase with each other and are diametrically opposed to the transverse center line of the torque bar 37. Linkage 42, which is pivotally connected on pin 40 at one end, is connected by pin to a reversed curve bell crank 43 which has a fan-shaped inner foot. The bell crank at its inner fan shaped portion and at the upper end thereof is pivotally secured to the side frame 12 by means of pivot pin 44 about which point it rotates for limited movement in a vertical plane. The pivot pin 45 by which linkage 42 is pivotally secured to the bell crank 43, is below and spaced from the pivot pin 44 of the bell crank 43. The gooseneck end 46 is reduced in width to permit the same to enter into the slot in the box 30 at the top of the leg member 26. The end 46 also carries a pair of rollers 47, one at either side adjacent the end thereof, which rollers bear against the lower inner face of the box 30. In assembling the bell crank 43, it will be observed that when the gooseneck end 46 with its rollers 47 is inserted within the box 30, the telescoping leg member 26 cannot be moved without moving the bell crank 43. This prevents the legs from falling out in the event they are raised off of the oor level for any reason.
Similarly, at the foot end of the bed there is a bell crank 43 of identical size and shape pivotally secured to the side rail 12 by the pin 48. At the lower end of the fan shaped end of the bell crank 43 isa pivot pin 50 which pivotally mounts linkage 51 at one end, which linkage is pivotally mounted at the other end on the pivot pin 41 of the arm 35.
The same system is repeated on the opposite side of the bed frame for the foot and head legs, except there is no need for an additional hydraulic cylinder. On the opposite side the torque bar 37 has an exact duplicate of the arm 35 which is mounted for rotation therewith, with the same counterparts of pins and linkages as before described.
Since the hydraulic cylinder 31 is intended for use with other similar cylinders operating other portions of the bed, it is mounted at one side and out of alignment with any of the other cylinders. This provides Ismoother operation.
Operation In order to retract or extend the legs 25 and 26 in unison and assuming that the leg members are in their maximum retracted position which is shown in full lines in FIGURE 2, the hydraulic cylinder 31 is actuated, the piston 33 moves outwardly to rotate the arm 35 and the torque bar 37 in a counter-clockwise direction. This in turn causes the pivot pins 40 and 41 to move in a counter-clockwise direction pulling the linkage 42 to the left as shown in FIGURE 2 and the linkage 51 to the right as shown in FIGURE 2. This causes both of the bell cranks 43 to rotate pivotally about their respective pivot pins 44 and 48 equally in the opposite directions causing the rollers to exert a downward pressure on the tops of the leg members 25 and 26, respectively. The leverage represented by the distance from the respective pivot pins 44 and 48 to the roller pins 47 is suicient to cause this pressure to slidably and telescopically move the legs outwardly which raises the bed upwardly with a smooth, even, sure action. The gooseneck ends 46 of the bell cranks 43 guide in the vertical leg Islots during raising and lowering. Hydraulic means are preferred because the action is smooth and sure, and the linkages make the movement equal at both sides and at both ends. The maximum height is attained when the arm 35 is rotated something less than 90. This maximum height is shown in full lines in FIGURE 3. It is apparent that any intermediate position can be secured and held merely by stopping the movement of the hydraulic cylinder. This method of raising or lowering a bed is extremely simple, positive, foolproof and tests show it to be free of any maintenance for many years of useful life.
While the hydraulic cylinder 31 may be actuated by electrical means, it is to be understood that any other suitable means may be used, including manual, and further, that any suitable means for rotating the arm 35 and the torque bar 37 is contemplated although the electrical hydraulic system is by far the most practical and eflicient.
It is to be understood that there are suitable stops and disconnectcircuits so Vthat the bed cannot be operated above its maximum low position or its maximum high position. This is to prevent damage to the bell cranks and to the slots in the leg housings 10 and 11.
1. Means for adjusting the height of a bed, comprising a bed frame having a pair of hollow foot legs and a pair of hollow head legs, a pair of parallel channel shaped side panels joining the foot and head legs at each side and suitable transverse braces, said hollow legs having vertical slots in the opposed faces at each side for a substantial distance from above the top of said side panels downwardly, leg members telescopically received within said hollow legs for slidable movement therein, bell crank members each. having one arm pivotally mounted on said side panels adjacent one of the hollow legs with the other arm passing through the hollow leg Islots and engaging the inner top ends of said telescoping leg members, link-- age means connecting each of said bell cranks for pivotal movement, and means for simultaneously and equally pivoting said bell cranks through said linkage to move the leg members within said hollow legs.
2. The adjustable height bed means of claim 1 wherein each telescoping leg member has a slotted box secured to the top thereof and the bell crank arm engaging 'the said top is mounted on rollers within said box and guides in said box slots to cause the up and down movement.
3. The adjustable height bed means of claim 1, wherein each telescoping leg member has a slotted box secured to the top thereof, the bell crank arms engaging said tops are mounted on rollers within said boxes and guides in the boxes wherein said linkages are coupled to a single rotating member for synchronized and uniform movement of all four leg members, and wherein the rotating member is driven by a controlled source of power.
4. A bed having means for raising and lowering its height with respect to the Hoor level, said means comprising hollow head and foot legs, each of said legs having a vertical slot, said slots facing each other longitudinally and in a vertical plane parallel to the side frames, channel side frames connecting the hollow head and foot llegs at either side and suitable transverse members, individual leg members telescopically received within said hollow legs for reciprocating movement therein, a box-like portion secured to the top of each leg member within said hollow legs, each of said boxes having slots in the side and top thereof in registry with the slots in the said hollow legs, a bell crank with one arm pivotally mounted within the channel side members adjacent each foot and head leg and the other arm passing through the adjacent leg and box slots so that the end thereof is within the said box in each instance, rollers mounted on the arms within said boxes for movement therein and preventing the leg members from being withdrawn from the hollow foot and head legs, means for rotating a torque bar, a torque bar and linkages connecting said torque bar and said bell cranks so that the bell cranks pivot uniformly and simultaneously in response to the rotation of the torque bar to raise or `lower the height of the bed from the lloor level.
5. The adjustable height means for a bed as in claim 4 wherein the torque bar is transverse of the bed frame and mounted for rotation between the two side frames, and wherein the means for rotating the torque bar is adjacent one of the side frames.
References Cited by the Examiner UNITED STATES PATENTS 2,527,111 lll/1950 Widrich 5--11 2,870,460 1/ 1959 Sanford 5-63 2,872,688 2/1959 Reichert et al. 5-63 2,885,692 5/1959 Wetzel et al. 5-63 2,917,753 l2/l959 Portis et al 5-60 3,050,744 8/ 1962 Mann et al 5--63 FRANK B. SHERRY, Primary Examiner.