Patent Publication Number: US-7712165-B2

Title: Bed with a retractable side barrier

Description:
The present application claims priority, under 35 U.S.C. §119(a), of French National Application No. 07 56470 which was filed Jul. 13, 2007 and which is hereby incorporated by reference herein. 
   BACKGROUND 
   The present disclosure relates to a bed with a retractable side barrier, and more particularly to a bed comprising a side barrier element that is movable between a high position and a low position in which it is retracted under the edge of the bed. The present disclosure relates more particularly to a mechanism that moves the barrier between its high position and its retracted, low position. 
   A patient bed is known that includes at least one retractable side barrier. The bed comprises a bottom bedstead or frame supporting a bedding plane, together with a side barrier element extending along the side of the frame. The barrier element, the frame of the bed (more particularly a longitudinal member thereof), and two parallel arms (respectively attached to the frame and to said barrier elements via hinges) form a deformable parallelogram mechanism enabling the barrier element to be moved between two stable positions, a high position above the mattress of the bed, to prevent a patient from falling out of bed, and a low position close to the frame of the bed. The barrier is lowered when it is desired to transfer the patient to give the patient care. 
   Several factors need to be taken into consideration when developing such a bed. 
   For the purpose of moving the bed (which is mounted on casters) it is desirable for the overall transverse size of the bed to be as small as reasonably possible so that it can pass through relatively narrow doors or so that it can be situated in small elevators. 
   Conversely, patient comfort may require a mattress to be as wide as possible. 
   Furthermore, when transferring a patient between a stretcher and the bed, it is desirable for the distance between the edge of the stretcher and the edge of the mattress to be as small as possible, the barrier then naturally being in its lowered position. 
   For all these reasons, proposals have been made for the barrier to be retractable under the mattress, beside the frame, when the barrier is in its lowered position. Mechanisms have therefore been devised for lowering the barrier, and then retracting it under the bed while it is in its low position. To follow such a path the barrier moves vertically downwards and while turning in its own plane, followed by moving transversely so as to become situated under the mattress and prevent the barrier constituting a troublesome obstacle while moving the bed or while moving a stretcher up to the bed. 
   SUMMARY 
   The mechanisms disclosed herein make it possible to improve the motion of such a barrier by combining rotation and transverse displacement so as to enable the barrier to be retracted in a single movement. 
   More particularly, the mechanism disclosed herein provides a bed with a retractable side barrier, the bed comprising a bed frame, a side barrier element extending along one side of said frame, and two parallel arms attached respectively via hinges to said frame and to said barrier element, wherein each arm is attached to said bed frame by a two-element telescopic mechanism comprising an inner element and an outer element, one of the elements being fastened to the frame and the other to said arm, and wherein these two elements are constrained relative to each other by a shape connection suitable for causing the transverse position of said barrier element to vary continuously while it is being moved in vertical pivoting. 
   When the barrier element is in its low position, the telescopic mechanism is fully retracted so that both arms of the side barrier element are retracted. 
   In some embodiments, for each telescopic mechanism, the element that is secured to the frame of the bed contains the element that is fastened to the arm. It may be welded to the frame. 
   According to one possibility, the shape connection comprises a stud carried by one element and a groove formed in the other element. 
   The studs of the two telescopic mechanisms enable the two movements, one in rotation and the other in transverse translation, to be combined, and they also enable the barrier to be attached to the element that is secured to the frame of the bed. 
   In one possible variant, for each telescopic mechanism, the stud is secured to the inner element and projects outwards, being engaged in the groove formed in the outer element. 
   The inverse arrangement is also possible, i.e. the stud may be secured to the outer element and project inwards, being engaged in the groove formed in the inner element. 
   The shape of the groove is adapted to the desired motion. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The mechanisms disclosed herein can be better understood and other features thereof appear better in the light of the following description of a bed in accordance with this disclosure, given purely by way of example and made with reference to the accompanying drawings, in which: 
       FIG. 1  is a fragmentary diagrammatic view of a bed with a retractable side barrier in accordance with this disclosure, the barrier being raised; 
       FIG. 2  is a view similar to  FIG. 1 , the barrier being lowered; 
       FIG. 3  is a detail view seen looking along arrow III of  FIG. 1 ; 
       FIG. 4  is a detail view seen looking along arrow IV of  FIG. 2 ; 
       FIG. 5  is a detail view showing a variant; and 
       FIG. 6  is a detail view showing another variant. 
   

   DETAILED DESCRIPTION 
   In the drawings, there can be seen a patient bed  11 , having a retractable side barrier comprising a bottom frame  13  supporting the bedding (mattress  15 ), a side barrier element  17  extending along a longitudinal side of the frame, and two parallel arms  19  respectively attached by hinges to the frame and to the barrier element. Together, the above-mentioned elements form a kind of deformable parallelogram enabling the barrier element to be moved substantially parallel to itself, essentially by pivoting the arms. 
   In accordance with this embodiment, each arm  19  is connected to the frame of the bed via a two-element telescopic mechanism  21  having an inner element  22  and an outer element  23 . The inner element  22  can move by sliding and in rotation inside the outer element  23 . In this example, the outer element is fastened to the frame, e.g. welded thereto. It is oriented perpendicularly to the longitudinal direction of the bed. The other element, i.e. the inner element  22 , is fastened to one end of the corresponding arm  19 . 
   These two elements  22 ,  23  are constrained relative to one another by a coupling arrangement comprising a stud  25  and a groove  26 . In the illustrative example, the groove  26  is helical and extends only partially around element  23  which is tubular. In some embodiments, the groove  26  is sufficiently long to permit the pin  25  to rotate through about 180 degrees while moving inwardly and outwardly when barrier element  17  is raised and lowered. Barrier element  17  may be a siderail of a hospital bed, for example. Fashioning groove  26  such that the angles of rotation of pin  25  is either more or less than 180 degrees is contemplated by this disclosure, as well. 
   More precisely, in the example shown in  FIGS. 1 to 4 , the stud  25  is secured to the inner element and projects outwards, being engaged in the groove  26  formed in the wall of the outer element. Each telescopic mechanism thus provides the connection between the frame  13  and one of the arms  19 . They are substantially identical, thus making it possible to vary the transverse position of the barrier element  17  (hinged on the other ends of the two arms) while simultaneously moving it in vertical pivoting. 
     FIG. 5  shows a variant in which the stud  25   a  is secured to the outer element  23  and projects inwards, being engaged in a groove  26   a  formed in the inner element. This groove may be a simple groove formed in the surface of the cylindrical inner element  22 . The groove  26   a , in some embodiments, is helical and extends around element  22 , which may be a solid post or a tubular post in some embodiments. In some embodiments, the groove  26   a  is sufficiently long to permit the element  22  to rotate through about 180 degrees while moving inwardly and outwardly when barrier element  17  (not shown in  FIG. 5 ) is raised and lowered. Fashioning groove  26   a  such that the angle of rotation of element  22  is either more or less than 180 degrees is contemplated by this disclosure, as well. 
   Another variant is shown in  FIG. 6  in which the inner element  22  carries two studs  35  projecting outwards and co-operating with parallel edges of a cam  37  defined in the wall of the outer element. The two studs  35  and the cam  37  define the connection having the above-mentioned shape. The cam is formed in the wall of the outer element by two cutouts or notches  39 , with the two end portions of the sleeve constituting said outer element  23 . The sleeve is secured to the bottom frame  13 . This variant makes it possible to obtain said outer and  23  directly by molding, without any subsequent machining. The edges of cam  37  (shown in phantom in  FIG. 6 ) may be helical in some embodiments. The cam  37  may be fashioned, in some embodiments, to permit pins  35  to rotate through about 180 degrees while moving inwardly and outwardly when barrier element  17  (not shown in  FIG. 6 ) is raised and lowered. Fashioning groove  26   a  such that the angle of rotation of pins  35  is either more or less than 180 degrees is contemplated by this disclosure, as well.