Abstract:
A patient support apparatus includes a frame having a first portion that is movable between a raised position and a lowered position to change an elevation at which a person is supported above a floor. Castors are coupled to the frame and are configured to rest upon the floor. An actuator is movable between a brake position in which at least one castor of the castors is braked and a release position in which the at least one castor is released. As the first portion of the frame is moved to the lowered position, the first portion automatically engages the actuator and moves the actuator to the brake position thereby to automatically brake the at least one castor.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a continuation of U.S. application Ser. No. 14/540,185, which was filed Nov. 13, 2014, now U.S. Pat. No. ______, which claims priority, under 35 U.S.C. §119(a), of European Application No. 13193375.6, which was filed Nov. 18, 2013, and each of which is hereby incorporated by reference herein. 
     
    
     BACKGROUND 
       [0002]    The present disclosure relates to a person support apparatus, such as a bed and with a mechanism suitable for adjusting the height and orientation of a patient support frame forming part of that bed. It is more particularly suitable for a hospital or long-term care (LTC) bed. 
         [0003]    Person support apparatus, such as hospital and long-term care beds, typically include a patient support deck and a support surface, such as a mattress, supported by the deck. The patient support deck may be controllably articulated so as to take up different support configurations. 
         [0004]    The patient support deck is supported on a deck support or intermediate frame and the deck support frame is provided with a mechanism for adjusting the height of the deck and hence the height of the support surface above the floor on which the apparatus is located, and to control the orientation or inclination of the deck and hence the patient support surface relative to the floor. Adjustment of the height is helpful to allow care givers to access the patient, and to facilitate patient movement into and out of the bed. The inclination of the patient support surface is also desirable so as to make the patient more comfortable, or to, for example, take up the Trendelenburg position in which the body is laid flat on the back (supine position) with the feet higher than the head by 12-30 degrees, or the reverse Trendelenburg position, where the body is tilted in the opposite direction. 
         [0005]    The deck support frame is supported on leg assemblies which are pivotally connected at their upper end to the deck support frame and which have linear actuators for pivoting the leg assemblies relative to the deck support frame and hence adjusting the height of the deck support frame. Separate and separately controllable head end and foot end leg assemblies are provided so that the height of the foot and head ends may be separately adjusted. The leg assemblies can be pivoted together by their respective actuators and thereby raise or lower the deck support frame whilst keeping it substantially parallel to the floor. Alternatively, one of the foot or head end assemblies can be pivoted to lower just one of the foot or head ends and thereby move the deck support frame into the Trendelenburg or reverse Trendelenburg positions. 
         [0006]    Known arrangements for pivoting leg assemblies relative to a deck support frame to allow the raising and lowering of the deck support frame include a leg element pivotally connected at its upper end to a guide element which is coupled to and can slide along the outside of longitudinal elements arranged parallel to, or forming, the sides of the deck support frame. Those known arrangements comprise a U-shaped guide element arranged on its side (i.e. with its open side extending in a vertical direction) and arranged around the outside of longitudinal elements having a rectangular cross-section. Such arrangements suffer from a number of problems. These include: i) a risk of trapping fingers in the guide element which moves along the outside of the longitudinal elements: (ii) a need to overcome the frictional forces between the inner surface of the slideable guide element and the outer surface of the longitudinal element when pivoting the leg assembly and thereby sliding; and (iii) a propensity for dust and dirt to collect on the surface of the longitudinal element and hence interfere with the sliding operation. 
         [0007]    US 2009/0094747 and US 2010/0050343 disclose alternative arrangements in which channels which correspond to U-shapes on their sides (i.e. with an open vertical side) are arranged on the sides of the intermediate or deck support frame and have follower or guide elements extending into the interior of the channels through the vertical open side. The follower or guide elements engage and run along an interior surface of the respective channels. 
         [0008]    US 2006/0021143 discloses a further alternative arrangement in which guide tracks or channels are defined by slots extending through the vertical sides of longitudinal bed frame elements, and the upper end of the respective leg assemblies are provided with followers extending sideways out from the upper end of the leg assemblies to extend through or into the slots. The followers run along the guide tracks defined by the slots through the vertical sides of the bed frame elements. 
         [0009]    A need exists for further contributions in this area of technology. 
       SUMMARY 
       [0010]    An apparatus, system and/or method according to the present disclosure includes one or more of the features recited below or in the appended claims, and which alone, or in any combination, may define patentable subject matter: 
         [0011]    The present disclosure, in a first aspect, provides a person support apparatus comprising: a person support frame for supporting a person support deck, the person support frame having two sides extending between a head end and a foot end; and a support assembly for supporting the person support frame and moving it relative to a floor surface, wherein the support assembly comprises at least one leg assembly pivotally coupled at a first upper end portion to the person support frame and coupled at its second lower end portion to floor engaging means, and an actuator element operable to move the leg assembly and thereby move the person support frame relative to the floor, wherein at least one of the sides of the person support frame comprises an inverted substantially U-shaped channel element having a substantially continuous upper surface, two substantially continuous side surfaces connected at their top edges to the upper surface, and a downward facing opening between the bottom edges of the two side surfaces, and the first upper end portion of the leg assembly includes a guide or follower element arranged to contact and run along an inner surface of the channel element. 
         [0012]    This arrangement results in a deck support frame which is robust and stable and can accommodate the changes in geometry necessary for movement or adjustment between the horizontal, Trendelenburg and reverse Trendelenburg positions. 
         [0013]    Some embodiments of the channel and roller mechanism change the height of a patient support deck by pivoting one or more leg assemblies relative to the under surface of the patient support frame. 
         [0014]    Features of some illustrative embodiments include the following: 
         [0015]    Some illustrative embodiments have a lower part count than known systems and are therefore likely to be both cheaper and more robust. More parts cost more to make and assemble and provide more elements capable of failure. 
         [0016]    The opening of the channel carrying the guide elements or rollers faces the floor. This means that dirt is less likely to enter it and interfere with the mechanism. Furthermore, any dirt that enters will not be visible in normal use. 
         [0017]    The leg assembly works vertically within the channel edges and a reduced force is therefore necessary to lift the patient support frame especially from the low position where the leg assemblies suspend a narrow angle relative to the underside of the patient support frame. The use of rollers in an optional embodiment rather than surfaces sliding relative to each other also reduces the frictional forces which must be overcome when moving the guide element. The use of a roller than a sliding element means that there is no need to overcome the friction between the sliding element and the frame element relative to which it slides thus reducing the force necessary to raise the deck support frame and makes the mechanism less likely to fail. 
         [0018]    The use of a mechanism which includes a guide element inside a channel element means that the outside surface of the longitudinal channel element can be used as a fixing area for accessories or other elements. 
         [0019]    Having the channel openly facing downwards and the guide element inside the channel make it harder for a patient or care-giver to trap their fingers or other body parts. 
         [0020]    Features described in relation to one aspect and/or embodiment of the present disclosure may equally be applied to other embodiments and/or aspects of the present disclosure. 
         [0021]    Additional features, which alone or in combination with any other feature(s), such as those listed above and/or those listed in the claims, may comprise patentable subject matter and will become apparent to those skilled in the art upon consideration of the following detailed description of various embodiments exemplifying the best mode of carrying out the embodiments as presently perceived. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    Illustrative embodiments will now be described in detail, by way of example only, with reference to the accompanying drawings, in which: 
           [0023]      FIGS. 1   a  and  1   b  are isometric and perspective views from, respectively, the foot and head ends of a patient support apparatus including a deck support frame according to one embodiment of the present disclosure; 
           [0024]      FIG. 2  is side view of the patient support apparatus of  FIG. 1  with the patient support deck in a lowered position; 
           [0025]      FIG. 3  is a view similar to that of  FIG. 2  but with the patient support deck in a lowered position; 
           [0026]      FIG. 4  is a detailed view of a section through the top of one of leg assemblies of the apparatus in  FIG. 1 ; 
           [0027]      FIG. 5  is an end view of an alternative embodiment according to the present disclosure having a braking mechanism, in which the deck support frame is at its lowermost position and the brake engaged; 
           [0028]      FIG. 6  is a detailed view of portion VI of  FIG. 5 ; 
           [0029]      FIG. 7  is a perspective view corresponding to the view of  FIG. 6 ; 
           [0030]      FIGS. 8   a  and  8   b  are diagrams setting out roller dimensions (in mm) for an embodiment according to the present disclosure; 
           [0031]      FIG. 9  is a diagram setting out dimensions (in mm) for a channel element suitable for use with the roller of  FIGS. 8   a  and  8   b;  and 
           [0032]      FIG. 10  is a diagram setting out dimensions (in mm) for a suitable brake lever and channel element. 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    Hospital beds typically include a deck supporting a mattress or other patient support element (not shown in the Figs.). The deck may be divided into articulated sections so as to create various seating and lying down configurations. Articulated beds with a controllable articulation system for the patient support surface are known and are not a novel and inventive part of embodiments of the subject disclosure so will not be described in detail. An example of such an articulated patient support surface is shown in EP 2 181 685 and WO 2004/021952 to which reference should now be made and whose contents are hereby expressly incorporated herein by reference. 
         [0034]    Referring to  FIGS. 1 to 3 , a hospital bed support assembly according to one embodiment of the present disclosure includes a deck support frame  3  to which a headboard and a footboard may be mounted at, respectively, its head  4  and foot  5  ends. The head board is mountable on head board plates  33  and the foot board on foot board plates  34 . The deck support frame has two leg or support structures  6  pivotally mounted to its under surface. Each of the leg structures or assemblies  6  includes a pair of legs  7  each coupled to the deck support frame  3  by a moveable upper pivot or guide element  8  at their deck or upper end  9 . The moveable upper guide elements can move parallel to the longitudinal axis of the deck frame. For example, the moveable upper guide element  8  of the left-hand leg in  FIGS. 2 and 3  can move in the directions shown by arrows D1 and D2. 
         [0035]    The lower portions of the legs  7  of each pair of legs are connected together by a lower bracing cross-element  10  at the bottom  12  of the legs. The lower cross-elements  10  are each in turn connected to a lower longitudinal or side element and able to rotate about their longitudinal axis. In the embodiment shown in  FIGS. 1 to 3 , each end of the foot end leg assembly lower cross-element is pivotally connected to a lower portion of a respective length extension element and the upper portion of each length extension element is pivotally connected to the lower longitudinal side element. The foot and head ends of the lower side elements  35  each have a castor or castor device  14  so that the support assembly can move over a floor or surface on which it is placed. 
         [0036]    A pair of stabilizer elements  16  is connected to each pair of legs. A stabilizer element is connected to and links each leg to the underside of the deck support frame. The stabilizer elements  16 , which are each coupled to a leg  7 , are pivotally connected at their first upper ends  17  to the underside of the deck support frame  3 . The upper ends  17  of each stabilizer are connected to a fixed upper pivot  18  displaced from the leg upper moveable pivot  8  of the respective leg, and are pivotally connected at their second lower ends  19  to the respective pair of legs at a pair of respective lower stabilizer pivots  20 . 
         [0037]    A stabilizer cross-element  37  is pivotally connected between the pair of stabilizers  16  for each leg assembly. The respective stabilizer cross-element is connected to each respective stabilizer at a point  36  between its upper  17  and lower  19  ends. 
         [0038]    An actuator-stabilizer yoke  21  is connected to each stabilizer cross-element at a point substantially mid-way along the stabilizer cross-element so that it is in the middle of the bed. The actuator-stabilizer yoke  21  is pivotally coupled to an end of an actuator  22  (which may be a hydraulic actuator, or a linear actuator such as model No LA27 actuators supplied by Linak U.S. Inc. located at 2200 Stanley Gault Parkway, Louisville Ky. 40223) which controllably extends and retracts an actuator rod  23  connected to the actuator-stabilizer yoke  21 . Extension and retraction of the actuator rod  23  causes the respective stabilizer cross-element  37  and hence the pair of stabilizers  16  connected to that stabilizer cross-element  37  to move and thence the pair of legs  7  connected to that stabilizer  16  to rotate relative to the deck support frame  3  and thence raises or lowers the deck support frame  3  and the patient support surface arranged on that deck support frame. The actuators  22  may be controlled by either the patient or a care-giver. Control mechanisms for such actuators are well known and may be either a foot operated pedal, control panel on the side of the bed, remote control or other control mechanism. Suitable actuators are well known and are therefore not described in detail in this application. They may be hydraulic, electric or pneumatic. An example of hydraulic actuators controlling the height of a deck is described in EP 2 181 685 and WO 2004/021952. 
         [0039]    Referring to  FIG. 1 , the deck support frame  3  is formed by three sides of a rectangle and comprises parallel side elements  24  connected at their head ends by a head frame element  25 . In the described embodiment there is no foot frame element closing the rectangle other than the foot board (not shown) when that is attached to the foot board plates  34  (not shown) but one could be provided if appropriate. One of the known patient support deck arrangements such as that described in EP 2 181 685 and WO 2004/021952 may be secured to the patient support frame. 
         [0040]    As shown in, for example,  FIG. 4 , the side rail elements each comprise a hollow channel element open, along at least a portion of its length, on its lower side  27 . The channel element is a modified inverted U-shaped channel in which a portion of the bottom edges  28  are lipped such that the sides of the channel extend partially across the bottom of the inverted U-shaped channel. 
         [0041]    The upper end of each leg is connected to two rollers  29 . The rollers  29  are supported on axles  30  running through the leg  7  and can rotate relative to the leg  7 . The upper end  31  of each leg passes through the gap or space  32  in the bottom of the channel elements  24  defining the sides of the deck support frame. The rollers  29  each engage the inner surface of the channel element. 
         [0042]    Referring to  FIGS. 2 and 3 , when the actuators  22  extend their respective rods  23  together to move the deck support frame  3  from a lowered position (see  FIG. 3 ) to a raised position (see  FIG. 2 ), the stabilizer element moves in direction E and pivots about its upper pivot. At the same time, the leg element pivots in direction F with its respective guide element moving in direction D1. As the guide element moves in direction D1 while the deck support surface is being raised, the respective set of rollers  29  roll relative to the respective channel element  24 . 
         [0043]    When the actuators  22  retract their respective rods  23  together to move the deck support surface from a raised position ( FIG. 2 ) to a lowered position ( FIG. 3 ), the stabilizer element moves in direction G and pivots about its upper pivot. At the same time, the leg element pivots in direction H with its respective guide element moving in direction D2. As the guide element moves in direction D2 while the deck support surface is being raised, the rollers roll relative to the channel element. 
         [0044]    Movement of the legs  7  and associated rollers  29  brought about by extension of the actuator rod to raise the deck support frame, pushes the rollers against the inner surface of the top of the respective channel element  24  so the roller rolls against that inner top surface of the channel. When the deck support frame is lowered by retraction of the actuator rod, the weight of the deck support frame and the patient support surface and patient supported thereon presses the inner top surface of the channel  24  against the respective rollers so that again the rollers roll along that top inner surface. 
         [0045]    The channel  24  is provided along a substantial part of its length with a lip portion  28  welded or otherwise attached to each of the bottom edges of the two sides of the channel element. This helps hold the rollers in place and, if the patient support deck is lifted manually or otherwise than using the actuators, pushes up against the bottom of the rollers such that they roll against the lipped bottom edges  28 . 
         [0046]    Moving the deck support frame into the Trendelenburg position or reverse Trendelenburg position is not illustrated in the Figs. However, it is achieved by having one of the leg assemblies in the raised position and the other in the lowered position and is otherwise the same as for lowering or raising the whole height of a substantially horizontal deck support frame. For the Trendelenburg position the foot end is raised to be about 15-30 degrees above the head end, whereas in the reverse Trendelenburg the head end is raised to be above the foot end. 
         [0047]    In a one embodiment of the patient support apparatus according to the present disclosure, at least one of the castors and/or castor devices at each of the foot and head ends of the apparatus are provided with a brake assembly with a brake lever as described in, for example, U.S. Pat. No. 7,703,157 and arranged to be contacted and pressed down by the lower surface of the channel element to lock or brake the respective castor or castor device when the respective portion of the deck support frame is lowered. 
         [0048]    Each of the castors includes a braking mechanism.  FIGS. 5 to 7  show how a braking mechanism of the type used in castors of the type supplied by Tente as parts reference 5944 USC125 R36 may be incorporated in an embodiment according to the present disclosure. In such castors, the castor wheels  38  are braked when a pliable braking element  39  is squeezed down by a braking surface  40  so that the sides of the braking element contact and push against the sides of the castor wheels. An alternative braking element is shown in U.S. Pat. No. 7,703,157 in which braking is by means of a floor engaging element which is pushed into contact with the floor when the braking surface is ousted downwards. Any castor with an actuator mechanism operable by being pressed down or contacted may be used. 
         [0049]    The braking surface  40  at the foot ends of the bed is pushed downward by the action of a braking lever  41  which may be actuated by, for example, the foot of a care giver on, as is shown in  FIGS. 5 to 7 , by contact with the underside of the channel element  24  as the bed is lowered to the lowermost position. The use of a guide element  8  which moves inside a channel  24  allows one to position the longitudinal channel  24  closer to the edges of the bed than is possible with the previous arrangements with a guide element on the outside of a channel. This means that the channel or longitudinal rod  24  can be positioned so it moves in a place sufficiently close to the wheels to itself directly engage the brake lever  41 . 
         [0050]    The brake surfaces (not shown) of the head end castors are connected to a respective foot end braking levers  41  by a rod element running inside each of the lower rail elements  35 . Movement of the braking lever  41  causes the rod to rotate and hence push the braking surfaces associated with the head end castors to move and hence brake or release the head end castors. 
         [0051]    Although certain illustrative embodiments have been described in detail above, variations and modifications exist within the scope and spirit of this disclosure as described and as defined in the following claims.