Patent Publication Number: US-8528704-B2

Title: Bed castor and brake assembly

Description:
FIELD OF THE INVENTION 
     The present invention relates to a bed castor and brake assembly for a bed, in particular a hospital bed. 
     BACKGROUND OF THE INVENTION 
     As it is often necessary to move hospital beds around a ward and also around a care home, such beds are typically provided with castors. Of course, a wheeled bed must be provided with a braking system to ensure that the bed can be set in one position. Many known hospital beds are provided with castors having integral brake mechanisms. A known castor of this type is provided with a cam coupled to a brake pad, the cam being rotatable to engage the brake pad with or to disengage the brake pad from a wheel of the castor. The cam and brake pad are typically provided internally of a connecting shaft of the castor. 
     As all four corners of such beds are typically provided with castors, it is not sufficient to brake a single castor. In practice, it is a requirement for all four castors to be braked. Of course, engaging the brake on all four castors separately can be difficult and systems have therefore been developed to link the braking systems of the castors together. Such systems are, however, complex in design. 
     The braking systems for such beds are typically provided with one or more pedals. As will be appreciated, such pedals are much used and often used hard, particularly in a hospital environment. It is not uncommon for the pedals to break or for components to come loose. This compromises the usability of the devices and often the safety and efficiency of the braking system. 
     SUMMARY OF THE INVENTION 
     The present invention seeks to provide an improved brake pedal or improved castor and brake assembly and an improved hospital bed. 
     According to an aspect of the present invention, there is provided a pedal for a brake assembly of a bed, the pedal being provided with an integral fitting for a brake component and with an integral fitting for a coupling member for coupling different brake mechanisms together. 
     Prior art pedals have provided fittings for only the brake components, any coupling to other brake mechanisms being provided by non-integral fittings. This complicates the brake assembly by requiring additional components and by increasing the chances of failure and possible locations for collection of dirt and germs. 
     Preferably, the brake fitting and the coupling member fitting are spaced from one another on the pedal. This provides for the pedal to exhibit both a rotating and a cam action for the two fittings. 
     Advantageously, the pedal is a moulded component. Preferably, the pedal is made from a plastics material. 
     In the preferred embodiment, the pedal includes at least one marker, the or each marker being over moulded on the pedal during moulding thereof. The feature of over moulding markers has the advantage of providing a much stronger coupling of markers to the pedal than is possible with glue and the like, as is used in prior art are devices. This can be particularly important where the markers are intended to indicate brake engaged and brake disengaged conditions. 
     It is preferred that all markers and labels provided on the bed are over moulded to the part to which they are attached. 
     According to another aspect of the present invention, there is provided a brake assembly for a bed including a plurality of pedal members as specified herein, at least one coupling member fittable to at least two adjacent pedals and operable to transfer to one pedal a motion corresponding to a motion imparted to the other or another pedal, and a brake mechanism coupled to the brake fittings of the pedals. 
     Advantageously, the assembly provides at least four pedals, arranged in opposing and side-by-side manner, pedals lying side-by-side being coupled together by said coupling members and pedals in opposing relationship being coupled together by a common brake actuator. In this arrangement, all the pedals can be coupled to one another, such that actuation of a single pedal will move all the interconnected pedals. 
     Preferably, the assembly includes a castor associated with each pedal, each castor including a brake pad coupled to the brake actuator. 
     According to another aspect of the present invention, there is provided a frame assembly for a bed including a brake assembly as herein specified, the frame assembly including a frame including fittings for receiving a plurality of castors and fittings for holding a plurality of pedals, at least one hollow strut member of the frame being provided for coupling opposing pedals such that the common brake actuator can pass though the hollow strut. 
     It is preferred that the or each coupling member for coupling together pedals lying in side-by-side manner is provided outside the frame struts, preferably disposed alongside an associated strut. This arrangement, it has been found, is advantageous in allowing a simpler structure and allowing a greater range of movement of the connecting member than would be possible with a connecting member located within a hollow strut of the frame. 
     According to another aspect of the present invention, there is provided a bed including a frame assembly as herein specified. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention are described below, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view in exploded form of an embodiment of pedal and showing part of an embodiment of connecting member; 
         FIG. 2  is a perspective view in exploded form of the pedal of  FIG. 1 , from the other side, and showing part of a brake actuator frame assembly; 
         FIG. 3  is a perspective view in exploded form of an embodiment of pedal, brake and castor assembly; and 
         FIG. 4  is a perspective view in exploded form of an embodiment of bed frame assembly including a plurality of the pedal, brake and castor assemblies of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION 
     Referring to  FIGS. 1 and 2 , an embodiment of pedal  10  for a bed brake assembly is shown. The pedal  10  is preferably formed from a single moulding of a suitably strong plastics material and includes first and second arms  12 ,  14 , each provided in this embodiment with a marker  16 ,  18 . The markers  16 ,  18  are in this example coloured covers, one in red and the other in green, to denote states of brake applied and brake released. These marker types are in common use in the industry. In this embodiment, the markers  16 ,  18  are over moulded on the pedal  10 , thereby forming in practice a single unitary structure. This structure has much greater longevity and strength than those which have markers which are, for example, glued onto the pedal or fitted by some form of snap or interference fit. 
     The pedal  10  is provided with two fittings  20 ,  22  for coupling with a brake actuator  24  and a coupling member  26  respectively. In this embodiment, the brake actuator  24  is of a type commonly used in the art, being a rod with a hexagonal transverse cross section. The fitting  20  in the preferred embodiment provides a hexagonal bore into which the actuator  24  is a tight fit. The front (outer) side  19  of the first fitting  20  also provides an aperture (as seen in  FIG. 1 ) to allow the passage of a bolt  28  whose threaded shank engages a corresponding threaded bore (not shown) in the end of the actuator  24 . The brake actuator  24  extends from the concave rear (inner) side  21  of the first fitting  20  at a shaft attachment location, and the arms  12  and  14  extend outwardly from an intermediate side  23  of the first fitting  20 . The bolt  28  secures the pedal  10  in place. 
     The second fitting  22  of the pedal  10  is located above the first fitting  20  to be spaced from the brake actuator  24 , and in a line with the first fitting  20  which is substantially perpendicular to the line made by the two arms  12 ,  14 . The rear (inner) side  25  of the second fitting  22  provides an aperture through which a fixing rod  30  can pass, the fixing rod  30  also passing through an aperture  32  in the coupling member  26  and mating with a spring clip  34  so as to fix the coupling member to the pedal  10  at the position of the second fitting  22 . The markers  16 ,  18  of the arms  12 ,  14  each define an actuation surface aligned along a plane oriented at least substantially perpendicularly to an axis extending between the shaft attachment location where the brake actuator  24  extends from the first fitting  20 , and the location at which the coupling member  26  is rotationally coupled to the second fitting  22 . 
     First and second caps  36 ,  38  snap fit onto the front (outer) sides  19 ,  27  of the first and second fittings  20 ,  22  of the pedal  10  to cover the front side of the fittings  20 ,  22 . 
     Referring now to  FIG. 3 , there is shown a preferred embodiment of pedal, brake and castor assembly. A castor  40 , of known form, includes a wheel  42 , which can rotate about a bushing  44 , and a coupling shaft  46 . Within the shaft  46  there is provided a cam mechanism and brake pad (both not shown). The brake pad in use can be urged by the cam onto the wheel  42  to stop it moving and can also be released therefrom by opposite rotation of the cam. First and second opposing round apertures  48  (only one of which is seen in  FIG. 3 ) are provided in the shaft  46  and in use receive the actuator rod  24 , as is described in further detail below. As is well known, the cam includes an appropriate fitting to receive the actuator rod  24  and in use rotates with rotation of the rod  24  to carry out the cam action which applies or releases the brake pad from engagement with the wheel  42 . As this design of castor with integral brake mechanism is well known in the art, it is not described in any further detail herein. 
       FIG. 3  also shows a part of a bed frame  50  to which the castor, brake and pedal assembly are fitted. The frame includes a first transverse strut  52  integral with a first longitudinal shut  54 . There are typically provided two transverse and two longitudinal struts as shown in  FIG. 4 . Of course, the struts  52 ,  54  can be either longitudinal or transverse, which one each is not being important. 
     The strut  52  is hollow and is provided with a cylindrical fitting  56  opening downwardly. The fitting  56  receives the shaft  46  of the castor  40  and is provided with two opposing round apertures  58  which in use align with the apertures  48  in the castor shaft  46  to allow the actuator rod  24  to pass therethrough and to rotate therein. The cylindrical fitting  56  also includes a hole  60  which aligns with a hole  62  in the castor shaft  46  for receipt of a fixing screw or bolt (not shown). 
     The pedal  10  fits onto the end of hollow strut  52 , such that the rounded internal shoulder  64  (best seen in  FIG. 1 ) overlies the strut  56  and provides for guided rotation of the pedal  10  about the strut  52 . The second fitting  22  of the pedal thus also overlies the strut  52 , as does the end of the coupling element  26 . As will be apparent from  FIG. 3  in particular, the coupling element  26  includes a bent bracket element (dogleg end)  68  and a straight elongate intermediate portion  70  extending from the bracket  68 . This allows the coupling element  26  to run alongside the strut  54 , substantially aligned therewith. 
     The first fitting  20  is substantially aligned with the centreline of the strut  52  such that depression of one of the arms  12 ,  14  of the pedal  10  will cause only rotation of the brake actuator rod  24 . On the other hand, such rotation will cause the second fixing  22  to move around an arc determined by the distance of the second fitting  22  from the first fitting  20 , that is of the radius as measured from the centre point set by the fitting  20 . This arcuate movement of the fitting  22  causes a similar movement in the coupling rod  26  which, by virtue of the length of the coupling rod, equates substantially to a lateral translation of the element  26 . 
       FIG. 4  shows an example of a base frame  80  for a bed, in particular a hospital bed. The frame  80  includes longitudinal and transverse struts  52 ,  54 , as per  FIG. 3 , arranged in a rectangular form, with four castors  40  and four associated pedal assemblies  10 . Two actuator rods  24  are provided, one for each pair of opposing pedal assemblies  10 , while two connecting elements  26  are provided, one for each pair of side-by-side pedal assemblies  10 . 
     When assembled, all the pedals and thus all the brake mechanisms are coupled to one another through the two actuator rods  24  and two coupling elements  26 . When one pedal  10  is turned, by depression of the appropriate arm  12 ,  14 , this causes rotation of the actuator rod  24  fitted thereto which in turn rotates the opposite pedal  10 . The rotation of the first pedal  10  also causes, through the translatory movement of the connecting element  26 , an equivalent rotation of the pedal lying to the side and thus, through the entire interconnected assembly, similar rotation of all the pedals  10 . As the rotation of one pedal  10  will either engage or disengage its associated castor brake in dependence upon the direction of rotation, through its actuator shaft  24 , all the castors will either be locked or will all be released by this single operation.