WO2018156032A1

WO2018156032A1 - A side rail

Info

Publication number: WO2018156032A1
Application number: PCT/NZ2018/050014
Authority: WO
Inventors: Anthony John Batley; Bruce Norton Moller; Angus Donald Ross Mcleod
Original assignee: Howard Wright Limited
Priority date: 2017-02-21
Filing date: 2018-02-20
Publication date: 2018-08-30

Abstract

The invention relates to a side rail for a care bed. The side rail may comprise an electronic user interface located on an interface support that is able to attach to and detach from the side rail. The user interface includes one or more inputs to control operation of the bed. Optionally, the user interface is a membrane keypad and may be curved to be located on a curved edge of the side rail.

Description

A SIDE RAIL

TECHNICAL FIELD

The present invention relates to a side rail for a bed, such as a hospital bed or nursing care bed.

BACKGROUND OF THE INVENTION

Side rails are commonly attached to the sides of hospital beds and nursing care beds to prevent patients falling out of bed. Many such beds are electrically powered to change position via user inputs on a user interface that may be located on the side rail. Typically, full bed controls are located on the outer side of the side rail for ease of access by a caregiver, whereas a more basic set of bed controls (such as back rest raise and leg raise) are located on an inner side of the side rail for ease of access by the patient.

However, user interfaces are often screwed to the side rails, increasing the risk that bacteria and grime may accumulate around the screws, presenting an infection risk. To reduce this risk, some side rails use user interfaces in the form of membrane keypads that are adhered to the surface of the side rail. A printed circuit board is located within the side rail, beneath the membrane keypad. Typically, the membrane keypad is electrically wired to an electronic controller, which may be located on a printed circuit board (PCB), and which forms part of a bed control system. The bed control system also comprises one or more actuators that are connected to the electronic controller of the user interface and that control movement of the bed. For example, the actuator(s) may be used to raise, lower and/or tilt the bed. The electronic controller may also be configured to control lighting, alarms, sound (such as radio or music), television, call bells, and the like. Additionally or alternatively, the bed control system may include separate lighting controls, alarm controls, sound controls and other components necessary for the comfort and care of a user of the bed.

To access the PCB for repair or replacement, the membrane keypad must be peeled away from the side rail, which destroys the keypad. The PCB is then repaired or replaced, adhesive residue is removed, and a new membrane keypad is then adhered to the side rail. The process is relatively labour intensive and the costs for each PCB repair or replacement are always incurred with the additional cost of replacing the membrane keypad.

Known plastic shell side rails with membrane keypads are blow moulded ; a process which produces a hollow shell side rail with very limited internal detail. As a result, these side rails provide limited options for mounting a membrane keypad to the side rail as it is not easy or possible to position and secure the PCB and electrical connectors (e.g. flexible ribbon and data cable) at any location within the interior of the side rail.

Known side rail user interfaces are located on the vertical side of the side rail, which makes it more difficult for a caregiver, when standing, to see and engage with the user inputs (such as buttons) on the user interface.

It is therefore an object of the present invention to provide a side rail for a bed that goes at least some way towards overcoming one or more of the disadvantages of the prior art or that at least provides the public with a useful choice.

SUMMARY OF THE INVENTION

In a first aspect, the present invention provides a side rail for an electronically controlled bed, the side rail comprising a body and a removable user interface support comprising an electronic user interface, wherein the body or interface support or both comprise one or more connectors to attach the interface support to the side rail body and to detach the interface support from the side rail body without removing the user interface from the interface support.

Optionally, the side rail further comprises an electronic controller to control movement of the bed, the electronic controller being electrically coupled to the user interface to receive control signals from the user interface. The electric coupling between the electronic controller and the user interface may comprise a ribbon cable. In one form, the electronic controller is provided by a printed circuit board.

The user interface may comprise one or more inputs to control operation of the bed.

Optionally, the user interface is a membrane keypad and may be curved to be located on a curved edge of the side rail body.

In one form, the interface support comprises a channel forming an interior region within the interface support. The controller may be located within the interior region of the interface support and connected to the electronic user interface.

In one form, the side rail body comprises first and second injection moulded side panels configured to attach together via a clip fit connection, a welded connection or an adhered connection. A substantially hollow region may be provided between the first and second side panels, within which a frame of the side rail is located. Optionally, the hollow region of the side rail body is configured to be in communication with an interior region of the interface support when the interface support is engaged with the side rail body.

In one form, the controller is located between the first and second side panels of the side rail body, and one or more electronic connectors connect the controller to the user interface.

In one form, the electronic user interface comprises a membrane keypad comprising a plurality of laminated layers. Optionally, the plurality of laminated layers may comprise one or more of an LED circuit layer, a keypad circuit layer, and a graphic overlay. Optionally, the membrane keypad may comprise one or more adhesive layers.

In one form, the interface support comprises a curved surface and the membrane keypad is substantially curved. Optionally, the interface support comprises an inverted substantially U-shaped body such that the lower portion of the U-shape forms a curved upper surface of the interface support. The membrane keypad may be provided on the curved upper surface of the interface support. One or more user inputs may be located on the curved upper surface of the membrane keypad.

In one form, the interface support is a cartridge.

In one form, the curved membrane keypad comprises at least one user input located on a curved area of the membrane keypad. Preferably, the user input is defined by embossed detail.

Also described herein is a side rail for a bed, the side rail comprising a removable cartridge configured to attach to and detach from the side rail without causing damage to components of the side rail or cartridge, wherein the cartridge comprises an electronic user interface that forms part of a control system for the bed.

In one form, the electronic user interface comprises a membrane keypad comprising a plurality of laminated layers. Preferably, the membrane keypad is substantially curved and is provided on an upper edge of the cartridge.

In one form, one or more user inputs are located on the curved surface of the membrane keypad.

Optionally, the side rail comprises first and second injection moulded side panels configured to attach together via a clip fit connection, a welded connection or an adhered connection. Preferably, a substantially hollow region is provided between the first and second side panels and within which a frame of the side rail is located. In one form, a printed circuit board and electronic connectors are also located in the hollow region between the first and second side panels. The electronic connectors optionally form part of a ribbon cable.

In one form, the cartridge comprises an interior region within which a printed circuit board is located and connected to the electronic user interface.

In a second aspect, the invention provides a method of forming a curved membrane keypad, the method comprising the steps of: providing a mould having a curved surface; applying separate layers of laminate material to the curved surface of the mould; and leaving to set to form a curved membrane.

In one form, the layers of laminate material are cured to form the curved membrane.

Optionally, the mould comprises an interface support, such as a cartridge, for a side rail for a bed, so that the curved membrane keypad can be formed directly onto the interface support.

Optionally, one or more adhesive layers are provided between adjacent layers of material.

In one form, the step (b) of applying separate layers of material to the curved surface of the mould comprises: applying an adhesive layer to the curved surface of the mould or a back surface of a first membrane layer, applying a first membrane layer to the mould, applying an adhesive layer to a top surface of the first membrane layer or a back surface of a second membrane layer, and applying a second membrane layer to the mould over the first membrane layer. Optionally, step (b) may further comprise applying an adhesive layer to a top surface of the second membrane layer or a back surface of a third membrane layer, and applying a third membrane layer to the mould over the first membrane layer.

In an alternative form, the step (b) of applying separate layers of material to the curved surface of the mould comprises: applying a sheet of adhesive to one or both surfaces of a first membrane layer, adhering a first membrane layer to the mould, and adhering a second membrane layer to the mould over the first membrane layer. Optionally, step (b) may further comprise (before adhering the second membrane layer to the mould) applying a sheet of adhesive to a top surface of the second membrane layer or a back surface of a third membrane layer, and adhering the second membrane layer to a third membrane layer.

In one form, the separate layers of material comprise one or more of an LED circuit layer, a keypad circuit layer, and a graphic overlay. In an embodiment, first, second, and third membrane layers of material comprise an LED circuit layer, a keypad circuit layer, and a graphic overlay.

In a third aspect, the invention provides an interface support for a side rail comprising a user interface comprising a curved membrane keypad. Preferably, the curved membrane keypad comprises at least one user input located on a curved area of the membrane keypad. The user input may be defined by embossed detail. The interface support may comprise a cartridge.

In a third aspect, the invention provides an electronically controlled bed having a side rail as described above. Any reference to prior art documents in this specification is not to be considered an admission that such prior art is widely known or forms part of the common general knowledge in the field.

As used in this specification, the words "comprises", "comprising", and similar words, are not to be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean "including, but not limited to".

As used in this specification, the term "side rail" refers to any safety side, cot side, rail, panel, or other system placed beside a bed to help prevent a person falling out of the bed.

BRIEF DESCRIPTION OF THE FIGURES

Preferred embodiments of the invention will now be described by way of example only and in relation to the following drawings in which :

Figure 1 is a front view of one form of side rail according to the present invention; Figure 2 is a rear view of the side rail of Figure 1 ;

Figure 3 is a partially exploded front perspective view of the side rail of Figure 1 showing a cartridge assembly separated from the side rail;

Figure 4a is a front view of one form of side rail and cartridge before the cartridge is attached to the side rail;

Figure 4b shows the cartridge and side rail of Figure 4a attached together;

Figure 5 is an exploded perspective end view showing a portion of a side rail and cartridge of the present invention;

Figure 6a is schematic cross-sectional end view of one form of cartridge according to the present invention;

Figure 6b is a schematic cross-sectional end view of one form of side rail according to the present invention;

Figure 6c schematic cross-sectional end view of the cartridge of Figure 6a attached to the side rail of Figure 6b;

Figure 7 is a partial cut away perspective view of a portion of an injection moulded side rail according to one aspect of the invention;

Figures 8a to 8e are schematic cross-sectional views showing the step of applying a laminate membrane keypad to one form of cartridge according to one aspect of the invention; and

Figure 9 is a cross-sectional view of one form of cartridge assembly attached to one form of side rail according to one aspect of the invention.

DETAILED DESCRIPTION

Figures 1 to 6c show one form of side rail 10 according to the present invention. The side rail is configured to be used with an electrically powered / electronically controlled care bed, such as a hospital bed or nursing care bed for example.

In one form, the side rail 10 comprises a body 100 comprising a front side wall 110a and a rear side wall 110b. The side rail 10 also comprises a user interface support structure 200 configured to be removably attached to the body 100 of the side rail 10. The user interface support structure 200 may be any structure that provides support for a user interface for the bed, such as a structure on which the user interface is mounted. For the sake of simplicity, the user interface support structure 200 will be referred to in this specification as a cartridge.

The cartridge 200 may be configured to attach to the side rail body 100 at any suitable location, such as on an upper edge or side edge or along an edge of an opening in the body of the side rail, for example. In one form, as illustrated, the body 100 of the side rail 10 comprises an opening or cutaway region 150 beneath a handle 140 of the side rail. In one form, the cartridge 200 is configured to attach to the side rail body so as to form an edge of the side rail body 100 that defines a portion of the opening or cutaway region 150, as shown in Figures 1 and 2. The edge may be angular or curved. The cartridge 200 comprises a body 250 comprising at least one substantially hollow region 260. Preferably, the cartridge body comprises a channel, the channel forming a hollow region 260 in the cartridge. In one form, as shown best in Figures 3, 5, 6a to 6c, and 9, the cartridge body 250 is substantially "U" shaped having rounded corners and a substantially continuous hollow region 260 along the length of the body 250. Where the cartridge 200 is located along an upper edge or portion of the side rail body, such as in the location shown in Figures 1 and 2, the cartridge body forms an inverted "U" like shape with rounded corners along the top of the cartridge. However, the cartridge body may form any suitable shape and may have rounded or angled corners. For example, in some forms, the cartridge body may comprise a substantially box-shaped cross-section.

The cartridge 200 also comprises an electronic user interface 300 comprising one or more user inputs by which a user can tilt, raise, or lower the bed or parts of the bed. In some forms, the user interface may also be used to operate lighting and/or to call a caregiver.

The electronic user interface 300 may be of any suitable form. The user inputs may also be of any suitable form, such as touch sensitive buttons, dials, or switches for example. In one form, the user interface comprises a control panel in the form of a membrane keypad comprising one or more user inputs 310 comprising buttons or touch sensitive switches that are connected to electronic circuitry, such as to a PCB. Each user input is configured to provide electronic signals to the circuitry when activated by a user (such as when depressed or touched). The electronic circuitry may comprise a controller configured to operate the relevant features (such as actuators to move the bed) based on signals received from the user input(s).

In one form, as shown in Figure 3, the cartridge 200 comprises an electronic membrane keypad 300 connected to a PCB 210 via one or more electrical connectors 220, such as wires or ribbon cables. The PCB 210 may also connect to an actuation system of the bed, such as via a data cable 230. The actuation system (not shown) may be any suitable actuation system comprising one or more actuators to raise, tilt, or lower the bed or parts of the bed, to turn a light on or off, to call a caregiver, and to carry out any other functions provided through the user interface 300.

The substantially hollow region/channel 260 of the cartridge 200 provides a space within which the electrical connectors 220 may be located. In one form, as shown in Figure 9, the PCB 210 may also be located within the hollow region 260 of the cartridge 200. In another form, the PCB 210 may be located within a substantially hollow region 160 provided in the side rail body 100.

The cartridge 200 and side rail body 100 may be configured so that the cartridge may be attached to and detached from the side rail body without causing damage to components of the side rail or the cartridge, including the electronic user interface and electronic circuitry. For example, if the side rail 10 comprises a PCB that needs to be repaired or replaced and the cartridge 200 comprises a membrane keypad 300, the cartridge 200 can be detached from the side rail body 100 without needing to remove (and therefore destroy) the membrane keypad 300.

Removable Cartridge

The cartridge 200 may be configured to attach to and detach from the side rail body

100 using any suitable form of connection system. In one form, the connection system is configured to allow the cartridge 200 to clip fit/snap fit to the side rail body 100 using one or more connectors. The connector(s) may be attached to or integral with the side rail body 100 and may be configured to engage with the cartridge 200 to detachably attach the two parts together. Conversely, one or more connectors may be attached to or integral with the cartridge 200 and may be configured to engage with the side rail body 100 to detachably attach the cartridge to the side rail body. In one form, both the side rail body 100 and the cartridge 200 may comprise connectors configured to engage with the respective other part 200, 100 to detachably attach the cartridge to the side rail body.

In one form, as shown in Figures 4a to 6c, the cartridge comprises two connectors

240a 240b projecting from a lower edge of the front of the cartridge body 250 and on the rear of the body 250. The connectors 240 comprise semi-flexible arms, each arm comprising a hook 241 at its free end. In one form, the connectors are plastic and are substantially resilient, but may flex to some extent when pushed back and forth. In one form, both the cartridge body and connectors are plastic and are moulded as a single part. In other forms, the connectors may be made from any other suitable material that is sufficiently resilient and flexible, such as metal for example.

The connectors 240 of the cartridge 200 are configured to engage with the side rail body 100 to attach the cartridge to the side rail body. In the embodiment shown in Figures 4a to 6c, the hooked ends of the connectors are configured to engage with a lip 170 of an opening or recess of the side rail body 100. As shown in Figures 6a to 6c, the side rail body comprises an opening 120 to receive the cartridge connectors 240. The cartridge body 250 is aligned with the opening 120 and then pushed into the opening 120 so that the connectors 240 push against sides 125 of the opening 120. The sides 125 of the opening 120 are spaced apart at a distance less than the distance between outer facing surfaces 242 of the connector hooks 241. Therefore, as the resilient and semi-flexible connectors 240 are pushed within the narrow opening 120, the connectors 240 are caused to flex toward each other, creating a spring tension in the connectors 240. Beneath the narrow opening 120 is a substantially hollow region 160 having a width larger than the width of the narrow opening 120 so as to form a lip 170 beneath the opening 120. As the cartridge connectors 240 are pushed further into the side rail body 100, the hooks are pushed past the narrow opening and into the larger hollow region 160. The spring tension in the resilient connectors 240 is at least partially released as the connectors 240 at least partially return to the non-flexed position. In this position, the hooked ends 241 of the connectors move away from each other and hook around the lip 170 of the side rail body 100 to attach the cartridge 200 to the side rail body 100.

To detach the cartridge from the side rail body 100, a user may squeeze together the sides/arms of the substantially "U" shaped cartridge body, which is semi-flexible, to cause the connectors to move toward each other and unhook from the lip 170. As the cartridge is being squeezed, it can also be pulled away from the side rail body 100 to retract the connectors 240 through the narrow opening 120 of the side rail body.

To provide a sufficiently flexible cartridge, the cartridge body is typically made of a semi-flexible plastic. However, it is envisaged that aluminium, steel, or any other suitably flexible, but robust material could also be used.

As will be appreciated, this is just one form of connection system for detachably attaching the cartridge to the side rail body. Any other suitable form of connection system may be used instead. For example, near an edge of the side rail, such as at an upper edge of the side rail body for example, the side rail body may comprise a ridge projecting from the front and rear surface of the side rail and substantially extending from one end of the side rail toward the other. The inner surface of one or both arms of the cartridge may comprise a channel or groove near the edge at the opening of the cartridge. The inner channel/groove substantially corresponds with the shape and dimensions of the ridge so that the ridge can be received within the channel/groove. In this form, the semi-flexible cartridge may be pushed over the side rail body, pushing the arms of the "U" shaped cartridge apart slightly until the ridge snap fits within the channel to allow the arms of the cartridge to substantially return to the non-flexed state and to attach the cartridge to the side rail. The cartridge may be removed by pulling the cartridge away from the side rail body with sufficient force to disengage the ridge and channel from each other.

By providing a detachable cartridge comprising an electronic user interface in the form of a keypad membrane, it is possible to remove the cartridge without having to remove (and therefore destroy) the keypad membrane; clean away the adhesive residue from where the keypad membrane was attached; and reapply a new keypad membrane. The cartridge system of the present invention therefore provides a faster, cheaper, and easier way of accessing the electronic circuitry, such as a PCB, connected to the electronic user interface.

Another advantage of providing a detachable cartridge for a side rail is that the cartridge, including the user interface and electronic componentry, can be sub-assembled separately to the main assembly line for the side rail body. By sub-assembling the cartridge, it is possible to orientate the cartridge for ease of assembly and to make automated assembly easier.

Injection moulded panels

In one form, as shown in Figures 5, 6b, 6c, and 7, the side rail 10 of the present invention may comprise a side rail body 100 comprising first 110a and second 110b injection moulded side panels configured to attach together via a clip fit connection, a welded connection, an adhered connection, or any other suitable connection system or combination of connection systems.

The first and second side panels 110a, 110b may each comprise a first surface that forms an outer surface of the side panel, and a second surface that forms an inner surface of the side panel. The second/inner surfaces of the side panels face toward each other when the side panels 110a, 110b are attached together to form the body 100 of the side rail 10. One or more side surfaces may project from the sides of the second surface of both side panels and may be configured to contact corresponding side surfaces of the opposite panel to provide an interior space between the side panels. Typically, the first and second side panels 110a, 110b will be attached together along the side surfaces, such as by welding or adhering the panels together to form the side rail body 100. In one form, the side panels are of a quadrilateral shape, such as a rectangular shape, and at least one side panel comprises four side surfaces that extend from the side edges of the side panel and extend toward the side edges of the other side panel. In another form, both side panels 110a, 110b may comprise side surfaces that extend from of the periphery of the second surface of each side panel. The distal edges of the side surfaces are configured to contact and be attached to (such as by welding or gluing or the like) corresponding distal edges of the side surfaces of the other side panel. Alternatively, one or more side surfaces may project from the second surface of only one side panel and may be configured to contact and be attached to the second surface or a peripheral edge of the second surface of the other side panel to provide an interior space between the side panels.

The connection system may be any suitable system of attachment, such as a hook and lip attachment, or a plug and socket attachment for example. In one form, the side panels 110a, 110b may comprise a connection system for attaching the side panels to each other. The connection system may be a clip fit system that is used alone or in combination with welding or adhering the two panels together.

In one form, as shown in Figure 5, at least one side panel comprises a connection system comprising connectors 130 in the form of one or more hooks and the other side panel comprises at least one lip of a recess or opening with which one or more of the hooks can engage to attach the side panels together. In another form, both side panels comprise connectors in the form of hooks 130 to engage with corresponding lips provided on the other side panel.

The connectors and/or lips may be integrally formed with the respective side panel during the injection moulding process or may be formed as separate components that are attached to the side panel.

The side panels 110a, 110b may be attached together to form a side rail body comprising a substantially hollow region 160 between the two panels 110a, 110b. In one form, a strengthening frame may be located within the hollow region 160. The frame may be of any suitable form to provide sufficient strength to the side rail 10. For example, the frame may comprise a substantially robust plastic or a metal, such as aluminium.

In one form, at least some of the electronic system of the side rail (such as a PCB 210 and/or electronic connectors 220 and/or data cable 230) may be located within the hollow region 160 of the side rail body.

The hollow region of the side rail body may be configured to be in communication with an interior region of the interface support when the interface support is engaged with the side rail body to form a cavity within which electronics of the electronic control system may be held.

By injection moulding the side panels 110a, 110b of the side rail 10, it is possible to accurately form the various parts of the side panels and to control the thickness of the panels and the various parts of the panels (such as reinforcing members and/or spigots projecting from the second surface of a panel) . It is also possible to achieve a high quality, substantially smooth, surface finish using injection moulding. Contrast this with blow moulding, in which the finished product is highly susceptible to shrinkage and the surface finish is often relatively poor.

Injection moulded side panels may also be made using a wide range of plastics and may include glass fibre reinforcing, whereas blow moulded panels are typically made from polyethylene or polypropylene.

It is also possible to easily access the interior of the side rail body 100 before attaching the two side panels 110a, 110b together. The ease of access to the interior allows a manufacturer to select and fit any suitable frame to the side rail 10 and to place any suitable electronics within any suitable location within the interior of the side rail body 100. Contrast this with the blow moulded side rail bodies of the prior art, in which the interior of the side rail is only accessible along a narrow opening at the peripheral edge of the side rail body and even that access is restricted by the side rail itself due to the nature of blow moulded parts.

Another advantage offered by separately injection moulding each side panel 110a, 110b is that it is possible to clip fit the side panels together, such as by using an integrally formed connection system, as described above, without needing to screw the panels 110a, 110b together. Regions surrounding screws are typically considered to be infection control points that require careful cleaning in medical care facilities. Therefore, by avoiding the use of screws, it is possible to minimise infection risk areas.

Yet another advantage provided by injection moulding is that, unlike a blow moulded product, an injection moulded product does not need to be trimmed and machined after being moulded. Consequently, manufacturing time and labour can be reduced by producing injection moulded side panels.

Curved membrane keypad In one form, the side rail of the present invention may comprise a user interface 300 comprising a curved membrane keypad. As shown in Figures 5, 8a to 8d, and 9, the membrane keypad 300 may be configured to attach to the removable cartridge 200. In another form, the membrane keypad 300 may be configured to attach to the side rail body, such as by attaching to one of the panels of the side rail body. Preferably, the membrane keypad 300 provides a curved edge or surface to the removable cartridge 200 or the side rail 10. In one form, the curved keypad 300 may be configured to curve around rounded corners at the base or mid-section of a substantially "U" shaped cartridge 200. Preferably, the U- shaped cartridge is inverted during use so that the base of the U forms the upper surface or edge of the cartridge and a pair of arms project from each side of the upper surface. The arms preferably define a channel extending beneath the cartridge and between the arms. The channel forms an interior region of the cartridge. In one form, the membrane keypad may be curved around the curved upper surface of the cartridge. By curving the membrane keypad at the upper surface of the cartridge, it is possible to see and access the keypad from above and from positions on either side of the cartridge and side rail. This allows both a patient and a caregiver to readily use the keypad 300.

The membrane type user interface may comprise more than one keypad . For example, a first keypad having patient controls that is oriented and positioned for convenient operation by a patient in the bed, and a second keypad with caregiver controls, oriented and positioned for convenient access from beside the bed. For example, the patient keypad may be located on the inner side of the side rail, while a second keypad may be located on an outside surface of the side rail or the upper surface of the user interface support, for ease of operation by a caregiver. A configuration having both patient and caregiver controls on a single membrane is advantageously more cost effective to produce and requires fewer steps to assemble. In an alternative form, the side rail may comprise two or more separate user interfaces. Such an embodiment may be appropriate in a configuration where the desirable location for the patient controls is not contiguous with a desirable region for the caregiver controls.

In an alternative form, the user interface may comprise an LCD screen to display one or more settings of the bed or inputs from the membrane keypad.

In one form, the membrane keypad 300 may be made from a plurality of layers laminated together. The applicant has found that if a flat multi-layer keypad is bent around a curve, the thickness and stiffness of the layered keypad and the shear forces between the layers cause the layers to separate or to resist bending sufficiently. Furthermore, by bending a multi-layered material in this way, the shear stresses between layers risk damage to the sensitive electronic circuitry and materials within the keypad. To avoid this problem, the applicant has developed a method of forming a curved keypad by gradually building up the layers of the keypad on a curved surface. By bending only one or some of the layers around a curve at one time and gradually adding layers until the membrane keypad is complete, the shear stresses between each layer are reduced and the individual layers bend more easily.

Figures 8a to 8e show one method of forming a multi-layered curved membrane keypad 300. As a first step, as shown in Figure 8a, a curved mould is provided, around which layers 301, 302 of the membrane keypad will be bent. In the form illustrated, the cartridge forms the mould so that the membrane keypad is applied directly to the cartridge. In this form, the cartridge may be substantially "U" shaped having rounded corners, as described above, or of any other suitable shape having a curved region on which at least a portion of the membrane keypad will be located .

The keypad 300 to be formed comprises multiple layers of different materials. In the example illustrated, the keypad comprises three layers of material. The layers include : an LED circuit 301 ; a keypad circuit 302; and a graphic overlay 303. In one form, the graphic overlay 303 comprises one or more user inputs. In one form, each user input comprises a button 304 that is configured to be depressed by a user to activate the user input(s). In another form, the user inputs may comprise touch sensitive switches/buttons 304 that may be defined by embossed detail or by any other suitable method of identifying the touch sensitive area of the user input.

The LED circuit 301 and the keypad circuit 302 may each be connected to an electronic connector 220. For example, the LED circuit 301 may be connected to an LED ribbon cable 220a and the keypad circuit 302 may be connected to a keypad ribbon cable 220b. Each ribbon connector 220 is wired to the controller. For example, each ribbon connector may be wired to a PCB 210 on which a controller, such as a microprocessor, is mounted.

It should be appreciated that the membrane keypad 300 may comprise any suitable number of layers required to conduct the functions of the keypad. For example, i n some forms, less than three layers may be required or more than three layers may be required to satisfy the keypad requirements. Regardless of the number of layers, the steps of forming the curved membrane keypad 300 are substantially the same.

One example of creating a layered membrane keypad will now be described. A layer of adhesive 305 is provided between each of the membrane keypad layers 301, 302, 303 and between the membrane keypad 300 and the mould/cartridge body 200. For example, a layer of adhesive 305 may be provided to the outer surface of the cartridge body on which the membrane keypad will be positioned, or on an inner surface of the first layer (in the form illustrated, the first layer is the LED circuit 301), or on both the cartridge body and the first layer. The first layer 301 of the membrane keypad is then laid over and bent around the curved body of the cartridge 200.

In one form, another layer of adhesive 305 is then placed on the outer surface of the first layer 301, the inner surface of the second layer 302, or on both the outer surface of the first layer 301 and the inner surface of the second layer 302. The second layer 302 is then placed on top of the outer surface of the first layer 301 and is bent around the curved first layer 301. In the process illustrated, the second layer 302 is the keypad circuit 302, which is placed on top of the LED circuit 301. The process of applying an adhesive 305 and then bending the next layer around the already curved layers mounted to the mould/cartridge 200 is repeated until all layers have been applied. In the embodiment illustrated, the graphic overlay 303 is the third and last layer to be applied to the mould/cartridge 200. The graphic overlay 303 is applied on top of the keypad circuit 302 and is attached to the keypad circuit 302 by a layer of adhesive 305, sandwiched between the two layers 302, 303 and applied in the same manner as described above and left to cure.

In another form, as illustrated, the adhesive layer 305 may comprise a sheet of adhesive, such as a double sided adhesive substrate. In this form, a sheet of adhesive may be applied to each of the inner and outer layers of the first layer 301. A double sided sheet of adhesive 305 may also be applied between the second layer 302 and third layer 303 to adhere these two layers together.

In one form, rather than bending each layer to the desired form individually, multiple layers (such as two layers for example) may be laminated together and then bent to the desired form, provided that the multiple layers do not become so thick that the shear forces between layers undermines the integrity of the keypad.

In one form, each layer or combination of layers may be applied to the whole of the cartridge 200 before the next layer or combination of layers is added. Alternatively, several layers may be applied to a portion of the cartridge 200 before being curved around the remainder of the cartridge. For example, the first 301, second 302, and third 303 layers may be adhered together at one end portion of each layer to form a single sheet comprising all three layers. The layered portion may then be adhered to one outer side surface of the cartridge 200, such as the rear surface. The free end portion of the first layer 301 (with adhesive applied to both the inner and outer surfaces) is then bent around the curved region of the cartridge 200. Optionally, the keypad layers 301, 302, 303 are sufficiently large to bend around and attach to the remaining outer surface of the cartridge body 200 so that both arms of the "U" shaped cartridge body 200 and the curved mid-section of the body 200 are covered in the layered keypad material 300. As a next step, the free portion of the combined second 302 and third 303 layers is bent around and adhered to the curved first layer 301. The layered keypad is then left to cure or set.

In another form, the membrane keypad 300 may be formed around a mould, as described above, but without adhering the first layer 301 to the mould. In this configuration, it is preferable that the first layer is applied to the mould and allowed to cure or set before subsequent layers are applied. Once the laminate structure of the keypad membrane is complete and has cured or set, the membrane 300 can be removed from the mould and applied to the cartridge 200 or other desired surface of the side rail 10 and secured in place using adhesive or any other suitable form of attachment. In one form, the keypad membrane is configured so that the user inputs/buttons/switches 304 are located on a curve where an arm of the "U" shaped cartridge curves toward the mid-point of the cartridge, as shown in Figure 8e. By providing the user inputs at this location, the curved membrane keypad provides the advantage that the user inputs can be seen by someone in the standing position (such as a care giver), as shown in Figure 9, or by someone lying down next to the side rail bearing the cartridge (such as a patient). Where the cartridge is placed on an upwardly facing edge of the side rail, the position of the user inputs on the curved upper surface also makes it easy for a caregiver to rest his or her finger on the desired user input in a semi-relaxed position for as long as required and with less chance of the finger slipping off the user input.

Although preferred methods of creating a curved membrane keypad have been described in relation to creating and mounting the keypad on a removable cartridge for a side rail, the methods may otherwise be used to create and mount a curved membrane keypad to the panel of a side rail, such as to a curved edge or surface of the panel.

In some forms, the curved membrane keypad may also offer the advantage of covering a manufacturing seam or other unsightly detail along a curved edge or surface of the side rail.

Although the invention has been described by way of example, it should be appreciated that variations and modifications may be made without departing from the scope of the invention as defined in the claims. Furthermore, where known equivalents exist to specific features, such equivalents are incorporated as if specifically referred in this specification.

Claims

What we claim is:

1. A side rail for an electronically controlled bed, the side rail comprising a body and a removable user interface support comprising an electronic user interface, wherein the body or interface support or both comprise one or more connectors to attach the interface support to the side rail body and to detach the interface support from the side rail body without removing the user interface from the interface support.

2. The side rail of claim 1, further comprising an electronic controller to control movement of the bed, the electronic controller being electrically coupled to the user interface to receive control signals from the user interface.

3. The side rail of claim 2, wherein the electric coupling between the electronic controller and the user interface comprises a ribbon cable.

4. The side rail of claim 2 or 3, wherein the controller is provided by a printed circuit board.

5. The side rail of any one of claims 2 to 4, wherein the interface support comprises a channel forming an interior region within the interface support.

6. The side rail of claim 5, wherein the controller is located within the interior region of the interface support and is connected to the electronic user interface.

7. The side rail of any one of claims 2 to 6, wherein the side rail body comprises first and second injection moulded side panels configured to attach together via a clip fit connection, a welded connection or an adhered connection.

8. The side rail of claim 7, wherein a substantially hollow region is provided between the first and second side panels and within which a frame of the side rail is located.

9. The side rail of claim 8, wherein the hollow region of the side rail body is configured to be in communication with an interior region of the interface support when the interface support is engaged with the side rail body.

10. The side rail of any one of claims 7 to 9, wherein the controller is located between the first and second side panels of the side rail body, and wherein one or more electronic connectors connect the controller to the user interface.

11. The side rail of any one of the preceding claims, wherein the electronic user interface comprises a membrane keypad comprising a plurality of laminated layers.

12. The side rail of claim 11, wherein the plurality of laminated layers comprise one or more of an LED circuit layer, a keypad circuit layer, and a graphic overlay.

13. The side rail of claim 12, further comprising one or more adhesive layers.

14. The side rail of any one of claims 0 to 13, wherein the interface support comprises a curved surface and the membrane keypad is substantially curved.

15. The side rail of claim 14, wherein the interface support comprises an inverted substantially U-shaped body such that the lower portion of the U-shape forms a curved upper surface of the interface support.

16. The side rail of claim 15, wherein the membrane keypad is provided on the curved upper surface of the interface support.

17. The side rail of any one of claims 14 to 16, wherein one or more user inputs are located on a curved upper surface of the membrane keypad .

18. The side rail of any one of the preceding claims, wherein the interface support is a cartridge.

19. An electronically controlled bed having a side rail according to any one of the preceding claims.

20. A method of forming a curved membrane keypad, the method comprising the steps of:

a. providing a mould having a curved surface;

b. applying separate layers of material to the curved surface of the mould; and c. leaving the layers to set to form a curved membrane.

21. The method of claim 20, wherein the mould comprises an interface support for a side rail for a bed, so that the curved membrane keypad can be formed directly onto the interface support.

22. The method of claim 20 or 0, wherein one or more adhesive layers are provided between adjacent layers of material.

23. The method of claim 22, wherein the step (b) of applying separate layers of material to the curved surface of the mould comprises:

applying an adhesive layer to the curved surface of the mould or a back surface of a first membrane layer;

applying a first membrane layer to the mould;

applying an adhesive layer to a top surface of the first membrane layer or a back surface of a second membrane layer; and

applying a second membrane layer to the mould over the first membrane layer.

24. The method of claim 2322, wherein the step (b) of applying separate layers of material to the curved surface of the mould further comprises:

applying an adhesive layer to a top surface of the second membrane layer or a back surface of a third membrane layer; and

applying a third membrane layer to the mould over the first membrane layer.

25. The method of claim 22, wherein the step (b) of applying separate layers of material to the curved surface of the mould comprises:

applying a sheet of adhesive to one or both surfaces of a first membrane layer; adhering a first membrane layer to the mould;

adhering a second membrane layer to the mould over the first membrane layer.

26. The method of claim 25, wherein the step (b) of applying separate layers of material to the curved surface of the mould further comprises, before adhering the second membrane layer to the mould :

applying a sheet of adhesive to a top surface of the second membrane layer or a back surface of a third membrane layer; and

adhering the second membrane layer to a third membrane layer.

27. The method of claim 20 or 0, wherein the separate layers of material comprise one or more of an LED circuit layer, a keypad circuit layer, and a graphic overlay.

28. The method of claim 24 or 26, wherein the first, second, and third membrane layers comprise an LED circuit layer, a keypad circuit layer, and a graphic overlay.

29. An interface support for a side rail comprising a user interface comprising a curved membrane keypad.

30. The interface support of claim 29, wherein the curved membrane keypad comprises at least one user input located on a curved area of the membrane keypad.

31. The interface support of claim 30, wherein the user input is defined by embossed detail.