Hospital bed and mattress having a retracting foot section

Information

  • Patent Grant
  • 6496993
  • Patent Number
    6,496,993
  • Date Filed
    Friday, January 5, 2001
    23 years ago
  • Date Issued
    Tuesday, December 24, 2002
    21 years ago
Abstract
A bed having a foot prop on an adjustable length deck foot section and a mattress with a length and thickness adjustable foot section and a thickness adjustable heel section. The adjustability of the deck and the mattress allows sizing of the bed to the occupant as well as heel management. The foot prop is also adjustable.
Description




BACKGROUND AND SUMMARY OF THE INVENTION




The present invention relates generally to adjustable beds and more specifically to a bed having an improved adjustable foot section.




There are many known bed designs that have adjustable foot sections. On beds that convert from a planar bed configuration to an upright chair configuration, the foot section is generally shortened as the foot section rotates from a horizontal to a vertical position. There are also beds having adjustable lengths wherein an attendant physically repositions the head or foot section of the bed to the desired length. These designs include a sliding telescopic foot section as well as a folding foot section equivalent to a “lazy boy” design. It is also known to deflate the foot section of the mattress when converting from a bed to a chair. For short occupants, there exists a need for adjustment of the foot prop or board in the chair position shorter than that attended by adjusting the length of the foot section.




The ability to adjust the length of the foot section independent of converting from a bed to a chair is also important. This would assist in maneuvering the bed in a confined locations during patient transport. It also allows the bed length to be customized to a patient's size. If a foot prop is provided at the end of the foot section, the adjustment of the foot section and the prop would prevent patient migration across the support surface of the bed. It would also provide support for the feet to thereby improve the patient's feeling of security. It could also be used in the prevention of peripheral neuropathy (“foot drop”). Positioning the end of the mattress relative to the patient substantially increases the ability to provide heel management. Heel management is wherein the heel is supported by the thigh and the calf and the heel has reduced pressure contact with the mattress.




Certain individuals who are confined to bed for an extended period of time are vulnerable to skin breakdown on the back of the heel. Protection of the skin in this area is important if initial indications of tissue failure are observed. If the breakdown process has progressed to a point of ulceration, protection of the heel area of the patient is essential to healing.




Reducing or eliminating the time an individual spends in a supine position will protect the heel area, although it may increase the risk of skin failure on other areas of the foot and body. The current practice for protecting the heel area of a patient while in the supine position utilizes foot support to reduce or eliminate pressure and shear on the back of the heel. Such support is often provided by placing an ordinary pillow or folded towel under a calf area of the patient's legs. Several different foam boot designs are known that strap to the leg or foot to reduce the effects of heel pressure. In addition, a conventional mattress is known in which removable sections are provided in a foot area.




All of these conventional support methods require a caretaker to add or remove components from the bed in order to control pressure on the heels of the patient. Components which are removed from the bed have the potential to get lost or mislaid. Components that are added to the bed provide an extra cost associated with the purchasing, cleaning, and disposal of the added components. There is also a cost in time for the caregiver who must go through multiple steps to initiate and maintain the support of the device.




The present invention provides a bed capable of achieving these goals. The bed includes a deck having a foot section of a variable length along the plane of the foot section. A foot prop is mounted to a first end of the foot section and extends transverse to the plane of the foot section. A mattress on the deck has a foot portion of adjustable length along the plane of the foot portion and variable thickness transverse to the plane of the foot portion. A heel portion of the foot portion of the mattress adjacent the foot prop has a thickness variable independent of the thickness of the remainder of the foot portion. The foot portion of the mattress includes a plurality of variable length elements separated by a plurality of variable thickness elements. The variable length elements are connected to operate simultaneously and the variable thickness elements are connected to operate simultaneously and both operate independent of the heel portion. Preferably, the heel portion, the variable length elements and the variable thickness elements each include one or more bladders which are inflatable and deflatable.




To achieve a chair bed, the foot section of the deck is pivotally mounted to the remainder of the deck. A first actuator varies the length of the foot section of the deck, a second actuator pivots the foot section of the deck and a third actuator varies the length of the foot portion of the mattress. A fourth actuator varies the thickness of the heel portion of the mattress and a fifth actuator varies the thickness of the remainder of the foot portion of the mattress. The second actuator is deactivated when it encounters a predetermined resistance. Preferably, this is during rotation down.




A control system includes an angle sensor and a length sensor connected to the foot section of the deck. Also, a foot prop sensor is connected to the foot section o,f the deck. As the length sensor senses the position of the end of the bed or it's length, the appropriate inflation or deflation of the bladders is made to adjust the length of the foot portion of the mattress. The angle sensor cooperates with the foot prop sensor and the control system so that the foot section cannot pivot to an angle which will allow egress form the end of the bed without removal of the foot prop. This is preferably in the range of 65° to 90° from horizontal.




The foot prop has at least one foot support surface and means are provided for mounting the foot support surface to the foot section of the deck at different distances from the end of the foot section. The mounting means includes one or a pair of sockets spaced along the length of the foot section to receive the foot prop. The foot prop may include a rod received in the sockets. The rod may be mounted asymmetrical with respect to a pair of opposed foot support surfaces. By rotating the foot prop 180°, the foot prop can be mounted in the same socket and achieve an adjustment. Alternatively, the rod may be symmetrically located and the distance adjusted by selecting one of a pair of sockets spaced along the length of the second foot section. The foot prop provides support from the horizontal to a chair is position up to an egress range of foot section angle.




Another method of shortening the length of the foot support surface beyond that which is produced by shortening the foot section of the deck is to not shorten nor thin the mattress foot portion when the foot section of the deck is shortened. The foot portion of the mattress can then be folded up the support surface of the foot prop. This decreases the distance of the foot support surface by the thickness of the mattress foot section.




The structure which allows adjustability of the length of the foot section of the deck includes a first section connected to the remainder of the deck and a second section movable relative thereto. Telescopic guides connect the first and second sections and the actuator also connects the first and second sections. Preferably, the actuator is between a pair of spaced telescopic guides connected to the first and second sections. Also, preferably, the telescopic guides includes three telescopic elements. The second foot section has a generally U-shaped cross section encompassing part of the top and lateral sides of the first section. The first section is a trapezoid having a large and small oppose surfaces and the large surface is the top of the first foot section. The foot section of the deck has a width smaller than the width of the remainder of the deck and the foot prop is mounted to lateral extensions of the foot section. The width of the foot section with the lateral extensions is substantially equal to the width of the remainder of the deck. Bumpers are also mounted to the lateral extensions.




To size a support surface of the bed to an occupant and provide heel management, the bed may be used in the following method. The length of the foot section with a foot prop thereon is adjusted until the foot prop is immediately adjacent the foot of an occupant on the support surface. The thickness of a portion of the support surface of the mattress below the heel of the occupant is reduced. The length of the foot section of the deck and the foot portion of the mattress are adjusted simultaneously. The foot section of the deck is adjusted using the first actuator, the foot portion of the mattress is adjusted using a second actuator and the thickness of one of the portions of the mattress foot portion is reduced using a third actuator.




A mattress includes a foot portion and a body portion within a ticking. The foot portion is secured to the ticking as an adjustable length. The foot section may either be corrugated foam of adjustable length or a plurality of bladders which are inflatable and deflatable to adjust the length. The bladders need not be secured to the ticking. The ticking includes at least one slot and the foot section includes a flap secured thereto and extends into the slot to secure the foot section to the ticking. The ticking includes an interior pocket and the slot is in the interior pocket. Magnets secured to the ticking for securing the mattress to the bed may also be provided in the pockets. A plate is also mounted to the foam displaced from the flat and straps are secured to the plate and join the foot section to the foot portion of the mattress to the body portion of the mattress. A slip cover is provided encompassing the foot section to allow easy movement of the foot portion relative to the ticking.











Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.




BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a schematic view of a patient on a bed with the foot section/portion fully extended.





FIG. 2

is a schematic view of a patient on a bed with the foot section/portion adjusted and illustrating the heel management according to the principles of the present invention.





FIG. 3

is a bottom view of the foot section of a mattress according to the principles of the present invention.





FIG. 4

is a perspective top view of the foot section of the deck according to the present invention and connected to the remainder of the deck.





FIG. 5

is a bottom exploded view of a foot section of the deck of FIG.


4


.





FIG. 6

is a bottom perspective view of 180° with respect to the respective view of

FIG. 5

of one section of the deck of FIG.


5


.





FIG. 7

is a top perspective view of the detail of the foot prop socket and safety switch according to the principles of the present invention.





FIG. 8

is a perspective view of the rotating mechanism according to the principles of the present invention.





FIG. 9

is an exploded perspective view of a mattress according to the principles of the present invention.





FIG. 10

is a perspective view of a foam foot portion of a mattress according to the principles of the present invention.





FIG. 11

is a bottom view of the foot portion of FIG.


10


.





FIG. 12

is a side view of the foot portion of

FIG. 10

with a cover according to the principles of the present invention.





FIG. 13

is a bottom view of the foot portion of FIG.


12


.





FIG. 14

is a partial perspective view of the foot end of a ticking for a mattress according to the principles of the present invention.





FIG. 15

is a perspective view of the foot section of the deck and a foot prop.





FIG. 16

is a perspective view of a modified foot section of the deck with a pair of foot prop sockets.





FIG. 17

is a view of the foot section of the deck shortened and the mattress foot section folded.





FIG. 18

is a schematic of the fluid controlled circuit for the foot angle actuator.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




As illustrated in the Figures, the bed will be discussed with respect to a deck


10


and a mattress


20


thereon. As illustrated in

FIG. 4

, the deck


10


includes a seat section


12


, a thigh section


14


and a foot section


16


mounted to a frame


18


. The deck would also include, but not shown, a head section also connected to the frame


18


. Since the present invention is directed specifically to the foot section


16


, the other portion will not be described in detail. The foot portion


16


may be used on any deck structure.




The retracting foot section of the present invention can be retracted while the bed is in its horizontal bed position. This permits the caregiver to adjust the overall length of the bed in either the bed position or the chair position. The overall bed length can be shortened by about 12-14 inches to facilitate transport of the bed. In other words, the retracting foot section reduces the bed length so that the bed can fit into smaller elevators. The shorter bed also has a smaller turning radius. The foot section can also be moved to its retracted position to save space during storage of the bed.




The retracting foot section of the present invention also decreases patient migration since the foot prop location may be adjusted to the height of the patient. Therefore, the bed size can be customized for the patient. The bed also includes a shearless pivot linkage disclosed in copending application Ser. No. 08/511,711 filed Aug. 4, 1995, the specification of which is incorporated herein by reference. The combination of the shearless pivot with the retracting foot section and foot prop reduces patient migration toward the foot end of the bed as the bed articulates.




The mattress


20


illustrated in

FIGS. 1 and 2

includes a body support portion


22


and a foot portion


24


. The foot section


24


includes a calf portion


26


which is variable in length and thickness and a heel portion


28


which is variable in thickness. One preferred embodiment of the mattress foot portion


24


is illustrated in

FIGS. 1-3

as including a plurality of bladders. A plurality of variable thickness bladders


30


are separated by variable length bladders


32


. The heel bladder


28


is separated from one of the variable thickness bladders


30


by a variable length bladder


32


. The uniaxial variable bladders are produced by gussets in the bladders.




Referring to

FIG. 3

, a control line


34


is connected to the foot mattress portion


24


and by line


36


to the first variable thickness bladder


30


. A line


38


at the other end of the first bladder


30


is connected to the second bladder


30


. Line


40


at the opposite end of the second bladder


30


connects the second bladder


30


to the third bladder


30


. A control line


42


is connected to line


44


of the foot portion


24


which is connected at its other end to the heel bladder


28


. A control line


46


is connected to the first variable length bladder


32


. All of the variable length bladders


32


are connected about the periphery of the foot portion


24


. A cover


48


for the foot portion is held together by snaps


50


. Preferably, the cover


48


is a slip or a shear promoting material, for example,


30


denier ripstop nylon which aids the movement of the foot section in the mattress ticking. This removes the shearing between the occupant and the ticking as the length of the mattress is changed. A strap


51


is secured to the cover


50


by the snaps which are rivets and ties the foot section to an adjacent section


22


of the mattress.




The control lines


34


,


42


and


46


are connected to a control module which selectively inflates and deflates the bladders. An example of the control module is that in U.S. Pat. No. 5,666,681 which is incorporated herein by reference. From the connection, all of the variable thickness bladders


30


are inflated and deflated simultaneously, all of the variable length bladders


32


are also inflated or deflated simultaneously. Alternatively, each of the variable length bladders may be individually controlled with additional control lines or other flow control mechanisms. All three types of bladders are independently controlled.




The foot section


16


of the deck includes a first section


52


connected to the frame


18


and the remainder of the deck and a second section


54


movable along the plane of the section


52


. A foot prop


56


is mounted to the second foot section


54


and extends transverse to the plane of the foot sections


52


and


54


.




To size the bed to the patient and provide heel management, an occupant is placed on the top surface of the mattress


20


as illustrated in

FIG. 1

with the calf of the patient resting on the foot mattress portion


24


. The foot deck section


54


is retracted onto the deck foot section


52


until the foot prop


56


is adjacent the foot of the occupant as illustrated in FIG.


2


. Simultaneously, the length adjusting bladders


32


are deflated so that the length of the portion


26


of the mattress is decreased, placing the heel of the patient above the heel bladder


28


. The heel bladder


28


is then deflated, decreasing its thickness such that the interference pressure on the heel of the patient is reduced. By independently controlling the length of the foot section of the deck, the length of the foot portion of the mattress and the thickness of the heel portion of the mattress, appropriate adjustment of the length of the bed is possible as well as heel management.




The foot section


16


of the deck may be pivotally connected to the frame so as to allow the foot section to drop and to be used in various styles of beds or chair beds. A separate and distinct actuator would be provided for the pivotal movement as well as the articulation of the other deck sections. This allows adjustment of the foot section for the length of a patient and heel management independent of articulation of the deck and mattress as well as reducing the length and thickness of the foot portion of the mattress as the deck is converted to a chair.




The foot section


16


of the deck will be explained with respect to references


4


-


8


. The first foot section


52


includes a top wall


58


and a pair of opposed lateral side walls


60


. Mounted to the bottom surface of top wall


58


by welding for example, are a pair of guide tubes


62


. An intermediate guide tube


64


is telescopically received with tube


62


and an end guide tube


66


is telescopically received in intermediate guide tube


64


. As will be discussed below, the end guide tube


66


is secured to the second foot section


54


. The pairs of telescopic guide tubes


60


,


64


and


66


guide the relative movement of foot section


54


with respect to foot section


52


. Plates


68


are connected between the guide tubes


62


and the bottom surface of the top plate


58


. Thus, the foot section


52


has a trapezoidal shape. This trapezoidal shape with the larger of the two parallel surfaces being the top wall


58


.




Also mounted to the under surface of the top wall


58


of the foot section is a hinge plate


70


which mates with a hinge plate


72


mounted to the deck frame


18


. This pivotally mounts the foot section


16


of the deck to the frame


18


. Mounted between the guide tube


62


are a pair of spaced end walls


74


and


76


.




The second foot section


54


includes a top wall


78


, a pair of side walls


80


extending therefrom and a pair of bottom walls


82


extending from side walls


80


. The top, side and bottom walls are made from one continuous piece of material. The second foot section


54


is generally U-shaped with bottom flanges


82


forming a C-channel with the side walls


80


and top walls


78


. Thus, the top and side walls of the foot section


54


encompass or surrounds a portion of the top and side walls of the foot section


52


. The foot section


54


includes an end wall


84


connected to the top wall


78


, the side walls


80


and the bottom walls


82


. Tube mounting assembly


86


mounts one end of the guide tube


66


to the end wall


84


of the foot section


54


.




The end wall


76


of the foot section


52


includes openings


87


and


88


, best seen in

FIGS. 4 and 6

, between the guide tube


62


. An actuator


89


shown in phantom in

FIG. 5

is connected to end wall


74


and has an input connections. The actuator


89


is preferably an air cylinder, and mounting connection


90


on end wall


74


is connected to a control line (not shown). The other end of actuator


89


is secured to wall


76


by bracket


92


in the opening


88


. Arm


94


extending from actuator


89


is secured to wall


84


of the second foot section


54


by bracket


96


. The actuator


89


is between the guide tubes


62


,


64


and


60


. The pair of guide tubes


62


,


64


and


66


provide uniform distribution of forces. Also, the guide tubes support the weight of the occupant's feet and minimizes friction between the walls of the foot section


52


and


54


. This prevents binding and rubbing between the foot section


52


and


54


.




Plastic wipers


98


are also connected to the underside of top wall


78


of the foot portion


54


to protect the sliding joint between the foot sections


52


and


54


and also to prevent the sheet and mattress from intrusion into the joint and jamming the foot section adjustment.




The foot section


54


includes lateral extensions


100


. Bushing


102


mounts a bumper or roller


104


to the lateral extension


100


. Socket


106


which receives the foot prop


56


is also included in the lateral extension


100


. Alternatively, a pair of sockets


106


and


107


may be provided on each extension


100


as shown in

FIG. 16. A

switch


108


is mounted to the socket


106


by fastener


110


as illustrated in FIG.


7


. Switch


108


indicates the presence of the foot prop in the end of the bed and is part of the control system. Alternatively, the switch


108


may be designed to also sense the presence of pressure on the foot prop produced by the foot of the occupant of the bed engaging the foot prop of the occupant of the bed.




Handles


128


are conveniently provided at the foot of the bed connected between the lateral extensions


100


and the foot section


54


. A cover


150


is mounted to the end wall


84


of the foot section


54


as shown in FIG.


5


. Slots


154


in the top of end wall


84


receives a stop


156


when the foot portion


24


of the mattress is made of foam as illustrated in

FIGS. 10-13

.




The width W


1


of the foot sections


52


and


54


is substantially the width of the frame


18


and smaller than the width W


2


of the frame


18


with its support surfaces. This accommodates side rails (not shown) mounted on the frame


18


in their lowered or tucked position as the foot section


16


pivots down. Width W


3


of the foot section


16


with the lateral extensions


100


may be substantially equal to the width W


2


, since the extensions will pivot below the side rails.




The length of the foot deck section


16


as well as the angle of the foot section


16


with respect to the frame


18


are determined by length sensor


114


and angle sensor


116


mounted to the first foot section


52


at tube


62


by bracket


112


. A sensor crank


118


is mounted to the length sensor


114


at one end and its other end is mounted to sensor link


120


. The sensor link


120


extends through the opening


87


in the wall


76


and is connected at its other end to a pivotal connection


122


to the end wall


84


of the foot section


54


. The length sensor


114


may be for example, a potentiometer wherein the crank


118


and link


120


rotate the potentiometer with a change of the length of the foot section


54


with respect to foot section


52


.




A link


124


is connected to the angle sensor


116


at a first end by crank


123


and is pivotally connected at the second end to pivot leg


126


(shown in

FIG. 6

) mounted to hinge plate


72


(

FIG. 4

) which is connected to the deck frame


18


. The angle sensor


116


may also be a potentiometer to determine the pivotal position of the foot section


16


with respect to the deck frame


18


.




A pair of links


130


are pivotally mounted at one end to bracket


132


which is mounted to end wall


76


of the first foot section


52


. The other end of links


130


are pivotally connected between brackets


134


and


136


mounted onto rod


138


. The other end of brackets


136


is pivotally connected by brackets


140


to end wall


142


of the frame


18


. Brackets


144


in the midsection of rod


138


connect rod


146


of actuator


148


to the rod


138


. The other end of the actuator


148


is connected to the frame


18


. A cover


150


has one end (not shown) connected to the frame


18


and its other end connected to brackets


152


which are mounted on end face


142


of the frame


18


.




The actuator


148


determines the articulation or angular position of the foot section


16


of the deck. The actuator


148


illustrated in

FIG. 18

includes rod


146


connected to piston


147


. A pump


210


is connected to the opposite sides of piston


147


by raising valve


212


and lowering valve


214


. Connected between the pump


210


and the valves


212


and


214


are filters


216


, restriction


218


and check valves


220


. Check valves


220


prevent the pressurized fluid in the actuator


148


from flowing back towards pump


210


. The other side of piston


147


is connected to reservoir


222


by lowering return valve


224


and raising return valve


226


. Filter


228


connects the reservoir


222


to the return valves


224


and


226


and a filter


230


connects reservoir


222


to the pump


210


.




To extend the rod


146


, electrical valves


212


and


226


are actuated to connect the respective sides to the pump


210


and reservoir


222


. This raises the foot section


16


. To lower the foot section


16


, and retract the rod


146


, electrical valves


214


and


224


are activated to respectively connect the opposite sides of the piston


147


to the pump


210


and reservoir


222


. As a safety feature, relief valve


232


is connected between the output of pump


210


and the reservoir


222


. Thus, if the pressure at the output of the pump builds up to an unsafe level, relief valve


232


provides a flow back to the reservoir


222


.




As another safety feature, a relief valve


234


is connected between the output of valve


214


and the reservoir


222


. Since valve


214


provides the output of the pump to the piston


147


to lower the foot section, if the pressure in the lowering should exceed the setting of relief valve


234


, the excess pressure will be relieved back to reservoir


222


. This is a safety feature in that if the foot section


16


engages an object in its lowering, the piston


147


and rod


146


will stop moving and pressure will build up on that side of the piston. To prevent crushing of an object or a person or part of a person, relief valve


234


will operate. As an alternative to the relief valve


234


, a pressure sensor may also be provided and the valve


214


may be closed or valve


226


opened. By way of example only and not by way of limitation, whereas the relief valve


232


for the pump may be set at


900


PSI, the relief valve


238


for the actuator


148


may be set at approximately 180 PSI.




The electronics portion


160


of the controller as illustrated in

FIG. 4

is mounted to the frame


18


below the seat section


12


and the thigh section


14


of the deck. The controller


160


is connected to the length sensor


114


by wire


162


, to angle sensor


116


by wire


164


and to the prop sensor switch


108


by wire


166


. The sensor crank


118


and sensor link


120


are hollow or U-channel and the wire


166


for the prop traverses the foot section


116


through the channel in the sensor crank


118


and sensor link


120


. As the length sensor


114


sense the position of the end of the bed or it's length, the appropriate inflation or deflation of the bladders is made to adjust the length of the foot portion of the mattress. The angle sensor


116


in combination with the foot prop sensor


108


does not allow the foot section to pivot to an angle, for example in the range of 65° to 90° degrees from the horizontal, which will allow egress from the end of the bed without removal of the foot prop. This prevents the occupant from standing on the foot prop. Any angle less than this range will provide foot support in a chair position which is not selected for ease of egress.




Details of the mattress


20


is illustrated in FIG.


9


. Ticking


170


receives the body portion


22


and a foot portion


24


. Two examples of each portion is illustrated. The body portion


22


could include a foam seat portion


172


and a foam back portion


174


. Alternatively, it may include a bladder seat section


176


and a bladder back section


178


. The foot section


24


could include a foam foot portion


180


or the bladder foot portion


28


,


30


and


32


of FIG.


3


. The control lines


34


,


42


and


44


have a bend which corresponds to the juncture of the back and seat section of the mattress where a majority of the bending of the mattress occurs. Any combination of feet section may be used with any combination of seat and back section.




The body portion


22


and the foot portion


24


fit within the ticking


170


. The ticking


170


is a stretchable, breathable thermal plastic which is impervious to bacteria. The seams of the outer ticking of the mattress are formed by continuous ultrasonic welding. Therefore, the seams do not require any stitches which can permit fluid leakage. The ultrasonically welded seams are impermeable to fluids and bacteria so that the seams of the ticking prevent leakage into an interior region of the mattress.




Magnets


182


are provided at the foot end and the head end of the ticking


170


in interior pockets


184


as illustrated in FIG.


14


. These magnets secure the foot and head end of the bed to the frame or deck. If the frame is metal, no additional magnets are needed. If not, magnets are also provided on the supporting deck or frame.




The details of the foam foot portion


180


is illustrated in

FIGS. 10-13

. A foam core


186


is corrugated along its length or longitudinal axis. Preferably, the foam is low-ILD, visco elastic foam. Its ILD is in the range of 8-12 and is preferably


10


. The length of the foam foot portion


186


may be, for example, 27 inches and is capable of being shortened to 13.5 inches. This is an example of one foot portion. The corrugation allows the foot portion to diminish in length. Also, the load-ILD allows the foot portion to compress upon the weight of the patient. This will help reduce the pressure on the heel. Also, by providing one of the valleys adjacent to the foot end of the foot portion


186


, the heel may rest in the valley and therefore offer a valley or decreased area under the heel.




A portion of the foam


186


adjacent to the remainder of the deck is tapered at


188


. This mates with a tapering


173


of the foam seat portion


172


. This is to accommodate articulation between the foot portion and the seat or thigh portion. The foot end of the foam


186


has tapered corners


190


. This allows them to lay adjacent to the foot prop


56


.




Bonded to the bottom of the core


186


adjacent to the deck end is a torque plate


192


, as illustrated in FIG.


11


. Prior to bonding, half of a male/female snap rivets


194


are inserted through the torque plate


192


. An attachment plate


196


is also bonded to the bottom of the core


186


adjacent to the foot end. Only the cross-half section is bonded and the ends are left free as flaps.




The core


186


is provided within a slip cover


198


which includes a zipper


200


as illustrated in

FIGS. 12 and 13

. The cover


198


preferably is a shear promoting material, for example,


30


denier ripstop nylon which aids the movement of the foam foot portion in the ticking


170


. The flaps of attachment plate


196


extend through slots


202


in the bottom of the slip cover


198


. This secures the foot end of the core


186


to the slip cover


198


. The other end of the core


186


is secured within the cover


198


by snap rivets


206


extending through straps


204


and to be received in the mating snap


194


of the torque plate


192


. The straps


204


secure the foam of the foot portion


180


to the adjacent seat portion of the mattress within the ticking


170


. The flap ends of the attachment plates


196


extending through the cover


198


are also received in slots


208


of pockets


184


as are the magnets


182


of FIG.


14


.




As illustrated in

FIG. 15

, the foot prop


56


has opposed foot support surfaces


55


and


57


. The general shape of the foot prop


56


is trapezoidal in cross-section. The distance D between the parallel surfaces


55


and


57


may be, for example, 2½ inches. A pair of rods


59


extend from the bottom surface of the foot prop


56


and are received in sockets


106


in the second foot section


54


. Although the foot section


16


is shortened or retracted when the deck rotates from its flat or planar position to the chair position, for very short occupants, the foot prop


56


would still not provide support for the feet of the short occupant. In such a case, the foot prop


56


can be rotated 180° with respect to that shown in

FIG. 15

such that the planar surface


57


would be the foot support surface. It would be 2 inches closer to the patient than if surface


55


was the foot support surface.




As an alternative, a pair of sockets


106


and


107


spaced along the length of the foot section may be provided in each extension


100


as illustrated in FIG.


16


. The distance E between the sockets


106


and


107


again, may be, for example, 2½ inches. This will allow the foot prop


56


to be moved from sockets


106


to sockets


107


and thereby shortening the end by 2½ inches. Rotating the foot prop


56


such that the surface


57


becomes a support surface, would shorten it an additional 2 inches. Thus, an adjustment of 4½ inches can be obtained using the configuration of FIG.


16


. Additional sockets may be provided to give additional adjustments.




It should also be noted that although the cross section of the foot prop


56


is shown as trapezoidal, any cross sectional configuration which provides a differential between the two opposed supporting foot surfaces may be used.




It is important that the foot prop


56


has the parallel surface


55


as a support surface when the deck is in its planar position and that it is in sockets


106


. Otherwise, it would overlap the mattress and prevent the end section from inflating to the appropriate height. Sensors and controls can be provided in the sockets


106


and


107


as well as some sensible indicia on


59


to indicate which socket it is in and which surface,


55


or


57


is adjacent the foot. Once this is sensed, the inflation of the foot section would be prevented until either the foot prop


56


has been removed or it is in socket


106


with surface


55


being the foot support surface. Also, as previously discussed, the control should not allow the foot section to rotate beyond, for example, 65° with respect to the horizontal if the foot prop is mounted in either of the sockets


106


or


107


. This allows the foot prop to be available when the foot section is in a chair position while preventing it from being used when the foot section is lowered to permit egress.




Another method of changing the position of the foot support surface of the foot prop


56


greater than that achieved by the adjustment of the foot section


16


of the deck is illustrated in FIG.


17


. While the foot section


16


is adjusted from its extended to its contracted shortened position, the mattress foot portion


24


is not. shortened nor made thinner. The non-shortened portion of the foot portion


24


of the mattress then extends up one of the support surfaces of the foot prop


56


and forming a foot support surface. If the thickness of the foot portion


24


of the mattress


20


is, for example, five inches, this will shorten the length of the foot section by five inches. Also, if the reversible foot prop, as illustrated in

FIGS. 15 and 16

is used, this would add an additional 7½ to 9½ inches of adjustment.




Although

FIG. 17

illustrates further decreasing the length of the deck in the planar or total horizontal position, the same adjustment can be made as the foot section of the deck and mattress are rotated down from the horizontal position towards the chair position. The controller would have to be modified so as to not simultaneously adjust the height or length of the foot section of the mattress


24


during the rotational and shortening of the foot section of the deck.




Although the present invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example only, and is not to be taken by way of limitation. The spirit and scope of the present invention are to be limited only by the terms of the appended claims.



Claims
  • 1. A bed having an adjustable length deck, the deck comprising:a first section connected to a remainder of the deck; a second section movable in a common plane with the first section; a pair of spaced telescopic guides displaced from lateral edges and connecting the first and second sections; and a first actuator directly connecting the first and second sections.
  • 2. A bed according to claim 1, wherein the second section has a generally U-shaped cross-section encompassing part of a top and lateral sides of the first section.
  • 3. A bed according to claim 1, including a foot prop having at least one foot support surface and means for mounting the foot support surface to the second section of the deck at different distances from an end of the second section.
  • 4. A bed having an adjustable length deck, the deck comprising:a first section connected to a remainder of the deck; a second section movable in a common plane with the first section; a pair of spaced telescopic guides displaced from lateral edges and connecting the first and second sections; and a first actuator connecting the first and second sections, the telescopic guides including three telescopic elements.
  • 5. A bed having an adjustable length deck, the deck comprising:a first section connected to a remainder of the deck; a second section movable in a common plane with the first section; a pair of spaced telescopic guides displaced from lateral edges and connecting the first and second sections; and a first actuator connecting the first and second sections, the actuator being between the pair, of spaced telescopic guides.
  • 6. A bed having an adjustable length deck, the deck comprising:a first section connected to a remainder of the deck; a second section movable in a common plane with the first section; a pair of spaced telescopic guides displaced from lateral edges and connecting the first and second sections; and a first actuator connecting the first and second sections, the second section has a generally U-shaped cross-section encompassing part of a top and lateral sides of the first section, the first section being trapezoidal having a large and small opposed surfaces, and the large surface being the top side of the first section.
  • 7. A bed having an adjustable length deck, the deck comprising:a first section connected to a remainder of the deck; a second section movable in a common plane with the first section; a pair of spaced telescopic guides displaced from lateral edges and connecting the first and second sections; and a first actuator connecting the first and second sections, the first and second sections of the deck having a first width smaller than a second width of the remainder of the deck, the second section including lateral extensions and a prop mounted to the lateral extensions and extending transverse to the plane.
  • 8. A bed according to claim 7, wherein a third width of the foot section with the lateral extensions is substantially equal to the second width.
  • 9. A bed having an adjustable length deck, the deck comprising:a first section connected to a remainder of the deck, the first section being pivotally mounted to the remainder of the deck; a second section movable in a common plane with the first section; a pair of spaced telescopic guides displaced from lateral edges and connecting the first and second sections; a first actuator connecting the first and second sections; a second actuator connected to and pivoting the first section; and means for deactivating the second actuator when it encounters a predetermined resistance.
  • 10. A bed having an adjustable length deck, the deck comprising:a first section connected to a remainder of the deck; a second section movable in a common plane with the first section; a pair of spaced telescopic guides displaced from lateral edges and connecting the first and second sections; a first actuator connecting the first and second sections; a prop mounted to the second section of the deck; a prop sensor connected to the second section; and a length sensor connected to the first section.
  • 11. A bed having an adjustable length deck, the deck comprisinga first section connected to a remainder of the deck, a second section movable in a common plane with the first section, and a first actuator connected to the second section to move the second section relative to the first section, the first section being trapezoidal in cross section and having opposed surfaces, one of which includes a large surface and the other of which includes a small surface, the top side of the first section including the large surface.
  • 12. A bed having an adjustable length deck, the deck comprisinga first section connected to a remainder of the deck, a second section movable in a common plane with the first section, and a first actuator connected to the second section to move the second section relative to the first section, the first section being trapezoidal in cross section and having opposed surfaces one of which includes a large surface and the other of which includes a small surface opposed to the large surface, the top side of the first section including the large surface, the first and second sections of the deck having a first width smaller than a second width of the remainder of the deck; the second section including lateral extensions and a prop mounted to the lateral extensions and extending transverse to the common plane.
  • 13. A bed having an adjustable length deck, the deck comprisinga first section connected to a remainder of the deck, a second section movable in a common plane with the first section, and a first actuator connected to the second section to move the second section relative to the first section, the first section being trapezoidal in cross section and having opposed surfaces one of which includes a large surface and the other of which includes a small surface opposed to the large surface, the top side of the first section including the large surface, the first section being pivotally mounted to the remainder of the deck, the bed including a second actuator connected to and pivoting the first section and means for deactivating the second actuator when it encounters a predetermined resistance.
  • 14. A bed having an adjustable length deck, the deck comprising:a first section connected to a remainder of the deck; a second section movable in a common plane with the first section; a first actuator connected to the second section to move the second section relative to the first section; and a foot prop extending transverse to the second section of the deck, the foot prop being removably and reversibly mounted to the second section of the deck, the foot prop having a first orientation relative to the remainder of the deck and a second orientation relative to the remainder of the deck after being removed and reversed from the first orientation and mounted to the second section of the deck, the foot prop including two opposed foot support surfaces asymmetrical with respect to the mounting of the foot prop to the second section of the deck.
  • 15. A bed according to claim 14, wherein the foot prop includes a rod which received in a socket of the foot section and the rod is asymmetrical with respect to the two opposed foot support surfaces of the foot prop.
  • 16. A bed according to claim 14, wherein the first section is pivotally mounted to the remainder of the deck.
  • 17. A method of adjusting a foot support surface extending up from a foot end of an occupant support surface of an occupant support, the occupant support includes a) a deck having an adjustable foot section and a foot prop extending up from the foot section adjacent the foot end and b) padding on the deck, having a foot portion and having the occupant support surface, the method comprising:adjusting the length of the foot section of the deck with the foot prop to its shortest length; and providing the foot support surface displaced from the foot end by at least one of a) repositioning, with respect to the foot section of the deck, a surface of the foot prop which is transverse to the occupant support surface to become the foot support surface and b) positioning a part of the foot portion of the padding adjacent the transverse surface of the foot prop such that the occupant support surface of the part of the foot portion becomes the foot support surface.
  • 18. A method according to claim, 17 wherein the foot prop has two opposed transverse surfaces asymmetrical with respect to the mounting of the prop to the foot section of the deck; and the repositioning of the foot prop includes rotating the foot prop 180° degrees and remounting to the foot section of the deck.
  • 19. A method of adjusting a foot support surface extending up from a foot end of an occupant support surface of an occupant support, the occupant support includes a deck having an adjustable foot section and a foot prop extending up from the foot section adjacent the foot end and padding on the deck, the padding having a foot portion and defining the occupant support surface, the method comprising:adjusting the length of the foot section of the deck to its shortest length while in a substantially horizontal orientation; and moving the foot support surface relative to the foot section of the deck.
  • 20. The method of claim 19, wherein the adjusting step occurs independent of movement of the foot section relative to the remainder of the deck.
  • 21. The method of claim 19, wherein the foot prop is removed from, reversed relative to, and repositioned on the foot section of the deck during the moving step.
  • 22. The method of claim 19, wherein the foot portion of the padding is moved from being adjacent to the foot section of the deck to being adjacent to the foot prop during the moving step.
  • 23. A bed having an adjustable length deck, the bed comprising:a deck including a main section, a first section connected to the main section, a second section movable in a common horizontal plane with the first section, and a first actuator positioned to move the second section relative to the first section while the first and second sections remain in the common horizontal plane, and a continuous mattress positioned over the main, first, and second sections of the deck.
  • 24. The bed of claim 23, wherein the first section is pivotably connected to main section of the deck at a pivot location and the first actuator is connected to the first section between the pivot location and the second section.
  • 25. The bed of claim 23, further comprising a second actuator configured to move the first section relative to the main section of the deck.
  • 26. The bed of claim 23, wherein the first actuator is connected to the first section at at least two longitudinally spaced apart locations.
  • 27. The bed of claim 23, wherein the first and second sections are configured to move between a substantially horizontal bed position and a lowered chair position and the first actuator remains in substantially the same orientation relative to the first and second sections during movement of the first and second sections between the bed and chair positions.
  • 28. A bed having an adjustable length deck, the bed comprising:a deck including a main section, a first section connected to the main section, a second section movable in a common plane with the first section, a telescopic guide connecting the first and second sections, and a first actuator configured to move the second section relative to the first section, the telescopic guide including first set of guide tubes having a first guide tube and a second guide tube slidably received by the first guide tube, and a continuous mattress positioned over the main, first, and second sections of the deck.
  • 29. The bed of claim 28, wherein the tubular members are round.
  • 30. The bed of claim 28, wherein the first set of guide tubes includes a third tubular member slidably received by the second tubular member.
  • 31. The bed of claim 30, wherein the first guide tube is mounted to the first section, the third guide tube is mounted to the second section, and the second guide tube is configured to move relative to the first and second sections during adjustment of the length of the deck.
  • 32. The bed of claim 28, wherein the telescopic guide further includes a second set of guide tubes and the first actuator is positioned between the first and second sets of guide tubes.
CROSS REFERENCE

This is divisional of U.S. patent application Ser. No. 09/120,125, filed Jul. 22, 1998, now U.S. Pat. No. 6,212,714, which is a continuation-in-part of U.S. patent application Ser. No. 08/901,840, filed Jul. 28, 1997, now U.S. Pat. No. 6,151,739, which is a continuation of U.S. patent application Ser. No. 08/367,829, filed Jan. 3, 1995, now U.S. Pat. No. 5,666,681; a continuation-in-part of U.S. patent application No. 09/018,542, filed Feb. 4, 1998, now U.S. Pat. No. 6,163,903; and a divisional of U.S. patent application Ser. No. 08/511,711, filed Aug. 4, 1995 now U.S. Pat. No. 5,715,548 and claims benefit of U.S. Provisional Patent Application No. 60/059,772, filed Sep. 23, 1997 with respect to common subject matter.

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